Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 352 AM EDT Mon Jul 12 2021 Valid 12Z Mon Jul 12 2021 - 12Z Wed Jul 14 2021 ...Heavy rain and potential flooding for parts of the Eastern U.S. and the Desert Southwest... ...Heat wave continues for much of the western U.S. through early this week... More unsettled weather returns to the Northeast U.S. to begin the week as a slow moving warm front and surface low advances northward and leads to widespread moderate to heavy rain with embedded thunderstorms. It appears the heaviest rainfall will likely be across eastern Pennsylvania and eastward towards the greater New York City metro area, where some patchy 1 to 3 inch totals are possible through Wednesday morning. This may lead to some potential flooding and rises on area rivers, especially over urban areas that have received above average rainfall over the past week. A Moderate Risk of excessive rainfall is in effect for this area given the highly saturated grounds and the additional heavy rainfall expected. Portions of the Deep South are also expected to have bad weather through early Tuesday as deep moisture from the Gulf of Mexico surges northward ahead of a nearly stationary frontal boundary, which should eventually dissipate. The heaviest rain is anticipated across central and northern Alabama, and some 3+ inch rainfall totals are within the realm of possibility where repeated rounds of thunderstorms develop. In terms of severe weather potential, there is a Slight Risk of severe thunderstorms across portions of the central Florida Peninsula on Monday owing to greater instability, with damaging winds being the main threat. The intense heat wave that has been setting records across the southwestern U.S. has peaked for most areas, with a gradual return to more seasonal temperatures by later in the week. However, excessive heat warnings remain in effect from California to Utah since readings will still be well above normal for Monday. Some additional record highs are likely on Monday, although not as many as this past weekend. It is also worth noting that overnight lows have also been impressive with this heat wave, with lows failing to drop below the lower 90s for the normally warmer locations of the Desert Southwest. Some localized relief from the extreme heat may arrive in the form of monsoonal showers and storms each day across portions of Arizona and New Mexico. Some of these storms will produce heavy rainfall that may result in flooding for flood prone areas. Hamrick Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php