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 in the onshore flow

NEAR TERM /UNTIL 6 AM FRIDAY MORNING/

Main Highlights through Tonight:

- Isolated strong storms possible this afternoon into evening

A pattern shift is ongoing, with onshore winds keeping coastal high temperatures below 90 today and shifting focus for storms further inland as the Atlantic sea breeze pushes west this afternoon. Over most inland areas, scattered to numerous showers and storms are expected this afternoon and evening, with potential as well for a few isolated strong storms. DCAPE is not super impressive, but there is plenty of surface instability present. The primary hazard would be gusty winds around 40-50 mph, however with higher PWATs any training/slow moving storms may pose a localized flooding risk, especially over typical flood prone areas.

Convection will wane off after sunset, with some lingering activity possible over north central Florida. Tonight, some patchy inland fog will be possible near locations that receive heavy rainfall today.

SHORT TERM /6 AM FRIDAY MORNING THROUGH SATURDAY NIGHT/

Main Highlights This Period:

- Daily Thunderstorms with Locally Heavy Rainfall - High Risk for Rip Currents Northeast FL Beaches Friday

An inverted trough with above average precipitable water over 2.2" sweeps over the FL peninsula Friday and extends northward across southeast GA into Saturday. Southeast steering flow 10-15 kts Friday will bring morning coastal showers and isolated storms with coverage expanding inland into the afternoon. Greater storm coverage will be across northeast FL where moisture will be increasing from the south. Inland showers and storm fade Friday evening, but coastal convection will continue through the night as the trough axis approaches. Saturday, steering flow shifts more to the south but weakens to less than 10 kts with high moisture lingering over northeast FL and also expanding across southeast GA. The deep moisture, weak storm motion, lingering low level inverted trough and diurnal instability will bring the risk of localized heavy rainfall as afternoon and evening showers and storms increase in coverage. At this time, the Weather Prediction Center has the local area highlighted under a Marginal Risk (level 1 out of 4) of flash flooding rainfall on Saturday.

High temperatures will trend average in the lower 90s inland the upper 80s to near 90 coast with daily peak heat index values near 100. Muggy and mild overnight lows will range in the 70s.

LONG TERM /SUNDAY THROUGH THURSDAY/

Main Highlights This Period:

- Daily Thunderstorms - Heat Advisory Potential Returns Next Week

High pressure builds across the FL peninsula early next week with extended models diverging mid to late week regarding how fast the ridge breaks down and yields to troughing trying to carve southward down the southeast Atlantic sea board. Extended consensus favors a local warming trend in temperatures and increasing dew pts with southwest low level flow off of the Gulf of America increasing local heat index values Monday to Wednesday to near local Heat Advisory criteria with heat index values 108-110 deg possible. Daily thunderstorm chances will trend lower than average given the upper ridge bringing increased subsidence and drier mid/upper level air Monday to Wednesday. Even given isolated storms, they could be strong given high DCAPE and capable of strong wet downbursts.

AVIATION /00Z FRIDAY THROUGH 00Z SATURDAY/

Deep tropical moisture and onshore flow will continue a chance of showers and/or thunderstorm this evening through 03-04Z with best chances at GNV/VQQ/SGJ and have included TEMPO groups for TSRA and MVFR conds. Otherwise expect mostly VFR conds the remainder of the night with abundant clouds at multiple layers. Some MVFR fog possible at VQQ/GNV due to wet ground conditions from rainfall this afternoon. Approaching tropical wave from the Atlantic on Friday will lead to above normal rainfall chances in the onshore flow with at least -SHRA chances by 12-15Z, then widespread showers and TEMPO TSRA activity with MVFR CIGS and IFR VSBYS at all terminals starting in the 15-18Z time frame and continuing through the end of the period. Have placed the best timing possible at the terminals with earliest timing for coastal terminals to later timing at the inland NE FL terminals. Gusty winds to 30 knots in TSRA activity along with breezy East winds at 12-13G18-20 knots through the daytime hours.

MARINE

High pressure centered over Bermuda will build westward toward the United States east coast through the weekend shifting flow from east and southeast today to more east late this week and into the upcoming weekend. A trough of low pressure will move into the area on Friday, which will increase east winds up to 15 knots with seas building to near 5 feet from Friday into Saturday. Daily rounds of showers and thunderstorms will also continue, some of which will produce strong gusty winds, heavy rain, and frequent lightning strikes.

Rip Currents: A wind shift to a more southeast/onshore flow along with some increase in wind waves will build surf/breakers to 2-3 feet today with a Moderate rip current risk expected. Friday into the weekend sees potential surf/breakers of 3-4 feet and corresponding increased rip current risk.

FIRE WEATHER

Prevailing southeast winds Friday with morning showers and isolated coastal storms shifting inland through the afternoon and early evening expanding in coverage especially across northeast Florida. Breezy southeast winds will impact coastal areas Friday. There will be an increase in shower and storms Saturday with a weak front lingering over the area under light southerly winds. Daytime dispersion will be generally good Friday then generally good to fair Saturday with increased rainfall across the area. Humidity will remain above critical values.

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 72 93 72 92 / 30 40 40 70 SSI 78 88 77 89 / 30 40 70 70 JAX 74 90 75 90 / 30 50 60 80 SGJ 76 88 75 88 / 50 80 60 80 GNV 72 90 73 89 / 50 70 20 90 OCF 72 89 73 89 / 70 80 20 80

JAX WATCHES/WARNINGS/ADVISORIES

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