textproduct: Jacksonville

UPDATE

Issued at 821 AM EDT Sun Aug 31 2025

For the latest NE FL and SE GA Daily Key Messages please visit: https://www.weather.gov/media/jax/briefings/nws-jax-briefing.pdf

Forecast on track for increasing Northeast winds with heavy rainfall threat along the Atlantic Coastal areas, mainly along the NE FL coast and areas from I-95 east towards the beaches. Northeast wind surge as high pressure builds down the SE US coastline will push sustained winds into the 15-25 mph with wind gusts of 30-35 mph at times, strongest for beachfront locations as this wind surge along the SE GA coast this morning moves down the NE FL coast this afternoon. Some of the blended model guidance is suggesting peak wind gusts around 40 mph along the Atlantic Coast, but not enough confidence for a Wind Advisory at this time. Temps will remain below normal with the cloud cover and rainfall along the Atlantic Coast with highs only around 80F, while further inland expect enough breaks in the clouds for temps to reach into the middle 80s.

SYNOPSIS

Issued at 450 AM EDT Sun Aug 31 2025

Early morning surface analysis depicts weak low pressure (1011 millibars) situated over the Gulf Stream waters adjacent to northeast FL, with coastal troughing beginning to sharpen over our near shore Atlantic waters. The low pressure center was located along a nearly stationary frontal boundary that stretches across north central FL and extends westward just to the south of the northern Gulf coast. Meanwhile, strengthening high pressure (1026 millibars) was building eastward from the Great Lakes region to New England and the Mid-Atlantic states. Aloft...deep troughing prevails over the eastern third of the nation, with ridging building from Texas and the Four Corners region northward through the Plains states. Latest GOES-East derived Total Precipitable Water imagery indicates that a much drier air mass was filtering over locations along and north of Interstate 10, where PWATS have fallen below 1.5 inches for locations north of Waycross and 1.6 - 1.75 inches elsewhere. Deeper moisture has been shunted southeastward to north central and coastal northeast FL, where PWATS remain mostly in the 1.8 - 2 inch range. Low pressure offshore was allowing for lower stratus clouds and a few light showers to pinwheel along our Atlantic coastal communities, with low and mid level stratocumulus clouds expanding in coverage elsewhere. A convergent band of heavier downpours was setting up over the offshore waters adjacent to northeast FL, with this activity moving slowly southward. Otherwise, temperatures and dewpoints at 09Z have fallen to the mid and upper 60s for inland portions of southeast GA and northern portions of the Suwannee Valley, with mostly lower 70s elsewhere.

NEAR TERM

(Today and Tonight) Issued at 450 AM EDT Sun Aug 31 2025

Our local pressure gradient will tighten from north to south today as strong high pressure stretching from the Great Lakes states eastward to New England will wedge down the southeastern seaboard. This feature will gradually push a broad, weak low pressure center located off the southeast GA coast southward in tandem with a frontal boundary that has been stuck over our region. Strengthening low level northeasterly flow will increase convergence along the southeast GA and northeast FL coasts during the predawn and early morning hours, with a tight moisture gradient in place along the I-95 corridor allowing for slow moving covergent bands of showers to increase in coverage and intensity early this morning. Meanwhile, a drier air mass will continue to filter into inland portions of southeast GA as well as northern portions of the Suwannee Valley today, allowing for breaks in the late morning cloud cover that will allow temperatures to warm back into the 80s for the first time in 3 days.

Heavy showers and a few embedded thunderstorms will slowly shift southward as the day progresses, with the drier air mass likely limiting coverage to scattered by this afternoon for coastal southeast GA. Locally heavy rainfall will be possible along the I-95 corridor in northeast FL through this afternoon, with amounts around 1 inch at most locations by later this evening, with localized totals of 2-3 inches possible at coastal locations. Breezy north-northeasterly winds and stubborn low level stratus and marine stratocumulus should keep highs in the low to mid 80s at coastal locations today.

A tight local pressure gradient will persist tonight, with the best coastal convergence remaining along the northeast FL coast, with persistent bands of locally heavy downpours potentially shifting inland across Clay and Putnam Counties as well. Breezy onshore winds will keep lows in the mid 70s along the northeast FL coast and the lower 70s for coastal southeast GA. Meanwhile, the drier air mass and clearing skies overnight will again allow lows to fall to the mid and upper 60s for inland southeast GA and northern portions of the Suwannee Valley.

SHORT TERM

(Monday through Tuesday night) Issued at 450 AM EDT Sun Aug 31 2025

The frontal boundary from the past weekend will continue to push south of the local area towards central FL as drier air continues to move into the area. This will limit precipitation chances for much of the interior locations of SE GA and NE FL. Onshore NE flow will become established as coastal troughing develops, allowing for gusty conditions along the coast. Scattered to numerous showers/storms will move in from the Atlantic towards coastal locations, with higher chances over coastal NE FL. WPC has highlighted coastal NE FL and north central FL counties for a Marginal Risk of Excessive Rainfall on Monday, with the Marginal Risk Excessive Rainfall only expected along the north central FL counties on Tuesday as the frontal boundary begins to shift.

LONG TERM

(Wednesday through Saturday) Issued at 450 AM EDT Sun Aug 31 2025

By midweek, the frontal boundary over central FL will continue to shift northward as a weak surface low develops along the eastern sea board. The lifting boundary will allow for shower and storm coverage to increase from south to north across on Wednesday. By the later part of the upcoming week, drier conditions will once again begin to build into the local area as the front and low moves further towards the NE and the arrival of a dry cold front from the NW will see precipitation chances begin to trend downward once again.

AVIATION

(12Z TAFS) Issued at 714 AM EDT Sun Aug 31 2025

LIFR CIGS at SSI/GNV/JAX/CRG/VQQ this morning will expand to SGJ as the NE wind surge pushes down the Atlantic Coast with best rainfall chances at the coastal TAF sites, while should be able to cover inland locations with VCSH. The increase in winds to 10-15 knots with gusts to 20-25 knots will slowly lift CIGS back into MVFR levels through the afternoon hours. NE winds remain gusty at the coastal TAF sites with rainfall chances through tonight, while a lowering of CIGS back to IFR levels at GNV/VQQ/JAX expected later tonight time frame.

MARINE

Issued at 450 AM EDT Sun Aug 31 2025

Low pressure located over the Gulf Stream waters adjacent to the GA coast will shift slowly southward across the offshore waters adjacent to northeast FL in tandem with a frontal boundary. Meanwhile, strengthening high pressure extending from the Great Lakes eastward across New England will wedge down the southeastern seaboard, sending a surge of northeasterly winds and building seas across our local waters from north to south today. Small Craft Advisory conditions will overspread the waters north of St. Augustine this afternoon as speeds increase to around 20 knots, with Caution conditions of 15-20 knots reach the waters south of St. Augustine later today. Seas will build to the 3-5 foot range across the waters north of St. Augustine this afternoon, with 2-4 foot seas for the waters south of St. Augustine. Seas will then build to Caution levels of 4-6 feet north of St. Augustine tonight and 3-5 feet for the waters south of St. Augustine. Seas will then peak on Monday and Monday night, with 5-7 foot seas for the waters north of St. Augustine, while seas reach Caution levels of 4-6 feet south of St. Augustine.

Waves of showers and embedded thunderstorms will impact our local waters through midweek. Northeasterly winds will begin to gradually weaken by late Tuesday and Wednesday, allowing for seas to gradually subside. Coverage of showers and thunderstorms will then decrease later this week as prevailing winds shift to westerly ahead of a series of approaching cold fronts.

Rip Currents: Strengthening onshore winds from north to south across our region today will create a high risk of rip currents as breakers build to the 2-4 foot range this afternoon. Northeasterly winds will become windy on Monday, with breakers building further to the 3-5 foot range, keeping a high risk in place at all area beaches. Persistent onshore winds and only slowly subsiding surf conditions, with breakers generally remaining in the 2-4 foot range, will likely keep a high risk in place at all area beaches through midweek.

HYDROLOGY

Issued at 450 AM EDT Sun Aug 31 2025

Heavy rainfall potential will mainly remained confined along the I-95 corridor and Atlantic Coastal Counties through midweek, with additional rainfall totals of 1-3 inches expected, with locally higher amounts possible. The Weather Prediction Center (WPC) has maintained "Marginal" Risks (level 1 of 4) for these areas through midweek, highlighting the risk for mainly localized flooding. Lower total amounts expected over inland northeast and north central FL, but with daytime heating, any of the isolated thunderstorm activity will still have heavy rainfall potential. However, the main threat will still be along the Atlantic Coastal areas, where narrow convergent rain bands set up in the strong onshore wind pattern that develops later today, with downpours potentially "training" or repeatedly impacting the same locations within some of these rain bands.

PRELIMINARY POINT TEMPS/POPS

AMG 85 66 84 63 / 40 20 10 0 SSI 83 73 83 73 / 40 30 40 20 JAX 84 72 84 71 / 50 40 60 20 SGJ 85 75 85 74 / 70 60 70 30 GNV 87 71 86 69 / 50 30 50 10 OCF 87 71 86 72 / 70 40 60 10

JAX WATCHES/WARNINGS/ADVISORIES

FL...High Rip Current Risk through late Monday night for FLZ124-125- 138-233-333.

GA...High Rip Current Risk through late Monday night for GAZ154-166.

AM...Small Craft Advisory until 11 PM EDT Monday for AMZ450-470.

Small Craft Advisory from noon today to 11 PM EDT Monday for AMZ452-472.

Small Craft Advisory from 4 PM this afternoon to 11 PM EDT Monday for AMZ454-474.