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

- Frost/ Light Freeze Tonight through Early Thursday Morning. Freeze Warning for Inland Southeast GA, Northeast & North Central FL. Frost Advisory for along and West of I-95.

- Elevated Wildfire Danger at Inland Locations this Afternoon. Minimum Relative Humidity Values of 20-25% and West- Northwest Winds of 10-15 mph Expected Inland.

- Small Craft Advisory Tonight for the Offshore Coastal Waters.

- Isolated Thunderstorms & Beneficial Rainfall Expected Saturday and Saturday Night.

UPDATE

Late morning surface analysis depicts Arctic high pressure (1029 millibars) centered over Deep South Texas. Aloft...troughing prevails over the eastern half of the nation, creating deep and dry northwesterly flow across our region. Latest GOES-East derived Total Precipitable Water imagery indicates that PWATS are around or below one-third of an inch across our area. Despite sunny skies, breezy northwesterly winds that were driving cold air advection were only allowing temperatures to slowly rise following a frosty start at most locations, with temperatures at 15Z ranging from the upper 30s to the lower 40s, with dewpoints generally in the upper teens and lower 20s. ELEVATED FIRE DANGER CONDITIONS THIS AFTERNOON...

Surface ridging over Deep South Texas this morning will shift eastward across the western and then central Gulf while gradually weakening this evening and tonight. Meanwhile, a reinforcing shortwave trough and surface low pressure system pivoting across southern Ontario and the Great Lakes region this afternoon and evening will reinforce the longwave trough that remains in place across the eastern half of the nation. Despite sunny skies today, highs will remain in the mid to upper 50s area-wide due to cold air advection. Freeze warnings and Frost Advisories have been issued for all but the immediate northeast FL coast tonight as winds diminish this evening, although a light westerly breeze will continue overnight at coastal locations. Lows will fall to the 30-35 degree range to ring in the New Year early on Thursday morning, except around 40 at the northeast FL coast from Jacksonville Beach southward. Widespread frost is likely for locations along and west of the Interstate 95 corridor late tonight and early Thursday morning.

SHORT TERM /THROUGH FRIDAY NIGHT/

Early morning frost developments will continue through the end of the week with freezing conditions lessening on Friday as high pressure moves further east and prevailing flow shifts to become more out of the southwest ahead of an advancing cold front pressing in from out of the northwest, with chances for convection increase over inland southeast Georgia during the overnight hours on Friday. Temperatures will warm to the seasonal average with daily max temps rising into the mid to upper 60s by Friday with overnight low temperatures similarly rising into the upper 40s and lower 50s before the weekend.

LONG TERM /SATURDAY THROUGH TUESDAY/

Showers with embedded thunderstorms and breezy southwesterly winds will develop across the forecast area on Saturday with dry weather conditions settling in over the region by Sunday, following the frontal passage, with dry weather expected to persist into next week. Temperatures will drop by Sunday, following the frontal passage, with daily high temps and overnight min temps rising to be above the seasonal average by the middle of next week.

AVIATION /12Z WEDNESDAY THROUGH 12Z THURSDAY/

VFR conditions will prevail at the regional terminals. West- northwesterly winds will remain sustained around 10 knots from shortly after sunrise through around 21Z. Surface winds will then shift to westerly towards 22Z, with speeds diminishing to around 5 knots by 23Z and then continuing through 12Z Thursday.

MARINE

High pressure will slowly weaken as it pushes eastward from Deep South Texas this morning across the Gulf tonight and Thursday, becoming centered over south Florida by Friday. Gusty west- northwesterly winds today will briefly increase tonight for portions of the offshore waters, where a Small Craft Advisory will be in effect through Thursday morning. Winds will shift to southwesterly while briefly diminishing from Thursday afternoon through Friday. Weak low pressure developing over the lower Mississippi Valley on Friday will shift eastward across the southeastern states on Saturday, moving offshore on Saturday night. This storm system will bring showers and a few embedded thunderstorms to our area on Saturday and Saturday night, along with Small Craft Advisory conditions for the offshore waters. Breezy northerly winds are forecast in the wake of this storm system on Sunday and Sunday night.

Rip Currents: Southeast GA Beaches: Moderate Today, Low on Thursday Northeast FL Beaches: Low Today and Thursday

FIRE WEATHER

West to northwesterly winds continue today, with cold and dry air remaining over the region. The dry air will bring Min RH values into the 20s area-wide again today. The driest air will be over inland southeast Georgia with RH values in the lower 20s, a bit higher over northeast Florida where min RH values will be in the mid to upper 20s. With winds 10-15 mph with higher gusts up to 20-25 mph and ongoing drought, elevated fire danger conditions expected over inland areas (both Southeast GA and Northeast FL). Fair to good dispersions continue through midweek. A gradual increase in low level moisture expected by Friday. A low pressure system will bring a wetting rainfall to the area Saturday into Saturday night. Dry conditions arrive by midday Sunday into early next week.

FOG POTENTIAL AND OTHER REMARKS: Widespread frost and freeze over inland locations early this morning with frost melting by the late morning hours. Isolated thunderstorm potential Saturday into Saturday evening, with locally heavier rainfall amounts up to 1-2 inches. Fog not expected the next couple of mornings.

PRELIMINARY POINT TEMPS/POPS

AMG 54 31 62 36 / 0 0 0 0 SSI 54 36 63 42 / 0 0 0 0 JAX 56 33 65 37 / 0 0 0 0 SGJ 56 36 64 41 / 0 0 0 0 GNV 57 32 66 39 / 0 0 0 0 OCF 57 31 65 39 / 0 0 0 0

JAX WATCHES/WARNINGS/ADVISORIES

FL...Freeze Warning from 1 AM to 8 AM EST Thursday for FLZ021-023- 024-030-031-035-120-136-137-140-220-232-236-237-240-322- 340-422-425-522. Frost Advisory from 3 AM to 8 AM EST Thursday for FLZ038-124- 125-132-325-433-533-633. GA...Freeze Warning from 1 AM to 8 AM EST Thursday for GAZ132>136- 149-151>153-162-163-165-250-264-350-364. Frost Advisory from 3 AM to 8 AM EST Thursday for GAZ154-166. MARINE...Small Craft Advisory from 11 PM this evening to 10 AM EST Thursday for AMZ470-472.