923 FXUS64 KHUN 080545 AFDHUN Area Forecast Discussion National Weather Service Huntsville AL 1245 AM CDT Tue Jul 8 2025 ...New AVIATION... .NEAR TERM... (Rest of tonight and Tuesday) Issued at 1014 PM CDT Mon Jul 7 2025 Scattered coverage of showers and thunderstorms that occurred in the afternoon have largely dissipated with the lost of daytime heating and resultant instability. Some isolated activity was heading ENE from NE Mississippi. Most of convection that occurred earlier was near a weak convergence axis, that extended from south of Russellville Lynchburg. Some locally heavy rain did occur, with ~2.25" at the Muscle Shoals airport, and other spots in Franklin county AL and TN both having local reports of over an inch. After a toasty day with highs as warm as 98 in Muscle Shoals, 95 Huntsville and Scottsboro, 94 Decatur and Meridianville, 93 in Albertville, Vinemont Fort Payne, and 91 Fayetteville and Winchester. Area temperatures at 10 PM were in the 70s to 80 in Huntsville with light winds. With generally clear skies and good radiational cooling expected, low temperatures should cool into the upper 60s to lower 70s. Higher levels of moisture left over from recent heavy rain will be conducive for the development of fog, some of it locally dense. Areas of fog formation will be in those normally fog prone spots, as well as areas that received moderate or heavy rainfall earlier. Fog that develops should dissipate with the advent of daybreak. Another very warm to hot day is expected for the Tennessee Valley, with temps heating into the lower 90s (a few mid 90s in the hottest spots). Dewpoint values higher in the 73-75 degree range will produce heat index values from the upper 90s to 105 degrees. Areal coverage of the warmest readings per output from the morning NBM is too low for heat advisory issuance. Will closely examine the new blends that should run shortly and revisit that possibility. And like this afternoon, strong daytime heating will produce CAPE values from 500-1500 J/kg, with some 2000 J/kg readings in the most unstable spots. Higher instability from an infusion of more moisture will yield scattered at times numerous showers and thunderstorms mainly Tue afternoon. With precipitable water amounts in the 1.6-1.8 inch range, locally heavy rainfall amounts and frequent lightning is possible. An inverted-V sounding profile expected in the late morning and afternoon infers a strong outflow wind potential as possible microbursts. Otherwise mainly "general" intensity storms are expected. Areas that received moderate to heavy rainfall today will be more susceptible to experience runoff and flooding issues Tue afternoon and evening, should they be impacted by heavy rainfall again. && .SHORT TERM... (Tuesday night through Thursday) Issued at 1014 PM CDT Mon Jul 7 2025 Shower activity should decrease in coverage and intensity Tue evening, but probably will not all go away as has occurred the past few days, thanks to a more humid and unstable environment. An upper level pattern shift will occur, as an upper level low moving across SE Manitoba moves over the Great Lakes, and induces weak troughing over the eastern CONUS. Slightly lower heights from the trough amplifying will increase overall instability over this region, and help bring higher chances of showers and thunderstorms for the mid/latter part of the week. Overall precipitable water amounts rise into the 1.7-2" range from Wednesday into the upcoming weekend. This will produce convection with very heavy rainfall, gusty outflow winds and frequent lightning. Runoff from these showers, especially if that repeatedly impact a similar area could end of producing flooding. We will closely monitor this potential on what areas could be impacted by the heaviest showers. The Weather Prediction Center has much of the area in a daily Marginal Risk for excessive rainfall into the weekend. More clouds and higher rain chances should result in a bit cooler conditions for the mid week. Before showers become more widespread Wed afternoon, highs should rise into the upper 80s to lower 90s. Not as hot with heat index values rising into the mid 90s to 103 degrees. With somewhat higher rain chances, highs Thursday will "only" warm into mid 80s to around 90. Lows Tue and Wed nights should cool into the lower 70s. && .LONG TERM... (Thursday night through Monday) Issued at 1014 PM CDT Mon Jul 7 2025 The area will remain in moist environment as we go into the weekend and early next week. This will keep chances for more daily showers and thunderstorms in the forecast. A similar setup to Wed and Thu should continue to close out the week, with mainly afternoon convection and early evening showers and storms. High temperatures Friday and Saturday should range in the mid 80s to around 90, with 60-70 percent rain chances. Rain chances should be lower (around 50 percent) on Sunday and Monday, as mean troughing begins retreating to the north and upper ridging slowly builds back. Lesser rain chances and a little more direct sun should help high temperatures rise into the upper 80s and lower 90s. && .AVIATION... (06Z TAFS) Issued at 1245 AM CDT Tue Jul 8 2025 VFR conditions will be the predominant flight category at each terminal through the period. The one exception may be in the late afternoon/evening when scattered TSRA develop -- which may produced localized MVFR conditions if they impact either terminal. However, confidence was too low to deviate from VFR conditions at this time. && .HUN WATCHES/WARNINGS/ADVISORIES... AL...None. TN...None. && $$ NEAR TERM...RSB SHORT TERM....RSB LONG TERM....RSB AVIATION...AMP.24