470 FXUS62 KTAE 131049 AFDTAEArea Forecast Discussion National Weather Service Tallahassee FL 649 AM EDT Sat Sep 13 2025
...New AVIATION...
.NEAR TERM... (Today and tonight) Issued at 159 AM EDT Sat Sep 13 2025
Once again, persistence will be a good forecast for today and tonight.
Satellite-derived Precipitable Water imagery reveals a dry air mass, with PW values in the 1-1.1 inch range. The 00z JAX balloon sounding showed 3-4 subsidence inversions below 650 mb, so the air mass is also stable. Surface dewpoints are running in the lower 60s, after bottoming out in the upper 50s during the well mixed late afternoon hours on Friday.
Meanwhile, water vapor imagery shows a digging shortwave near Tallahassee that will further amplify the already-amplified 500 mb trough extending southwest from the NC Piedmont. In response, the thunderstorm-riddled surface trough extending north out of the Bahamas will deepen a bit more today, tightening the pressure gradient to its west and further strengthening our NE surface flow today. This will reinforce the dry air mass in place. Temperatures will trend downward by a modest 1-3 degrees. For tonight, inland locations which decouple will certainly have potential to drop into the 50s, though most places will keep a little wind with lows in the 60-65 degree range on Sunday morning.
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.SHORT TERM and LONG TERM... (Sunday through Monday night) Issued at 159 AM EDT Sat Sep 13 2025
Little sensible day-to-day change is expected through Wednesday, as a blocking pattern will keep an upper trough in place over the Carolinas and Georgia. This will amount to a continuation of cool nights, seasonably hot afternoons, northeast surface winds, and a dry air mass.
From a synoptic perspective, the amplified 500 mb trough will become cutoff from the mid-latitude flow on Monday, as a strong upper high builds across the Great Lakes and sets up a Rex Block pattern. So downstream, a surface trough will continue between the Bahamas and the NC coast, with high pressure over the Northeast U.S. pushing NE winds down the Carolina and Georgia coastal plain into our region.
The upper high over the Great Lakes region will weaken on Thursday and Friday, so the pattern will start to un-block and deamplify. The persistent 500 mb trough over the Southeast U.S. will exit off to the northeast. Without upper support, the surface trough north of the Bahamas will dissipate, so our low-level flow will become more easterly. This will bring a little more maritime influence from off the Atlantic, sending dewpoints upward into and/or through the 60s. PW values will moisten to 1.5+ inches over the FL Big Bend and perhaps far south Georgia by Thursday night and Friday, supporting the first low-end rain chance in the 7-day forecast.
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.AVIATION... (12Z TAFS) Issued at 643 AM EDT Sat Sep 13 2025
Continued VFR thru the period with prevailing NE winds sustained in the 10-12-kt range later today. Occasional gusts near 20 kts are likely. Minimal cloud cover is expected. Northeast winds slacken to about 5 kts after sunset.
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.MARINE... Issued at 159 AM EDT Sat Sep 13 2025
Northeast flow will persist through Wednesday in the gradient between high pressure to the north and a persistent trough of low pressure extending north from the Bahamas. Northeast flow is favorable for nighttime and morning surges of wind off the land, and relative lulls during the afternoon. Winds will peak as fresh breezes during the nocturnal wind surge tonight.
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.FIRE WEATHER... Issued at 159 AM EDT Sat Sep 13 2025
The prolonged period without rain will continue through at least next Thursday, with the next low chance of rain waiting until next Friday for our Florida Big Bend districts. Otherwise, gusty northeast surface winds will peak in strength this weekend but continue through next Wednesday, reinforcing the dry air mass across the region.
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.HYDROLOGY... Issued at 159 AM EDT Sat Sep 13 2025
No flooding is expected for the next 7 days.
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.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.
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.PRELIMINARY POINT TEMPS/POPS... Tallahassee 88 63 89 63 / 0 0 0 0 Panama City 90 66 90 67 / 0 0 0 0 Dothan 88 61 88 62 / 0 0 0 0 Albany 87 60 88 61 / 0 0 0 0 Valdosta 87 60 88 60 / 0 0 0 0 Cross City 89 63 90 62 / 10 0 10 0 Apalachicola 87 67 85 70 / 0 0 0 0
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.TAE WATCHES/WARNINGS/ADVISORIES... FL...None. GA...None. AL...None. GM...None. &&
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NEAR TERM...Haner SHORT TERM...Haner LONG TERM....Haner AVIATION...IG3 MARINE...Haner FIRE WEATHER...Haner HYDROLOGY...Haner
NWS TAE Office Area Forecast Discussion