Area Forecast Discussion
Issued by NWS
Issued by NWS
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932 FXUS62 KTAE 240722 AFDTAE Area Forecast Discussion National Weather Service Tallahassee FL 322 AM EDT Tue Sep 24 2024 ...POTENTIAL TROPICAL CYCLONE NINE LIKELY TO BRING MULTIPLE IMPACTS TO OUR AREA ON THURSDAY... ...New NEAR TERM, SHORT TERM, LONG TERM, MARINE, FIRE WEATHER, HYDROLOGY... .NEAR TERM... (Today and tonight) Issued at 259 AM EDT Tue Sep 24 2024 One more day of dry and warm conditions are on tap today with highs in the low to mid 90s. Ridging aloft begins to get shoved off to the east by a large trough swinging south across the Plains, allowing for rain chances to begin to increase across the Gulf and near the coast overnight tonight. With rain chances increasing even Wednesday ahead of the hurricane, please take advantage of the great weather today to get your preparations underway or completed. && .SHORT TERM... (Wednesday through Friday) Issued at 259 AM EDT Tue Sep 24 2024 Attention turns to Potential Tropical Cyclone #9 (PTC9) beginning Wednesday, which according to latest NHC forecasts is likely to be a hurricane as it enters the southern Gulf of Mexico between Cuba and Mexico. Confidence is increasing for significant impacts across the region including major hurricane force winds, life threatening storm surge, flash flooding from heavy rainfall, and a few tornadoes. For Wednesday across the forecast area, the region will be between increasing southeasterly flow on gradient between surface high pressure in the Atlantic and the tropical cyclone well to our south, and a frontal boundary associated with a large upper level trough across the south-central US. Compared to prior forecasts, Wednesday is now appearing wetter, especially across our Panhandle counties, while scattered showers and storms associated with the very outer periphery of PTC9 likely won`t arrive until late Wednesday into Thursday morning. By Thursday morning, conditions could begin to deteriorate as the outer portions of PTC9 arrive, but it`s at this point where uncertainty in the forecast begins to vary in timing, intensity, and track. Latest 00z GFS ensembles have trended eastward some this morning and they continue to be some of the faster guidance in terms of landfall/impacts timing. Similar timing was noted with the Canadian ensembles. The 18z ensembles for the Euro were about 6 to 12 hours slower on average With that said, folks need to have preparations wrapped up by Wednesday night because tropical storm force conditions could arrive to our coastal communities as early as Thursday morning. A key point to highlight in all of the ensemble guidance is that a wide possibility of outcomes with respect to timing, intensity, and track is still on the table. This is important because as noted by NHC forecast wind radii, PTC9 is likely to be a very large storm. This means impacts from surge, rainfall, and wind will extend well away from the center. All locations along the northern Gulf and along the eastern portions of the Florida Big Bend and west coast of Florida are at risk currently for a major hurricane bringing significant wind, storm surge inundation, and rainfall. Additionally, PTC9 is likely to have a faster than usual storm motion as it accelerates north around landfall and moves inland. When combined with the storm`s large size and fast forward motion, significant winds and gusts could extend further inland than folks are typically accustomed to seeing during tropical systems. While we understand many individual`s first thoughts when evaluating their risk to PTC9 is to compare it to prior storms, we caution against doing so. Every tropical system brings a unique set of threats and hazards, and each system brings uncertainty that can leave you unprepared if you`re not ready for a *reasonable* worst case scenario. Don`t underestimate the danger you could experience with PTC9 just because you avoided impacts from previous storms. With watches likely today, if you are under a tropical/hurricane/surge watch or warning, be sure to check the forecast at weather.gov (type your zip code to see watches/warnings at your location) and read the tropical watch/warning text. These watches/warnings will list out conditions that you should be prepared for. These watches/warnings also list out reasonable worst case scenarios you should be ready for at your location. && .LONG TERM... (Friday Night through Monday) Issued at 259 AM EDT Tue Sep 24 2024 PTC9 quickly moves out of the forecast area on Friday after daybreak with the large upper level trough likely bringing in a period of dry conditions for the weekend. However, a trailing cold front associated with this trough could keep allow rain chances to return to the forecast later in the weekend or early next week. High temperatures will generally be in the upper 80s. && .AVIATION... (06Z TAFS) Issued at 110 AM EDT Tue Sep 24 2024 VFR conditions are expected through the period. && .MARINE... Issued at 259 AM EDT Tue Sep 24 2024 At 11 pm EDT, the center of Potential Tropical Cyclone 9 was over the northwest Caribbean. It will rapidly intensify while moving northward through the eastern Gulf on Wednesday and Wednesday night, making landfall likely as a major hurricane on the northeast Gulf coast on Thursday. Winds and seas will start to decrease on Friday as the tropical cyclone moves further inland and weakens. Broad low pressure over the Lower Mississippi Valley on Saturday will support gentle to moderate southwest breezes. && .FIRE WEATHER... Issued at 259 AM EDT Tue Sep 24 2024 Dry and warm conditions are forecast to continue today before rain chances increase Wednesday and Thursday as Potential Tropical Cyclone #9 approaches the area as a strong hurricane. Heavy rain and high winds will be expected with this system. Otherwise, there are no fire weather concerns. && .HYDROLOGY... Issued at 259 AM EDT Tue Sep 24 2024 Primary focus over the next 60-84 hours will be the approach and impact from potential tropical cyclone nine (PTC9). The tropical system is expected to be a quick mover, but the combination of rainfall ahead of the storm and then along the track of the storm will likely result in 3-6 inches of rain with isolated heavier amounts up to 10 inches. Because the vast majority of the rain will fall in a very short window of time, flash flooding will be the biggest concern, some of which could be considerable near the core of the storm. For that reason the excessive rainfall outlook for Thursday, as the system affects the region, has been increased to a moderate risk, or level 3 of 4, which is both indicative of the threat as well as the confidence at this time range. Some models are suggesting widespread heavy rainfall covering most or all of our river basins, moving from south to north, and this could lead to at least minor riverine flooding at many forecast points. In areas that exceed 6-8 inches of rain, moderate riverine flooding would be possible. As a reminder, river forecasts only include the next 48 hours of rainfall, so it will be until Wednesday afternoon until all of the rainfall associated with this system is included in our riverine forecasts. A flood watch has been issued to cover the threat of rainfall from PTC9 We are also looking at a potentially significant and major coastal flood threat from storm surge given the forecast with this system in Apalachee Bay. Apalachee Bay is especially sensitive to surge and small variations in track, intensity, and forward speed can cause major adjustments to the surge impacts. Nevertheless, at this point, confidence is increasing of a significant and major coastal flood impact in Apalachee Bay in association with this system. As we get closer to landfall, we`ll have more detail on specific surge values. Pay close attention to the advice of emergency management about any evacuation orders that are issued. Remember, storm surge is especially dangerous and destructive. If ordered to evacuate, heed the advice of emergency officials. Doing so can save your life! && .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 73 87 72 / 0 10 50 90 Panama City 90 74 85 72 / 20 50 80 90 Dothan 91 72 85 71 / 0 20 70 90 Albany 92 73 88 71 / 0 10 40 80 Valdosta 92 72 89 72 / 0 0 30 70 Cross City 93 73 90 74 / 0 0 60 80 Apalachicola 86 77 84 74 / 10 60 70 100 && .TAE WATCHES/WARNINGS/ADVISORIES... FL...Flood Watch from Wednesday evening through Friday morning for FLZ007>019-026>029-034-108-112-114-115-118-127-128-134. High Rip Current Risk through late Friday night for FLZ115. GA...Flood Watch from Wednesday evening through Friday morning for GAZ120>131-142>148-155>161. AL...Flood Watch from Wednesday evening through Friday morning for ALZ065>069. GM...None. && $$ NEAR TERM...Merrifield SHORT TERM...Dobbs LONG TERM....Dobbs AVIATION...Merrifield MARINE...Haner FIRE WEATHER...Merrifield HYDROLOGY...Godsey