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

- Long-Duration Cold Weather Outbreak through the Weekend. Dangerously Low Wind Chills This Morning Cold Weather Advisory in Effect. Hard Freezes Inland & Light Coastal Freezes This Morning, Tonight & Wed Night. Additional Light Freezes and Frost Possible Inland on Thurs & Fri Nights. Very Low Wind Chills (Single Digits & Teens) Possible Sat Night & Early Sun. Protect People, Pets, Plants, and Practice Safe Heating

- Gale Warning for the Northeast FL Waters This Morning

- Snowfall Probabilities Increasing on Saturday and/or Saturday Night. Probabilities for Minor Impacts (Transportation) of 20-25% Across Southeast GA

NEAR TERM /THROUGH TONIGHT/

Strong high pressure will build from the west northwest early this morning. As the gradient between the departing front and building high weakens, winds will diminish this morning, but remain somewhat elevated. The elevated winds will keep low levels stirred up enough to limit frost development despite the expected cold temperatures.

Lows this morning in the 20s will be common all the way to the beaches. With winds remaining elevated, wind chills in the teens are expected.

For Today, high pressure will build close to the region. Skies will remain clear. Cold advection will continue on a flow from the northwest to west. Temperatures Today, will be well below normal with highs ranging from the mid 40s over inland SE GA to the lower 50s over north central FL.

High pressure ridge will remain over area Tonight from high centered to the west northwest. An upper wave will move across region, bringing an increase in cloud cover. The added cloud cover will result in a little bit higher temperatures than this morning, but still unseasonably cold with another widepread freeze expected. Frost potential will be significant Tonight as wind will be on the light side.

Will leave watch in place for Tonight, and day shift can upgrade this to warning as needed, once current one for this morning expires. A few locations in NE FL may also reach criteria cold weather advisory again.

SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/

A gradual moderation in temperatures begins Wednesday, though values will remain well below seasonal normals. Afternoon highs will reach the lower to mid 50s across southeast Georgia and the mid to upper 50s across northeast Florida. Partly cloudy skies are expected with light NW winds at 510 mph.

Despite the very modest daytime warming, cold conditions persist Wednesday night. Clear skies and near-calm winds will support strong radiational cooling, with overnight lows falling into the mid to upper 20s inland and the mid 30s along the coast. Wind chills are expected to remain just above advisory criteria; however, sub- freezing temperatures will once again necessitate freeze products, along with widespread frost.

Cold and dry conditions continue Thursday under persistent surface high pressure. Afternoon highs will reach the mid 50s SE GA and upper 50s to lowers 60s NE FL with slight and modest uptick from Wednesdays high temperatures. Clear skies and light winds Thursday night will allow temperatures to fall back into the upper 20s inland and the lower to mid 30s near the coast, supporting another round of Freeze products and widespread frost. winds.

LONG TERM /FRIDAY THROUGH MONDAY/

LONG TERM /Friday through Monday/ Unseasonably cold and dry conditions persist through the end of the week into the beginning of next week. Freeze products are expected to be needed most nights through the period, with Cold Weather Advisories potentially returning by the weekend as sub-freezing temperatures continue.

High pressure shifts eastward Friday, allowing for modest daytime warming. Highs will reach the upper 50s to lower 60s north of I-10, and lower to mid 60s though cold air remains entrenched. Overnight lows will fall into the upper 20s to lower 30s SE GA, low to mid 30s NE FL, with widespread frost likely and Freeze products remaining probable for inland locations Friday night.

Potential Weekend Coastal Storm this Weekend

Global and ensemble guidance continue to suggest the development of a coastal low-pressure trough off our coast the first half of the weekend though considerable uncertainty remains regarding its strength, track, and timing. Confidence remains low in precipitation coverage and thermal profiles across southeast Georgia and northeast Florida. With the potential for a coastal storm developing in addition to cold temperatures expected during the upcoming weekend, we could see some winterly precipitation for portions of our region north of I-10 particularly Saturday and Saturday night.

A reinforcing surge of arctic air is expected to accompany and follow the system, with lows Saturday night into Sunday morning falling into teens and lower 20s. These temperatures, combined with breezy winds, could result in dangerous wind chills of single digits and teens and support Cold Weather Advisories and Freeze Warnings regardless of precipitation type. Any wintry precipitation potential would depend heavily on the eventual track and timing of potential coastal trough.

Sunday and Monday:

Following the departure of the coastal low, very cold conditions persist. Sunday highs will be in the upper 30s to lower 40s SE GA and lower to mid 40s for NE FL with overnight lows in the 20s. Wind chills will generally be in the teens Sunday night into Monday morning. A slight moderation is expected Monday, with highs returning to upper 40s and the lower 50s; however, overnight lows will remain cold enough to support additional freeze products.

The severity of the arctic cold for our region pertaining to planned outdoor events remains a big concern this weekend.

AVIATION /12Z TUESDAY THROUGH 12Z WEDNESDAY/

VFR conditions will prevail this 12z TAF period.

MARINE

High pressure will be the prevailing weather feature through Friday. Elevated winds and seas will continue this morning. Gale Warning will transition to a Small Craft Advisory this morning.

A low pressure system is expected to develop near the area over the weekend, then move off to the northeast. Small Craft Advisory to possibly Gale conditions possible this weekend.

Rip Currents: Despite offshore flow, moderate risk is noted for most areas beaches today. Elevated breakers are still expected, especially south of St Augustine which may lead to a slightly higher- end Moderate risk along that stretch of beach. Lighter winds (still offshore) and falling surf heights will reduce risk more by Tuesday, especially from Jax Beach northward.

FIRE WEATHER

- Critically Low RH Values Area-Wide Through Thursday

Dispersion values will trend downward on today and Wednesday across the region, with generally poor dispersions expected area-wide by Thursday as near-calm winds develop. Despite lighter winds, increasingly dry air will overspread the region, resulting in critically low minimum afternoon relative humidity values on today, falling into the upper teens to lower 20s across much of the area. Relative humidity values will recover slightly by midweek but are expected to remain near or below critical thresholds as dry conditions persist through the end of the week.

FOG POTENTIAL AND OTHER REMARKS: Frost and freeze conditions are expected during the overnight and early morning hours through much of the week.

CLIMATE

Daily records due to the arctic cold air outbreak are below:

------------------------------------- RECORD DAILY LOW MAXIMUM TEMPERATURES: -------------------------------------

January 31: - KGNV: 47/1909

------------------------------------- RECORD LOW TEMPERATURES: -------------------------------------

January 31: - KCRG: 33/2019

February 1: - KJAX: 24/1977 - KGNV: 25/1977 - KAMG: 22/1977 - KCRG: 29/1977

PRELIMINARY POINT TEMPS/POPS

AMG 47 26 52 26 / 0 0 0 0 SSI 49 32 54 34 / 0 0 0 0 JAX 50 27 57 30 / 0 0 0 0 SGJ 49 32 57 34 / 0 0 0 0 GNV 52 27 58 29 / 0 0 0 0 OCF 52 27 58 28 / 0 0 0 0

JAX WATCHES/WARNINGS/ADVISORIES

FL...Cold Weather Advisory until 10 AM EST this morning 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. Freeze Warning until 10 AM EST this morning 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. Freeze Watch from this evening through Wednesday morning 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. GA...Cold Weather Advisory until 10 AM EST this morning for GAZ132>136-149-151>154-162-163-165-166-250-264-350-364. Freeze Warning until 10 AM EST this morning for GAZ132>136-149- 151>154-162-163-165-166-250-264-350-364. Freeze Watch from this evening through Wednesday morning for GAZ132>136-149-151>154-162-163-165-166-250-264-350-364. MARINE...Small Craft Advisory until 7 AM EST this morning for AMZ450- 470. Gale Warning until 7 AM EST this morning for AMZ452-454-472- 474.