Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 340 PM EDT Wed Aug 08 2018 Valid 00Z Thu Aug 09 2018 - 00Z Sat Aug 11 2018 ...Unsettled wet weather from the Eastern U.S. to the southern Plains this evening, with a lingering heavy rainfall threat across the South Thursday and Friday... ...Near to record breaking heat likely out West... ...Monsoonal moisture will bring an elevated heavy rainfall/flash flood risk to portions of the Southwest and southern Rockies... Expect showers and thunderstorms to continue along and ahead of a front from the Northeast to the Southern Plains this afternoon and into tonight. Locally heavy rainfall along the boundary may lead to a threat for flash flooding and thus WPC has placed much of this region in a marginal to slight risk for excessive rainfall. The western portion of this boundary across the southern Plains is forecast to stall across the region which will elevate the flash flood and heavy rainfall threat for the next couple of days. WPC continues to highlight portions of the southern Plains to the Southeastern states within a marginal to slight risk for both Thursday and Friday. Meanwhile, a strong upper level ridge across the Western U.S. will bring hot and dry weather and poor air quality to much of the region during the short range period (through Friday). Near or record breaking temperatures in the 90s and 100s are possible Thursday and Friday, which are as much as 10 to 20 degrees above normal for this time of the year. Excessive heat warnings and heat advisories are in effect for much of the Northwest and into parts of the northern Rockies to high Plains, as well for parts of the Southwest. These poor conditions will only exacerbate the fire weather concerns out West, particularly for those areas already dealing with wildfires. Monsoonal moisture rounding the base of a strong upper level ridge over the western U.S. will keep mainly diurnally driven showers and thunderstorms in the forecast across the Southwest through the rest of the work week. Heavy rainfall and localized flash flooding, especially along the favored terrain is possible. WPC has portions of the Four Corners states and the southern Plains in a marginal to slight risk the next couple of days. Santorelli Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php