Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 421 PM EDT Mon Aug 13 2018 Valid 00Z Tue Aug 14 2018 - 00Z Thu Aug 16 2018 ...Heavy Rain Possible Over the northern Mid Atlantic and Northeast... ...Heavy rain possible over the Southern Plains this afternoon/tonight, stretching into the Middle Mississippi Valley on Tuesday... ...Fire Weather Concerns continue across the western U.S.... A quasi-stationary front extending along the coast of the New England, the Mid-Atlantic and Southeast will result in chances of showers and thunderstorms through the next couple days. A surface low pressure system embedded in this frontal system, combined with a strong upper level low, will allow for strong moisture advection into the northern Mid Atlantic and southern New England, where rain and thunderstorms will be likely today through Tuesday. The Weather Prediction Center has issued a slight risk of excessive rainfall and flash flooding in this region through tonight. Furthermore, eastern Pennsylvania, southern New York, and northwest New Jersey are outlined in a moderate risk through tonight, highlighting that rain and flash flood potential will be greatest in this area. Flash Flood Watches and warnings are also currently in effect this afternoon for this region as well. The threat for flash flooding will taper off through the day Tuesday as the upper level low driving this system shifts inland and loses strength, becoming an open wave. Meanwhile, the southern extent of the above mentioned frontal system will stretch back into the Southern Plains where it will combine with another surface low pressure feature and strong upper level system. This will result in strong advection of warm and moist air into the Southern and Central Plains from the Gulf of Mexico, producing scattered to numerous showers and thunderstorms. These will slowly shift eastward through at least mid-week as the surface and upper level low also make a slow eastward progression. The Weather Prediction Center has outlined a portion of the Central and Southern Plains as being in a slight risk for excessive rainfall and flash flooding through tonight. This area will transition slightly eastward and encompass a portion of the Middle Mississippi Valley for Tuesday and Tuesday night, and then continue into the Middle Mississippi and Ohio Valley for Wednesday and Wednesday night. A Flash Flood Watch is currently in place across western Oklahoma and far Northwest Arkansas. Elsewhere, Air Quality Alerts also remain in place across a large portion of Central California as well as across inland Washington and northern Idaho as wildfires continue to infuse the air with copious amounts of smoke. Red Flag warnings and Fire Weather Watches are also in effect for much of Nevada, as well as portions of southern Wyoming. Weak monsoonal moisture and daytime heating will aid in producing showers and thunderstorms over parts of the Southwest/Great Basin and the Southern/Central Rockies through this evening. Wix Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php