Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 359 PM EDT Sun Jul 09 2023 Valid 00Z Mon Jul 10 2023 - 00Z Wed Jul 12 2023 ...Heavy rain is likely to produce the potential for significant flash flooding throughout parts of the Northeast tonight and into New England on Monday... ...Additional rounds of severe weather and flash flooding persist across the Central/Southern Plains and Lower Mississippi Valley... ...Anomalously hot weather continues for portions of the Florida Peninsula, Texas, and the Southwest... A consolidating frontal system near the northern Mid-Atlantic coastline tonight when combined with anomalous atmospheric moisture content will create an environment ripe for flash flooding. Based on current radar observations heavy rain this afternoon already stretches from northeast Maryland to southern New York State, with a fast moving line of storms extending into eastern North Carolina as well. This corridor of intense rainfall rates has produced areas of significant flash flooding in eastern Pennsylvania this afternoon, with the threat expected to gradually expand and linger through the overnight hours as the associated storm system is slow to exit the region. A Moderate Risk (level 3/4) of Excessive Rainfall is in effect from New England to the Mid-Atlantic through early Monday morning, as well as Flood Watches. Residents and visitors are advised to heed any warnings and never drive through a flooded roadway. If driving is necessary, be sure to check current road conditions before venturing out as over 50% of all flash flooding deaths occur within vehicles. By Monday, the significant flash flooding threat is expected to remain over parts of New England and could become extremely dangerous throughout parts of Vermont and the Champlain Valley bordering nearby New York State. Several additional inches of rainfall falling within a relatively short period of time over mostly saturated ground could lead to significant flash and river flooding impacts. Where terrain is most susceptible, mud slides cannot be ruled our across Vermont as well. The system should finally exit much of the region by Tuesday morning and only offer a few remaining scattered shower chances. Further south along an associated frontal boundary stretching from the Southeast to the Southern Plains, additional shower/storm chances exist tonight in the Mid-South. Locally heavy rain could lead to scattered instances of flash flooding, as well as a threat for damaging wind gusts. By Monday, the severe weather threat becomes more widespread throughout the Great Plains, with scattered chances for damaging wind gusts and large hail extending as far north as the Upper Midwest near an approaching cold front. This cold front will also focus additional heavy rain and severe thunderstorm potential on Tuesday from central Nebraska to southern Iowa. Hot weather is expected to continue early this week across much of the Southern Tier, including the Southwest, Texas, and Florida Peninsula. Highs in the Southwest and southern High Plains are forecast to reach above the century mark, with 110s possible in the afternoon hours across Arizona. Excessive Heat Warnings and Heat Advisories are in effect. Additionally, the combination of high temperatures and oppressive humidity may allow for heat indices to approach 115 degrees throughout parts of South Texas. Elevated heat indices may also extend deeper into central Texas and create the potential for dangerous conditions if citizens are unable to find relief in air conditioned buildings. High heat indices are also located over parts of southern Florida, where Heat Advisories are in effect in order to highlight forecast heat indices up to 110 degrees. Snell Graphics available at https://www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php