Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 415 PM EDT Sun Jul 22 2018 Valid 00Z Mon Jul 23 2018 - 00Z Wed Jul 25 2018 ...Heavy rain and flash flooding to continue across the Mid-Atlantic and Northeast... ...Unsettled weather expected across the central and eastern Gulf of Mexico.... ...Severe weather possible across the Northern and Central Plains through tonight... ...Dangerous heat to continue across the southern central and portions of the western U.S... Several days of heavy rainfall are expected across the Mid Atlantic and Northeast. Heavy rain will continue across the coastal mid-Atlantic this evening as a low pressure system that has been traversing northward up the mid-Atlantic Coast, falls apart while moving inland this evening. Portions of the coastal Mid Atlantic are under a moderate risk of excessive rainfall through tonight, due to the threat of moderate to heavy rainfall on top of already saturated soils from impressive rains that moved through the region yesterday. Meanwhile, an expansive frontal system that pushed across much of the southeast over the last 24 hours has now slowed significantly as it nears the Gulf of Mexico coast and extends northward into the mid Atlantic. This frontal boundary is acting as the focus for showers and thunderstorms across these regions. Much of Florida, southern Georgia, and southern Mississippi remain in a slight risk for severe thunderstorms this evening and overnight. A severe thunderstorm watch has also been issued by the Storm Prediction Center, valid until 8pm EDT this evening for this same area. A slight risk of severe thunderstorms will be possible along southern Louisiana and southern Alabama during the day Monday as the frontal system becomes stalled along the coast. A strong surge of easterly flow along the entire Atlantic coast over the next several days will result in continued rain across this region. Excessive rainfall and flash flooding are likely for these areas, as has been outlined in the Days 2 and Days 3 Excessive Rainfall Outlook issued by the Weather Prediction Center. Another frontal system will slide across the northern High Plains today--firing off convection along the boundary which will continue into the overnight. Severe thunderstorms will be possible, particularly from North Dakota southward into western Nebraska--where the Storm Prediction Center has issued a slight risk. By Monday, a plume of moisture will extend into the eastern High Plains of Colorado and New Mexico where flash flooding could occur along favorable terrain. Thunderstorms will also impact the Central Great Basin and along the Sierra Nevada mountain range over the next couple of days. These regions could also see isolated flash flooding from this convective activity. Dangerous heat remains in place across the southern Plains, lower Mississippi Valley, and much of the Southwest and far western United States. This heat is expected to remain in place through Monday across the southern Plains and Lower Mississippi Valley, and through at least mid-week for the Southwest and much of the western coast. Excessive heat watches, warnings and heat advisories are currently in place across these regions. By Tuesday, the Desert Southwest will see temperatures climb well above 110 degrees--with places like Phoenix, AZ forecast to reach 117 degrees, Las Vegas, NV forecast to reach 114 degrees, and locations in southern California nearing 120 degrees for highs. Wix Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php