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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 to Numerous Mainly Afternoon and Evening Thunderstorms Across North Central and Northeast FL Today. Activity Shifts into Portions of Southeast GA Early this Evening.

- Strong Storm Potential this Afternoon and Evening, Mainly Along the I-95 Corridor. Stronger Storms May Produce Wind Gusts of 40-55 mph, Frequent Lightning Strikes, and Locally Heavy Downpours.

- Scattered to Numerous Thunderstorms this Weekend and Early Next Week. Daily Rounds of Heavy Downpours Could Result in Localized Flooding. Strong Storms are Possible, with Wind Gusts of 40-55 mph and Frequent Lightning Strikes.

- Heat and Humidity Builds Middle to Late Next Week.

NEAR TERM /THROUGH TONIGHT/

Main Highlights For Tonight:

- A few strong thunderstorms possible this afternoon/evening

A stalled frontal boundary will remain draped across SE GA today creating a gradient in available moisture with PWATs ranging from 1.2 in. in inland SE GA to 2+ in. in north-central FL. Lingering convection in the NE Gulf will continually shift onshore potentially affecting Marion, Gilchrist and Alachua counties in the early-mid morning hours. Drier air/lower PWATs over inland SE GA will likely limit convective coverage for this area, with the highest coverage of showers and thunderstorms generally along and south of I-10 and towards the coasts. A few stronger thunderstorms capable of producing 40-55 mph may be possible with the presence of some drier air and the nearby frontal boundary aiding with synoptic lift along with the usual inland-moving sea breezes. Highs will be slightly lower today in the low to mid 90s. Heat indices should remain just below advisory criteria in the 100-107 F range. Convection will wane after sunset with the loss of daytime heating. A few showers and storms may once again move into the I-75 corridor from the NE Gulf in the pre-dawn hours. Overnight lows in the low-mid 70s.

SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/

Main Highlights This Period:

- Rounds of Showers and Thunderstorms, with Strong Storms Possible During the Afternoon and Evening Hours.

- Heavy Rainfall and Localized Flooding Possible this Weekend.

A near stationary frontal boundary will begin to lift and dissipate near the GA coast Saturday as an upstream trough moves from the mid MS Valley into the OH and TN Valleys through Sunday which will help drive another frontal boundary southeastward into the southern MS valley/portions of the deep south. Moist SW flow off the Gulf waters will prevail each day as the Atlantic high pressure surface ridge remains well to the southeast. The Gulf seabreeze will move well inland Saturday with an initial round of showers and thunderstorms shifting eastward across north central FL, with the resulting outflows working north and east to the Atlantic coast and then interacting with the seabreeze before zippering northward into coastal SE GA with additional storms over inland SE GA due to the outflows and shortwave energy aloft to continue new development of storms. Above normal moisture levels (PWATs over 2.0 inches), strong diurnal heating, and convergence along the front and seabreezes will generate numerous showers and thunderstorms with isolated strong to severe storms where storms merge with the outflows/seabreeze.

Sunday, the trough will move towards the southern Appalachians into Sunday night, becoming elongated north to south as the Atlantic ridge begins to build westward towards the FL coast which will slow the surface front across the deep south just northwest of our area. The squeeze between the two mid to upper level features will yield increasing low level SW flow and tap higher moisture levels into the area with PWATs surging to near daily records of 2.20-2.40 inches. This will allow for widespread showers and thunderstorms across inland zones while coverage is slightly less along the coast. In addition to isolated strong to severe storms, locally heavy rainfall will be possible with training storms that could lead to flooding in low lying and urban locations. The Weather Prediction Center has a marginal risk of excessive rainfall in place this weekend. Breezy SW winds 10-15 mph will prevail on Sunday with gusts to 20-25 mph ahead of storms.

Temperatures will begin the weekend near normal with highs in the low 90s and lows in the low to mid 70s. Additional clouds on Sunday will lead to below normal highs in the mid to upper 80s inland to near 90 at the coast and I-95.

LONG TERM /MONDAY THROUGH THURSDAY/

Main Highlights This Period:

- Scattered to Numerous Thunderstorms Early Next Week. Daily Rounds of Heavy Downpours Could Result in Localized Flooding. Strong Storms are Possible, with Wind Gusts of 40-55 mph and Frequent Lightning Strikes.

- Decreasing Coverage of Thunderstorms by Midweek, with Heat and Humidity Building Towards the End of Next Week.

The period will begin with a weakening shortwave trough to the north across the southern Appalachian mountains with Atlantic high pressure ridging building into the Bahamas and south FL with breezy SSW winds. Shortwave energy from the trough and the convergence along the Gulf and Atlantic seabreezes will lead to numerous to widespread thunderstorms in the afternoon.

As the trough lifts away to the NNE on Tuesday and Atlantic ridging moves across the south and central FL peninsula, a more typical Seabreeze regime of Afternoon thunderstorms from Seabreeze interactions will begin with scattered to numerous storms. The SW flow will decrease with Seabreezes merging near US-17 in the afternoon with southeast winds behind the Atlantic seabreeze.

Wednesday into Thursday, Atlantic high pressure surface ridge axis will lift into SE GA with flow prevailing from the southeast and favoring a more inland progressing Atlantic seabreeze with scattered afternoon thunderstorms with Gulf/Atlantic seabreezes merging between highway 301 and I-75.

Temperatures will begin with highs a little below normal Monday and near normal Tuesday, then inland highs will be above normal Wednesday and Thursday with near normal coastal highs in the upper 80s to low 90s due to the onshore southeast flow. Lows will remain near normal with lows trending above normal in the low 70s inland and mid 70s at the coast with coastal lows warming to the upper 70s by Thursday.

AVIATION /12Z FRIDAY THROUGH 12Z SATURDAY/

VFR conditions will prevail at the regional terminals through at least 17Z. Showers and thunderstorms developing along and west of Interstate 75 this morning will likely expand eastward early this afternoon as the Gulf sea breeze and outflow boundaries shift activity towards the GNV terminal towards 18Z. Convection should then approach the rest of the northeast FL terminals from the west between 19Z - 00Z, followed by outflow boundaries and the Atlantic sea breeze potentially spreading activity towards the SSI terminal after 21Z. TEMPO groups for briefly gusty surface winds and IFR visibilities during heavier downpours were used at the northeast FL terminals, and confidence was high enough to now include a PROB30 group for these same conditions at SSI through around 02Z Saturday. Convection should end by 03Z, with VFR conditions then prevailing. Southwest to westerly surface winds will become sustained at 5-10 knots at the regional terminals by 15Z, followed by the Atlantic sea breeze developing and moving westward past the SSI and SGJ coastal terminals by 18Z, where surface winds will shift to southeasterly at 10-15 knots. The Atlantic sea breeze should move past the CRG and then JAX terminals by 20Z. Once convection dissipates after sunset, surface winds will shift to southerly at 5-10 knots at the regional terminals, followed by southwesterly winds around 5 knots after 06Z.

MARINE

A frontal boundary will linger over the Georgia waters through Saturday before dissipating on Sunday. Another front slowly enters the Deep South Sunday into early next week. This will lead to a prevailing offshore flow through early next week, with a daily south- southeast wind surge over the nearshore waters in the wake of the Atlantic sea breeze. A few offshore moving thunderstorms may be strong with gale force gusts possible.

Rip Currents: Low to marginal moderate risk of rip currents is expected through the end of the week at NE FL and SE GA beaches with surf/breakers of only 1-2 feet due to the generally offshore flow and weak swells.

FIRE WEATHER

- Strong Storms and Locally Heavy Downpours Possible Each Day through Early Next week.

An active pattern will persist again today as a frontal boundary remains nearly stationary just north of the FL/GA state line across Southeast Georgia. Light westerly winds 5-10 mph over SE GA and Southwesterly winds 8-12 mph will become southeasterly at the coast behind the afternoon Atlantic seabreeze 8-12 mph with gusts 15-20 mph. A wave of energy aloft and lift along the front and seabreezes will create numerous showers and thunderstorms in the afternoon and evening hours, especially for locations south and east of Waycross, GA. The front will remain into the weekend with coverage of thunderstorms increasing into Sunday as another front approaches from the northwest. The front will stall Monday with continued numerous to widespread afternoon showers and thunderstorms. Locally heavy rainfall is possible into early next week along with isolated strong to severe afternoon thunderstorms.

Dispersions will be in the good range through the weekend as surface and transport winds increase slightly by Sunday while cloud cover increases and limits mixing heights. MinRH values may drop below 40% today over far interior GA.

Fog Potential: Significant fog development is not expected during the next several mornings. As mentioned above, strong thunderstorms are possible during the afternoon and evening hours each day through early next week, with gusty winds of 40-55 mph possible within stronger activity. In addition, outflows from distant thunderstorms may also produce gusty and erratic winds.

PRELIMINARY POINT TEMPS/POPS

AMG 95 74 92 73 / 30 20 70 60 SSI 92 78 91 76 / 30 10 70 60 JAX 94 75 91 73 / 60 30 70 50 SGJ 91 74 90 74 / 60 30 70 50 GNV 92 74 90 72 / 50 40 70 60 OCF 91 74 90 73 / 60 60 80 60

JAX WATCHES/WARNINGS/ADVISORIES

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