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 & Frost Tonight into early Tue Morning. Hard Freeze across Inland Southeast GA. Light Freeze Coastal Southeast GA, Suwannee Valley & Inland Northeast FL. Widespread to Areas of Inland Frost

- High Risk for Rip Currents Through Tuesday

- Small Craft Advisory through Tonight

UPDATE

Latest satellite imagery and surface observations show cloudy/mostly cloudy skies lingering over much of northeast FL and parts of far southeast GA. These clouds will have an impact on the temps tonight, but a little uncertain on how far to cancel warnings. For now, removed Union county from the freeze as it looks like only mid 30s there for tonight. For parts of Camden, Nassau, Baker and possibly part of the Suwannee Valley, freeze area will be limited in area and duration, if any. Otherwise, modified the sky cover and temps/dewpoints in this evening update.

SHORT TERM /THROUGH TUESDAY NIGHT/

L/W trough is already east of the Atlantic coast but there is a weak disturbance on the backside of the trough that will work southeast across FL tonight. S/W ridging will then work east across the northeastern Gulf and our area tomorrow and Tuesday evening. At the surface Arctic high pressure was centered to our northwest this morning and it will continue to slowly settle into the region tonight. This will provide better radiational cooling conditions for much of the area given lighter winds in the boundary layer, mostly clear to clear skies, and dry surface conditions. Coldest locations will be in southeast Georgia where winds will be lightest both in the boundary layer and low levels. Biggest concern with respect to temps dropping tonight will be winds in the low levels. Models continue to indicate winds of 15 to 20 kt around h925 through the evening and possibly the overnight hours. Even if the boundary layer can decouple there would still be some minor mixing from the stronger winds between 1k and 2500 ft above the surface. This is mainly the case for portions of northeastern Florida. However, winds will be lighter over southeastern Georgia and right across the border towards I-10. A Freeze warning is already in effect for tonight for all of southeast Georgia and most locations along and west of a line from northwest of Jacksonville to Trenton.

We begin to moderate tomorrow but it will be another cool day. We will see s/w ridging tomorrow with low level temps beginning to inch back up while the surface high shifts to our east. H925 temps will be around 8-10C and this should equate to highs in the 60s. In addition as the high shifts east we will see moisture start to return with dewpoints back in the upper 30s across southeastern Georgia and mid 50s across the southeastern portions of the outlook area. /CAB/

LONG TERM /WEDNESDAY THROUGH MONDAY/

Active pattern in place across the CONUS as the next trough and cold front will quickly be on the way. Disturbance currently working east into the 4 corners region and digging into Mexico will be crossing the Lower and Mid MS Valley Wednesday while the base of the trough will deepen and close off over Mexico hanging back to the southwest. This first disturbance de-amplifies as it moves into the southeastern CONUS Wednesday night but it will induce a deeper Gulf moisture to surge north into the central and eastern Gulf Coast states.

A strong and deeper trough embedded in the northern stream flow will surge out of the Pacific northwest and across the Continental Divide Wednesday night. This much deeper trough will quickly work east-southeast across the Mississippi Valley and amplify over the eastern CONUS. This will help to drive a cold front through the area late Thursday/early Friday. This front will bring a return of scattered showers and perhaps a rumble or two of thunder. The front will quickly exit the area and coastal waters Friday afternoon with drier and slightly cooler air working back into the region. This airmass will not be long for the area as the rather active and generally zonal pattern will quickly lead to moderation again late Saturday and Sunday. High pressure in the mid levels may begin to take over hading into next week. /CAB/

AVIATION /00Z TUESDAY THROUGH 00Z WEDNESDAY/

Low stratocumulus clouds at MVFR category look to continue most of the night and have pushed back any improvement until Tuesday morning and even then it looks like areas to widespread MVFR may be lingering over the area. The guidance shows much lower MVFR chances by 07z-12z, but that looks very questionable. Looked at the IFR probabilities and these area fairly low and have not seen any reports of IFR so no TEMPO groups look needed for that. However, showed SCT decks for JAX, VQQ, and GNV at about 800 ft later tonight. Isolated shower activity associated with a sfc trough offshore look to stay east of SGJ through Tuesday. For sfc winds, mainly north-northeast about 6-12 kts through Tuesday. Should be lighter winds around the 04z-12z time frame.

MARINE

Winds will continue to lower/subside today into tonight as high pressure settles into the region. Winds return to onshore from the SE on Tuesday but remains light. Next frontal passage arrives Thursday with shower and a few storms possible. Winds shift to offshore from the north Friday into Saturday potentially reaching Exercise Caution headlines in this time range.

Rip Currents: High risk through Tuesday for all beaches.

FIRE WEATHER

High pressure continues to build into the area today with drier air working into the region. However, this will only bring Min RH values down into the upper 30% range across portions of southeast Georgia but will remain in the upper 40s to near 60% elsewhere. Breezy conditions currently will relax across the region with generally light winds the next few days. Another cold front will work into the area Thursday and Thursday night bringing scattered showers to the area.

FOG POTENTIAL AND OTHER REMARKS: A Freeze Warning tonight is in effect for all of southeast Georgia, the Suwannee Valley, and for locations west of a line from northwest Jacksonville to Trenton in northeast Florida with widespread frost possible this evening and overnight. Patchy to areas of fog formation will be possible for inland portions of northeast and north central Florida during the predawn and early morning hours on Wednesday. Patchy to areas of frost formation will be possible across inland portions of southeast Georgia on Tuesday night and early Wednesday morning. /CAB/

PRELIMINARY POINT TEMPS/POPS

AMG 26 58 34 65 / 0 0 0 0 SSI 35 59 47 64 / 0 0 0 10 JAX 35 63 44 70 / 0 0 0 0 SGJ 48 65 52 71 / 0 0 0 10 GNV 38 68 46 74 / 0 0 0 0 OCF 40 69 48 75 / 0 0 0 0

JAX WATCHES/WARNINGS/ADVISORIES

FL...Freeze Warning until 9 AM EST Tuesday for FLZ021-023-024-120- 220-322-422-522. High Risk for Rip Currents through Tuesday evening for FLZ124-125- 138-233-333. GA...Freeze Warning until 9 AM EST Tuesday for GAZ132>136-149- 151>154-162-163-165-166-250-264-350-364. High Risk for Rip Currents through Tuesday evening for GAZ154-166. MARINE...Small Craft Advisory until 1 AM EST Tuesday for AMZ452-454-470. Small Craft Advisory until 10 AM EST Tuesday for AMZ472-474.