Area Forecast Discussion
Issued by NWS
Issued by NWS
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390 FXUS62 KTAE 231440 AFDTAE Area Forecast Discussion National Weather Service Tallahassee FL 1040 AM EDT Thu May 23 2024 ...New UPDATE... .UPDATE... Issued at 1038 AM EDT Thu May 23 2024 No major changes were made to the forecast, as it looks to remain on track. && .SYNOPSIS... Issued at 427 AM EDT Thu May 23 2024 A turn to light low-level southerly and southwesterly flow will moisten the air mass just enough for isolated pop-up showers and thunderstorms over inland areas through Saturday. A strong upper ridge on Sunday will suppress any convection on that day. Meanwhile, a slow warming trend through Sunday, plus the infusion of muggy dewpoints above 70, will allow the heat index to reach 100 in spots on Saturday and Sunday. A front will drag through the Southeast States on Monday and Tuesday, increasing chance for strong thunderstorms. && .NEAR TERM... (Today and tonight) Issued at 427 AM EDT Thu May 23 2024 A strong 500 mb ridge axis will extend today from the southwest Gulf to northeast Florida. This will generally suppress convective development. However, a turn to light low-level southerly flow today will locally enhance lift in the terrain-favored area of seabreeze convergence well north of Apalachicola. Precipitable Water (PW) values will be flirting with the 1.5-inch value, which is a loose threshold for supporting deep, moist convection. So isolated pop-up showers and thunderstorms are possible this afternoon, with the gridded forecast showing a bullseye from Marianna to Blakely. Otherwise, the turn to southerly flow will favor expanding the patchy fog forecast on Friday morning to cover much of the forecast area. && .SHORT TERM... (Friday through Saturday night) Issued at 427 AM EDT Thu May 23 2024 Little sensible change is expected on Friday and Saturday. The 500 mb ridge axis will retreat back to the southwest Gulf on Friday night, with mid-level flow becoming northwesterly. Modest mid-level drying will push PW values down to just below 1.5 inches, which will hold back afternoon convection to isolated coverage over inland areas at the most. Low-level south and southwest winds off the Gulf will moisten dewpoints above 70F this weekend well inland. This will push the heat index at an increasing number of locations to near 100F on Saturday afternoon. && .LONG TERM... (Sunday through Wednesday) Issued at 427 AM EDT Thu May 23 2024 The 500 mb high over the Southwest Gulf will rebound strongly across the northeast Gulf on Sunday, with 500 mb heights of 5900+ meters expected over our FL counties. This will even more effectively suppress any attempts at convective development. Strong late May sunshine and the warming aloft will bring the hottest temperatures of this stretch on Sunday afternoon, with 90-95 expected over inland areas. Dewpoints of 70-75F will again push heat index values into the 95-100F range. Increasing thunder chances are in the forecast for Monday and Tuesday. The tail end of a low-amplitude and progressive upper trough will brush by the forecast area around Tuesday. This will push a late season cold front from Mississippi across Alabama and Georgia. Proximity of the front will bring an increased chance of storms. Timing is problematic at this point, with some guidance bringing the highest thunder chances across on Monday, while a larger collection of guidance peaks thunder chances on Tuesday. Regardless, we will be looking at moderate to possibly strong convective instability, PW values of 1.5-1.7 inches representing deeper surface-based moisture, and bulk shear of 30-40 knots. This combination of parameters favors a few strong multi-cell clusters, which mainly come with gusty winds. Isolated severe storms would be possible. By Wednesday, the front will have limped south into the Gulf, and low-mid level northwest-northerly flow will dry out and stabilize the air mass. The drier air mass will bring a return of pleasantly cool morning lows in the 60s around the middle of next week. && .AVIATION... (12Z TAFS) Issued at 622 AM EDT Thu May 23 2024 IFR in fog at ECP should lift ~13Z. Otherwise, VFR conditions today with a SCT deck of fair weather cumulus developing. Toward the latter portion of the TAF period late tonight, there is the potential for fog at all TAF sites, but it`s too early to pin down more specifics given the spatial and temporal uncertainty. && .MARINE... Issued at 427 AM EDT Thu May 23 2024 A broad area of high pressure from the Bahamas to the southeast Gulf will bring a turn to gentle southerly and southwesterly breezes over the waters today, which will then last through Sunday. Southwest breezes will increase on Monday and become moderate, in advance of a cold front moving from Mississippi into Alabama and Georgia. South of that front, thunderstorm coverage will start to increase over the waters around Monday night. && .FIRE WEATHER... Issued at 427 AM EDT Thu May 23 2024 Seasonably moderate fire weather conditions will prevail through Saturday. Near normal temperatures are forecast, while south to southwest winds off the Gulf will add a little extra mugginess and moisture to the air mass this weekend. Good dispersion values are expected over inland districts each afternoon through at least Saturday, thanks to a seasonably deep mixed layer and light to moderate transport winds. Isolated pop-up thunderstorms are possible over inland areas each afternoon. An increasing coverage of thunderstorms will come on Monday and Tuesday, when some storms could be strong. Patchy fog is possible over the Florida Panhandle and Lower Alabama districts through sunrise this morning. On Friday morning, patchy fog will expand into more of the Florida Big Bend, Alabama Wiregrass, and Southwest Georgia districts. && .HYDROLOGY... Issued at 427 AM EDT Thu May 23 2024 In the absence of rain since Sunday to recharge river headwaters, flood flows from heavy rains on the 17th and 18th are now routing into lower portions of the Choctawhatchee, Ochlockonee, Aucilla, and Withlacoochee Rivers. The only rivers expecting sustained rises in the days ahead will be the Florida reach of the Withlacoochee, and the Suwannee. Rainfall over the next 7 days will generally remain well under 1 inch, which is hydrologically insignificant. && .SPOTTER INFORMATION STATEMENT... Spotter activation is not requested. However, spotters are always encouraged to safely report significant weather conditions when they occur by calling the office or tweeting us @NWSTallahassee. && .PRELIMINARY POINT TEMPS/POPS... Tallahassee 91 68 91 71 / 10 0 10 0 Panama City 86 72 85 74 / 10 10 10 10 Dothan 89 68 88 72 / 20 0 20 10 Albany 89 68 89 70 / 20 0 10 10 Valdosta 92 69 92 71 / 20 0 10 0 Cross City 91 68 91 68 / 0 0 0 0 Apalachicola 83 72 84 74 / 0 0 10 10 && .TAE WATCHES/WARNINGS/ADVISORIES... FL...None. GA...None. AL...None. GM...None. && $$ NEAR TERM...Haner SHORT TERM...Haner LONG TERM....Haner AVIATION...LF MARINE...Haner FIRE WEATHER...Haner HYDROLOGY...Haner