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

- Scattered Thunderstorms This Evening. Main Strong Storm Hazard Area: Inland Locations Along U.S.-301

- Waves of Showers and Thunderstorms Beginning on Thursday. Heavy Rainfall and Localized Flooding will be a concern. Widespread 2-4 Rainfall Totals Forecast through Tuesday.

- Hot and Humid - Daily Heat Index 95- 105F through Friday.

NEAR TERM /UNTIL 6 AM THURSDAY MORNING/

Main Highlights This Period:

- Thunderstorm chances this evening, with a few strong storms possible.

High pressure will be centered to the east this evening. This pattern change will lead to more of a flow from the southwest, allowing Gulf moisture to push into area. This will keep precipitation chances inland going through the night.

SHORT TERM /6 AM THURSDAY MORNING THROUGH FRIDAY NIGHT/

Main Highlights This Period:

- Waves of Showers and Thunderstorms Overspread Our Region from South to North Beginning on Thursday.

- Strong storm potential on Thursday afternoon along the I-95 corridor. - Heat index upper 90s to lower 100s for portions of our area during the afternoon hours on Thursday and Friday.

An overall shift to a more southwesterly-westerly flow over the region as high pressure over the western Atlantic begins a southeastern shift. This will open up a lane for tropical moisture to be brought into the area from the Gulf, with PWATs expected to increase and range from 2" to 2.5" through the work week. The southwesterly-westerly flow will also shift convective activity more towards the I-95 corridor and the Atlantic coast. Periods of heavy downpours will be possible for any storms that do develop, with localized flooding for any slow-moving storms or if training of storms develop. The southwesterly flow will also filter in warmer temperatures to the area, with daytime highs in the upper 80s to lower 90s Thursday and Friday. With the increased moisture and the warmer temperatures, heat indices will reach into the upper 90s with a few spots nearing 100. Overnight Lows in the 70s across NE FL, with the upper 60s across SE GA.

LONG TERM /SATURDAY THROUGH WEDNESDAY/

Main Highlights This Period:

- Waves of Showers and Thunderstorms Expected to Continue, with Beneficial Rainfall Totals Forecast Area-Wide.

- Clouds and Cooler Temperatures Expected Early Next Week. Shower and storm chances will persist through the weekend as a front pushes towards SE GA and begin to slow and potentially stalling over parts of the area during the later part of the forecast period. With overall flow continuing to be from the west, much of the activity will be pushed towards the I-95 corridor and Atlantic coast during the weekend. By next week, the amount and coverage of activity will be dependent on the location of the front. With current guidance suggesting the front slowing down and stalling across NE FL, this would see higher chances of precipitation for locations along the boundary, with highest chances across north central FL.

Temperatures will be in the 80s with warmest temperatures across NE FL, with some locations potentially in the lower 90s during the weekend. A downward trend in temperatures as the cold front dips across the area at the start of next week.

AVIATION /00Z THURSDAY THROUGH 00Z FRIDAY/

Thunderstorms moving briskly from south to north will impact the VQQ and JAX terminals through around 03Z, with brief wind gusts of 30-35 knots possible, along with IFR to possibly LIFR conditions during heavier downpours. Confidence in impacts at CRG and SSI was too low to indicate TEMPO impacts from thunderstorms after 02Z, but a PROB30 group was placed at these TAF sites for brief wind gusts of 25-30 knots and IFR visibilities during heavier downpours during the 02Z- 04Z time frame. Confidence is currently too low to indicate anything other than vicinity shower activity at SGJ after 02Z, but please check for amendments as the evening progresses, as convection could expand further eastward than what is currently anticipated. Heavy thunderstorms moving northward across north central FL should remain east of the GNV terminal tonight. Convection will exit our region by 06Z, with IFR to LIFR conditions expected to develop at VQQ after 07Z. VFR conditions should then prevail at the regional terminals after 12Z. Periods of MVFR ceilings around 1,500 feet could develop after 14Z, and another round of convection is expected to impact the terminals after 16Z Thursday. Confidence in timing and impacts remains too low to indicate anything other than PROB30 groups throughout the afternoon hours at this time.

MARINE

The region will be between high pressure to the southeast, and a frontal zone to the north Tonight through Friday. The frontal zone will settle across the area over the weekend, and remain nearly stationary into the middle of next week.

Rip Currents:

Offshore flow will begin to decrease risk Thursday and through the Weekend.

FIRE WEATHER

- Low Daytime Dispersions Over Interior Se Ga Thursday And Friday.

Showers and isolated storms will linger during the overnight hours into the early morning hours on Thursday. A shift to southwesterly winds will allow for the Gulf breeze to push further inland by the afternoon to evening hours on Thursday and Friday, with convective activity pushing towards I-95 and the Atlantic coast. With increased moisture advection from the Gulf, widespread waves of downpours are forecast area-wide into the weekend, which may be followed by a late season cool front early next week. Lowering mixing heights will bring Poor dispersions for portions across SE GA on Thursday and Friday.

FOG POTENTIAL AND OTHER REMARKS: Significant fog is not expected into early next week, but patchy morning fog will be possible in areas where heavy rain fell during the previous afternoon. Erratic winds are expected during periods of thunderstorms.

PRELIMINARY POINT TEMPS/POPS

AMG 69 83 68 83 / 60 70 40 80 SSI 75 86 73 84 / 40 80 50 80 JAX 73 88 71 87 / 50 90 50 80 SGJ 74 88 73 87 / 40 60 30 80 GNV 71 87 71 88 / 70 80 20 80 OCF 72 86 73 87 / 70 70 30 60

JAX WATCHES/WARNINGS/ADVISORIES

FL...High Risk for Rip Currents until midnight EDT tonight for FLZ124- 125-138-233-333. GA...None. MARINE...None.