Near Term [Through Tonight]...
A cold front continues to trek across the southeastern CONUS today with a convective boundary just east of AAF to FZG. This is bringing scattered showers and thunderstorms to the area once again. The HRRR is handling our atmospheric conditions pretty well so far today, so adjusted PoPs toward recent runs.
Coverage will be highest in southeast Alabama, southwest Georgia, and over the coastal waters. Some of these storms will last into the early overnight hours, particularly near the AL-FL border.
Showers over our eastern coastal waters will likely generate once again in the early hours of Wednesday morning.
Highs today will be in the low-mid 90s, around 90 along the coast, and lows tonight will be in the low to mid 70s, with temperatures cooler in southeast Alabama.
Short Term [Wednesday Through Thursday Night]...
A surface cold front will slowly push southeast by tomorrow, likely reaching the northern and northwest parts of our forecast area. The front will not represent a significant transition in surface temperatures as it stalls in the northern part of our area in the next 24-36 hours, but there will be a fairly substantial precipitable water and low-level dewpoint gradient across the boundary.
Behind the front, PWATs should fall to around 1.5 inches by Thursday afternoon which is below the 20th percentile for August at TLH. Ahead of the front, PWATs should remain above 2 inches which is slightly above normal.
This setup should limit rain chances in the northern and northwest parts of our forecast area both Wednesday and Thursday.
However, showers and storms will be likely in the southeastern part of our area, especially closer to the Suwannee River.
Both high-resolution and global models suggest a continuation of the recent convective timing: thunderstorms quickly develop and expand in coverage offshore in the 06-12Z timeframe, and then affect the coastal areas and the Florida Big Bend in the morning hours, with more scattered development in the afternoon elsewhere.
Highs may be limited in the coastal areas and the Florida Big Bend where early cloud cover and rain is more likely. Elsewhere mid-90s seem likely inland.
There will be the potential for locally heavy rainfall and isolated flooding during the period - mainly in the Florida Big Bend and especially in the Taylor, Dixie, and Lafayette County area. KTLH radar has already indicated 2-4" of rain in much of those counties since Monday morning, with convection-allowing models indicating isolated additional rainfall of upwards of 5" will be possible by Wednesday evening.
More on this in the hydrology section.
Long Term [Friday Through Tuesday]...
A drier air mass should continue to advect into the area for Friday and Saturday, which should reduce rain chances over much of our forecast area except for perhaps the far southeast corner.
PWAT values are then forecast to increase again Sunday into early next week to more normal levels as deeper southwest flow sets up.
Temperatures should be relatively close to normal.
Scattered to numerous convection is expected to develop once again this afternoon and coverage is more than sufficient to warrant an explicit mention in the TAFs.
VFR will prevail for the most part, with the exception of drops to MVFR for storms near the terminals.
Showers and thunderstorms should be fairly widespread across the coastal waters for the next several mornings ahead of a stalling cold front just to the north.
Winds and seas may be higher near storms.
Through Wednesday evening, winds of 10-15 knots should create widespread 2-3 foot seas.
Weaker winds thereafter will promote seas of 2 feet or less.
Despite a drier airmass moving into the region this week, relative humidity values will remain above critical thresholds.
Red flag criteria will not be met.
There will be a chance for some isolated flooding in the Florida Big Bend in the next couple days - particularly in Dixie, Taylor, and Lafayette Counties. Radar estimates indicate that 2-4 inches of rain has fallen across much of those counties since Monday morning. While average rain totals through Thursday should be on the order of 2-3 inches, isolated amounts at least double that could contribute to localized areas of flooding.
Elsewhere, slow-moving storms and a moist atmosphere mean that flooding cannot be ruled out in the remainder of the Florida Panhandle and Big Bend, as well as extreme southern Georgia. However, localized flooding is less likely in those areas.
Any flooding would likely be confined to urban areas, low-lying spots, or smaller basins and streams (if it occurs).
Preliminary Point Temps/PoPs...
Tallahassee 74 93 74 95 73 / 30 60 20 40 20
Panama City 79 91 77 91 76 / 30 40 20 30 20
Dothan 72 94 71 94 71 / 30 30 20 20 10
Albany 73 94 71 94 70 / 30 30 20 20 10
Valdosta 73 95 72 95 72 / 30 60 20 40 20
Cross City 75 91 74 91 73 / 40 60 20 60 30
Apalachicola 78 90 77 90 76 / 30 60 20 40 20