The images above use daily precipitation statistics from NWS COOP, CoCoRaHS, and CoAgMet stations. From
top to bottom, and left to right: most recent 7-days of accumulated precipitation in inches; current month-to-date
accumulated precipitation in inches; last month's precipitation as a percent of average;
water-year-to-date precipitation as a percent of average.
Additional Precipitation Links: (will take you to an outside website)
High Plains Regional Climate Center's ACIS Maps
The top two images show Climate Prediction Center's Precipitation and Temperature outlooks for 8 - 14 days. The middle image shows the 3 months Precipitation outlook. The bottom left image shows the Weather Prediction Center's Quantitative
Precipitation Forecast accumulation for the seven days between Tuesday 12Z and ending Tuesday 12Z. The
bottom right image shows the Climate Prediction Center's most recent release of the U.S. Seasonal
Wednesday-Friday: The large-scale weather pattern is expected to be relatively calm and seasonal between now and Friday afternoon. There will be enough heat and moisture in the region for afternoon thunderstorms to develop over the mountains. The Central Rockies, Sangre de Cristos, and San Juans are expected to receive over half an inch of precipitation. Totals farther west in the UCRB and on the eastern plains will likely be lower. The low elevations of the basin and extreme eastern Colorado may not receive any precipitation at all.
The Weekend and Beyond: As a cold front dives into the region Friday evening the precipitation will shift to the east side of the Continental Divide while the basin dries out. Weekend accumulations are expected to average over 0.50" for eastern Colorado with the heaviest totals over the northern Front Range and Sangre de Cristos. Some areas are likely to be missed, but this activity will be less convective than the precipitation we have been seeing over the past several months. Rainfall totals should be closer to, but still not anywhere near, uniform. The drier, clearer air will keep the UCRB and eastern Colorado dry Monday through Wednesday of next week. Some small accumulations may still be possible for south and southeast Colorado.
Precipitation: The UCRB is predicted to be drier than average over the 8-14 day time period as drier air from the north shuts off monsoonal flow. Eastern Colorado, however, will see an increased chance of above average precipitation over this time frame due to increased frontal activity. Beyond two weeks the Climate Prediction Center is forecasting equal chances of above and below average precipitation for the Upper Colorado River Basin and eastern Colorado.
Temperature: Over the 8-14 day time frame there is an increased likelihood of below average temperatures for the UCRB and eastern Colorado as some cooler air is anticipated to plunge southward this weekend. The fall season is forecasted increased chances of above average temperatures.
Drought: Development of new drought is predicted as being unlikely for any given location in the Upper Colorado River Basin and eastern Colorado over the August through October time frame. Pockets of additional D0 and D1 in places that are trending drier, however, would not be surprising.
Above is the most recent release of the U.S. Drought Monitor map for the UCRB region.
the proposed changes for this week, with supporting text.
Summary: August 23, 2016
Last week, the Upper Colorado River Basin saw another week with cooler than average temperatures and below average precipitation. The majority of the basin saw less than 0.25 inches. The San Juan Mountains saw up to 1.00 inch, which is close to normal for this time of the year.
For August, most of the northern portion of basin received between 0.50 and 1.00 inches of new precipitation. This is on the drier side for this time of year. South of the Colorado mainstem has seen at least 1.00 inch of precipitation, with the San Juan Mountains seeing at least 2.00 inches, which is near normal.
An area of concern is Moffat County into western Routt County. SPIs in Hayden are now dry out to 6-months. Modeled soil moisture is still in the normal range, but drier soils are starting to creep into the northern part of the county.
East of the basin also saw cooler than average temperatures. Southeastern Colorado, mainly south of I-70, saw precipitation amounts in the 0.50 to 1.00 inch range through most of the area. Some areas did see over 2.00 inches. Northeast Colorado didn't fare as well, seeing less than 0.10 inches over much of the area. Most of the Front Range saw between 0.50 to 1.00 inches last week.
Areas of D0 and D1 did receive precipitation last week, however it wasn't enough to erase deficits in this area.
UCRB: It is recommended the D0 in eastern Utah be extended farther east into Moffat and western Routt counties, CO. Precipitation through this area has been sparse and starting to show on soil moisture products. Satellite derived vegetation health still looks good through most of this area, however the modeled soil moisture is starting to show drying and the few SPI stations are showing dryness.
Again, an area we do not monitor, but have noticed northern Utah and the Wasatch Range. D0 and D1 should be expanded into this area.
Eastern Colorado: Status quo.
**Disclaimer: The above recommendations are recommendations only, based on data, impacts, and
input from local experts. These recommendations are sent to the U.S. Drought Monitor author on Tuesdays. The USDM author
has sole discretion on final changes made in the region and can accept, reject, or modify the above recommendations
and may have additional modifications. Additionally, any recommendations discussed during the NIDIS webinars that are agreed upon
by the local experts and USDM author are still subject to change. Changes are final and official as of Thursday
morning, and can be viewed on the official U.S. Drought Monitor website.
Additional Drought Index Links: (will take you to an outside website)
Palmer Drought Severity Index for Climate Divisions Updated Weekly
WestWide Drought Tracker's PDSI Updated Monthly
Surface Water Supply Index