Area Forecast Discussion
Issued by NWS
Issued by NWS
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864 FXUS62 KTAE 181620 AFDTAE Area Forecast Discussion National Weather Service Tallahassee FL 1220 PM EDT Sat May 18 2024 ...New UPDATE... .UPDATE... Issued at 1216 PM EDT Sat May 18 2024 No updates appear necessary to the forecast at this time. && .NEAR TERM... (Today and tonight) Issued at 349 AM EDT Sat May 18 2024 One more potential round of severe weather is on tap for this morning and afternoon as we watch the last of a series of disturbances over the last few days finally push through. As of 3am ET showers and thunderstorms were already beginning to develop well off to our west and northwest in southern Louisiana and Mississippi as the shortwave ejects east out of the mid-level trough currently over Arkansas. All these are expected to continue east through the morning and afternoon and bring widespread showers and storms to the forecast area across southeast Alabama, southwest Georgia, the Florida Panhandle and the Big Bend. Surface instability is somewhat lacking currently but plenty of elevated instability is currently in place as evidenced by convection quickly developing to our west as the forcing arrives. The main challenge this morning and afternoon is the convection evolution. Currently, fairly stable surface conditions are in place thanks to a large outflow boundary from Friday evening storms, but this boundary has largely stopped it`s southward progression and across the Panhandle is already starting to lift back north with a more unstable airmass moving in. This is evident by looking at surface obs further west where surface dewpoints are in the upper 70s compared to the low 70s near TLH. As the forcing moves east this morning, we should see a gradual uptick in the coverage of storms. The severe threat these pose will be questionable given the lack of surface based storms overland currently, but with heating of the day and increasing coverage, a gradual uptick in severe probabilities is expected as storms move into the eastern portions of the Panhandle and southwest Georgia around mid-morning. Storms generally get to Big Bend and south- Georgia late this morning and into the early afternoon hours and this is likely when severe probabilities will be their highest (pending a failure mode below not happening). One potential failure mode for severe weather developing today would be to keep an eye on storms currently across southern Louisiana. With the better surface instability still across the Gulf waters, it`s possible the storms ongoing there could throw off a lot of cloud cover and potentially limit low-level instability that can develop across our area later this morning and into the afternoon. Regardless, even if these lower the threat for severe weather, the strong shortwave rotating through and elevated instability should at least pose some threat for isolated damaging wind and/or hail today should the greater instability not develop. Additionally, precipitable waters remaining high will bring a risk for localized flood due to high rainfall rates in any storms, especially if those storms traverse over areas that received high rainfall amounts on Friday. && .SHORT TERM... (Sunday through Monday night) Issued at 349 AM EDT Sat May 18 2024 An upper level trough will be exiting the region on Sunday with the last of the remaining showers and thunderstorms clearing out through the day. There is a 40%-70% chance for showers and thunderstorms on Sunday however; some storms may be strong to severe for the eastern Big Bend counties and along the I-75 corridor, as it will be warm with dew points in the 70s, and remaining instability. The SPC has highlighted the extreme SE Big Bend in a Marginal (level 1 of 5) Risk for severe storms. Cooler air aloft is expected to filter in by the afternoon from the northwest. Upper level ridging will begin building in the west Sunday afternoon into Monday. PoPs on Monday will be limited to the I-75 corridor at around 35% as a shortwave passes through. Temperatures for the short term will have highs in the upper 80s to around 90 degrees. Because of the northerly flow, our GA counties may only reach the mid-80s for highs for Sunday and Monday. Overnight lows will be in the mid 60s. && .LONG TERM... (Tuesday through Friday) Issued at 349 AM EDT Sat May 18 2024 Upper level ridging builds through the week, allowing for warming temperatures and mostly dry weather. Highs will be in the low 90s with overnight lows in the mid to upper 60s. && .AVIATION... (12Z TAFS) Issued at 638 AM EDT Sat May 18 2024 MVFR/IFR conditions prevail through daybreak as low stratus from previous rains linger. Through today, expect conditions to improve to MVFR and possibly VFR at more eastern terminals near VLD, while our more western terminals at ECP/DHN likely remain MVFR/IFR through much of the morning and early afternoon. Attention turns to another round of strong to severe storms that approach from the west in the next few hours at ECP/DHN. These spread east through the morning bringing localized IFR visibilities along with the potential for localized 30 to 40 knot wind gusts. Rain will linger after severe storms go through with IFR/MVFR conditions lingering into the evening and possibly overnight hours. && .MARINE... Issued at 349 AM EDT Sat May 18 2024 A line of thunderstorms is likely to move across the waters this morning and evening, bringing strong to severe wind gusts. A weak front will move across the waters today and tonight, and stall on Sunday, bringing renewed chances of showers and thunderstorms. High pressure will pass across the northeast Gulf on Sunday night, and then elongate along the U.S. Eastern Seaboard on Monday and Tuesday allowing for more favorable boating conditions. && .FIRE WEATHER... Issued at 349 AM EDT Sat May 18 2024 Fire weather concerns will be low through the beginning of next week. This is mostly due to the wet pattern we`re currently in. While rain chances lessen Sunday and into early next week, the widespread rainfall totals from the weekend will likely have been around 1 to 3 inches which is well above normal for this time of year and no significantly dry air mass is expected into much of next week. && .HYDROLOGY... Issued at 349 AM EDT Sat May 18 2024 A Flash Flood Watch remains in effect for the entire region except the SE Big Bend in FL, Lowndes and Lanier Counties in GA, through 4 PM EDT / 3 PM CDT Saturday. Another 1-2 inches is expected with localized higher amounts possible. Due to already saturated soils, flash flooding will be a concern with training thunderstorms. The region along and west of the Apalachicola River Basin is highlighted in a Slight (level 2 of 4) risk for excessive rainfall today, while areas to the east are covered in a Marginal (level 1 of 4) risk for excessive rainfall. The Withlacoochee River at Valdosta (Skipper Bridge Road) and Quitman as well, as the Ochlockonee River at Concord, continue in minor flood stage. && .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 68 87 67 86 / 40 40 10 20 Panama City 70 85 69 87 / 40 10 0 10 Dothan 66 85 66 85 / 30 20 0 10 Albany 66 83 65 84 / 30 40 10 10 Valdosta 68 86 67 84 / 60 60 20 20 Cross City 69 86 67 87 / 70 60 20 40 Apalachicola 71 84 71 83 / 60 20 10 10 && .TAE WATCHES/WARNINGS/ADVISORIES... FL...Flood Watch until 8 PM EDT /7 PM CDT/ this evening for FLZ007>018-026-027-108-112-114-115-118-127. High Rip Current Risk through late Sunday night for FLZ108-112- 114-115. GA...Flood Watch until 8 PM EDT this evening for GAZ120>131-142>148- 155>159. AL...Flood Watch until 7 PM CDT this evening for ALZ065>069. GM...None. && $$ NEAR TERM...Dobbs SHORT TERM...Montgomery LONG TERM....Montgomery AVIATION...Dobbs MARINE...Montgomery FIRE WEATHER...Dobbs HYDROLOGY...Montgomery