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 33 34 35 36 37
-- Highlight Changed Discussion --
-- Discussion containing changed information from previous version are highlighted. --
351 FXUS62 KTAE 150838 AFDTAE AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TALLAHASSEE FL 438 AM EDT Mon Sep 15 2014 .Near Term [Through Today]...
-- Changed Discussion --
The low-mid level flow (1000-500mb) will be from the southeast early this morning before veering to the south to southwest by this afternoon. This will bring a surge of moisture on the east side of tropical wave northward with PWATs increasing into the 2.0" to 2.2" range. This combined with abundant moisture already in place in the mid to upper levels along with the presence of a quasi-stationary front across our CWA will be the focus for widespread convection today. Thus, PoPs are in the likely category (60-70%) for all zones. The showers/storms will continue to be slow movers increasing the threat for locally heavy rain and isolated flooding of low lying and poor drainage areas. However, widespread flooding is not anticipated either today or throughout the short term period described below, so while monitored, the threat for flash flooding still appears minimal at this time. Also, most areas today will see max temps in upper 80s to around 90 degrees. .Short Term [Tonight Through Wednesday]... The end of the very stagnant synoptic weather pattern which has dominated our region for much of the month of September thus far is finally in sight. This pattern, which has resulted in unseasonably warm and wet conditions in the absence of any organized tropical activity, has indeed helped many areas catch up in rainfall from the record or near record dry conditions this past meteorological summer. For example, Tallahassee had its driest period of June, July, and August of all time with with only 8.99 inches of rainfall, which happens to be the only time on record this period has ever been below 10 inches. Through Sept. 14, 5.14 inches of rain has already fallen this month, and if 3.86 inches of additional rain were to fall during the next 3 days (which is certainly possible), then the September rainfall would already exceed that of the entire summer. The defining features of this month so far (which is also averaging nearly 3 degrees above normal in temperature every day) have been characterized by a weak Sfc pressure gradient and a stubborn "dirty" upper level ridge (with plenty of deep layer moisture (PWATs between 1.8" and 2.2") continuing to flow into the CWA from western Atlantic and Gulf of Mexico. This ample moisture will remain in place across the region through at least Tuesday night, and with the upper ridge finally expected to break down and retrograde westward, a steepening upper level trof will initially help energize the above mentioned Sfc boundary, increasing the chances for another period of heavy rainfall on Tuesday, possibly lingering into Tuesday night. While mean storm total rainfall amounts are generally expected to be in the 1" to 3" inch range across the entire region, isolated amounts of 3" to 5" or even 4" to 6" could be possible (especially near the coast of the FL Panhandle and western Big Bend) before all is said and done on Wednesday. However, since these higher amounts should be isolated as well as spread out over 3 days, the threat for any widespread flooding appears minimal at this time. Additionally, during each successive run of the Global Models during the past few days, the trend in both the GFS and ECMWF has been to accelerate the steepening of the trof which will help push the stalled out boundary through as a cold front on Wednesday and Wednesday night. This will put a quick end to the heavy rain chances, and may even bring a slight taste of fall to the region by the end of the week. .Long Term [Wednesday Night Through Sunday]... As the upper level trough deepens and moves south, the stalled frontal boundary will move off to the southeast bringing in slightly drier air. With the drier air behind the trof and cold front, PoPs drop into the 10 to 30% range for the upcoming period. We will see a taste of cooler temperatures with highs in the mid 80s and lows in the mid to upper 60s.
-- End Changed Discussion --
&& .Aviation...
-- Changed Discussion --
[Through 06Z Tuesday] Low clouds with restricted visibility can be expected at DHN, ABY, and VLD in the pre-dawn hours. Cigs could approach airport minimums around sunrise. Thereafter, VFR conditions are expected at all terminals through midday when conditions may fluctuate between VFR and MVFR as numerous showers/Tstms develop across the area. Winds will be light from the southeast to southwest.
-- End Changed Discussion --
&& .Marine...
-- Changed Discussion --
With a stalled out frontal boundary to the north of the coastal waters, the surface pressure pattern will remain stubbornly tight today into Tuesday, allowing for south to southwest winds of 10 to 15 knots and 2 to 4 foot seas. Thereafter, winds and seas will slowly diminish behind the cold front on Wednesday and Thursday, as the winds become offshore. Then, by the end of the week and into next weekend, a strong ridge of high pressure will build in to the northeast of the marine area, creating a tight pressure gradient once again, with favorable conditions for easterly surges.
-- End Changed Discussion --
&& .Fire Weather...
-- Changed Discussion --
Red flag conditions are not expected at least through the end of the workweek.
-- End Changed Discussion --
&& .Hydrology...
-- Changed Discussion --
As mentioned above, a widespread 1 to 3 inches of storm total rainfall (with isolated higher amounts) is expected to fall across the HSA during the next few days. While this may cause some rises on our area rivers and streams, it is unlikely to bring any of them to flood stage, especially with the highest rainfall amounts expected closer to the coast.
-- End Changed Discussion --
&& .Preliminary Point Temps/PoPs...
-- Changed Discussion --
Tallahassee 90 72 89 70 91 / 70 40 70 50 30 Panama City 89 76 87 74 88 / 70 50 70 50 20 Dothan 89 71 89 69 90 / 60 40 60 30 20 Albany 92 71 90 69 90 / 60 40 60 30 20 Valdosta 90 71 89 69 90 / 60 40 70 50 30 Cross City 91 71 87 69 88 / 60 30 70 50 40 Apalachicola 87 77 86 76 86 / 70 50 70 50 30
-- End Changed Discussion --
&& .TAE Watches/Warnings/Advisories...
-- Changed Discussion --
FL...High Rip Current Risk through late tonight for Coastal Bay- Coastal Franklin-Coastal Gulf-South Walton. GA...None. AL...None. GM...None.
-- End Changed Discussion --
&& $$ NEAR TERM...BARRY SHORT TERM...GOULD LONG TERM...WESTON AVIATION...BARRY MARINE...GOULD FIRE WEATHER...BARRY HYDROLOGY...GOULD

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