Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 402 AM EDT Thu Aug 09 2018 Valid 12Z Thu Aug 09 2018 - 12Z Sat Aug 11 2018 ...Unsettled wet weather from the Eastern U.S. to the southern Plains with a lingering heavy rainfall threat across the South through Friday... ...Near 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... Much of the southern tier of the U.S. will be in a wet pattern through the end of the week. As a surface low lifts northeast through New England a cold front will pass through the Northeast while the trailing end slows from the Mid-Atlantic to the Central/Southern Plains. Moisture streaming northward over the boundary will initiate widespread convection, and with the stagnant nature of this boundary, storms will likely pass over the same locations. This will increase the risk for flash flooding. Additionally, 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 will be possible, especially along the favored terrain. WPC has a slight risk for excessive rainfall in effect for portions of Arizona, New Mexico, and from Northeast Texas to northern Alabama today, then primarily from Arizona to central Texas this weekend. With a strong ridge anchored over the West temperatures will continue to rise, especially for parts of the Pacific Northwest, Intermountain West and the Northern High Plains. Hot and dry conditions are expected from the interior Pacific Northwest to eastern Montana. Near or record breaking temperatures in the 90s and 100s are forecast through 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 from Washington and Oregon to Montana. Ongoing wildfires continue to cause poor air quality issues. The hot and dry conditions will only exacerbate the fire weather concerns out West, particularly for those areas already dealing with wildfires. Campbell Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php