Forecast Discussion
846 FXUS64 KMEG 241748 AFDMEG Area Forecast Discussion National Weather Service Memphis TN 1248 PM CDT Wed Apr 24 2024 ...New AVIATION... .UPDATE... Issued at 1000 AM CDT Wed Apr 24 2024 Skies remain cloudy across extreme southern sections of the Mid- South this morning with mostly sunny skies over the remainder of the region. The clouds are ahead of a weak cold front that is pushing south and will be in central Mississippi this afternoon. Behind the front, drier air has been moving in place this morning with a rain free afternoon and evening expected for the region. Temperatures are not that much cooler behind the front so highs this afternoon will be in the mid to upper 70s. ARS && .SYNOPSIS... Issued at 444 AM CDT Wed Apr 24 2024 Slightly warmer temperatures are forecast today, despite the passage of cold front this morning. This front will return north as a warm front tonight, spreading more humid air into the Midsouth that will persist through the weekend. Scattered showers and isolated thunderstorms will be possible on Thursday. Increased cloud cover and rainfall will hold temperatures down by several degrees, especially over eastern Arkansas. Above normal temperatures will prevail Friday and Saturday, with additional showers and a few thunderstorms along and west of the Mississippi River. Thunderstorm chances will increase across all the Midsouth by early Monday, focused along a Pacific cold front and aided by an upper level low pressure system. && .DISCUSSION... (Today through Tuesday) Issued at 444 AM CDT Wed Apr 24 2024 A progressive mid-spring pattern will continue through early next week. For today, northwest flow aloft will prevail, downstream of an upper ridge axis over the plains. A weak cold front will move through north MS this morning, then wash out over central MS this afternoon. The front will return north on Thursday, as the upstream upper ridge axis approaches. Several models depict a shortwave, possibly convectively-enhanced, topping the ridge and moving southeast into the Midsouth Thursday afternoon. Precipitable water values will top 1.5 inches, along a theta-e gradient extending from northeast AR into north MS. Elevated instability up to 500 J/kg will support a few thunderstorms Thursday afternoon. The upper ridge axis will move through the Midsouth Thursday night, limiting rain chances. Southwest flow aloft will prevail from Friday through Sunday, as two consecutive upper lows lift from the 4-corners region into the central plains and upper Midwest. With the exception of eastern AR and the MO bootheel, convective inhibition should limit storm coverage over the Midsouth during this period. Thunderstorm chances will increase late Sunday night and Monday, in advance of a progressive southern stream trough lifting into the southern plains. Unlike the closed lows lifting into the upper Midwest in the previous days, this southern branch system will bring height falls and a Pacific cold frontal passage through the Midsouth. Models have come into slightly better timing agreement, with the current consensus focusing thunderstorms along the front early Monday, around the diurnal minimum of convective instability. Precipitable water values around 1.8 inches will support locally heavy rainfall, if adequate instability can be realized to support widespread thunderstorms. Warm and mainly dry conditions will likely follow for the middle of next week, as an upper ridge builds over the southern plains and lower MS River Valley. PWB && .AVIATION... (18Z TAFS) Issued at 1248 PM CDT Wed Apr 24 2024 VFR conditions are expected to prevail at most sites through the TAF period. Shower activity may impact JBR and MEM as early as 13z tomorrow, but confidence in the exact timing of this activity remains too low for the inclusion of anything beyond VCSH at this time. && .MEG WATCHES/WARNINGS/ADVISORIES... AR...None. MO...None. MS...None. TN...None. && $$ PUBLIC FORECAST...PWB AVIATION...JPR