Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 359 PM EDT Wed Sep 06 2017 Valid 00Z Thu Sep 07 2017 - 00Z Sat Sep 09 2017 ...Heavy rainfall and severe weather possible for portions of the East coast tonight... ...Temperatures continuing to be well above normal for much of the Western U.S.... Expect heavy rainfall to continue ahead of a slow moving cold front across the Mid-Atlantic and Northeast this evening. Thunderstorms may contain severe weather and flash flooding - with both SPC and WPC highlighting much of the area in a marginal to slight risk. See products issued by those centers for more details. Heavy rainfall lifts northward through the Northeast into Thursday as well, coming to an end by Thursday afternoon. Behind this, showers and thunderstorms are forecasted to continue for a few days underneath the upper level system lingering across the Great Lakes. The southern edge of the cold front appears to stall across Florida by Thursday night and into Friday which should keep showers and thunderstorms in the forecast across the Peninsula and the Gulf Coast. Behind the departing cold front off the East Coast, temperatures will be below seasonable values across much of the eastern half of the nation with afternoon highs 5 to 10 degrees below normal. Strong upper-level ridging out West will maintain the very warm temperatures, with places across the northern Intermountain West and High Plains seeing afternoon highs as much as 10 to 20 degrees above normal. Hot temperatures and very dry conditions will also continue to bring a fire weather threat across parts of the Pacific Northwest where red flag warnings are in effect. Upper level troughing moving towards the Northwest coast though may bring some scattered showers and storms on Thursday which should help moderate temperatures, at least along the immediate coast. Elsewhere, monsoonal moisture streaming into the Southwest and southern Rockies should keep mainly diurnally driven showers and Thunderstorms across these regions through the short range period. Energy dropping southward along the west coast may bring an increase in activity by Friday with WPC highlighting parts of the region in a marginal to slight risk for flash flooding. And while Tropical Storm Katia in the western Gulf of Mexico is not expected to directly impact the US, parts of far south Texas may see some light to moderate precipitation associated with the system on Friday. Santorelli Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php