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

- Freeze Warning Late Tonight for Inland Southeast GA. Light Freeze Forecast for Locations West of I-95 in Southeast GA.

- Small Craft Advisory through Monday Morning.

- Freeze Watch Late Monday Night for Inland Southeast GA.

- Small Craft Advisories Likely Late Wednesday Night through Thursday Night. Gale Conditions will be Possible.

- Widespread Freeze on Thursday Night and Friday Morning. Hard Freeze Potential Inland, Light Freeze Likely at Coastal Locations.

UPDATE

Evening surface analysis depicts strong high pressure (1035 millibars) building southeastward from the Ozarks and the Tennessee Valleys. This feature has pushed a cold front southward towards south FL. Aloft...a potent trough was pivoting across New England, with brisk westerly flow aloft above 550 millibars (around 17,000 feet) locally per the evening sounding at Jacksonville. Otherwise, a cutoff trough near Baja California, in combination with a 140-knot jet streak at 250 millibars (around 35,000 feet) off the Mid- Atlantic coast was spreading a veil of high altitude cirrus and cirrostratus cloud cover throughout our region. A northwest to northerly breeze was advecting a colder and much drier air mass into our region this evening, with temperatures at 02Z falling into the upper 40s and lower 50s across southeast GA, where dewpoints have rapidly crashed through the 20s early this evening. Temperatures were falling through the low and mid 50s elsewhere, with dewpoints falling to the low and mid 30s.

High cloud cover will continue to stream over our area tonight due to deep westerly flow aloft along the northern Gulf coast and the southeastern states. Cold air advection will continue beneath this veil of high cloud cover, with a northerly breeze adding an extra chill to the air, especially later tonight at coastal locations. A light advective freeze appears to be on track for most inland locations in southeast GA by the predawn and early morning hours on Monday, where lows will fall to the lower 30s. Lows for coastal southeast GA and inland northeast and north central FL will generally fall to the mid and upper 30s, ranging to the low and mid 40s for coastal northeast FL. Wind chill values should remain above Cold Weather Advisory criteria later tonight and early Monday morning, but will still fall to the mid to upper 20s for most of southeast GA and for inland locations along the Interstate 10 corridor, with 30s forecast elsewhere. The persistent northerly breeze overnight and falling dewpoint values should preclude significant frost formation.

SHORT TERM /THROUGH TUESDAY NIGHT/

Surface high pressure ridge will settle overhead of the region Tuesday. A wave will develop over the Gulf, under an upper trough, and lift northeast across central FL Wednesday and Wednesday night as a cold front dips into the southeastern US. Isolated to scattered showers are expected, with the greatest chances over SE GA.

Near normal temperatures for Tuesday and Tuesday night, with readings a little below Wednesday and Wednesday night.

LONG TERM /WEDNESDAY THROUGH SUNDAY/

Waves will continue to move northeast across FL Thursday, as the upper trough dips into the Carolinas. Best shower chances Thursday will be across north central FL. Below normal temperatures expected Thursday.

The upper trough will move off to the northeast Thursday night, as surface high pressure builds to the northwest. A cold airmass will advect into the region through the night, with a widespread freeze forecast.

High pressure ridge will be nearly overhead through Friday night, with mainly clear skies and temperatures remaining below average.

Another upper trough will dip into region Saturday through Sunday with a surface front moving through. A few showers will be possible over the weekend. After a seasonal day on Saturday, below average temperatures for Saturday night and Sunday following the surface front.

AVIATION /00Z MONDAY THROUGH 00Z TUESDAY/

VFR conditions will prevail through at least 15Z Monday at the regional terminals. Marine stratocumulus pushing onshore along the northeast FL coast during the late morning and afternoon hours on Monday will likely create ceilings of 3,000-4,000 feet at SGJ after 15Z. Confidence was high enough to indicate a borderline MVFR ceiling at SGJ towards 23Z Monday. Otherwise, high altitude cloud cover will likely prevail at the terminals through the TAF period. Northwesterly surface winds sustained at 5-10 knots this evening will shift to northerly towards 04Z, with speeds increasing to around 10 knots overnight, except 10-15 knots and gusty at SGJ. Surface winds will then shift to north-northeasterly by 16Z, with speeds increasing to 10-15 knots, except around 15 knots and gusty at SGJ. Surface winds will then shift to northeasterly after 21Z, with speeds decreasing to 5-10 knots, except around 10 knots at SGJ.

MARINE

Small Craft Advisory conditions will continue through late Monday morning as strong high pressure builds into the southeastern states. High pressure will then begin to weaken on Monday afternoon along the northern Gulf coast, allowing north northeasterly winds to gradually diminish through Tuesday afternoon as coastal troughing over our near shore waters lifts northward. Showers will develop on Wednesday ahead of a cold front that will be entering the southeastern states, with this activity continuing through early Thursday. This strong cold front will cross our local waters on Thursday morning. Small Craft Advisory conditions are forecast to begin late Wednesday night as westerly winds strengthen just ahead of the front, followed by strong northwesterly winds from Thursday afternoon through Thursday night in the wake of the frontal passage, when Gale conditions will be possible. High pressure will then build directly over our local waters on Friday and Friday night, allowing for winds and seas to diminish.

Rip Currents: Southeast GA Beaches: Moderate on Monday Northeast FL Beaches: High on Monday

FIRE WEATHER

- Critically low RH values over Inland Southeast GA on Monday and Tuesday afternoons - Areas of low dispersions on Tuesday - Patchy high dispersions for Inland Southeast GA on Wednesday - High dispersions on Thursday

High pressure will build to the northwest Today, then build overhead Tuesday. A wave of low pressure will move across FL Wednesday into Thursday as a cold front moves across the southeastern US, producing shower chances. HIgh pressure will build to the northwest again Thursday night, then overhead on Friday. A cold front will move southeast across area Saturday into Saturday night. High pressure will build to the northwest Sunday.

FOG POTENTIAL AND OTHER REMARKS: A light freeze is expected over inland Southeast GA tonight and Monday night. A widespread freeze is forecast for Thursday night, with hard freeze potential at inland locations. A light inland freeze is forecast on Friday night.

PRELIMINARY POINT TEMPS/POPS

AMG 31 54 29 61 / 0 0 0 0 SSI 38 53 39 60 / 0 0 0 0 JAX 37 57 37 64 / 0 0 0 0 SGJ 48 59 45 64 / 0 0 0 10 GNV 39 62 39 67 / 0 0 0 0 OCF 40 64 42 67 / 0 0 0 10

JAX WATCHES/WARNINGS/ADVISORIES

FL...None. GA...Freeze Warning from 3 AM to 9 AM EST Monday for GAZ132>136-149- 151>153-163-165-250-264-350-364. Freeze Watch from late Monday night through Tuesday morning for GAZ132>136-149-151>153-162-163-165-250-264-350-364. MARINE...Small Craft Advisory until 10 AM EST Monday for AMZ450-452-454- 470-472-474.