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

- Daily Afternoon & Evening Thunderstorms Wednesday through Friday. Heavy Rainfall Potential Wed & Thurs for NE FL

- High Risk of Rip Currents for NE FL beaches

NEAR TERM /THROUGH TONIGHT/

Highlights Today and Tonight:

- Localized Fog and low stratus early this morning inland areas

- Scattered to numerous storms across NE FL Today with gusty winds and heavy downpours, mainly south of the I-10 corridor

Light NE flow early this morning over inland areas will lead to another round of low stratus/patchy fog towards sunrise, with some locally dense fog possible across inland SE GA and Suwannee Valley, but widespread dense fog not expected. Otherwise, still expect another day with trough over the Atlantic Coastal waters to push onshore this morning with scattered showers and isolated storms and some brief heavy downpours along the I-95 corridor, then with diurnal heating this activity will spread inland with the East Coast sea breeze that will tap into deep tropical moisture with PWATs over 2 inches across NE FL to produce numerous showers and storms with gusty winds and heavy rainfall, with best chances of localized flooding along the I-75 corridor of inland NE FL as this activity meets the Gulf Coast sea breeze, and while the activity will be moving steadily to the West at 10-15 mph, expect some isolated 2-3 inch amounts in the more intense storm activity along with a few strong storms with gusty winds to 40-50 mph over inland areas. Slightly lower PWATs below 2 inches across inland SE GA will likely lead to lower coverage there with PoPs of 20-50%, while POPs of 60- 90% are expected across most of NE FL, especially south of the I-10 corridor. Max temps top out in the upper 80s/near 90F along the Atlantic Coastal areas and I-95 corridor in the onshore flow and earlier start to convection, with lower 90s inland, although some middle 90s can be expected to the NW of Waycross over inland SE GA where less convection is expected. Peak heat indices still fairly typical for early September in the 100-105F range. Storms still on track to end across inland areas around sunset, while the onshore flow will keep ongoing scattered showers and storms over the Atlantic Coastal waters through the overnight hours, with some isolated convection reaching the coast at times late at night. Low temps near seasonable values in the lower/middle 70s inland and upper 70s along the Atlantic Coast.

SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/

Main Highlights This Period:

- Daily shower and thunderstorm potential, with strong storms possible over inland locations

Persistent onshore flow through the period will bring offshore showers towards the coast during the early morning hours and then towards inland locations by the afternoon hours. A more southeasterly flow during this period will drive coverage of showers and storms across NE FL and a majority of SE GA. Elevated moisture levels, above 2", will bring the potential for periods of heavy rainfall for any shower or storm that does develop. Currently, chances of precipitation range in the 60% to 80% chances each day, with the highest coverage of activity on Thursday. WPC continues to highlight a Marginal Risk of Excessive Rainfall for all of NE FL and a majority of SE GA on Thursday. The inland progression of the Atlantic sea breeze will again bring increased chances for thunderstorm development for central to western locations of NE FL and SE GA each afternoon hours. Each evening to early morning hours will have the potential for patchy inland fog.

Warmer temperatures away from the coast as daytime highs in the upper 80s to lower 90s, and dewpoints in the mid to upper 70s each afternoon will allow for Heat Index values to rise above 100F for some locations during the late morning, with passing showers and storms limiting temperatures from rising much.

LONG TERM /SATURDAY THROUGH TUESDAY/

Main Highlights This Period:

- Daily Thunderstorms, Isolated Strong Storms Possible Inland.

Southwesterly-westerly flow develops this weekend ahead of a cold front dipping along the southeastern US . By Saturday, with a shift to a southwesterly flow, showers and storms will shift in from west to east. Ahead of the cold front on Sunday, increased chances of showers and storms for much of the area as moisture continues to be brought in from the Gulf. The question remains how far south the front will actually sink across the southeastern US and thus the FL peninsula. But regardless, still expect to see good coverage of showers and storms heading into Labor Day as the sea breezes move inland during the afternoon hours with moisture aloft remaining around the 2" range for PWATs.

Temperatures in the lower to mid 90s over the weekend, with Heat index values rising over 100F could bring a chance for heat advisory criteria to be met, but temperatures may be kept in check with passing showers.

AVIATION /06Z WEDNESDAY THROUGH 06Z THURSDAY/

Low stratus and fog will begin to develop away from the coast with MVFR VSBY and IFR/LIFR CIGS at JAX, VQQ, and GNV between 08-10Z as winds become calm while staying very light and easterly along the coast with few to scattered CIGS 1.5-2.5 kft. VFR conditions will resume after 13Z as east northeast winds increase over inland areas to 5-8 knots. Coastal showers approaching from the east will move onshore to SGJ by 10Z and shift towards CRG through 13Z. Scattered showers and thunderstorms will press inland through the late morning hours to JAX, then shift further inland to VQQ and GNV through 18- 19Z. Have PROB30 groups for morning showers moving onshore to SGJ/CRG and then afternoon thunderstorm potential yielding MVFR VSBY/CIGS. Rain and thunderstorm chances this afternoon will be greatest over Northeast Florida with diminished coverage over Southeast Georgia, so only have VCSH there. Shower coverage will diminish by 23Z, but sooner near the coast. VFR conds will linger through sunset and into the evening hours at the end of the TAF period.

MARINE

Onshore flow and troughing over the waters will keep the potential for waves of showers and isolated thunderstorms in the forecast through Friday. Winds transition and shift westerly by Saturday Night into Sunday as a frontal boundary enters the southeast states. Several rounds of showers and thunderstorms are possible during the upcoming weekend and into early next week as the frontal boundary stalls over the local waters.

Rip Currents: Slight uptick in longer period swells will push surf into the 3-4 ft range for the NE FL beaches and will post a High Risk of Rip Currents for both Today and Thursday, but will maintain a Moderate Risk for the SE GA beaches with surf of 2-3 ft.

FIRE WEATHER

PATCHY LOW DISPERSIONS OVER NORTH CENTRAL FLORIDA TODAY AND - Friday LOW DISPERSIONS ALONG THE COAST FRIDAY AND THIS WEEKEND..

Onshore flow continues through midweek bringing early morning showers across coastal locations, and then towards inland locations as the Atlantic sea breeze moves inland. By the afternoon hours, amplified showers and thunderstorms will be possible with diurnal heating. With weaker winds aloft, dispersions will continue to generally be in the poor to fair range much of the week, particularly over north central FL, and coastal locations by this weekend. Moisture advecting in from the Atlantic will help maintain Good min RH values across the area.

Fog Potential: Gusty and erratic winds can be expected in and near thunderstorms with briefly localized flooding rainfall. Late night and early morning patchy fog and low stratus will be possible, especially in areas that received more rainfall.

PRELIMINARY POINT TEMPS/POPS

AMG 94 73 90 73 / 20 10 70 0 SSI 87 78 88 78 / 30 20 60 10 JAX 89 75 89 75 / 40 30 60 10 SGJ 87 76 87 76 / 70 40 50 10 GNV 89 74 90 73 / 90 40 70 30 OCF 89 73 91 74 / 90 40 80 30

JAX WATCHES/WARNINGS/ADVISORIES

FL...High Risk for Rip Currents through Thursday evening for FLZ124-125- 138-233-333. GA...None. MARINE...None.