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Intermountain West Climate Dashboard
The Intermountain West Climate Dashboard is intended to replace some features of the Intermountain West Climate Summary by serving climate graphics that are automatically updated as often as the original providers post them on their respective websites (the update frequency is listed under each graphic). We are also posting text briefings once or twice per month, based on the climate graphics. Note: the text in the latest briefing may not be fully consistent with the climate graphics in the Dashboard, depending on the weather and updates in the graphics since that briefing was posted.
Click on any graphic to view a full-sized version, and click again to reduce it. You can enlarge multiple graphics at the same time, and click-drag to move them around your desktop.
NEW (May 6, 2013): The text briefings now have embedded thumbnails of the graphics that you can click to enlarge as in the Dashboard itself, so you don't have to toggle between the briefing and the Dashboard.
The name of each graphic below is linked to the page for that graphic at the provider's website.
See this page for detailed descriptions of all of the Dashboard graphics, or click the
above each graphic to see the description of that graphic.
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Skip down to the briefings (Latest briefing: May 6, updated May 7)
Recent Temperatures and Precipitation, and Current Snowpack
| 30-day Precip as % Avg (HPRCC)
(updated daily)
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Current Snowpack as % Median
(NRCS)
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Drought Monitoring |
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| State Drought Monitors (NDMC) |
3-month Standardized Precip Index (SPI) (HPRCC)
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12-month Standardized Precip Index (SPI) (HPRCC)
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 Colorado |
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 Utah |
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 Wyoming |
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Current Streamflow, Forecasted Streamflow |
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| Current Streamflow - CO (USGS)
(updated daily) |
Current Streamflow - UT (USGS)
 (updated daily) |
Current Streamflow - WY (USGS)
(updated daily) |
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| Monthly & Seasonal Climate Outlooks (NOAA CPC)
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Precipitation Forecasts, Drought Outlook |
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| Experimental Seasonal Precip Guidance (SWcast) (NOAA ESRL PSD)
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ENSO Conditions & Forecasts |
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| ENSO Prediction Plume (forecasts of Nino 3.4 SST) (IRI)
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Latest Monthly Briefing - May 6, 2013 (updated May 7)
Highlights
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Recent snows have improved the runoff picture, but most of the Intermountain West is still facing low or very low 2013 spring-summer runoff with reservoirs already at low levels
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April precipitation was mixed for the region, with northern and central Colorado, portions of Wyoming, and eastern Utah being wetter than average, and northern Utah, southwestern Wyoming, and southern Colorado being mainly drier than average.
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Snowpacks in eastern Utah, much of Wyoming, and northern and central Colorado saw large gains in April, reaching near-normal peak levels and delaying snowmelt. Southern Colorado and southern Utah did not see these gains and meltout began early, from well-below-normal peaks.
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May 1 forecasts for spring-summer streamflow for the region are still below-average or well-below-average except in far northwestern Wyoming, but are generally improved from the April 1 forecasted flows across Wyoming, northern and eastern Utah, and northern and central Colorado.
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The NOAA CPC seasonal climate outlooks show a dry "tilt" for spring and summer precipitation for most of our region. In contrast, the “SWcast” for April–June shows a wet tilt over much of Colorado.
NEW: Click on the thumbnail images in the text below to bring up the full-sized graphic
April Precipitation and Temperatures, and Current Drought
April brought a mixed bag of precipitation for the region 
, with storms consistently favoring northern and central Colorado, portions of Wyoming, and eastern Utah, with some areas seeing over 200% of normal precipitation. Conversely, northern Utah, southwestern Wyoming, and southern Colorado were mostly skipped by these storms and saw below-average precipitation. The HPRCC Water Year Precipitation map 
shows that the wetter areas in April have emerged as the largest "green islands" of above-average water-year precipitation, in a sea of drier-than-normal conditions since October 1. Southeastern Colorado remains by far the driest part of the region over that period, with isolated pockets in southern Colorado and in Utah also seeing less than 50% of average October–April precipitation.
Several severe cold-air outbreaks led to April temperatures 
being colder than average across the region , except for parts of southeastern Utah and southwestern Colorado. Dozens of daily record-low minimum temperatures were set during April throughout the region, including 2°F in Boulder, CO on April 10, and -7°F in Cody, WY on April 9, which was also a monthly record for April.
The latest US Drought Monitor 
, representing conditions as of April 30, shows further improvement in regional drought conditions since late March; extreme (D3) drought in central western Colorado and central Wyoming has been upgraded to D2 and D1. While majority of the region is still classified in severe (D2) or worse drought, relatively little is now in D3 and D4, with the largest and most persistent area of D4 occupying most of southeastern Colorado.
Current Snowpack and Streamflows
As reported in the previous briefing, a series of storms after April 8 significantly boosted snowpacks in many mountain areas, with the last storm sweeping in on April 30. This late in the season, the % of normal SWE values, as seen in the the Current Basin Snowpack map 
from NRCS, can be misleading since nearly all SNOTEL sites have typically begun to melt out by now. But it is fair to say that the basins in northern and central Colorado, northeastern Utah, and much of Wyoming clawed their way back to near-normal (90–100%) snowpack conditions at the higher elevations by May 1. Snowpacks in southern Utah and southern Colorado did not seem the same boost in April as the basins to the north, and the snow there has been melting out steadily since mid-April, leaving May 1 values at 70% of normal or less, even at the highest elevations. Overall, the snowpack picture for the region is generally improved over April 1.
In Colorado, the new snow in April was accompanied by two substantial dust-on-snow events, with the storm on April 15–16 depositing dust from the San Juans to the Front Range. The dust loading in the San Juans is now similar to the high-dust springs of 2009 and 2010, and has been speeding up the snowmelt. In the northern and central mountains of Colorado, the dust layers are still buried for the most part, but once exposed will likewise cause earlier meltout than in the absence of dust. As WWA researcher Jeff Deems was quoted in the Denver Post, the April snow was "a mixed blessing" because of the dust deposition.
In the maps of current streamflows across the three states 
, the “normal” category is most frequently reported, but with more gages in the below-normal categories than above-normal, particularly in Wyoming. The Green River near Greendale, UT gage, was in the 12th percentile, at only 55% of the median flow for May 2, probably reflecting delayed snowmelt with the recent storms. Similarly, the Colorado River near the CO-UT State Line was in the 24th percentile, at 63% of the median flow for May 2. These flows should improve relative to normal as snowmelt picks up over the next few weeks.
Spring-Summer Streamflow Forecasts
Like the snowpacks, the May 1 spring-summer streamflow forecasts from NOAA and the NRCS are generally improved across the region compared with April 1, except in southern Colorado and southern Utah. The NRCS Westwide Streamflow Forecast Map 
shows a strong north-south gradient, with basins in northern Wyoming forecasted to have near-average (90–109%) or below-average (70–89%) runoff; in southern Wyoming, northern and central Colorado, and northern and eastern Wyoming, mainly below-average (70–89%) or well-below-average (50–69%) runoff; and in southern Utah and southern Colorado, far-below-average (25–49%) runoff. Only a few small basins remain in the very lowest category (<25% of average). For Lake Powell inflows, the official CBRFC forecast for May 1 is at 3.0 MAF (42% of average), slightly higher than the April 1 forecast of 2.7 MAF.
The runoff outlook for the region is lower than the final snowpack numbers (and their late-season improvement) would suggest, which reflects the unusually dry soil moisture last fall that is expected to significantly reduce runoff efficiency. (NOTE: While NRCS and NOAA continue to collaborate on streamflow forecasts, the forecast values are no longer being strictly coordinated between NRCS and some of the RFCs, including the CBRFC.)
Seasonal Climate and Drought Forecasts
The latest monthly Climate Outlooks released on April 30 by NOAA CPC show a slight dry tilt for precipitation for May
in northern and western Wyoming. The seasonal outlooks released April 18 show a tilt towards drier-than-average conditions for the May–July perio 
for all of the region, with the strongest tilt over western Colorado and eastern Utah. For the June–August period 
, the area with dry tilt shrinks and shifts to southeastern Colorado. The CPC Climate Outlooks once again show enhanced odds for above-normal temperatures for the upcoming seasons 
, consistent with the long-term warming trend. The latest CPC Seasonal Drought Outlook 
released May 2 projects that drought conditions will persist for most of our region, but some improvement is expected in far eastern Wyoming and the eastern half of Colorado over the next three months.
The latest PSD Precipitation Forecast Guidance ("SWcast") 
released April 12 for April–June 2013 conditions, continues to show a wet tilt for spring and early summer for Colorado, though shifted more to eastern Colorado compared with the SWcast released in March. A modest tilt towards dry conditions is forecasted for northwestern Utah. The SWcast released April 15 for late summer (July–September) 
continues the slight dry tilt for northwestern Utah, and also for extreme north-central Colorado and southern Wyoming, with a slight wet tilt for eastern Colorado.
ENSO indicators 
continue to show ENSO-neutral conditions, on the cool (La Niña) side of neutral. Since last fall, ENSO conditions have not exerted much influence on the climate system, nor on the seasonal forecasts. The models in IRI's mid-April ENSO Prediction Plume 
indicate a strong consensus towards ENSO-neutral conditions continuing through next summer and fall, with the dynamical models tending towards the warm side of neutral, and the statistical models tending to stay on the cool side.
Previous Briefings
April 24, 2013
Current Snowpack
Several potent spring storms since April 8 have given the snowpacks a significant late boost in Wyoming, northern and central Utah, and northern and central Colorado, with many SNOTEL sites accumulating 2-6" of SWE over the two-week period. The Current Basin Snowpack map from NRCS shows many basins across the region now having 90–110% of median snowpack for April 23. While these values this late in the season can be misleading—the median snowpack curve has peaked and is declining at most sites after mid-April—the "current SWE as % of peak" values, especially at the highest-elevation sites, suggest that most of this recent increase in % of median is "real" and will be reflected in greater runoff than was forecasted on April 1.
The recent storms did not benefit southern Colorado and southern Utah nearly as much as farther north, and these basins remain at well below median snowpack.
Seasonal Climate and Drought Forecasts
The latest monthly and seasonal Climate Outlooks released on April 18 by NOAA CPC show no tilt for precipitation for May, but a tilt towards drier-than-average conditions for the May–July period for all of the region, with the stongest tilt over western Colorado and eastern Utah. For the June–August period. the area with dry tilt shrinks and shifts to southeastern Colorado. The CPC Climate Outlooks once again show enhanced odds for above-normal temperatures for the upcoming seasons, consistent with the long-term warming trend. The latest CPC Seasonal Drought Outlook released April 18 projects that over most of our region drought conditions will persist, but some improvement is expected in far eastern Wyoming and the eastern half of Colorado over the next three months.
April 5, 2013
Highlights
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The Intermountain West is facing very low 2013 spring-summer runoff with reservoirs already depleted by dry conditions in 2012
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March precipitation was below-average over nearly all of our region
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April 1 SWE was below normal across the region, with most basins between 70-85% of normal
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April 1 spring-summer streamflow forecasts call for less than 70% of average runoff in nearly all basins, with less than 50% of average runoff in many basins
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The NOAA CPC seasonal climate outlooks show a dry "tilt" for late spring and early summer precipitation for most of our region, though the one-month outlook for April has no such tilt.
March Precipitation and Temperatures, and Current Drought
March was drier than average across the vast majority of the region, with driest conditions (>50% of average) in southern and northeastern Wyoming, southern Colorado, and northern and southeastern Utah. Only scattered areas saw above-average precipitation. The mountains across the region generally saw below-average precipitation. The HPRCC Water Year Precipitation map shows that almost the entire region has seen below-average precipitation since October 1. The largest area with <50% of average October–March precipitation is in southeastern Colorado.
March temperatures were warmer than average across most of Utah and in southwestern Colorado, and cooler than average elsewhere in the region. The largest cold anomalies, up to 6°F below average, were in northeastern Colorado and northern Wyoming.
The latest US Drought Monitor, representing conditions as of April 2, shows little change in regional drought conditions since early March. Most of the region is still classified in severe (D2) or worse drought: Colorado, 89% (unchanged since March 5); Wyoming, 84% (unchanged); and Utah, 46% (down from 52%).
Current Snowpack and Streamflows
With below-average March precipitation across nearly all mountain areas, snowpacks continued to slip with respect to normal (1981-2010 median) accumulation. April 1 SWE was well below normal across the region, with most basins between 70–85% of normal. Utah April 1 basin SWE was generally lower than on March 1, ranging from 70–90% of normal. In Colorado, April 1 basin SWE was similar to the March 1 values, at 66–82% of normal. In Wyoming, there was more variability, with the individual basin SWE ranging from 63–97% of normal. The April 1 basinwide SWE for the Upper Colorado River above Lake Powell slipped to 73% of normal, compared to 78% on March 1, and 84% on February 1.
In the maps of current streamflows across the three states, far more gages are in the below-normal categories than above-normal, particularly in Colorado. The Green River near Greendale, UT gage, was only in the 8th percentile, at 56% of the median flow for April 5. The Colorado River near the CO-UT State Line was in the 10th percentile, at 57% of the median flow for April 5.
Spring-Summer Streamflow Forecasts
The April 1 spring-summer streamflow forecasts from NOAA CBRFC and the NRCS are lower across the region than the March 1 forecasts. The NRCS Westwide Streamflow Forecast Map shows that most basins in our region are now expected to see well-below-average (50-69%) runoff or far-below-average (25-49%) runoff. Basins in northern Wyoming are in relatively better shape with forecasted below-average (70-89%) runoff. Several basins have slipped to the very lowest category (<25% of average).
For Lake Powell inflows, the official CBRFC forecast for April 1 is again lower than the previous months’, at 2.7 MAF (38% of average), compared to the March 1 forecast of 3.4 MAF. The very dry runoff outlook for the region reflects both the below-normal snowpacks and the unusually dry soil moisture last fall, which is expected to significantly reduce runoff efficiency in the spring. (NOTE: While NRCS and NOAA continue to collaborate on streamflow forecasts, the forecast values are no longer being strictly coordinated between NRCS and some of the RFCs, including the CBRFC.)
Seasonal Climate and Drought Forecasts
The latest monthly Climate Outlooks for April, released on April 1 by NOAA CPC, now show no tilt for April precipitation for our region, in contrast with a dry tilt in the previous outlook, and a tilt towards warmer temperatures for April over the region, especially Utah and Colorado.
As reported in the previous briefing: The latest seasonal (3-month) Climate Outlooks released on March 21 by NOAA CPC show a tilt towards drier-than-average conditions for late spring and early summer for western Colorado and all of Utah. The CPC Climate Outlooks continue to show enhanced odds for above-normal temperatures for the upcoming seasons, consistent with the long-term trend towards warmer conditions.
The latest CPC Seasonal Drought Outlook released April 4 projects that over most of our region drought conditions will persist, but some improvement is expected in far southeastern Wyoming and northeastern Colorado over the next three months.
ENSO indicators continue to show ENSO-neutral conditions on the cool (La Niña) side of neutral, and so we continue to see little influence of ENSO on the seasonal forecasts. The models in IRI's mid-March ENSO Prediction Plume indicate a consensus towards ENSO-neutral conditions continuing through next summer and fall.
March 22, 2013
Current Snowpack
The pattern seen in February with the region's snowpacks has continued since March 1, with storm tracks favoring Colorado and eastern Wyoming, where snowpacks have seen slight to moderate gains with respect to average conditions. Conversely, snowpacks in many Utah basins and in western Wyoming have slipped back. As a result, the Current Basin Snowpack map from NRCS shows nearly all basins across the region having 70–90% of average snowpack for March 22. Northwestern and north-central Wyoming have the highest basin snowpack levels, though still below average. The basinwide snowpack for the Upper Colorado River above Lake Powell as of March 22 is at 80% of average, up slightly from 78% of average on March 1. Last year at this time, the Upper Colorado River basinwide snowpack was almost identical to this year, at 81% of average. However, in 2012 the snowpack had reached a very early peak around March 20, while there is still the opportunity for further accumulation this year.
Seasonal Climate and Drought Forecasts
The latest monthly and seasonal Climate Outlooks released on March 21 by NOAA CPC continue to show a tilt towards drier-than-average conditions for late spring and early summer for western Colorado and all of Utah; this dry tilit is stronger than in the previous outlooks. The CPC Climate Outlooks continue to show enhanced odds for above-normal temperatures for the upcoming seasons, consistent with the long-term trend towards warmer conditions. The latest CPC Seasonal Drought Outlook released March 21 projects that over most of our region drought conditions will persist, but some improvement is expected in eastern Wyoming and northeastern Colorado over the next three months.
March 7, 2013
Highlights
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February precipitation was mainly below-average for the region, with the driest conditions across Utah; eastern Colorado and central Wyoming saw above-average precipitation.
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Snowpacks are now below-average in nearly every basin across the region after a dry February caused the snowpacks in Utah and western Wyoming to lose ground compared to average conditions
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The March 1 spring-summer streamflow forecasts for the region call for well-below-average (<70%) runoff in nearly all basins, reflecting both the low snowpacks and the unusually low soil moisture last fall
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The NOAA CPC seasonal climate outlooks show a dry "tilt" for spring and early summer precipitation for most of our region, though the one-month outlook for March has no tilt. In contrast, the “SWcast” for April–June shows a wet tilt over Colorado and eastern Utah.
February Precipitation and Temperatures, and Current Drought
February was drier-than-average across most of the region, with Utah overall the driest of the three states, especially in the far western and southern parts of the state. Mountain areas in northern Colorado and central and eastern Wyoming were generally favored by the prevailing storm tracks, and ended up with at least average precipitation, as did the plains adjacent to Colorado’s Front Range, and central Wyoming's basins. Mountain areas across Utah and in western Wyoming saw below-average precipitation. The HPRCC Water Year Precipitation map shows that almost the entire region has been drier than average since October 1. Southeastern Colorado remains the driest part of the region over that period, with less than 50% of average October–February precipitation.
February temperatures were colder than average across the region, except for parts of western and northeastern Wyoming. As in January, the largest cold anomalies, up to 15°F below average, were over Utah and were associated with persistent surface inversions. In northern Utah, a strong inversion caused another serious air pollution episode from February 2nd–6th.
The latest US Drought Monitor, representing conditions as of March 5, shows some improvement in regional drought conditions since late January; an area of extreme (D3) drought in far western Colorado and eastern Utah was upgraded to D2, and a nearby area of D2 in southwestern Colorado and southeastern Utah was upgraded to D1. But the great majority of the region is still classified in severe (D2) or worse drought: Colorado, 89% (down from 100%); Wyoming, 84% (down from 86%); and Utah, 52% (down from 66%).
Current Snowpack and Streamflows
The distribution of precipitation in February tended to reduce the disparity among the region’s basin snowpacks by March 1, with the basins that had been the driest (eastern Colorado and eastern Wyoming) seeing gains and those that had been the wettest (most of Utah, and northwestern Wyoming) seeing losses compared to the average conditions. In Colorado, February brought mainly near-average accumulations, so that March 1 snowpack values, at 65–80% of average, were similar to the February 1 values, with slight declines in the southwestern basins and increases east of the Continental Divide. In Wyoming, the western portion of the state saw below-average accumulation and March 1 snowpack levels declined significantly, to 79–91% of average. Across the rest of the Wyoming, March 1 snowpack values were generally improved, if slightly, compared with February 1. In Utah, however, all basins saw below-average accumulation, leading to March 1 snowpack values that were significantly lower than February 1, at 73–96% of average. Overall, nearly all basins in the region have below-average March 1 snowpacks.
In the maps of current streamflows across the three states, many gages are still ice-affected and not reporting, especially in Wyoming. Of the gages that are reporting, the “normal” category is most frequently reported, but there are many more gages in the below-normal categories than above-normal, particularly in Colorado. The Green River near Greendale, UT gage, was in the 20th percentile, at 75% of the median flow for March 5. The Colorado River near the CO-UT State Line was in the 19th percentile, at 70% of the median flow for March 5.
Spring-Summer Streamflow Forecasts
The March 1 spring-summer streamflow forecasts of the season were just released by NOAA CBRFC and the NRCS. The NRCS Westwide Streamflow Forecast Map shows that most basins in our region are now expected to have much-below-average (50-69%) spring and summer runoff, with basins in central and southwestern Utah and northern Wyoming being in relatively better shape with forecasted below-average (70-89%) or near-average (90-109%) runoff. Several basins have slipped to the far-below-average category (25-49%) category, including overall Lake Powell inflows; the official CBRFC March 1 forecast has been reduced to 3.4 MAF, only 49% of average, compared to the February 1 forecast of 3.85 MAF. The very dry runoff outlook for the region reflects both the below-average snowpacks and the unusually dry soil moisture last fall, which is expected to significantly reduce runoff efficiency in the spring. (NOTE: While NRCS and NOAA continue to collaborate on streamflow forecasts, the forecast values are no longer being strictly coordinated between NRCS and some of the RFCs, including the CBRFC.)
Seasonal Climate and Drought Forecasts
The latest monthly Climate Outlooks for March, released on February 28 by NOAA CPC, show no tilt for precipitation for our region for March, except for the extreme southwestern corner of Utah, and a tilt towards colder-than-average conditions for March over the region, especially Wyoming. The latest seasonal Climate Outlooks released on February 21 by NOAA CPC show a tilt towards drier-than-average conditions spring and early summer across most of the region, with the area of dry tilt covering more of the region than last month’s outlooks for spring. The CPC Climate Outlooks continue to show enhanced odds for above-normal temperatures for the winter and spring seasons for at least Utah and Colorado, consistent with the long-term trend towards warmer conditions. The latest CPC Seasonal Drought Outlook released February 21 projects that the drought conditions across our region will persist, through at least May 2013, and as seen in the previous outlook, some improvement is expected in far northern Wyoming.
The latest PSD Precipitation Forecast Guidance ("SWcast"), released March 5 for April–June 2013 conditions, forecasts a wet tilt for spring and early summer for all of Colorado and much of Utah, with the strongest tilt towards wet conditions (>10%) over western and south-central Colorado and far eastern Utah. A modest tilt towards dry conditions is forecasted for far northern Utah. (We will try to update soon with more explanation of the SWcast and why it might differ from the CPC forecast.)
As has been the case since fall 2012, ENSO conditions are not exerting much influence on the climate system, and thus the seasonal forecasts. ENSO indicators continue to show ENSO-neutral conditions on the cool (La Niña) side of neutral. The models in IRI's mid-February ENSO Prediction Plume indicate a consensus towards ENSO-neutral conditions continuing through next summer and fall.
February 4, 2013 (updated February 6 and 7)
Highlights
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January precipitation was patchily distributed across the region; western Colorado, southeastern Utah, and north-central Wyoming ended up wetter than average, with most other areas drier than average
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After storms in the last week of January roughly balanced out dry conditions the rest of the month, snowpacks remain below average across Colorado and southeast Wyoming, and near or above average in Utah and the rest of Wyoming
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The January 1 forecasts for spring-summer streamflow call for below-average flows in nearly all basins in the region; the February 1 forecasts that have been released thus far show a similarly dry outlook
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The NOAA CPC seasonal climate outlooks, as well as the “SWcast”, continue to show a slight dry "tilt" for late winter and spring precipitation for the southern half of our region, but the one-month outlook for February has a wet tilt based largely on the storms forecasted for the next week
January Precipitation and Temperatures, and Current Drought
January saw a very uneven distribution of precipitation across our region, in both space and time. The first three weeks of January were quite dry, with two systems in the last week generating most of the month’s moisture. Most mountain areas in western and central Colorado ended up with above-average precipitation, as did eastern Utah and north-central Wyoming. Drier-than-average conditions predominated in southern Wyoming and, yet again, in eastern Colorado. The HPRCC Water Year Precipitation map shows that while January aided some areas, most of the region remains drier than average since October 1. Southeastern Colorado is still the driest area in the region, with less than 50% of average October–January precipitation.
Perhaps the most notable aspect of January’s weather was the cold anomaly over most of Utah and portions of western Colorado, with monthly temperatures more than 10°F below average. Intrusions of Arctic air were followed by upper-level ridging and calm winds, leading to persistent surface inversions. Moab, Utah ended up with a record-cold January monthly average of 8.6°F, or 18°F below normal, and more than 5°F below the previous record. In northern Utah, a particularly strong inversion caused a serious air pollution episode from about the 18th to the 26th.
The latest US Drought Monitor, representing conditions as of January 29, shows very little change in drought conditions since January 1. The vast majority of the region is still classified in severe (D2) or worse drought: Colorado, 100% (up from 95%); Wyoming, 86% (unchanged), and Utah, 66% (up from 64%).
Current Snowpack and Streamflows
The dry first three weeks of January saw regional snowpacks decline with respect to the typical trajectory—especially in Colorado, where this slippage was dramatic. But the final, snowy, week salvaged the month for most basins, bringing conditions close to where they were on January 1 in terms of percent of average. The NRCS Current Basin Snowpack map on February 1 showed that Colorado and southeastern Wyoming basins remain well below to below average, with the South Platte and Arkansas near record-low levels at about 60% of average. In the rest of Wyoming and in Utah, snowpacks are generally near-average or slightly above average. In Utah’s Wasatch Range, the mountain snowpack slipped to about 85% of average even as the urban areas and foothills experienced above-average snowfall, thanks to “upside-down” storms. The February 1 basinwide snowpack for the Upper Colorado River above Lake Powell was 84% of average, compared to 86% of average on January 1.
In the maps of current streamflows in the three states, most gages are ice-affected and not reporting, as is normal for this time of year. The Green River near Greendale, UT gage, was in the 40th percentile, at 81% of the median flow for February 1.
Spring-Summer Streamflow Forecasts
See the previous briefing for details of the January 1 streamflow forecasts for spring–summer 2013. The general outlook for the region is drier than average, reflecting the snowpack anomalies. The next (February 1) streamflow forecast map should be posted by NRCS (and on the Dashboard) around February 10th; we expect no major changes in the regional outlook from the January 1 forecasts. The Colorado Basin River Forecast Center (CBRFC) has released their official February 1 forecasts here; there are slight improvements in the forecasted flows for the San Juan and Uncompahgre basins compared with January 1, but the forecasts are generally lower than on January 1 elsewhere in the Upper Colorado Basin and eastern Great Basin. The official CBRFC February 1 forecast for April–July Lake Powell inflows has slipped to 3.85 MAF, only 54% of average, compared to the January 1 forecast of 4.4 MAF. (NOTE: While NRCS and NOAA continue to collaborate on streamflow forecasts, the forecast values are no longer being strictly coordinated between NRCS and some of the RFCs, including the CBRFC.)
Seasonal Climate and Drought Forecasts
The latest monthly Climate Outlooks for February, released on January 31 by NOAA CPC, shows a wet tilt for most of Utah and western Colorado through February, reflecting the weather model guidance showing a tendency towards troughs (= moisture) over that area in the first half of February. It is also consistent with the wet forecast for our region seen in the 5-day QPF for the February 6–11 period. The latest seasonal Climate Outlooks released on January 17 by NOAA CPC continue to show a slight tilt towards drier-than-average conditions for the late winter and spring in the southern portion of our region, with the area of dry tilt covering more of Colorado and Utah than the previous outlooks. The CPC Climate Outlooks continue to show enhanced odds for above-normal temperatures for the winter and spring seasons, consistent with the long-term trend towards warmer conditions. The latest CPC Seasonal Drought Outlook released January 17 projects that the drought conditions across our region will persist, through at least April 2013, with a slight change from previous outlooks, in that some improvement is expected in far northern Wyoming.
The latest PSD Precipitation Forecast Guidance ("SWcast"), released January 23 for January–March 2013 conditions, continues to forecasts a dry tilt in late winter for most of Utah and Colorado, with the strongest tilt towards dry conditions (>10%) in north-central Colorado—though the model skill is marginal in northern Colorado for this season. A modest tilt towards wet conditions is forecasted for far northern Utah. Overall, this dry outlook for Utah and Colorado is mostly unchanged from the forecast made in November, and is consistent with a continued cold North Pacific (PDO-) in conjunction with a warm North Atlantic (AMO+).
As has been the case since last fall, the seasonal forecasts are not being influenced by ENSO, since the ENSO indicators continue to show ENSO-neutral conditions—though tipping most recently towards La Niña conditions—and the models in IRI's mid-January ENSO Prediction Plume show a consensus towards ENSO-neutral conditions continuing through next summer.
January 23, 2013
(see addition January 25, at bottom)
Current Snowpack
After strong gains in December, an extended stretch of drier-than-normal weather across the region since January 1 has caused snowpacks to slip backwards with respect to average conditions, especially in Colorado and eastern Wyoming. The Current Basin Snowpack map from NRCS shows Colorado basin snowpacks ranging from 55–68% of average, and mainly from 30–70% of average in eastern Wyoming. In Utah and western Wyoming, nearly all basins have between 80–100% of average snowpack. The basinwide snowpack for the Upper Colorado River above Lake Powell as of January 23 is at 71% of average, down sharply from 86% of average on January 1.
Spring-Summer Streamflow Forecasts
The first spring-summer streamflow forecasts of the season, valid January 1, were released by NOAA CBRFC and the NRCS in early January. The NRCS Westwide Streamflow Forecast Map shows most basins in our region expected to have below-average (70-89%) or much-below-average (50-69%) spring and summer runoff, with several basins expected to have near-average (90-109%) runoff in central Utah and northwestern Wyoming. IMPORTANT NOTE: While NRCS and NOAA continue to collaborate on streamflow forecasts, the forecast values are no longer being strictly coordinated between NRCS and some of the RFCs, including the CBRFC. For example, the NOAA CBRFC January 1 forecast for Lake Powell April-July inflows is 4400 KAF, 61% of average. The NRCS forecast for the same point is for 4000 KAF, 56% of average. Also note that all of the January 1 forecasts do not reflect the declines in snowpack since the first of the month.
Seasonal Climate and Drought Forecasts
The latest monthly and seasonal Climate Outlooks released on January 17 by NOAA CPC continue to show a slight tilt towards drier-than-average conditions for the late winter and spring in the southern portion of our region, with the area of dry tilt covering more of Colorado and Utah than the previous outlooks. The CPC Climate Outlooks continue to show enhanced odds for above-normal temperatures for the winter and spring seasons, consistent with the long-term trend towards warmer conditions. The latest CPC Seasonal Drought Outlook released January 17 projects that the drought conditions across our region will persist, through at least April 2013, with a slight change from previous outlooks, in that some improvement is expected in far northern Wyoming.
[Added January 25:] The latest PSD Precipitation Forecast Guidance ("SWcast"), released January 23 for January–March 2013 conditions, continues to forecasts a dry tilt in late winter for most of Utah and Colorado, with the strongest tilt towards dry conditions (>10%) in north-central Colorado—though the model skill is marginal in northern Colorado for this season. A modest tilt towards wet conditions is forecasted for far northern Utah. Overall, this dry outlook for Utah and Colorado is mostly unchanged from the forecast made in November, and is consistent with a continued cold North Pacific (PDO-) in conjunction with a warm North Atlantic (AMO+).
January 3, 2013
Highlights
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December was generally wetter than average west of the Continental Divide, but mostly drier than average to the east
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Snowpack conditions improved in December but remain below-average across Colorado and in parts of Wyoming; snowpacks are near- or above-average in Utah and most of Wyoming
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The NOAA CPC climate outlooks now show a slight dry "tilt" for winter and early spring precipitation for the southern half of our region
December Precipitation and Temperatures, and Current Drought
December was wetter overall in our region than November and October, with most mountain regions seeing above-average precipitation for the month, including western and central Colorado, western Wyoming, and far northern Utah. There were also large areas with drier-than-average conditions, especially eastern Wyoming and most of eastern Colorado. Despite the December gains in many areas, the HPRCC Water Year Precipitation map shows that after the first quarter of the 2013 water year, nearly all of the region is drier than average, with some areas like southeastern Colorado seeing less than 50% of average October–December precipitation. December was cooler than average over most of the region, with the wetter areas generally seeing the below-average temperatures, and the drier parts of Wyoming and Utah being warmer than average. The latest US Drought Monitor, representing conditions as of January 1, shows a modest reduction in the area of severe (D2) and extreme (D3) drought conditions since late November, but the vast majority of the region is still classified in severe (D2) or worse drought: Colorado, 95%; Wyoming, 86%, and Utah, 66%.
Current Snowpack and Streamflows
As reported in the December 21 briefing, snowpacks across Colorado saw large gains in December. Even so, the NRCS Current Basin Snowpack map shows that Colorado—and southeastern and north-central Wyoming—still lag well behind average conditions for early January. In the rest of Wyoming and in Utah, snowpacks kept pace with normal accumulations during December and are near-average or slightly above average. The January 1 basinwide snowpack for the Upper Colorado River above Lake Powell was 86% of average, up sharply from 60% of average on December 1.
In the maps of current streamflows in the three states, note that most gages are now ice-affected and not reporting, as is normal for this time of year. The gages that are reporting are mostly showing normal (green) streamflows, below-normal (yellow), or much-below normal (brown) flows for the date, with very few in the above-normal categories. The Colorado River near Cisco, UT gage, was in the 13th percentile, at 76% of the median flow for December 2.
Seasonal Climate and Drought Forecasts
As reported in the December 21 briefing, the latest monthly and seasonal Climate Outlooks released on December 20 by NOAA CPC are now showing a slight tilt towards drier-than-average conditions for the winter and early spring in the southern portion of our region. The IRI's mid-December ENSO Prediction Plume shows a strong model consensus that ENSO-neutral conditions will continue through next spring, and only a slight chance of an El Niño or La Niña event emerging in that time frame. The CPC Climate Outlooks continue to show enhanced odds for above-normal temperatures for the winter and early spring season, consistent with the long-term trend towards warmer conditions. The latest CPC Seasonal Drought Outlook released January 3 once again projects that the drought conditions across our region will persist, through at least March 2013.
December 21, 2012
Current Snowpack
More favorable storm tracks since December 1 have led to widespread increases in the snowpack across the region, with the most dramatic gains being seen in Colorado and eastern Utah. The Current Basin Snowpack map from NRCS shows Colorado basin snowpacks ranging from 58–81% of average, compared to 30–50% as of December 1. Utah basin snowpacks are all near or above average, while Wyoming basin snowpacks are near or above average except in the southeast corner of the state, where they are below average. The basinwide snowpack for the Upper Colorado River above Lake Powell as of December 21 is at 86% of average, up from 60% of average on December 1.
Seasonal Climate and Drought Forecasts
The latest monthly and seasonal Climate Outlooks released on December 20 by NOAA CPC are now showing a slight tilt towards drier-than-average conditions for the winter and early spring in the southern portion of our region. The CPC Climate Outlooks continue to show enhanced odds for above-normal temperatures for the winter season, consistent with the long-term trend towards warmer conditions. The latest CPC Seasonal Drought Outlook released December 20 again projects that the drought conditions across our region will persist, through at least March 2013.
December 3, 2012
Highlights
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November, like October, was drier than average for most of the region, and the 2013 water year is off to a dry start
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Early-season snowpack is extremely low across Colorado and eastern Utah, but generally near-average for other parts of Utah, and Wyoming
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The official NOAA CPC climate outlooks show no "tilt" for this winter's precipitation for our region; the NOAA PSD forecast guidance has a drier outlook
November Precipitation and Temperatures, and Current Drought
November was again much drier than average across most of the region. Most of eastern and central Colorado, southeast Wyoming, and eastern Utah saw less than 25% of average precipitation for the month. Conditions were wetter-than-average in north-central and southwest Wyoming and portions of northern Utah. According to the HPRCC Water Year Precipitation map, the first two months of the 2013 water year have left nearly all of the region drier than average, with most of Colorado and eastern Utah seeing less than 50% of average October–November precipitation. November was also a warm month, with temperatures 2° to 6°F above average over most of the region and up to 10°F above average in south-central Wyoming. The latest US Drought Monitor, representing conditions as of November 27, shows nearly all of the region still classified in severe (D2) or worse drought conditions. There was little change in the drought conditions across the region during November; a small pocket of D1 in north-central Colorado worsened to D2.
Current Snowpack and Streamflows
We are now far enough into the snow season (on average, 20-25% of seasonal accumulation occurs by December 1) that the percent-of-average data reported in the Current Basin Snowpack map from NRCS reliably reflect conditions on the ground. The regional snowpack map shows a pronounced difference between the generally near-average conditions in Wyoming and Utah, and the very low snowpacks in far eastern Utah and across Colorado. The Colorado statewide snowpack as of December 1 was around 40% of average, which is near the lowest level recorded since the mid-1980s. (Of the six years since 1986 with similarly low early-season snowpack across Colorado, two years (2008 and 2009) rebounded to above-average snowpacks by April 1, while one (2010) recovered to near-average conditions, and the remaining three remained well below average through the spring, including 2000 and 2002.) The December 1 basinwide snowpack for the Upper Colorado River above Lake Powell was about 60% of average.
Current streamflows in the three states reflect the gradient in recent precipitation and snowpack, with Wyoming gages generally reporting normal (green) streamflows for the date, with more gages in the below-normal (yellow) and much-below normal (brown) categories in Utah, and yet more in Colorado. The Colorado River near Cisco, UT gage, was in the 13th percentile, at 76% of the median flow for December 2.
Seasonal Climate and Drought Forecasts
As reported in the previous briefing, the latest monthly and seasonal Climate Outlooks released on November 15 by NOAA CPC are showing equal chances (EC) for above-normal or below-normal precipitation for the December through March period, with this lack of "tilt" reflecting the strong likelihood of ENSO-neutral conditions continuing through this period, as seen in the IRI's mid-November ENSO Prediction Plume. If this occurs, it will be the first ENSO-neutral winter since 2003-04. The CPC Climate Outlooks continue to show enhanced odds for above-normal temperatures for the winter season, consistent with the long-term trend towards warmer conditions. The latest CPC Seasonal Drought Outlook released November 15 projects that the drought conditions across our region will persist through at least February 2013.
The latest PSD Precipitation Forecast Guidance ("SWcast"), released November 19 for January–March 2013 conditions does find a signal in the pattern of past years with similar ocean-atmosphere conditions, apart from ENSO, and forecasts a dry tilt over that period for most of Utah and Colorado, with the strongest tilt towards dry conditions (>10%) in north-central Colorado—though the model skill is marginal in northern Colorado for this season and lead-time. A modest tilt towards wet conditions is forecasted for far northern Utah. Overall, this is a drier outlook for Utah and Colorado than the January–March forecast issued in late September, due to the now lower (almost zero) probability of El Niño while still having a warm North Atlantic Ocean and cold eastern North Pacific Ocean.
November 15, 2012
The latest monthly and seasonal Climate Outlooks released today (November 15) by NOAA CPC look very similar to those earlier this fall, showing equal chances (EC) for above-normal or below-normal precipitation for the December through March period. This lack of "tilt" for our region reflects that ENSO indicators in the tropical Pacific such as Nino 3.4 sea surface temperatures, after briefly flirting with El Niño, have returned to neutral conditions, and the vast majority of ENSO forecast models compiled for IRI's mid-November ENSO Prediction Plume call for ENSO-neutral conditions to continue through the winter. The CPC Climate Outlooks continue to show enhanced odds for above-normal temperatures for the winter season, consistent with the long-term trend towards warmer conditions. The latest CPC Seasonal Drought Outlook, also released November 15, projects that the drought conditions across our region will persist through February.
November 6, 2012
October saw the dryness of the 2012 water year continue, with nearly all of the region drier than average since October 1 except for scattered areas in southern and western Wyoming and extreme northeast Utah, according to the HPRCC Water Year Precipitation map. Portions of northwest Colorado, southern Colorado, and central and southern Utah saw less than 25% of average precipitation for the month. The latest US Drought Monitor, released November 1, shows nearly all of the region still classified in severe (D2) or worse drought conditions. There was little change in the drought conditions across the region during September.
We are still very early in the snow season, and the long-term average SWE for November 6 at many SNOTEL sites is less than 1". Thus the percent-of-average data reported in the Current Basin Snowpack map from NRCS may not be a reliable measure of conditions. That said, examining only reports from the high-elevation/high-accumulation SNOTEL sites confirms the impression from the map that the snowpack is above-average in northern Utah, and generally below average in the rest of the region, with Colorado basins being well below average except in the north-central mountains.
Compared to early October, there are now more stream gages across the three states reporting below-normal (yellow) and much-below normal (brown) current streamflows, especially in western Colorado and northern and eastern Utah. Four gages in Colorado and one in Wyoming are showing record-low flows for the date (November 5).
The latest monthly and seasonal Climate Outlooks released on October 18 by NOAA CPC continue to show equal chances (EC) for above-normal or below-normal precipitation for the October through January period, reflecting the likelihood of either ENSO-neutral or weak El Niño conditions during this period, as seen in the IRI's mid-October ENSO Prediction Plume. The CPC Climate Outlooks continue to show enhanced odds for above-normal temperatures, consistent with the long-term trend towards warmer conditions. [The preceding text is unchanged from the October 23 briefing]. The latest CPC Seasonal Drought Outlook released November 1 projects that the drought conditions across our region will persist through at least January 2013.
October 23, 2012
The latest monthly and seasonal Climate Outlooks released on October 18 by NOAA CPC continue to show equal chances (EC) for above-normal or below-normal precipitation for the October through January period, reflecting the likelihood of either ENSO-neutral or weak El Niño conditions during this period, as seen in the IRI's mid-October ENSO Prediction Plume. The CPC Climate Outlooks continue to show enhanced odds for above-normal temperatures, consistent with the long-term trend towards warmer conditions. The latest CPC Seasonal Drought Outlook also released October 18 projects that the drought conditions across our region will persist through at least December.
Thus far in October (and the beginning of the 2013 water year), according to the HPRCC Water Year Precipitation map, precipitation has been well below-average across the region except for small areas in north-central Colorado and southwestern Utah. Over the next 4-5 days a storm system is forecasted to bring significant precipitation to northern and eastern Colorado, northern Utah, and much of Wyoming.
As of October 23, the Current Basin Snowpack map from NRCS shows a misleading picture for Utah as there are are actually very few SNOTEL sites in that state, and across the region, reporting any SWE on the ground. [Correction 10/24: The deleted wording did not distinguish sites that were not reporting any data from sites that were reporting zero SWE. And more sites are now reporting data on 10/24, compared to the previous day. See this SNOTEL map from NRCS for a clearer depicton of current site-level data across the West.] Most SNOTEL sites across the region are reporting below-average precipitation since October 1, consistent with the HPRCC precipitation map, which does not include SNOTEL data.
October 1, 2012
September was drier than average across Wyoming, western Colorado, and much of Utah. Wetter-than-average conditions prevailed in central Colorado, far western Utah, and other parts of Utah. Over the just-completed 2012 water year, nearly all of the region was drier than average, with about half the region receiving less than 70% of average precipitation. The latest US Drought Monitor reflects the widespread long-term dryness, with nearly all of the region mired in severe (D2) or worse drought conditions, including small areas of D4 in far northeastern and southeastern Colorado.
The very first snowpack accumulations of the season are being reported by the SNOTEL network. The majority of stream gages reporting across the three states have flows in the normal range, but with many gages at below-normal and much-below normal flows also scattered throughout the region.
The latest monthly and seasonal Climate Outlooks from NOAA CPC show equal chances (EQ) for above-normal or below-normal precipitation for the October through January period, and enhanced odds for above-normal temperatures during that period, consistent with the long-term trend towards warmer conditions. The latest CPC Seasonal Drought Outlook projects that the drought conditions across our region will persist through at least December. The latest experimental precipitation forecast guidance from NOAA ESRL PSD shows enhanced chances for wetter-than-average conditions in eastern Colorado for the October-December period.
This summer, conditions in the tropical Pacific appeared to be in a rapid transition to El Nino, but that transition has slowed in the past month, and NOAA has not yet announced an El Nino. The most recent ensemble of ENSO prediction models forecasts that conditions will either remain on the warm side of ENSO-neutral, or transition to weak El Niño conditions through the winter season.
University of Colorado Boulder 
