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

- Cold Weather Outbreak Tonight through Tuesday Morning. Extreme Cold Warning Tonight Wind Chills 5-10F. Hard Freeze Sunday Night & Inland Freeze Monday Night with Frost

- Rain & Snow Mix Today Portions of Southeast GA. Winter Weather Advisory for Minor Transportation Impacts. Rain & Snow Wintry Mix - Less than 0.5 snow accumulation

- Gale Warning Late Today through Sunday. Lower than normal low tides tonight with offshore Gales

- Gusty Winds Today & Tonight Coast & North-Central Florida. Peak gusts 40-50 mph - Secure vulnerable objects

NEAR TERM /THROUGH TONIGHT/

A dynamic weather period over the next 24 hrs as low pressure deepens offshore of the Carolina Atlantic coast today, with a trailing cold front moving southward across the local area this morning. Advertised a a low chance of light rain showers mainly across our north-central FL zones this morning ahead of the frontal passage, otherwise prevailing dry conditions and mostly cloudy skies as temperatures warm into the 40s across inland southeast GA to the 50s across northeast Florida.

This the low east of the Carolinas strengthens, the local pressure gradient tightens as a weak trough on the west-side of the surface slides down the SC-GA coast. Wrap-around moisture on the west side of the surface low, forcing near this southward moving wake trough and cooling temperatures behind the morning cold front passage across southeast GA all still support an initial rain to rain/snow to then snow event really still focused near the Altamaha River Basin this afternoon into the evening hours. The main change overnight was to extended the footprint of the Winter Storm Advisory near the Altamaha River basin a tier of counties southward to include Bacon, Pierce, Brantley and Camden counties where several recent high resolution models showed a southward shift in the light snowfall footprint into the early evening.

The Winter Weather Advisory is issued to message little to minor impact potential mainly to transportation due to snowfall accumulations less than 1 inch across our local area. For this event, snowfall accumulations are expected to be less than 0.50 (high confidence) with an upper bound of 1 inch having less than 10% chance of occurrence right along and north of the Altamaha River basin. There is high confidence of no freezing rain. Snow flurries (no accumulations) will be most likely toward the beaches into the evening hours, including the northeast Florida beaches, as cold NW air moves across the warmer waters. Precipitation over land areas will end by midnight and truncated the end time of the winter weather advisory to end by 1 am tonight.

A wind advisory remains in place for coastal areas and several north- central FL counties as gusty/blustery WNW winds increase to sustained 20-30 mph this afternoon with gusts of 40-50 mph (strongest at the coast this evening). Winds will gradually diminish toward daybreak Sunday as the pressure gradient begins to loosen and Gulf Coast high pressure noses in from the west, but not before the combined impact of the blustery winds and extremely cold post- frontal Arctic airmass bring dangerously cold wind chills to the local area.

The current Freeze Warning and Extreme Cold Warning remain in place for tonight, but did adjust the begin and end times for each product to reflect anticipated begin and end times of the sensible weather criteria for each hazard. Temperatures are forecast to fall below freezing quickly this evening after sunset with a widespread hard freeze tonight for all of southeast GA and northeast FL, with sub- freezing temperatures expected for 14-16 hrs through mid-morning Sunday. Wind chills will fall into the teens for most locations by midnight tonight, with the extremely cold values of 5-10 degrees expected through mid-morning Sunday with a duration of 8-10 hrs.

Although flurries and light snow are exciting for our local area, the main sensible weather hazard in the short term is the extreme cold. Please ensure people, livestock, pets, plants, and crops are protected from the extreme cold tonight. If venturing outdoors tonight or early tomorrow morning, dress in multiple layers and if you can, limit your time outdoors. Please practice fire safety and never leave open flame unattended. Leave at least 3 ft of space around space heaters.

SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/

The low will track away to the northeast Sunday and Sunday night, as high pressure builds to the west northwest. This high will settle overhead Monday into Monday night.

This will be a dry period.

Temperatures will be well below normal Sunday, with highs in the 40 to 45 degree range. Winds will remain elevated Sunday. Dangerously cold wind chills in the single digits in the morning, will slowly improve into the 30s in the afternoon. Another cold night Sunday night with lows in the lower to mid 20s. Winds will be lighter, so wind chills not as cold. Temperatures will recover into the 50 to 55 degree range Monday. Lows Monday night below freezing inland, but just above along the coast.

LONG TERM /TUESDAY THROUGH FRIDAY/

The high will move off to the east Tuesday through Wednesday morning. The position of the high, will result in a flow from the southwest Tuesday, allowing temperatures to moderate into the lower 60s. Lows in the 30s are forecast for Tuesday night, but except for a few patchy inland locations, area is expected to be above freezing.

A cold front will move southeast across the area Wednesday and Thursday, bringing a chance for a round of showers. Temperatures will be near to a little above normal Wednesday, then trend below Thursday.

High pressure will build from the southwest Thursday night into Friday, with below normal temperatures.

AVIATION /12Z SATURDAY THROUGH 12Z SUNDAY/

As low pressure strengthens offshore of the Carolina coast today, a cold front will move across the local terminals, trailed by an increase in WNW winds into the afternoon of sustained 15-25 kts with gusts of 30-35 kts, potentially near 40 kts at SSI and SGJ around 00z. The best chance of showers and then potentially transitioning to snow will be at SSI late afternoon through 03z, with brief MVFR conditions, but confidence in snow and restrictions too low at this time to include in the prevailing TAF.

Cloud cover decreases from NW to SE after 00z tonight as winds inland fall into the 15-20 kt range with gusts 25-30 kt and coastal locations remain elevated. VFR conditions expected after 03z through 12z Monday.

MARINE

Low pressure will strengthen offshore of the Carolina Atlantic coast today as a trailing cold front presses across the local waters. Strengthening offshore flow will increase this afternoon with Gale conditions expected across all local waters by this evening as a mix of rain and snow moves across portions of southeast Georgia then southward across local waters overnight. Frequent gusts up to 50 kts are expected tonight as the strong low center tracks northeast away from the local waters. As strong offshore flow develops today into tonight, a period of very low water levels is likely tonight around low tide. Winds and seas begin to subside late Sunday into Monday to Small Craft Advisory conditions as high pressure builds across the Gulf Coast states. The high builds over the Florida peninsula Tuesday with seas falling below Advisory levels. The next cold front approaches from the west Wednesday with a chance of rain showers.

Rip Currents: Moderate risk today and tomorrow as strong offshore flow develops and combined seas increase. Rough breakers tonight of 4 to 6 feet.

FIRE WEATHER

- Inland MinRH values less than 30 percent Sunday and Monday - Widespread high dispersions Sunday and Monday - Areas of high dispersions Wednesday

A strengthening area of low pressure will move to the northeast of the area over the weekend. Elevated winds can be expected over the weekend, with dangerously cold wind chills Sunday morning. High pressure will build for Monday and Tuesday. A cold front will move through Wednesday into Thursday bringing a chance for showers. High pressure will build to the southwest Friday.

FOG POTENTIAL AND OTHER REMARKS: Significant fog is not expected this morning or Tonight. Light snow is possible this evening over parts of inland southeast GA, with very light accumulations under a half inch possible. Snow flurries will be possible near the coasts as well Tonight.

TIDES/COASTAL FLOODING

The combined impact of already seasonably low astronomical tides and stronger WNW offshore winds tonight could create very low mean lower low water levels at coastal locations.

CLIMATE

Daily records challenged by the arctic cold air outbreak are below:

Record Low Maximum Temperatures:

Saturday, January 31: JAX 40/1909 CRG 43/1977 GNV 47/1909 AMG 44/1948

Sunday, February 1: JAX 42/1900 CRG 44/1980 GNV 41/1909 AMG 42/1980

Record Low Temperatures:

Sunday, February 1: JAX 24/1977 CRG 29/1977 GNV 25/1977 AMG 22/1977

Monday, February 2:

JAX 23/1979 CRG 27/1980 GNV 25/1980 AMG 19/1951

PRELIMINARY POINT TEMPS/POPS

AMG 44 18 41 21 / 20 10 0 0 SSI 51 22 43 27 / 30 30 0 0 JAX 54 19 44 23 / 0 0 0 0 SGJ 57 22 45 27 / 0 0 0 0 GNV 54 19 46 23 / 0 0 0 0 OCF 56 19 46 21 / 20 0 0 0

JAX WATCHES/WARNINGS/ADVISORIES

FL...Freeze Warning from 7 PM this evening to 11 AM EST Sunday for FLZ021-023-024-030-031-035-038-120-124-125-132-136>138- 140-220-225-232-233-236-237-240-322-325-333-340-422-425- 433-522-533-633. Extreme Cold Warning from 9 PM this evening to 10 AM EST Sunday for FLZ021-023-024-030-031-035-038-120-124-125-132- 136>138-140-220-225-232-233-236-237-240-322-325-333-340- 422-425-433-522-533-633. Wind Advisory from 3 PM this afternoon to 7 AM EST Sunday for FLZ031-038-124-125-132-136>138-140-225-232-233-236-237- 240-325-333-340-425-433-533-633. GA...Freeze Warning from 7 PM this evening to 11 AM EST Sunday for GAZ132>136-149-151>154-162-163-165-166-250-264-350-364. Extreme Cold Warning from 9 PM this evening to 10 AM EST Sunday for GAZ132>136-149-151>154-162-163-165-166-250-264- 350-364. Wind Advisory from 3 PM this afternoon to 7 AM EST Sunday for GAZ154-166. Winter Weather Advisory from 1 PM this afternoon to 1 AM EST Sunday for GAZ133>136-151>154-165-166. MARINE...Gale Warning from 1 PM this afternoon to 1 PM EST Sunday for AMZ450-452-454-470-472-474.