Marine Weather and Tide Forecast for Gainesville, FL

SHORT TERM
(Thursday through Friday night)
Issued at 305 AM EDT Wed May 21 2025

Broad troughing extending from the Upper Midwest southeastward to the Mid-Atlantic states will be reinforced by a potent, negatively-tilted shortwave that will dig southeastward from the Great Lakes states. Fast westerly flow will prevail along the base of the trough over the Deep South, with a 120-knot jet streak at 250 millibars (around 35,000 feet) shifting eastward from the southern Appalachians on Thursday morning to offshore of the NC Outer Banks by Thursday night. This feature should push a slow moving frontal boundary that will be positioned across north central FL on Thursday morning southward to the Interstate 4 corridor in central FL by the afternoon hours. Scattered showers and a few embedded thunderstorms will remain possible for north central FL through early afternoon, and mostly cloudy skies along the frontal boundary should keep highs in the upper 80s for these locations. Meanwhile, low level flow will shift to west- northwesterly in the wake of this front for areas along and north of I-10, which will advect a much drier air mass into southeast GA and for areas along the I-10 corridor in northeast FL. Thin cirrus and a dry air mass, featuring dewpoints falling to the low and mid 50s during the afternoon hours, should allow highs to climb to the lower 90s for most inland locations along and north of I-10.

Cooler and drier air will filter across the rest of our region on Thursday night as skies clear and inland winds decouple, setting up radiational cooling. Lows will fall to the low and mid 60s inland, ranging to the upper 60s to around 70 at coastal locations.

Surface ridging will then build into the southeastern states on Friday as dry northwesterly flow aloft prevails across our region. Full sunshine and a dry air mass will allow highs to soar to the upper 80s and lower 90s, with mid 90s possible across north central FL. Dewpoints crashing through the 50s across inland southeast GA and the low/mid 60s across northeast and north central FL will keep heat index values around or just under actual air temperatures on Friday.
Radiational cooling on Friday night will result in lows falling the 55-60 degree range across inland southeast GA and the 60-65 range elsewhere inland, while a persistent northwesterly breeze keeps coastal lows generally in the upper 60s.

LONG TERM
(Saturday through Tuesday)
Issued at 305 AM EDT Wed May 21 2025

Deep troughing over New England will be slow to lift northward on Saturday, and this feature will maintain a dry west-northwesterly flow pattern aloft across our area. Surface ridging will build into the Deep South, shifting low level flow to northeasterly, which will keep highs at coastal locations in the mid 80s. Full sunshine and a very dry air mass will boost inland highs to the upper 80s for locations from Waycross northward and 90-95 elsewhere for areas west of the I-95 corridor.
Afternoon dewpoints will again crash through the 50s across inland southeast GA and the low to mid 60s elsewhere, except upper 60s at coastal locations. Heat index values will again be held in check by this dry air mass. Radiational cooling again on Saturday night will allow inland lows to fall to the low and mid 60s, while a light onshore breeze keeps coastal lows in the lower 70s.

Heights aloft will begin to rise on Sunday as low and mid level ridging begin to build over the FL peninsula. Surface ridging will shift further offshore of the southeastern seaboard, shifting low level flow to south-southeasterly, with onshore surface winds keeping coastal highs in the upper 80s. A lingering dry air mass and filtered sunshine will allow highs to soar well into the 90s for inland locations, with just enough moisture in place to develop isolated convection along inland moving sea and lake breezes over portions of north central FL during the late afternoon hours.
Dewpoints remaining in the 60s will yield maximum heat index values around 100. Overnight lows will begin to moderate on Sunday night, with upper 60s expected inland and low to mid 70s at the coast.

Deep-layered ridging situated off the southeastern seaboard and troughing emerging over the Plains States on Memorial Day will create a gradually strengthening southwesterly flow pattern. Increasing low level moisture will ignite widely scattered diurnal convection on Monday and scattered diurnal convection on Tuesday. Highs on Monday will soar to the mid 90s inland and around 90 at the coast, with maximum heat index values climbing to the 100-105 range. Increasing cloud cover and rain chances on Tuesday will knock a few degrees off daytime highs across southeast GA, while heat and humidity prevail elsewhere. Lows early next week will only fall to around 70 inland and the low or mid 70s at coastal locations.

Another broad, negatively-tilted trough may become established towards midweek across the Upper Midwest, Great Lakes, and Ohio Valley. This trough will drive a frontal boundary into the Deep South, creating at least scattered showers and thunderstorms across our area. Highs will fall to the 85-90 degree range as cloud cover thickens.

AVIATION
(06Z TAFS)
Issued at 101 AM EDT Wed May 21 2025

Stratus and fog is expected to advect northeast across area from the Gulf early this morning, providing potential for restrictions. A cold front will move southeast through region this afternoon and evening. Thunderstorms will be possible associated with this boundary, and a few may become strong to severe. Based on latest model guidance have timed out a prob30 group for best convective chances later Today. This timing may need to be adjusted as the expected weather develops.

MARINE
Issued at 305 AM EDT Wed May 21 2025

A cold front will move southeast across the area through Tonight.
Showers and thunderstorms will accompany this boundary. Weak high pressure will build to the northwest overnight into Thursday. A weak front will pass through Friday into Friday night. High pressure will build to the northwest Saturday, then to the northeast Sunday.

Rip Currents: Low Today, Moderate Thursday

FIRE WEATHER
Issued at 305 AM EDT Wed May 21 2025

Strong to isolated severe thunderstorms developing this afternoon will be capable of producing strong wind gusts, hail, and frequent lightning strikes, mainly for locations along and north of the I-10 corridor. Breezy westerly surface and transport winds will otherwise develop this morning, creating high daytime dispersion values for most inland locations, with good values extending to coastal locations. Surface and transport winds will shift to northwesterly overnight tonight through Thursday morning.

A much drier air mass will plunge into our area on Thursday afternoon, with long durations of critically low humidity values possible at inland locations. Surface and transport winds will shift back to a westerly direction on Thursday afternoon, with breezy transport speeds for locations north of Waycross creating high daytime dispersion values. Good values are forecast elsewhere across inland southeast GA, while more cloud cover yields fair values for inland northeast and north central FL and poor values are forecast at coastal locations. Surface wind speeds should remain below Red Flag Criteria on Thursday afternoon at inland locations. Breezy west-northwesterly transport winds across southeast GA on Friday will create another day of high daytime dispersion values, while lighter speeds elsewhere generally yield good values.

PRELIMINARY POINT TEMPS/POPS
AMG 89 63 89 62 / 30 0 0 10 SSI 89 70 88 69 / 40 0 0 0 JAX 94 68 90 63 / 40 10 10 0 SGJ 94 71 87 68 / 30 20 10 10 GNV 92 69 88 63 / 20 30 20 10 OCF 91 71 87 65 / 10 20 30 10

JAX WATCHES/WARNINGS/ADVISORIES
FL...None.
GA...None.
AM...None.