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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

- Isolated Strong Thunderstorms Possible Along the I-10 corridor and portions of southeast GA Late this Afternoon & Evening.

- Beneficial Rainfall Expected Across Southeast GA through Sat Night

- Locally Heavy Rainfall Develops Across Northeast FL on Sunday. Isolated Thunderstorms Possible South of I-10. Severe Weather Not Anticipated.

- Severe to Extreme Drought Continues for Inland Areas.

- Light Freezes & Frost Possible Inland on Mon & Tues Nights.

- Moderate Rip Current Risk Today at Area Beaches.

NEAR TERM /THROUGH TONIGHT/

Late morning surface analysis depicts a wavy frontal boundary extending from the FL/GA border southwestward across the FL panhandle. Meanwhile, weakening high pressure (1029 millibars) was centered over coastal . Aloft...deep west-southwesterly flow prevails across the southeastern states, as our area lies between stout ridging over eastern Cuba and the southeastern Bahamas and troughing that is situated from the Upper Midwest eastward across the Ohio Valley and New England. Shortwave energy and a weak wave of surface low pressure along the frontal boundary traversing the Deep South was igniting elevated convection across the Ocmulgee and upper Altamaha River basins in southeast GA, with most activity occurring for locations north of Douglas, Alma, and Jesup. These locations remain north of the frontal boundary in the "cool sector", where temperatures and dewpoints at 15Z remain stuck in the upper 40s and lower 50s. Otherwise, breaks in the mostly mid and high altitude cloud cover were developing across northeast FL and coastal southeast GA, in the "warm sector" of this storm system, allowing temperatures and dewpoints to climb into the 60s, while temperatures were already rising into the 70s across north central FL.

The aforementioned wave of low pressure along the slow moving frontal boundary will push east-northeastward across the FL/GA border this afternoon, resulting in strengthening isentropic ascent / overrunning across southeast GA, where another and more widespread round of moderate to heavy showers and possibly a few elevated thunderstorms, especially during the late afternoon hours. A few surface-based thunderstorms may develop around sunset from the Suwannee Valley eastward along the Interstate 10 corridor, where CAPE values in the "warm sector" will rise to the 500-1,000 j/kg range. Bulk shear values around 50 knots could create a briefly strong storm for locations along or just north of I-10 before instability weakens early this evening, with the main threat being a localized downburst wind gust of 40-50 mph and frequent lightning strikes. The window for stronger storms will close early this evening with the loss of daytime heating and the surface wave of low pressure moving offshore of the northeast FL and southeast GA coast. Temperatures in the "warm sector", or from the Okefenokee Swamp and coastal southeast GA southward will rise to the 70s, with highs around 80 for locations south of I-10. Highs may remain stuck in the 50s in the "cool sector" for locations near the Ocmulgee and Altamaha River basins, with 60s in between for the rest of inland southeast GA.

Weakening convection will accompany this storm system's frontal boundary as it slips southeastward this evening, potentially bringing beneficial downpours to north central and coastal northeast FL through around midnight tonight. Isentropic ascent / overrunning will remain in place in the wake of the frontal wave overnight across southeast GA, where light rainfall and drizzle will likely develop as a deck of low stratus cloud cover expands across our region from north to south. Locally dense fog may also develop in the immediate wake of the frontal passage by the predawn and early morning hours, especially across north central FL, where lows will only fall to the lower 60s. Weak cool air advection will otherwise allow lows to fall to the upper 40s and lower 50s for southeast GA and northeast FL.

SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/

A messy but beneficial rain pattern will continue to set up this weekend. For Saturday, a cold front will be across the southern zones Saturday morning and slowly ease southwards weak high pressure moves just north of the area. This occurs as weak shortwave disturbances ride west to east in the prevailing west to southwest aloft. The front should slide into central FL by Saturday night but it will begin to stall as the flow aloft backs in response to moderately strong shortwave energy moves into the central U.S. This latter system will begin to form a surface low over the northern Gulf Saturday night. The front will push back into north central FL Sunday into Sunday night with a couple of waves of low pressure moving along the front, with moderate to strong synoptic lift affecting the area in conjunction with plenty of moisture across the area. A complex surface low will finally move offshore of the southeast U.S. coast Monday morning with a trailing cold front noted over north central FL at that time.

Max temperatures will generally be below normal, except for the far south zones where some mid to upper 70s possible on Saturday. Chilly for interior southeast GA with highs about 55 to 60. Lows will be above normal given the abundant cloud cover expected and the high chances of rain.

As far as weather, high chances of rain, categorical above 75 percent for southeast GA on Saturday, with this enhanced rain chances slowly move southeastward into Saturday night and Sunday. Otherwise, likely rain for just above any location Saturday through Sunday night. Have a small chance of thunder for Sunday as better low level convergence is available and there is scant buoyancy in tandem. Any thunder probably will move offshore Sunday night as the sfc low tracks offshore gradually. Severe weather is not anticipated at this time.

We have additional rainfall amounts of about 1-2 inches forecast for Saturday into Sunday night. There is potential for 3-4 inches during this period.

LONG TERM /MONDAY THROUGH THURSDAY/

Surface low pressure along the front shifts well northeast of the area on Monday with trailing cold front sweeping southward over the FL peninsula. Surface high pressure initially over the Ohio and TN valley area will shift southward into mid week. A coastal trough seems to form by Tue and into early Wed keeping the coastal northeast FL breezy at times but no rain is mentioned at this time. The high does begin to shift south of the area Wed night, with a weak dry front possibly moving into the forecast area on Thursday.

There could be some lingering patches of rain early Monday but should be rain-free by midday through the rest of the mid week period as the high builds into the area and the dry front approaches.

Overall, chilly/below normal temperatures this period with potential for inland light freeze and/or frost for southeast GA.

AVIATION /12Z FRIDAY THROUGH 12Z SATURDAY/

Multilayered clouds over the region at this time with some MVFR cigs around SSI at times that will eventually become prevailing. At the same time, some shower activity will continue pushing in from the west during the day and into the evening hours. A period MVFR cigs appears probable for portions of northeast FL as well by the early afternoon, improving a bit in the afternoon but additional low clouds will move in from the west later today that will bring IFR to the terminals by the evening hours, first at SSI forecast to be about 22z, Duval terminals by 00z-01z, then GNV and SGJ by 03z-06z. LIFR looks probable after 06z with low cigs and vsby with scattered rains expected as well. TSRA chances are low enough to preclude mention in the TAFs at this time. Lastly, included LLWS for Duval TAFs and SSI with the JAX VWP showing 30-35 kt at 1-2 kft and guidance suggesting it for a few hours after 12z.

MARINE

Weak low pressure moving across the FL panhandle late this morning will move east-northeastward across our region this afternoon, accompanied by showers and possibly an isolated thunderstorms through this evening. This storm system's cold front then crossing our local waters tonight and Saturday morning. A wave of low pressure will then develop along this front just south of the northeast FL waters on Saturday night, with widespread rainfall and a few embedded thunderstorms overspreading our area through Sunday night. Low pressure will then strengthen as it moves offshore on Sunday night and Monday, resulting in strengthening northerly winds as rainfall ends, with Small Craft Advisory conditions likely from Monday through at least early Tuesday.

Rip Currents: SE GA Moderate this afternoon NE FL Moderate this afternoon

FIRE WEATHER

Mostly cloudy and wet for today through and the weekend. Multiple rounds of rainfall are expected through the weekend ahead of an approaching cold front that will move through Sunday night. The showers will be heaviest today over Southeast GA into the Suwannee Valley with the axis of heavier showers moving into Northeast FL late Saturday into much of Sunday before ending by Sunday Night. Isolated thunderstorms are possible with the heavier showers as well, but no severe storms are expected.

The clouds, low mixing heights, and the lighter winds will allow for low daytime dispersions through the weekend.

PRELIMINARY POINT TEMPS/POPS

AMG 48 56 45 60 / 60 90 60 40 SSI 52 62 50 63 / 50 80 80 60 JAX 53 66 52 64 / 30 60 80 70 SGJ 58 71 56 69 / 20 40 70 80 GNV 59 73 56 69 / 20 50 70 80 OCF 62 76 58 72 / 20 50 70 80

JAX WATCHES/WARNINGS/ADVISORIES

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