Area Forecast Discussion
Issued by NWS Huntsville, AL
Issued by NWS Huntsville, AL
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546 FXUS64 KHUN 051939 AFDHUN Area Forecast Discussion National Weather Service Huntsville AL 239 PM CDT Wed Jun 5 2024 ...New NEAR TERM, SHORT TERM... .NEAR TERM... (Tonight) Issued at 239 PM CDT Wed Jun 5 2024 Morning cloud cover has largely dissipated, making for mostly clear to partly cloudy conditions across the Tennessee Valley this afternoon. In response, temperatures have warmed into the mid to upper 80s in most locations as of 1930z, with between 1000-2000 J/kg of SBCAPE developing across the area in a very moist air mass. This can be seen with PWATs reaching the 1.6-1.8" range, with dewpoints in the mid 60s. The main driver of convection this evening will be a shortwave trough swinging across the Deep South and remnant MCV (from last night`s convection) over the Mid South all ahead of a southeastward advancing cold front. This activity will develop to the west over northern Mississippi and western Tennessee, moving into the Tennessee Valley during the 00-06z timeframe. Low-level lapse rates of 7 to 7.5 C/km and effective shear values (though modest) will support at least a limited threat for a few strong storms around sunset. However, after sunset, lapse rates will become close to moist adiabatic, hindering updraft strength in this activity. Thus, the main threat with convection will be locally heavy rainfall (given the very moist environment) and frequent lightning. This activity will continue to push eastward and gradually taper off and weaken late tonight into early Thursday morning. && .SHORT TERM... (Thursday through Saturday) Issued at 239 PM CDT Wed Jun 5 2024 Any lingering morning convection will quickly sweep eastward into Georgia and a drier air mass will sweep into the area in wake of the cold front that will push into the region on Thursday. Cloud cover will also dissipate, making for a beautiful afternoon. With plenty of sunshine, highs in the mid to upper 80s and lower RH values between 45-55 percent will be common. Thursday evening/night will be quite comfortable as this drier air mass filters in, with overnight lows dropping into the lower 60s in most locations underneath a clear sky. High pressure at the surface on Friday will make for another beautiful, sunny day as highs will climb into the low to mid 80s. && .LONG TERM... (Saturday through Tuesday) Issued at 330 AM CDT Wed Jun 5 2024 Looks like we will be stuck in this northwesterly flow pattern through the extended forecast. An upper low straddling Ontario and Quebec will be anchored there and a few shortwaves will round the trough providing us chances of rain through Monday. The associated sfc low will have a cold front extending through the OH Valley and back into the Lower MS Valley that will head into the TN Valley and Southeast this weekend. Ahead of these features, cloud cover will increase on Saturday and low chances (20-30%) of showers and thunderstorms will return. Coverage will increase to ~40% on Sunday as the front draws near. During this time, a lobe of energy will phase with the upper level trough, shifting it eastward. The GFS is the most progressive with this and wants to bring in ridging by Monday. Will wait for better model consensus and instead stick with the NBM on keeping low chance of POPs in through Monday. Cooler and drier air will filter in behind the front, providing drier conditions and more sunshine on Tuesday. Daytime highs through the extended will be near or slightly below seasonable values, staying in the upper 70s to lower 80s. Lows on the other hand will remain warm through the weekend and become more seasonable behind the front returning to the lower 60s. && .AVIATION... (18Z TAFS) Issued at 1159 AM CDT Wed Jun 5 2024 SHRA/TSRA will redevelop late in the day into the evening hours as a shortwave trough swings across the region. At times these storms may produce localized MVFR conditions due to reduced visibilities and ceilings. AWWs and amendments may be needed should a storm impact either terminal. Have handled this with TEMPOs and/or PROB30 groups for now. This activity will gradually dissipate from west to east late in the period as they push eastward into Georgia. && .HUN WATCHES/WARNINGS/ADVISORIES... AL...None. TN...None. && $$ NEAR TERM...AMP.24 SHORT TERM....AMP.24 LONG TERM....JMS AVIATION...AMP