Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 402 PM EDT Mon Jul 23 2018 Valid 00Z Tue Jul 24 2018 - 00Z Thu Jul 26 2018 ...Moderate risk of flash flooding possible across the Mid-Atlantic and Northeast today and Tuesday... ...Dangerous heat to continue across the south-central U.S. and portions of the western U.S... Hot and mostly dry conditions will prevail across much of West Coast, Southwest and the western Gulf states over the next few days. A majority of these locations have heat advisories or excessive heat warnings in effect as temperatures are expected to be above or well-above normal. Areas across southern California, southern Nevada and Arizona, along with central Texas, have forecast highs ranging from 100 to 110s. Additionally, these hot and dry conditions will maintain an increase threat of fire danger - very dry vegetation can catch fire and spread quickly in these conditions. On the flip side, the East Coast will be in a prolonged wet period with many areas prime for flooding. An upper low will bring copious amounts of moisture across the East Coast--and combining this with a frontal boundary draped across the Carolinas and into the Mid-Atlantic will bring unsettled weather the next few days. Showers and thunderstorms will be widespread with embedded heavy rain. Portions of the Mid-Atlantic received several inches of rain this past weekend and soil conditions range from saturated to water-logged. Additional heavy rain activity will maintain and elevated risk for flooding. Excessive rainfall outlooks are in effect from the Carolinas to New York with a focused area with a moderate risk of flash flooding over northern Virginia/Maryland/southern Pennsylvania. A frontal system will sweep across the Mississippi Valley and central Plains bringing showers and thunderstorms along its boundary. Convection will continue across this region as deep moisture continues to advect north from the western Gulf of Mexico. A slight risk of flash flooding is possible particularly in favorable terrain. In addition, the Sierra Nevada mountains can also expect diurnally driven thunderstorms--where a marginal risk of flash flooding is possible. Elsewhere, showers and thunderstorms in northwest Florida will be possible into Tuesday. Some of these thunderstorms could move quite slowly and produce heavy downpours--leading to a marginal risk of flash flooding for today. Campbell Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php