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

- Red Flag Warning this Afternoon for Southeast GA & Northeast FL. Long Durations of Critically Low Humidity Values at All Inland Locations Tuesday

- Freeze Warnings and Cold Weather Advisories Tonight through Tuesday Morning. Tonight: Freeze Warnings Area-Wide, with Hard Freezes for Inland Locations West of I-95. Cold Weather Advisories Tonight for Northeast & North Central FL. Tuesday Night: Light Freeze Inland & Widespread Frost w/ Patchy Frost at Coastal Locations

- Small Craft Advisory Through Tuesday Morning

- Beneficial Rainfall and Isolated Thunderstorms Expected Thursday Night & Friday

NEAR TERM /THROUGH TONIGHT/

WEATHER CONCERNS: - Red Flag Warning (Critical Fire Weather) through this evening for the entirety of the area - Widespread freeze, inland hard freeze tonight - Dangerously low wind chill values over northeast FL tonight - Cold Weather Advisory

Dry and cool conditions have overtaken the area today behind the frontal passage yesterday, as well as breezy conditions with sustained winds still in the 10-20 mph range with gusts up to 25-30 mph. Despite mostly sunny skies, the breezy northwest flow will only allow for temps primarily in the 50 to 55 degree range, and a few spots over interior GA may not make it out of the 40s. Critical fire weather also persists this afternoon and evening, with a Red Flag Warning area wide.

Winds will finally start to noticeably subside after sunset and tonight as surface high pressure nudges closer to the area. This will especially be the case towards the early morning hours Tuesday and inland/north and west of the St. Johns River Valley. Cool air mass and better radiational cooling conditions will result in colder min temps Tuesday Morning, with widespread mid to upper 20s expected for most except for those in close proximity to the coast & St. Johns River where low 30s are forecast. Though the wind will not be as much of a factor as Sunday Night, there will still be enough of a breeze to meet Cold Weather Advisory criteria across northeast FL, as apparent temperatures will run a bit colder in the mid 20s. Criteria is not quite expected to be met over GA at this time, though still quite chilly with wind chills in the low to mid 20s. Patchy frost will be possible across the area as well, though a bit of a breeze and very dry dewpoints and soil should keep significant frost from developing.

SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/

Main Highlights During the Period: - Critically Low Humidity Values at Inland Locations on Tuesday

- Light Freeze Inland with Widespread Frost on Tuesday Night

- Warming Trend Begins on Wednesday

Broad mid to upper level trough axis will exit the area on Tuesday with more zonal flow developing Tuesday night and early Wednesday. New shortwave energy will drop into the Ohio and TN valley on Wednesday into Wednesday night. At the surface, surface high pressure center around 1025 mb will build in over the area Tuesday and shift into south central FL Tuesday night and Wednesday morning. This high will then move east of the FL peninsula late Wednesday, with a ridge axis still extending across central FL Wednesday night. Rising heights and full sun on Tuesday will bring max temps back up to upper 50s to around 60 (still below normal) with a much weaker pressure gradient with northwest flow transitioning to westerly in the aftn. Tuesday night, not as cold as Monday night, but certainly below normal again in the lower to mid 30s with a higher chance of areas to widespread frost given light winds and much higher sfc RH values. Can't rule out the need for a freeze warning for some locations and probably will need a frost advisory eventually. One caveat to a lower temp forecast and frost is that some mid to high clouds are likely for nrn parts of per latest consensus and GFS solution.

On Wednesday, much better warm-up as thicknesses continue to rise with highs in the lower 70s for most areas, with breezy southwest winds. Have boosted winds and wind gusts a little above the NBM guidance based on NAM and NBM90th winds. Mainly partly cloudy skies expected as mid to upper level moisture increases and low level moisture increases off the Gulf waters. Wednesday night, flow turns more southerly as the high moves further away from us, and should see some better moisture return in the low levels. Some patchy fog possible, but too early to justify it and low level wind may be too strong for it. Lows more mild in the mid 40s south zones where the lighter winds and less cloud are located, and then the lower 50s northwest zones where winds are stronger, albeit only 5-10 mph and more clouds will be located. Can't rule out sprinkles far inland southeast GA zones toward early morning.

LONG TERM /THURSDAY THROUGH MONDAY/

Main Highlights During the Long Term Period: - Beneficial Showers and Possibly a Few Storms Late in the Week through the Upcoming Weekend

Prevailing southwest flow expected Thursday with highs well into the 70s all areas and to the coast. We can't rule out 80 deg readings for eastern parts of northeast FL. Breezy southwest winds around 15 mph with gusts potentially around 30 mph. Generally dry conditions may exacerbate the fire weather concerns given the winds but rh value will be criteria. Isolated to scattered showers possible for inland southeast GA which expands southeastward into Thursday night with higher rain chances too, as the mid to upper level trough dips into the eastern U.S. with a surface cold front moving to SC to central GA to the far western FL panhandle by early Friday morning. Isolated storms possible for southeast GA Thursday night as the front nears the area.

On Friday, high rain chances upwards of 60-75 percent are forecast for the area as the cold front moves into the region coupled with PWATs of about 1.4 inches. Not much instability to work with but shear will be moderately strong so continued to mention isolated to scattered thunderstorms. Some risk for a few stronger storms over far southeast GA but mostly located in northeast FL. The front will continue to push slowly southeast Friday night and may briefly stall.

A lot of the mid to upper level energy will shift east of the area Saturday while the front continues to drop south into central FL area by later on Saturday. Lingering precip chances of about 30-50 percent on Saturday but any moderate or heavy precip will have exited the area during Friday or Friday night. Lower chances of about 20-30 percent on Sunday and Monday due to a passing shower, but overall dry conditions are more likely. Sfc high pressure builds in late Saturday just north of the area and continue into Sunday.

Above normal warmth will prevail, especially Thursday and Friday despite expected cloud cover, with highs generally in the 70s inland, possibly reaching the lower 80s for north central FL, and lows remaining in the 50s. Onshore winds and cool shelf waters may keep coastal highs in the upper 60s, especially for southeast GA.

AVIATION /18Z MONDAY THROUGH 18Z TUESDAY/

VFR conditions are expected to prevail for the forecast period. Only operational concern is breezy northwesterly winds persisting, which will subside around/after sunset tonight. Winds will become lighter and more variable by during the day Tuesday with VFR expected to continue.

MARINE

High pressure will slowly move towards the area through Tuesday as intense low pressure continues to lift northeast away from the region. Small Craft Advisory conditions expected rest of today and tonight before winds and seas gradually subside on Tuesday as the weakening high pressure center shifts southeastward towards the Florida peninsula. This high pressure center will then shift offshore of the southeast Florida coast by Wednesday afternoon, with south-southwesterly winds prevailing across our local waters through Friday. Showers and possibly a few thunderstorms will overspread our local waters on Friday and Friday night as a frontal boundary stalls over our area. A wave of weak low pressure potentially developing along this front could keep shower chances in place for at least a portion of the upcoming weekend.

Rip Currents: Moderate rip current risk continues today for the northeast Florida and southeast Georgia beaches. This risk drops slightly for Tuesday as offshore winds subside.

FIRE WEATHER

- RED FLAG WARNING REST OF TODAY

- POCKETS OF HIGH DAYTIME DISPERSION VALUES THIS AFTERNOON

- ELEVATED NIGHTTIME DISPERSION VALUES FOR COASTAL NORTHEAST FLORIDA TONIGHT

- CRITICALLY LOW RH VALUES TUESDAY

- HIGH DAYTIME DISPERSION VALUES WEDNESDAY AND THURSDAY

A Red Flag Warning is in effect this afternoon for all of northeast FL and southeast GA, due to critically low humidity values, northwesterly winds sustained at 15-20 mph, and ongoing extreme drought conditions. Strong transport winds will create pockets of high daytime dispersion values, with good to marginally high values forecast elsewhere. Breezy northwesterly transport winds will keep nighttime dispersion values elevated for coastal northeast Florida tonight.

Diminishing northwesterly surface and transport winds on Tuesday morning will shift to westerly during the afternoon hours. Long durations of critically low humidity values are expected at all inland locations. Surface and transport winds will then shift to southwesterly on Wednesday, with increasing speeds resulting in high daytime dispersion values at most inland locations, with good values expected for coastal locations. Strong south-southwesterly surface and transport winds will prevail on Thursday, creating high daytime dispersion values at most locations. Beneficial rainfall is possible late this week, with a few thunderstorms possible.

FOG POTENTIAL AND OTHER REMARKS: Widespread freezing temperatures are forecast late tonight and early Tuesday morning, with a hard freeze likely for inland southeast Georgia, the Suwannee Valley, and portions of inland northeast and north central Florida. Patchy frost formation will be possible late tonight and early Tuesday morning area-wide. A light freeze and widespread frost are then expected at most inland locations late on Tuesday night and early Wednesday morning, with patchy to areas of frost possibly extending to coastal locations.

CLIMATE

Record Low Temperatures on Tuesday at our designated climate sites:

Tues, February 24: KJAX: 27/1989 KCRG: 27/1989 KGNV: 25/1989 KAMG: 24/1964

PRELIMINARY POINT TEMPS/POPS

AMG 25 56 34 71 / 0 0 0 0 SSI 31 56 40 67 / 0 0 0 0 JAX 26 60 34 72 / 0 0 0 0 SGJ 31 58 36 71 / 0 0 0 0 GNV 26 61 32 72 / 0 0 0 0 OCF 26 61 31 71 / 0 0 0 0

JAX WATCHES/WARNINGS/ADVISORIES

FL...Red Flag Warning until 7 PM EST this evening 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 from midnight tonight to 9 AM EST Tuesday 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. Cold Weather Advisory from 2 AM to 9 AM EST Tuesday 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...Red Flag Warning until 7 PM EST this evening for GAZ132>136- 149-151>154-162-163-165-166-250-264-350-364. Freeze Warning from midnight tonight to 9 AM EST Tuesday for GAZ132>136-149-151>154-162-163-165-166-250-264-350-364. MARINE...Small Craft Advisory until 7 AM EST Tuesday for AMZ450-452-454- 470-472-474.