#Drought news: D0 and D1 expanded around #Denver, 30 days of below normal precip for #Colorado lowers streamflow

Click here to go to the US Drought Monitor website. Here’s an excerpt:

For the USDM 7-day period ending on September 27, a low pressure system produced above-normal precipitation in the western High Plains southwestward into the much of the Mountain West. The frontal boundary that was associated with the low produced copious amounts of rainfall for the Southern Plains stretching northward into Upper Midwest. Parts of the Mid-Atlantic also saw above-normal precipitation for the period. Drier-than-normal conditions existed for much of the country east of the Mississippi, especially for the Ohio Valley. Temperatures were as much as 10 degrees above normal for the parts of the Midwest while the Southwest and Northwest were cooler than normal. These warm and dry conditions in the nation’s eastern half contributed to expansion of drought in the Northeast and Southeast, while drought conditions improved in the High Plains and parts of the South. Please note that the Drought Monitor depicts conditions valid through Tuesday morning, 8 a.m., EDT (12 UTC); any of the recent locally heavy rain which fell after Tuesday morning (September 27) will be incorporated into next week’s drought assessment…

High Plains and Midwest
In the middle of the USDM period, an inch of rainfall fell in the drought stricken areas of the High Plains. As a result, short term dryness was removed in northwest North Dakota and multiple levels of drought were contracted in western South Dakota. It was reported that some small grasses have greened up and winter wheat planting is going full steam ahead. However, an extended dry period in the northeastern part of South Dakota kicked off the soybean harvest, and harvest activities should increase this coming week. Precipitation during the last 30-days in Montana and Wyoming was much above normal, which contributed to improved conditions in southern Montana, western Wyoming and eastern Idaho. Streamflow levels at 7 and 14 days were at or above average, while the 30-day percent of normal precipitation was more than 200 percent of normal…

In Colorado, below normal precipitation during the past 30 days was reflected in the low streamflows, resulting in a small expansion of D0 in the central part of the state. Stations in and around Denver were showing near-extreme to extreme dryness at the 3-4 month time scale, resulting in the expansion of D0 and D1 in the area. Due to the unseasonably high precipitation totals in eastern Utah, SPIs have shifted from negative to positive through the six month timescales. It was reported that the benefits of this could be seen in both the soils and streams…

It is the dry season in much of the western U.S. , so no changes were made during this USDM shift…

Looking Ahead
During the next few days, a strong upper level low pressure system stalls out over the Ohio Valley providing much needed drought to the Mid-Atlantic region. As much as 3-6 inches of rain is forecasted, so flooding and flash flooding is possible in some areas. Some of the areas that were placed in D0 status this USDM week may see several inches of rain from this event. Please note that the Drought Monitor depicts conditions valid through Tuesday morning, 8 a.m., EDT (12 UTC); any of the recent locally heavy rain which fell after Tuesday morning (September 27) will be incorporated into next week’s drought assessment. Meanwhile, the rest of the CONUS will be relatively quiet. For average temperatures during the next few days, the largest positive anomalies are forecasted to occur in the West, Northwest, and High Plains. The largest negative anomalies should be concentrated in the Midwest and are forecasted to gradually slide southward. For the second half of the next USDM period, much cooler than normal temperatures return to the West Coast, while the warmer than normal temperatures are confined to much of the area east of the Rockies. The 6-10 day outlooks from CPC show an increase probability of warmer than normal temperatures for the eastern half of the country and the western half has the best chance of cooler than normal temperatures. There is an increased probability that above normal precipitation will fall in the Northern Rockies and High Plains while the probability is best for below normal precipitation to occur in the Southeast.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s