Area Forecast Discussion (AFD)
Issued by Huntsville, AL (HUN)
000 FXUS64 KHUN 242339 AFDHUN Area Forecast Discussion National Weather Service Huntsville AL 639 PM CDT Mon Jun 24 2019 .UPDATE... For 00Z TAFS. && .NEAR TERM...(Tonight) Issued at 226 PM CDT Mon Jun 24 2019 A weak front is moving through the region this afternoon, serving as a focus for a few scattered showers and thunderstorms. As of 19:30z, modest forcing across the area and some weak CINH has suppressed much of this activity. However, over the next 2-3 hours, do expect to see an uptick in convection, thanks to an axis of more unstable air (SBCAPE values up to 3000 J/kg and MLCAPE up 1500 J/kg) across Northeast Alabama. This thermodynamic environment and forcing along the boundary should be enough to generate a few strong to marginally severe storms in a 20-23z window along this feature. Rain/thunder chances will decrease steadily by sunset as the boundary pushes into Georgia. In wake of this boundary, a more stable air mass will filter into the Tennessee Valley region. With drier air helping to erode the remaining cloud cover, a mostly clear to partly cloudy night is expected after midnight. Lows will bottom out in the upper 60s across much of the valley. .SHORT TERM...(Tuesday through Wednesday) Issued at 226 PM CDT Mon Jun 24 2019 Zonal flow aloft will develop on Tuesday and Wednesday across the Ohio and Tennessee Valleys, with high pressure at the surface trying to build in from the south and east. More westerly flow on Tuesday will help to mitigate our rain/thunder chances on Tuesday, and we may be looking at a mostly dry forecast save for an isolated diurnally driven storm or two -- along with a partly sunny day. A weak shortwave that will pass through the Mississippi Valley Tuesday night and into the Tennessee Valley on Wednesday. This feature will serve to provide sufficient lift for potentially another round of scattered showers and storms. The denser cloud cover on Wednesday may help keep temperatures in check and we may be looking at highs in the mid 80s. The shower and thunderstorm activity should wane by Wednesday evening and we should be transiting to a drier forecast as highs pressure begins to build in late this week. .LONG TERM...(Wednesday night through Sunday) Issued at 226 PM CDT Mon Jun 24 2019 High pressure will attempt to build back into the Tennessee Valley region Thursday and Friday into the weekend. Due to the strength of the ridge and the subsidence from it, expect a drier trend to develop as diurnal convection is suppressed, especially Thursday and Friday. There will be enough moisture underneath the ridge to allow for isolated to perhaps widely scattered convection each day -- but this activity will to tied to the daylight should diminish after sunset. Thus, generally expect most locations to remain dry. As the high gets shifts into Texas and the Southern Plains region late in the forecast period, it's possible a weak area of low pressure from the Gulf squeezes north into Alabama. This feature could provide a slightly better chances for showers and storms Saturday and Sunday, though the details of this remain much more uncertain. Otherwise, temperatures will remain close to seasonable levels for late June, with highs in the upper 80s to lower 90s and lows in the upper 60s to lower 70s. && .AVIATION...(For the 00Z TAFS through 00Z Tuesday evening) Issued at 639 PM CDT Mon Jun 24 2019 VFR conds are xpcted well into Tue, as a weak frontal boundary moves ewd across the region late tonight. Mid/high clouds will gen prevail into the daytime hrs Tue, as drier air begins to filter into the area in the wake of the frontal passage. West winds around 10kt will also become light/var later this evening before increasing near 7kt Tue morning. && .HUN WATCHES/WARNINGS/ADVISORIES... AL...NONE. TN...NONE. && $$ NEAR TERM...AMP.24 SHORT TERM...AMP.24 LONG TERM...AMP.24 AVIATION...09 For more information please visit our website at weather.gov/huntsville.