textproduct: Jacksonville

KEY MESSAGES

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

- Dangerously Hot & Humid Weather Continues Through Mid-Week. Near Record High Temperatures Forecast through Wednesday. Heat Advisories in Effect Area-Wide Today, with Heat Indices up to 112 expected. Extreme Heat Watch Possible for Portions of Our Area on Wednesday.

- Only Isolated Thunderstorms this Afternoon and Evening, mainly south of I-10. Briefly Gusty Winds, Frequent Lightning Strikes & Heavy Downpours Possible within Stronger Storms

- Strong to Severe Thunderstorms are Possible on Wednesday Afternoon and Evening Area-Wide. Damaging Wind Gusts, Isolated Tornadoes, Frequent Lightning Strikes, and Localized Flooding Due to Heavy Downpours are Possible.

- Daily Rounds of Widespread Showers and Thunderstorms, with Strong to Isolated Severe Storms Possible Each Afternoon and Evening from Thursday through Monday.

NEAR TERM /THROUGH TONIGHT/

Main Highlights For Today and Tonight:

- Very Hot and Humid, Heat Advisory area-wide, Heat Indices 108-112F.

- Isolated afternoon/evening storms, mainly south of I-10.

Very hot and humid weather pattern continues today, as slightly drier air mass aloft with PWATs of 1.6 to 1.9 inches will support only isolated to scattered storm activity this afternoon/evening. Max temps into the upper 90s over inland areas, with a few near 100F readings expected from the I-10 corridor northward across inland SE GA, generally middle 90s expected along the Atlantic Coast as the West to Southwest steering flow will only allow the East Coast sea breeze to push inland to the I-95 corridor this afternoon. These well above normal temps and low level humidity will produce another afternoon with peak heat indices in the 108-112F range and Heat Advisory headlines are already posted from 11am-8pm. A few peak heat indices around 113F will be possible along the I-95 corridor from Brunswick to JAX metro area, but not enough confidence to issue Extreme Heat Warning at this time due to some lingering high clouds today that could remove a few degrees for expected Max Temps. The W- SW flow off the NE Gulf will inject enough moisture across NE FL, mostly south of the I-10 corridor, to support scattered afternoon and/or evening storms along both the Gulf and East coast sea breeze fronts and a few strong storms with gusty winds to 40-50 mph and heavy rainfall possible, but the warmer temps in the mid levels will keep the overall severe threat fairly low. Only isolated storms possible across SE GA, as sea breeze remains pinned to the Atlantic Coast there. Any convection this evening across NE FL should end shortly after sunset, with fair skies and very humid conditions with above normal temps as SW winds remain elevated at 5-10 mph and low temps will only fall into the upper 70s inland and lower 80s along the Atlantic Coast.

SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/

Main Highlights This Period:

- Rounds of showers and thunderstorms, with strong to severe storms possible.

- Extreme Heat Watch may be needed Wednesday.

A frontal boundary will extend across area through this period. The boundary will be over SE GA Wednesday, and closer to the GA/FL line Thursday. The combination of ample moisture, and frontal convergence will lead to above average convective coverage. On Thursday, with the front closer to the GA/FL line, drier air to its north will result in lower chances over interior SE GA.

Temperatures will continue above seasonal levels this period.

LONG TERM /FRIDAY THROUGH MONDAY/

Main Highlights This Period:

- Daily rounds of mainly afternoon and evening thunderstorms, which may become strong to severe.

The frontal boundary will wave north and south over area, but will mainly linger over southern GA this period. Due to ample moisture, and frontal convergence above average precipitation chances forecast. A wave will move east along the boundary Saturday night into Sunday, further enhancing convective coverage.

Temperatures will be above normal Friday, then trend near to a little below for the weekend into early next week.

AVIATION /12Z TUESDAY THROUGH 12Z WEDNESDAY/

VFR conditions will prevail at the regional terminals. Only isolated showers and thunderstorms are expected to develop after 18Z through around 03Z Wednesday, with confidence in potential impacts now too low to indicate anything other than vicinity showers at the northeast FL terminals, with dry weather expected through the TAF period at SSI. Depending on forecast trends, vicinity thunderstorm coverage could be added at a few of the northeast FL terminals during the 18Z TAF cycle. Westerly surface winds will become sustained at 5-10 knots at the regional terminals by 14Z. The Atlantic and Gulf sea breeze boundaries will develop during the early afternoon hours and will progress inland this afternoon, shifting surface winds to southeasterly at 10-15 knots at the SSI and SGJ coastal terminals by 18Z, while the Gulf sea breeze shifts surface winds to southwesterly around 10 knots at GNV towards 21Z. South to southwesterly surface winds will remain sustained at 5-10 knots at the regional terminals during the evening and overnight hours.

MARINE

Prevailing southwesterly winds are forecast Today, with the afternoon sea breeze potentially triggering isolated to widely scattered thunderstorms through this evening, mainly for the northeast Florida waters. Another frontal boundary will sink into the Deep South late this week, with this feature becoming stationary during the weekend. Strong to severe thunderstorms will be possible well in advance of this front on Wednesday afternoon and evening across our local waters. Scattered to numerous thunderstorms will continue across the northeast Florida waters on Thursday and Friday, with less coverage currently forecast for the Georgia waters. Waves of showers and thunderstorms will then overspread all of our local waters during the upcoming weekend. Outside of expected thunderstorm activity, southwesterly winds will prevail and will strengthen ahead of the approaching front beginning towards midweek, with Caution conditions likely through the upcoming weekend and periods of Small Craft Advisory conditions possible.

Rip Currents: Low to marginal moderate risk of rip currents is expected today and Wednesday at Northeast FL and Southeast GA beaches with surf/breakers of only 1-2 feet.

FIRE WEATHER

- Heat Indices in the advisory range today.

- Extreme Heat Watch may be needed on Wednesday.

- Patchy to areas of high daytime dispersions this week.

A frontal zone will be over or near the region through the week, and into the weekend, producing above average chances for showers and thunderstorms from Wednesday through Sunday.

Fog Potential: Significant fog development is not expected during the next several mornings. Afternoon heat indices in the advisory range today. Extreme heat watch is possible on Wednesday. Daily thunderstorm chances increase beginning mid week. Gusty and erratic winds can be expected in and near storms.

CLIMATE

Daily record high temperatures and record warm minimum temperatures at our designated climate sites on Tuesday and Wednesday:

July 28: KJAX: 104/1872 80/1885 KGNV: 100/2025 77/2014 KAMG: 100/2006 78/2014 KCRG: 100/2025 80/2014

July 29: KJAX: 101/2025 80/1877 KGNV: 100/2025 79/2025 KAMG: 99/2025 77/2017 KCRG: 101/2016 79/2017

PRELIMINARY POINT TEMPS/POPS

AMG 99 78 98 74 / 0 10 40 30 SSI 96 80 100 79 / 10 10 60 40 JAX 99 79 99 76 / 20 0 60 60 SGJ 95 78 98 77 / 20 10 30 50 GNV 96 78 96 77 / 20 0 30 70 OCF 95 77 94 79 / 20 10 40 60

JAX WATCHES/WARNINGS/ADVISORIES

FL...Heat Advisory until 8 PM EDT this evening for FLZ021-023-024- 030-031-035-038-120-124-125-132-136>138-140-220-225-232- 233-236-237-240-322-325-333-340-422-425-433-522-533-633. GA...Heat Advisory until 8 PM EDT this evening for GAZ132>136-149- 151>154-162-163-165-166-250-264-350-364. MARINE...None.