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

- Isolated Strong Thunderstorms Possible Along I-10 and Portions of Inland Southeast Georgia this Afternoon. Hazards: Strong Wind Gusts of 40-50 mph, Frequent Lightning & Small Hail

- Beneficial Rainfall Across Southeast GA through Sat Night

- Periods of Heavy Rainfall Possible Across Northeast and North Central FL on Sunday and Sunday Night. Isolated TStorms 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.

NEAR TERM /THROUGH TONIGHT/

Early afternoon surface analysis depicts a wavy frontal boundary stretching from the Okefenokee Swamp in southeast GA southwestward across the FL Big Bend. A weak wave of low pressure (1012 millibars) was traversing this front near the FL/GA border. Meanwhile, weakening high pressure (1028 millibars) was centered over New England. Aloft...deep west- southwesterly flow prevails across the southeastern states, as our area lies between stout ridging over the southeastern Bahamas and broad troughing that extends from the Upper Midwest eastward across the eastern Great Lakes. Scattered convection was developing ahead of the frontal wave across the FL Big Bend and southern GA, with the "warm sector" nosing northward through the Okefenokee Swamp. Isentropic lift / overrunning continues in the "cool sector" from Waycross northward, where temperatures and dewpoints remain stuck in the 50s this afternoon. Temperatures across northeast and north central FL have soared into the 70s to around 80 as of 19Z, with dewpoints climbing to the mid and upper 60s.

The aforementioned wave of low pressure along the frontal boundary will push east-northeastward across the FL/GA border and Okefenokee Swamp this afternoon and will move offshore this evening, resulting in the frontal boundary slowing its forward progress as it moves south of Interstate 10 overnight. Showers and thunderstorms will increase in coverage and possibly intensity this afternoon in the "warm sector", with a few surface-based thunderstorms developing from locations south of Waycross southward across the Interstate 10 corridor, where CAPE values will rise to the 500-1,000 j/kg range. Bulk shear values around 50 knots could create a few strong storms through early this evening, mainly for locations along and north of I-10, before instability weakens before midnight. Stronger storms this afternoon and evening may create localized downburst wind gusts of 40-50 mph, small hail, frequent lightning, and briefly heavy downpours.

Weakening convection pushing southeastward across north central and coastal northeast FL will provide some brief but beneficial downpours 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/

Cold front will continue to take its time dropping southward throughout this weekend, with the key takeaway being mostly cloudy skies with periods of rain and generally light winds for the majority of the area through at least Sunday Evening. More detail for each period:

Saturday: Majority of rainfall during the day Saturday is expected to be over interior GA, mainly north and west of Waycross. However, just a bit of diurnal instability and slightly more breaks in the clouds may spawn a few showers and perhaps a thunderstorms over northeast FL, especially south of about SR-20. Cooler high temps will be expected area wide as the front nudges south. Expecting mainly 50s over interior GA, 60s surrounding the I-10 corridor, and low to mid 70s south of about SR-20.

Saturday Night & Sunday: Higher rainfall chances shift further south Saturday Night and through Sunday as the front continues to slowly nudge southward, with the highest PoPs and QPF expected to be across northeast FL but especially near the I-10 corridor. Otherwise mainly cloudy skies with lows a touch cooler Saturday Night: Mainly in the 40s across southeast GA and 50s over northeast FL. High temps Sunday will be similar to Saturday overall across northeast FL with mid 60s to low 70s common. Less of a gradient heading northward into GA on Sunday however thanks to lower rainfall coverage: in the upper 50s to mid 60s will be expected.

Sunday Night: Drier air both near the surface and aloft starts to slowly intrude into the region Sunday Night as a secondary front approaches from the northwest, likely entering southeast GA counties by early Monday Morning. Still enough moisture for rain chances to continue Sunday Night, especially from about I-10 southward in northeast FL though mainly dry elsewhere. Low temps will be similar to Saturday Night, with upper 40s to near 50 over interior GA and 50s over northeast FL.

LONG TERM /MONDAY THROUGH FRIDAY/

Drying trend expected overall through Monday as the aforementioned secondary front drops southward, settling over south FL by Tuesday. A few isolated showers will be possible Monday afternoon over interior GA as the base of an upper shortwave passes just north of this area, but otherwise dry for most Monday and especially Tuesday. Surface high pressure shift southward into the area through mid week, though A coastal trough will try to form by Tue and into early Wednesday, keeping the coastal northeast FL breezy at times though rain chances appear minimal at this time. The high makes further progress southward Wednesday night and through Thursday, as a weak dry front moves through the forecast area. Temps will trend mostly below normal early in the week before slowly rebounding closer to normal Wednesday/Thursday.

AVIATION /18Z FRIDAY THROUGH 18Z SATURDAY/

MVFR ceilings around 2,000 feet will prevail at the regional terminals through around 01Z Saturday. Showers and possibly a few embedded thunderstorms will approach the SSI terminal towards 21Z, with confidence high enough to indicate a TEMPO group for briefly gusty winds and MVFR visibilities at SSI through around 00Z. Activity will then push southeastward across the northeast FL terminals after 00Z, with confidence only high enough to include PROB30 groups for briefly gusty winds and MVFR visibilities during heavier downpours through around 04Z tonight. Low stratus ceilings will then overspread the regional terminals overnight, with IFR conditions developing by 02Z at SSI. Prevailing IFR to LIFR conditions will spread across the northeast FL terminals after 03Z, with IFR or lower conditions likely continuing through most of the day on Saturday at the regional terminals. Gusty southwesterly winds sustained at 10-15 knots will continue through around 22Z at the northeast FL terminals, with winds then shifting to northwesterly towards 00Z and speeds decreasing to around 5 knots or less overnight.

MARINE

Weak low pressure moving across our region late this afternoon will bring an increasing chance for showers and possibly an isolated thunderstorm through this evening before this feature moves offshore tonight. A cold front will then cross the northeast Florida waters overnight before stalling over north central Florida on Saturday and Saturday night. A wave of low pressure will then develop along this front just south of the northeast Florida waters on Saturday night, with widespread rainfall and a few embedded thunderstorms overspreading our local waters through Sunday evening. Low pressure will move offshore on Sunday night, resulting in strengthening northwesterly winds. High pressure will then build over the southeastern states early next week, creating strengthening northerly winds and Small Craft Advisory conditions.

Rip Currents: SE GA Moderate Saturday NE FL Low Saturday

FIRE WEATHER

Mostly cloudy and wet conditions will continue today and into the weekend as well as a cold front slowly sinks southward, moving through the area by 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 for 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. Cloud cover, rain coverage, and light winds will result in low mixing heights and low daytime dispersions through the weekend. Drier and seasonably cool conditions will be expected for the start of next week as weak high pressure builds over the region.

PRELIMINARY POINT TEMPS/POPS

AMG 48 56 44 60 / 50 90 50 40 SSI 52 60 50 63 / 70 80 70 50 JAX 53 66 51 67 / 70 70 70 60 SGJ 59 70 56 69 / 40 30 70 70 GNV 59 72 55 70 / 50 40 70 70 OCF 62 75 58 73 / 40 30 70 80

JAX WATCHES/WARNINGS/ADVISORIES

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