Area Forecast Discussion
Issued by NWS

Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary Off
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32
-- Highlight Changed Discussion --
-- Discussion containing changed information from previous version are highlighted. --
495 FXUS62 KTAE 290711 AFDTAE AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TALLAHASSEE FL 311 AM EDT Mon Sep 29 2014 ...Heavy Rainfall is Possible Today in South-Central Georgia and the Florida Big Bend... .Near Term [Through Today]...
-- Changed Discussion --
Heavy rain has had a difficult time materializing across most of the area, despite a tropical airmass in place with an upper trough approaching. The main limiting factor seems to be the convective complexes in the Gulf, which are disrupting low-level inflow into our forecast area. Guidance has insisted since yesterday that this will change as the thunderstorms over the Gulf weaken, but so far that has not happened. The HRRR has been particularly bad with this scenario, continually over-forecasting convection in our area in the first few hours of its forecast for most of the night. Because of this mesoscale issue, confidence remains low on the convective evolution and rainfall amounts across the area for the remainder of today. As long as significant convection remains over the Gulf, most of the area will not see heavy rain with the exception of a few points along the coast. That being said, satellite imagery has shown some gradual weakening of the MCS west of Tampa, and there has been a slow uptick in the rain and embedded convective coverage closer to our coast. The general movement of this has been more northerly rather than easterly as well, so perhaps things are beginning to change a little. However, the threat seems to have diminished enough across the northwest portions of the area to cancel the watch there. Still do not feel comfortable canceling the entire watch just yet though as there still appears to be a window for heavy rainfall and training echoes across portions of the area through this afternoon. The greatest potential appears to be across the Florida counties near the coast, but cannot completely discount portions of south central Georgia either. As the morning progresses, the western portions of the watch area may be able to be cancelled early, as well as the northern portions if convection does not develop there by mid to late morning. At any rate, we will be mostly rid of this system in the next 24 hours, and good riddance as it has been a tough one to forecast. .Short Term [Tonight Through Wednesday]... A shortwave upper level trough will swing northeastward through the Appalachian mountain range, lifting the stationary surface front currently laid out across NE FL from Cross City to Jacksonville today and tonight, finally pushing it out of the area Tuesday. Tonight, chances for showers and thunderstorms will be most likely (60-70%) in south-central Georgia and the Florida Big Bend, with lower chances (30-50%) to the west. The highest rainfall amounts will fall during the daytime hours, but isolated areas in south Georgia and the Big Bend (where PWATs will still be over 2") may see heavy rainfall early in the night. Tuesday through Wednesday, chances for showers and thunderstorms will be much lower (30% or less), with the highest chances staying in the eastern Big Bend. Lows tonight and Tuesday night will be in the mid to upper 70s. Highs will be in the mid 80s Tuesday, mid-upper 80s Wednesday. .Long Term [Wednesday Night Through Monday]... After a very wet pattern over much of the near and short term periods, we expect to have a brief break in the unsettled weather later on Tuesday and through Wednesday, as both Sfc and upper level ridging build in for a short time. Thereafter, showers and thunderstorms are expected to return to the fcst in earnest on Thursday and Friday, as the strongest cold front of the season thus far approaches from the NW. This cold front is expected to bring a real taste of fall to the region by Saturday and Sunday, with low temps possibly reaching the lower to middle 50s over the interior on Sunday morning, with much drier air also building in under the NW flow. High temps will still be very close to climo levels, however, generally in the lower to middle 80s on Sat and Sun. Before the frontal passage, above normal temperatures are expected to persist, with the warm and humid air struggling to budge.
-- End Changed Discussion --
&& .Aviation...
-- Changed Discussion --
[Through 06Z Tuesday] Periods of rain and low cigs are expected through most of the day with MVFR to IFR conditions. Some clearing is expected around DHN and ECP by the end of the day as the rain exits that area.
-- End Changed Discussion --
&& .Marine...
-- Changed Discussion --
A stationary front will finally exit the area Monday and Monday night, shifting the winds from southerly to westerly then northerly, returning back to southerly by mid week. Wind speeds will remain below headline criteria until early in the weekend, when another frontal passage may increase winds to cautionary levels.
-- End Changed Discussion --
&& .Fire Weather... Hazardous fire weather conditions are not expected over the next few days. && .Hydrology...
-- Changed Discussion --
We have started to trim back the flash flood watch from northwest to southeast, and additional trimming is likely through the day today as convection gradually moves to the east. The heavy rain threat is isolated, so main stem river flooding is unlikely. Isolated spots within the watch area could still pick up 4-6" of rain in a short period of time, but most locations will not see that much.
-- End Changed Discussion --
&& .Preliminary Point Temps/PoPs...
-- Changed Discussion --
Tallahassee 80 69 86 68 89 / 90 60 20 10 20 Panama City 83 70 86 71 87 / 90 40 20 10 20 Dothan 80 66 86 65 88 / 80 40 10 10 10 Albany 78 66 85 65 87 / 90 50 10 10 10 Valdosta 81 67 85 65 87 / 90 70 20 10 20 Cross City 83 70 86 67 88 / 90 60 30 20 20 Apalachicola 82 71 84 71 85 / 90 50 20 20 20
-- End Changed Discussion --
&& .TAE Watches/Warnings/Advisories...
-- Changed Discussion --
FL...Flash Flood Watch through this evening for Calhoun-Coastal Bay- Coastal Dixie-Coastal Franklin-Coastal Gulf-Coastal Jefferson-Coastal Taylor-Coastal Wakulla-Gadsden-Inland Bay- Inland Dixie-Inland Franklin-Inland Gulf-Inland Jefferson- Inland Taylor-Inland Wakulla-Lafayette-Leon-Liberty-Madison. GA...Flash Flood Watch through this evening for Baker-Ben Hill- Berrien-Brooks-Colquitt-Cook-Decatur-Dougherty-Grady-Irwin- Lanier-Lee-Lowndes-Mitchell-Thomas-Tift-Turner-Worth. AL...None. GM...None.
-- End Changed Discussion --
&& $$ NEAR TERM...DVD SHORT TERM...MOORE LONG TERM...GOULD AVIATION...DVD MARINE...MOORE FIRE WEATHER...DVD HYDROLOGY...DVD

USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.