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 Each Day Through the Weekend. Strong Storm Potential Each Afternoon and Evening. Daily Rounds of Heavy Downpours May Cause Localized Flooding

- Increasing Rip Current Potential Later This Week Through the Weekend

NEAR TERM /THROUGH TONIGHT/

Main Highlights through Tonight:

- Isolated strong storms and heavy rainfall possible through this evening

Showers with embedded thunderstorms are moving in off the Gulf, entering inland northeast Florida early this afternoon. We expect an uptick in convective coverage, as well as strong storm potential, over most of the area later this afternoon and evening as the Gulf and Atlantic sea breezes interact. Damaging wind gusts of 40-50mph is the primary concern today with any strong storm development, DCAPEs are currently pretty high over inland areas. Slower moving and/or training storms will also pose a localized flooding threat, especially over normally flood-prone and/or urban locations. Current GOES Precipitable Water analysis shows drier air generally over the northern Suwannee valley and interior southeast GA, so less storm coverage is forecast for those areas today. However, after sunset we may see some lingering showers and isolated storms closer to that region through around midnight. With clearing skies and calm winds, there may be enough low level moisture to support patchy inland fog in the pre-dawn hours over inland SE GA. Some early morning showers may move inland across the Atlantic coast as winds shift onshore, although they will mainly stay over the local waters.

SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/

Main Highlights This Period:

- Daily chances for isolated strong thunderstorms, with wind gusts and heavy rainfall the greatest hazards

Thursday, the open upper trough will weaken and lift away while Atlantic ridging aloft builds westward from Bermuda. The Atlantic surface ridge axis will move from NE FL into SE GA through the afternoon and allow for southeasterly low level flow that will support a progressive Atlantic seabreeze, turning southeast winds easterly behind the seabreeze passage. A ribbon of higher moisture will stretch from the Carolinas southward into the FL peninsula and support scattered coverage of thunderstorms near the coast becoming numerous west of highway 301 where Atlantic/Gulf seabreeze merger is expected.

Friday, breezy easterly winds prevail as high pressure ridge axis extends across central GA while an inverted trough moves into the FL coastal waters from the Atlantic waters. Slightly drier air will initially be in place early Friday with the axis of higher moisture arriving to the NE FL coast mid to late morning bringing coastal showers onshore. By afternoon, strong heating will spur numerous thunderstorms inland west of the St Johns river with coverage more widely scattered further northward across SE GA.

Each day, potential for isolated strong storms will exist along storm cell mergers with outflow/seabreeze boundaries that would support wind gusts to around 40-50 mph along with frequent lightning and locally heavy downpours that could lead to minor flooding in low lying, flood prone, and urban areas given slow storm motions.

Highs on Thursday and Friday will be in the low 90s inland and the upper 80s at the coast.

LONG TERM /SATURDAY THROUGH TUESDAY/

Main Highlights This Period:

- Daily chances for isolated strong to severe thunderstorms, with wind gusts and heavy rainfall the greatest hazards

This weekend, high pressure remains east northeast of the region over the Atlantic waters with an inverted trough over the southeast coast into NE FL. Morning coastal showers will spread onshore and translate to Numerous thunderstorms inland due to east to southeast onshore flow.

The high will sink southward early next week with the surface ridge axis shifting into central FL. This will allow more southerly low level flow pattern and lead to Gulf and Atlantic seabreezes merging east near I-95 and US-17 corridors. Drier air under the ridge will limit convection to scattered coverage. However, strong heating coupled with cooling mid level temperatures will support a threat of isolated strong to severe thunderstorms along cell mergers and seabreeze/outflow collisions that could create gusty downburst winds 40-60 mph and frequent lightning.

Highs will begin the period near average this weekend, and increase to above average into early next week due to less storm coverage. Lows will be near normal this weekend and trend a bit above normal Tuesday into Wednesday.

AVIATION /18Z WEDNESDAY THROUGH 18Z THURSDAY/

Showers and storms will mainly impact inland sites this afternoon and evening, with highest chances at GNV through around 02Z. Maintained the PROB30s for the Duval sites, and chances remain too low at SGJ and SSI to include convective impacts but they may see some passing showers.

MARINE

High pressure centered over Bermuda will build westward toward the U.S. east coast through the weekend shifting flow from southeasterly today to more easterly late this week and into the upcoming weekend. Daily rounds of showers and thunderstorms will also continue daily, some of which will produce gusty winds, heavy rain, and frequent lightning strikes.

Rip Currents: A wind shift to a more southeast/onshore flow along with some increase in long period swells will build surf/breakers to 2-3 feet by mid-week with a Moderate rip current risk expected and potentially surf/breakers of 3-4 feet by Friday into the upcoming weekend.

FIRE WEATHER

Scattered to numerous thunderstorms will develop over inland areas today with isolated strong thunderstorms focusing between I-95 and highway 301 as the Atlantic seabreeze pushes inland before merging with the Gulf seabreeze by mid to late afternoon. Southerly winds continue 5-10 mph turning southeasterly behind Atlantic seabreeze passage across I-95 early this afternoon. Similar trend in storm coverage inland expected Thursday with southeasterly winds as high pressure builds northeast of the area. Friday, more easterly winds will prevail with coastal showers moving onto the Northeast FL coast before midday with numerous thunderstorms inland in the afternoon. Isolated strong thunderstorm potential will remain each afternoon with storm outflows causing sudden and erratic wind shifts, locally stronger winds, and dangerous cloud to ground lightning in and near thunderstorms.

Overall light transport winds will keep dispersions in the fair range this afternoon and Thursday with breezier winds on Friday creating good level dispersions.

Fog Potential: Significant fog development is not expected, with shallow, patchy fog late overnight limited to areas that receive locally heavy rainfall.

PRELIMINARY POINT TEMPS/POPS

AMG 93 73 92 73 / 30 40 70 20 SSI 89 78 89 79 / 10 20 50 10 JAX 91 74 91 75 / 40 10 50 10 SGJ 89 75 90 77 / 30 10 40 10 GNV 90 72 92 73 / 50 20 60 10 OCF 90 73 91 73 / 50 20 60 10

JAX WATCHES/WARNINGS/ADVISORIES

FL...None. GA...None. MARINE...None.