Marine Weather and Tide Forecast for Lower Grand Lagoon, FL

SHORT TERM
(Today and Tonight)
Issued at 212 AM EDT Sat Oct 10 2026

Post-Tropical Cyclone Isaias continues to pull away and very quickly fill thanks to very strong shear. Most of the heavy rain and tornado threat has subsided for the rest of the night as instability wanes and dry air moves in.

However, there's still the potential for a trailing convergent band to set up over the eastern Big Bend into the I-75 corridor of south Georgia. Where this band sets up, some locally heavy rainfall is possible, especially if it ends up training. Thus, we'll still need to keep an eye on it through this afternoon.
There remains a Slight Risk (level 2 of 5) for the tornado risk in the eastern Big Bend and south central Georgia. This same location is also under a Slight Risk (level 2 of 4) for excessive rainfall to account for the training convection.

Farther to the west, in areas most impacted by Isaias, dry weather should prevail today, providing residents and responders good weather to begin recovery efforts.

Highs today will be in the upper 70s to lower 80s. Lows tonight will be in the upper 50s to lower 60s.

LONG TERM
(Sunday through Friday)
Issued at 212 AM EDT Sat Oct 10 2026

A stretch of dry weather is expected for much of the upcoming week as ridging builds across the southeast US. This will result in above normal temperatures returning to the area. Highs will climb back into the upper 80s. Lows will be in the 60s. A slight drop in temperatures is expected late next week as the ridge flattens out a bit more. Otherwise, no impactful weather is expected.

AVIATION
(06Z TAFS)
Issued at 116 AM EDT Sat Oct 10 2026

Widespread MVFR conditions with pockets of IFR and LIFR around the remnants of Hurricane Isaias and associated rainbands. Winds vary between TAF sites and gusting between 25-40 kts, with isolated higher gusts in rainbands. Winds back out of the S late tonight and remain gusty throughout Saturday as the storm continues pushing inland. Winds loosen by the end of the TAF cycle but lingering CIGs could keep flight conditions around MVFR Saturday afternoon, though uncertainty exists regarding the longevity of these ceilings. SHRA chances persist throughout Saturday afternoon for the eastern- most sites whereas ECP and DHN become mostly clear from rain by sunrise on Saturday.

MARINE
Issued at 212 AM EDT Sat Oct 10 2026

Conditions over the waters will rapidly improve today with strong southerly to southwesterly breezes becoming more moderate by this afternoon. Seas will also quickly subside through the day with 3-5 foot seas by this evening. Winds turn more northwesterly through Sunday into early next week with gentle breezes expected and seas around 1-2 feet.

FIRE WEATHER
Issued at 212 AM EDT Sat Oct 10 2026

Rain bands from Isaias will continue today over the eastern Big Bend into the I-75 counties in Georgia. Otherwise, strong southerly transport winds of 15-25 mph continue today. Drier conditions prevail Sunday into Monday with west to northwest transport winds around 10-15 mph. Some high dispersions are possible in south central Georgia on Saturday, particularly in Turner, Ben Hill, and Irwin Counties.

HYDROLOGY
Issued at 212 AM EDT Sat Oct 10 2026

A good chunk of our FL and GA counties aw about 1.5-3 inches of rain on average with localized amounts in the Big Bend near 5 inches. However, the heaviest rain fell near the center of Isaias with widespread 4-8 inches and localized amounts of 12-14 inches.
Residual standing water flooding continues in the areas that got the heaviest rainfall overnight.

Some locally heavy rain is possible today in the eastern FL Big Bend into the I-75 corridor of south Georgia where a trailing convergent rain band may set up. Given some tropical moisture remaining, high rain rates could lead to localized flash flooding if training occurs.

On the rivers, minor to moderate flooding is forecast along the Pea, Shoal, lower Choctawhatchee, Ochlockonee, and St. Marks Rivers. For the Pea and Shoal, we are seeing the rapid rises from the local basin contribution, but there is still water to be routed downstream, which makes some of these forecasts a bit trickier. The St. Marks also had a surge component as well as a rain component. Then the other rivers are mostly routed flow forecasts. Most of the rivers should crest in the next 1-2 days, then begin to fall.

Along the coast, the onshore wind component and elevated water levels will continue to lead to minor to locally moderate coastal flooding through this afternoon.

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 80 68 83 63 / 90 40 0 0 Panama City 80 69 81 67 / 30 10 0 0 Dothan 81 62 81 60 / 40 20 0 0 Albany 81 65 80 62 / 90 50 0 0 Valdosta 82 70 82 62 / 90 70 20 0 Cross City 85 74 85 64 / 80 80 40 0 Apalachicola 81 72 81 68 / 70 30 0 0

TAE WATCHES/WARNINGS/ADVISORIES
FL...Flood Watch through this evening for FLZ007>019-027>029-034-108- 112-114-115-118-127-128-134-326-426.

Tropical Storm Warning for FLZ007>018-027-108-112-114-115-118- 127-326-426.

Wind Advisory until 8 PM EDT this evening for FLZ019-028-029-034- 128-134.

High Rip Current Risk through late Sunday night for FLZ108-112- 114-115.

High Surf Warning until 10 AM CDT Sunday for FLZ108-112.

Storm Surge Warning for FLZ108-112-114-115-118-127-128-134.

High Surf Advisory until 11 AM EDT /10 AM CDT/ Sunday for FLZ114- 115.

GA...Flood Watch through this evening for GAZ120>131-142>148-155>161.

Tropical Storm Warning for GAZ120>127-142>146-155>158.

Wind Advisory until 8 PM EDT this evening for GAZ128>131-147-148- 159>161.

AL...Flood Watch through this evening for ALZ065>069.

Tropical Storm Warning for ALZ065>069.

GM...Tropical Storm Warning for GMZ730-735-751-752-755-765-770-772- 775.