Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 303 PM EDT Mon Sep 23 2024 Valid 00Z Tue Sep 24 2024 - 00Z Thu Sep 26 2024 ...Much needed rains possible from the Ohio Valley into the Central to Southern Appalachians, Upper Tennessee Valley and Mid-Atlantic... ...Rains from the developing tropical system in the western Caribbean may begin to affect the Florida Keys and South Florida on Wednesday... ...Much above average temperatures continue across the West into the Northern Plains and across the Gulf Coast into the Southeast... The large scale mid to upper level flow across the Lower 48 will continue to amplify over the next few days, comprised of a deepening upper trof from the eastern portions of the Plains into the Mississippi Valley, a building upper ridge across the interior West and the strengthening and re-positioning of an upper ridge off the Southeast coast. This amplification will be leading to impactful weather event over the next several days across large portions of the U.S. The initial impacts will be in the form of an expanding area of moderate to heavy rainfall potential from the Mid-West into the Lower Lakes, Ohio Valley, Upper Tennessee Valley, Central to Southern Appalachians into the Mid-Atlantic. Much of these areas are currently experiencing severe to exceptional drought conditions, with the expected 1 to 1.5 inch plus rainfall amount over the next two days bringing some relief to these drought conditions. With the dry conditions across these areas, river flooding will be unlikely. However, there is still at least a marginal risk of isolated flash flooding with the expected heavy rainfall amounts, especially if they occur over urbanized regions. More significant impacts to the above mentioned amplifying pattern will be the weakening of the mid to upper level ridge across the Gulf coast as the upper trof amplifies over the Lower Mississippi Valley and the upper ridge rebuilds off the Southeast. This in turn will be creating a path in the atmosphere, between the amplifying upper trof over the Lower Mississippi Valley and the re-positioning upper ridge off the Southeast coast, for the northwest movement of the developing tropical system over the northwest Caribbean toward the Yucatan Straits Tuesday into early Wednesday, and then a more north northeast track into the eastern Gulf Wednesday into Thursday. While the current official track of this system from the National Hurricane Center keeps the center of the storm well to the west of the Florida Keys, the outer bands of precipitation and squally weather on the east side of the storm may begin to affect the Florida Keys and South Florida on Wednesday. Additional major impacts from this storm likely across portions of Florida into the Southeast Thursday and Friday. Please refer to the National Hurricane Center for the latest updates on this system. The amplifying upper ridge across the interior West will be supporting widespread much above average temperatures over the next few days across nearly all of the West and into the Northern Plains. High temperatures across these regions are forecast to be as much as 10 to 20 degrees above average. Above average temperatures also likely across the Gulf Coast and into the Southeast. While temperatures are forecast to be much above across these areas over the next few days, there are not expected to be many record highs. However, more numerous record high morning temperatures are possible both Tuesday and Wednesday morning along the West coast and from portions of the southern Mid-Atlantic into the Southeast and Florida. Oravec Graphics available at https://www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php