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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

- Freeze Warning and Frost Advisory through 8 AM this Morning for Southeast GA and Inland Portions of Northeast & North Central FL

- Moderate Rip Current Risk at All Area Beaches through Thursday

- Isolated Thunderstorms Possible on Sunday for Northeast and North Central FL.

- Low Potential for Freezing Rain Sunday Night and Monday Morning Across Southeast GA

- Severe Drought Conditions Expanding Across our Region. Recent Freezes will Result in Drying of Available Fuels. Chances for Beneficial Rainfall Increase this Weekend.

NEAR TERM /THROUGH TONIGHT/

Overnight surface analysis depicts Arctic high pressure (1035 millibars) centered over the Delmarva peninsula, with the axis of this feature extending southward down the southeastern seaboard. Meanwhile, a wavy frontal boundary extends from the Ohio Valley through the Upper Mississippi Valley and the Plains states. Aloft...broad troughing positioned over the eastern two- thirds of the nation continues to de-amplify, with mostly zonal west-southwesterly flow at the base of this filling trough across the Deep South. Otherwise, reinforcing shortwave troughs continue to dive southeastward from the Canadian prairies across the Northern Plains, with these features then pivoting eastward across the Upper Midwest and eastern Great Lakes within the longwave trough. Fast west- southwesterly flow across our area continues to advect a veil of mostly thin cirrus cloud cover across our most of our area. Latest GOES-East derived Total Precipitable Water imagery indicates that a dry air mass persists across our area, but PWATs have rebounded slightly to the 0.3 - 0.5 inch range. Winds at inland locations have decoupled, allowing temperatures to fall to the 30-35 degree range at many locations as of 07Z. A developing north to northwesterly breeze at coastal locations was keeping temperatures much warmer, with values ranging from the upper 30s to upper 40s. Dewpoints ranged from the upper 20s for locations near the Altamaha / Ocmulgee Rivers in southeast GA to the lower 40s along the northeast FL coast.

Troughing aloft will remain positioned to the north and northwest of our region through tonight. Fast west- southwesterly flow above 700 millibars (around 10,000 feet) will continue, with a jet streak progressing across the Appalachians likely creating a thickening high altitude cloud shield across our area tonight. Meanwhile, Arctic high pressure moving off the Delmarva coast early this morning will continue to extend its axis southwestward across our region as a weak coastal trough takes shape over our near shore waters. The dry air mass in place across our region should prevent the coastal trough from generating any shower activity, and marine stratocumulus should remain south of our region. Low level flow will continue to gradually veer, signaling a warming trend for our region following another frosty start to the day at many inland locations. Filtered sunshine and mostly light winds at inland locations will allow highs to climb to the mid and upper 60s for locations along and north of the Interstate 10 corridor, while locations in north central FL climb to the 70-75 degree range this afternoon. The coastal trough will generate a cool north- northeasterly breeze for areas along and east of I-95 that will keep highs in the 60-65 degree range, as our recent cold spell has dropped shelf waters over the near shore Atlantic waters down to the mid and upper 50s.

Thickening mid and high altitude cloud cover will keep temperatures much warmer across our region tonight. Low level moisture will continue to gradually increase, with PWATs climbing above 0.5 inches this evening and then reaching the 0.75 - 1 inch range towards sunrise on Thursday. This warm air advection pattern would normally create fog and low stratus ceilings across our region, but thickening cloud cover aloft may prevent this from occurring. Lows tonight will remain in the 40s, except lower 50s for coastal northeast FL.

SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/

High pressure weakens over the western Atlantic as a much stronger arctic high pressure dives southeastward from Saskatchewan into the upper Plains region for the end of the work week. This arctic high will push a cold front into the SE US on Thursday and then approach the area on Friday. A few showers may develop ahead of the front in inland SE GA late Friday as it moves southward through the area Friday night. A warming trend takes hold with flow shifting from ESE on Thursday to SSW on Friday. Temperatures will rise above seasonable and potentially develop an afternoon sea breeze. Daytime highs will range from the upper 60s along the SE GA coast to around 80 in north-central FL. Overnight lows will range from the mid 40s to upper 50s. Low level moisture gradually increases bringing a return of inland morning fog.

LONG TERM /SATURDAY THROUGH TUESDAY/

Strong arctic high pressure centered over upper MS river valley on Saturday will shift eastward into New England on Sunday. A strong upper level disturbance will move into the SW U.S. over the weekend which will help trigger surface low development in the Gulf. This low pressure system is forecast to track across the northeast Gulf near the FL/GA state line later this weekend, and then move east offshore of the southeast U.S. coast Sunday night into early Monday. Another area of low pressure may develop off the Carolina coast Saturday night and translate northeastward on Sunday. These two lows will help lift the frontal boundary draped over central FL back northward as a warm front. Strong warm air advection builds into NE FL and potentially SE GA Saturday night into Sunday in the wake of the warm front. Showers will move into SE GA early Saturday and then begin to spread into NE FL on Saturday night as dynamics ahead of the Gulf low begin to increase ascent across the area while low level flow is northeasterly. Showers should further develop Sunday into Sunday night as a trailing cold front presses down into the region from out of the north. Models have continued their downward trend on the potential for freezing rain developing across SE GA Saturday night into Sunday night. Better chances for winter weather remain north of our area with this weekend system. There still remains uncertainty and ultimately will depend on the track of the Gulf low and location of the arctic airmass. But, confidence is low that shallow cold air will be able to overcome the warm air being ushered in from the SSW to produce freezing rain in our area. Confidence is now increasing for isolated thunderstorm potential across NE FL for Sunday into Sunday night due to ample Gulf moisture and increasing instability. High temperatures this weekend will have a large north-south gradient ranging from the low-mid 50s to low 80s. By Monday morning, the surface low should be offshore with the trailing cold front into central FL continuing to press south. Overrunning clouds expected Monday with a chilly airmass over the region to start the next week. Another freeze and a hard freeze, for well inland zones, looks likely Monday night as the clouds begin to clear out. Tuesday, mostly clear and high pressure moving into the area but chilly and dry air and another freeze Tuesday night.

AVIATION /12Z WEDNESDAY THROUGH 12Z THURSDAY/

VFR conditions will prevail at the regional terminals. Periods of broken high cloud cover will continue through tonight. North- northeasterly winds at SSI and SGJ will increase to 5-10 knots towards 13Z. Light north-northeasterly surface winds will develop at the inland terminals shortly after sunrise, with winds then shifting to northeasterly while increasing to 5-10 knots by 15Z. Northeasterly winds will increase to around 10 knots at the coastal terminals towards 15Z. Surface winds will then diminish after 00Z at the inland terminals, while winds shift to northerly around 5 knots at the coastal terminals.

MARINE

High pressure centered along the Mid-Atlantic coast will push offshore today, with this feature extending its axis southwestward along the southeastern seaboard through Friday. Breezy northeasterly winds will gradually diminish this evening, with light northerly winds then prevailing through Friday. A developing winter storm system over the central and southern United States late this week and Arctic high pressure building to the north of our region will drive a cold front southward across our waters on Friday night and Saturday, with a surge of northeasterly winds expected to briefly overspread our local waters from north to south early this weekend. Scattered showers may accompany this frontal passage, with a wave of low pressure then developing along this boundary near our region by Saturday night and Sunday. This storm system's warm front will lift northeastward across our local waters, resulting in winds shifting to southwesterly, with chances for showers and a few embedded thunderstorms increasing by late in the weekend. Another cold front will cross our local waters by Sunday night and Monday, with strengthening north-northwesterly winds forecast in the wake of this frontal passage early next week.

Rip Currents: Southeast GA Beaches: Moderate through Thursday Northeast FL Beaches: Moderate through Thursday

FIRE WEATHER

High pressure shifts off the mid-Atlantic coast today shifting winds to be east-northeasterly. Light winds and relatively lower mixing heights will result in poor dispersions across southeast Georgia but good mixing heights will result in good dispersions in north-central FL today. Above seasonable temperatures will increase mixing heights through the week but light winds will cause fair to poor dispersions with pockets of low dispersions Thursday and Friday. Moisture gradually increases through the end of the week as a cold front approaches late Friday. Showers return late Friday and continue into the weekend.

FOG POTENTIAL AND OTHER REMARKS: Freezing and frost conditions expected inland areas this morning. Patchy inland fog possible early Thursday morning and Friday morning.

PRELIMINARY POINT TEMPS/POPS

AMG 64 42 72 46 / 0 0 0 0 SSI 63 47 65 52 / 0 0 0 0 JAX 68 46 72 51 / 0 0 0 0 SGJ 66 53 70 54 / 0 10 0 0 GNV 71 49 77 51 / 0 0 0 0 OCF 73 50 77 52 / 0 10 0 0

JAX WATCHES/WARNINGS/ADVISORIES

FL...Freeze Warning until 8 AM EST this morning for FLZ023-024-322. Frost Advisory until 8 AM EST this morning for FLZ030-031-035- 136-232-236-425. GA...Freeze Warning until 8 AM EST this morning for GAZ132>136-149- 151>153-162-163-165-250-264-350-364. Frost Advisory until 8 AM EST this morning for GAZ154-166. MARINE...None.