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. Sunday: Strong thunderstorm Risk near U.S. Highway 301 & I-75 corridors. Main Storm Hazards: Lightning, Localized flooding & Gusty Winds

- Moderate Rip Current Risk at All Area Beaches. Increased Rip Current Risk Possible Late Next Week

NEAR TERM /THROUGH TONIGHT/

Highlights Today and Tonight:

- Heavy rainfall/localized flooding remains the main threat from thunderstorm activity today, mainly between the US-301 and I-75 highway corridors

Stalled frontal boundary across SE GA will dissipate today as high pressure ridge continues to build north of the region. This will continue the development of an East to Southeast steering flow and with the combination of deep tropical moisture with PWATs over 2 inches across the local NE FL/SE GA area, expect another day with scattered to numerous showers and storms that will develop along the East Coast sea breeze and push inland to the US 301 and I-75 corridors through the afternoon hours. Heavy rainfall will continue as the main threat from storm activity, although a few strong storms with gusty winds to 40-50 mph and frequent lightning are expected as well, but the overall severe weather threat remains on the low side. Max Temps will top out in the upper 80s along the I-95 corridor and Atlantic Coastal areas, while lower 90s are expected further inland and will combine with high humidity levels for peak heat indices in the 100-105F range. Overnight lows will remain in the lower/middle 70s inland and upper 70s along the Atlantic Coast, along with some patchy fog/low stratus over inland areas towards sunrise on both mornings.

SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/

Main Highlights This Period: (Sunday through Monday night)

- Daily Thunderstorm Potential - Low Flooding Rain Risk Inland Northeast Florida

Easterly flow and coastal troughs will continue bring morning coastal showers and isolated thunderstorms to primarily coastal areas both Monday and Tuesday, with diurnal heating then shifting these rain chances inland through the afternoon and evening. The best chance of isolated stronger storms will focus generally west of HWY 301 and towards and west of the I-75 corridor during the late afternoon and early evening hours where sea breeze and other convective boundary mergers focus. Higher chances of showers and storms will remain focused across northeast FL for both Monday and Tuesday as stacked high pressure ridging moves very little north of the region, supporting greater subsidence the further north into Georgia you go. Deep moisture remains in place across the area as precipitable water averages near or over 2 inches each day, and therefore this combined with weak steering flow < 10 kts will persist a flooding rainfall threat as the primary hazard along with gusty downburst winds. Rain chances tapper off inland each night around the 10 pm to midnight time frame, then resurrect near the Atlantic coast overnight with easterly flow. Patchy inland late night fog will also be possible each night and into the early morning hours.

Temperatures will trend near to slightly above average this period with highs in the upper 80s along the Atlantic coast and parts of the St. Johns River Valley to lower 90s well inland. Muggy overnight lows will range in the 70s.

LONG TERM /WEDNESDAY THROUGH SATURDAY/

Main Highlights This Period: (Tuesday through Friday)

- Daily Thunderstorms, Isolated Strong Storms Possible Inland - Increased Rip Current Risk Possible By Mid-Week

The overall pattern changes little through much of the upcoming week, as high pressure centered to our north changes very little in strength and position. This will maintain a similar onshore flow regime as the previous several days, with the focus for higher chances of showers and t'storms focused generally inland after overnight and morning showers near the coast.

The only other feature worth mentioning will be the movement of the tropical wave that is the Remnants of Tropical Storm Dolly, which could have some indirect impacts to our region regardless of development. The upper level dynamics with this passing wave could enhance lift and increase tropical moisture across northeast FL, which would favor increased rain chances and storm strength, as well as more elevated rip current risk thanks to a slightly tighter pressure gradient and/or more introduced long period swells reaching the coast.

Temperatures will trend slightly above average during the long term period.

AVIATION /06Z SUNDAY THROUGH 06Z MONDAY/

Main concern for the overnight hours will be some lower clouds and scattered vsby restrictions for most terminals. Lower clouds will move onshore at times overnight thanks to an offshore inverted trough, though restrictions are not forecast at this time. Only restrictions for the overnight hours included was at GNV and VQQ, where FG/BR is expected. Any restrictions are expected to clear throughout the morning hours, with confidence high enough to include PROB30 groups at all airfields diurnally on Sunday. Lowest confidence is for coastal sites, as TSRA development may be mostly inland thanks to another day of onshore flow. Convection will end late in the TAF period in the 00-02Z time frame with mainly VFR conds through the late evening hours.

MARINE

Onshore winds continue this weekend as high pressure builds to the north of the local waters and remains in place through much of next week. This will focus chances for showers and thunderstorms mainly inland, with lower chances across area waters overall.

Rip Currents: A more solid Moderate risk of rip currents will develop this weekend in the onshore flow as surf/breakers slowly increase to 2 to 3 feet. This pattern will continue into early next week as well.

FIRE WEATHER

East to southeast winds will mainly prevail through at least the next several days with high pressure centered to our north. Showers and thunderstorm chances will remain high thanks to the onshore flow, plenty of moisture, and a weak frontal zone across southern GA. The best chance for strong thunderstorms will be generally towards Highway 301 to I-75 and areas further west. Outside of rainfall, dispersions will be only in the fair range thanks to the onshore flow and weaker winds aloft.

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 will be possible, especially in areas that received more rainfall.

PRELIMINARY POINT TEMPS/POPS

AMG 90 72 90 72 / 60 30 60 10 SSI 86 77 87 77 / 50 30 50 10 JAX 89 74 89 74 / 60 20 50 10 SGJ 87 75 87 76 / 50 30 40 20 GNV 91 73 90 73 / 70 30 70 10 OCF 91 73 91 73 / 80 50 70 20

JAX WATCHES/WARNINGS/ADVISORIES

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