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 & Evening from Waycross, GA Southward. Frequent Northwesterly Wind Gusts 25-35 MPH, Min Humidity Values of 20-25%. Fire Weather Watch Area-Wide on Mon Afternoon & Early Evening

- Freeze Warning North of I-10 Tonight & Low Wind Chills Area-Wide Early Mon

- Freeze Watches Area-Wide on Mon Night and Early Tues Morning. Cold Weather Advisories Possible for Northeast and North Central FL. Light Freeze and Widespread Frost Expected Tues Night and Early Wed Morning

- Gale Warning this Afternoon through Mon Afternoon

- Extreme Drought Prevails Across Most of Our Region

UPDATE

KEY CHANGES AND UPDATE MESSAGES: - Wind Advisory Issued for areas along and north of I-10 today - Decreased humidity during the afternoon - Increased overnight wind speeds tonight - Lowered the minimum Wind Chill values tonight

A powerful arctic blast will follow behind the departing cold front as its parent low pressure system undergoes rapid intensification today. As the low deepens, the wind response will strengthen, the already robust, cold air advection and the corresponding surge of dry, arctic air into the air through the afternoon and evening.

Before the temperatures begin to plummet, a tightly packed gradient between the "bombing" surface low and strong arctic high pressure will lead to strong winds across the area today and tonight. Based on upstream surface and the 925 mb observed winds, a Wind Advisory was issued due to the increasing probability of wind gusts around 40- 45 mph for areas along and north of I-10 this morning and afternoon.

Winds will lighten some tonight but breezy winds, with gusts to 20- 25 mph, overnight will lead to dangerously cold wind chill values tonight as temperatures plunge toward or push below the freezing mark. A Cold Weather Advisory will be considered with the next forecast package for all of NE FL and SE GA.

SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/

MAIN WEATHER CONCERNS (Monday - Tuesday Night: - Gusty Northwesterly Winds and Low Humidity Increase the Wildfire Danger on Monday

- Widespread Freeze & Dangerously Cold Wind Chills Monday Night

- Critically Low Humidity Values at Inland Locations on Tuesday

- Light Freeze Inland with Widespread Frost on Tuesday Night...

Deep troughing positioned over the eastern third of the nation on Monday will pivot offshore by late Tuesday, with its associated intense surface cyclone off the New England coast on Monday morning migrating north-northeastward across Atlantic Canada on Tuesday. Deep and dry northwesterly flow in the wake of this departing storm system will remain in place across our region during this time period.

Despite sunny skies on Monday, strong cold air advection and a tight pressure gradient will only allow highs to reach the upper 40s to around 50 for southeast GA and the 50-55 range elsewhere. Dewpoints plunging through the teens inland and lower 20s at coastal locations will combine with northwesterly winds sustained at 15-20 mph with frequent 25-30 mph gusts to create another day of potential Red Flag conditions, especially for northeast and north central FL.

Weakening Arctic high pressure will pivot eastward along the northern Gulf coast on Monday night, resulting in a loosening local pressure gradient that will yield gradually decreasing northwesterly winds, especially at inland locations. A hard freeze is likely across inland southeast GA, the Suwannee Valley, and for inland locations along the I-10 corridor in northeast FL, with a light freeze extending to coastal locations. The northwesterly breeze will drop wind chill values down to the low and mid 20s, likely prompting Cold Weather Advisories for northeast and north central Florida in subsequent forecasts later today.

Arctic high pressure will gradually weaken as it settles over the FL peninsula on Tuesday afternoon and night. Sunny skies and a very dry air mass will result in highs rebounding to the mid and upper 50s area-wide on Tuesday. Dewpoints remaining in the teens and 20s will keep at least an elevated wildfire danger in place across our area despite decreasing west-northwesterly surface winds, with long durations of critically low humidity values forecast at all inland locations.

Although cirrus cloud cover will begin to enter our area from the northwest on Tuesday evening, decoupling winds early in the evening will create radiational cooling, with a light freeze expected at most inland locations and areas to potentially widespread frost inland and at least patchy frost extending to coastal locations, where lows will fall to the mid and upper 30s.

LONG TERM /WEDNESDAY THROUGH SATURDAY/

Main Hazards During the Long Term Period: - Warming Trend Begins on Wednesday

- Beneficial Showers and Possibly a Few Storms Late in the Week through Next Weekend

Flow aloft will quickly transition to zonal by midweek and then southwesterly on Thursday downstream of a quickly approaching trough of Pacific origins. At the surface, Arctic high pressure will continue to weaken as it pushes offshore of the southeast FL coast by Wednesday afternoon. Temperatures will quickly moderate on Wednesday as southwesterly low level flow develops shortly after sunrise. Inland highs should approach late February climatology, with values climbing to the upper 60s and lower 70s, while colder shelf waters keep coastal highs in the mid to upper 60s. Lows on Wednesday night will remain in the 40s area-wide.

Shower chances will gradually increase downstream of the next approaching frontal boundary from Thursday afternoon through Thursday night, mainly for locations north of Interstate 10. A dry air mass will initially linger across most of northeast and north central FL on Thursday, with showers possible by late afternoon across mainly inland southeast GA as PWATs begin to increase. Model blends currently indicate scattered showers traversing our region on Thursday night and Friday, with enough instability ahead of an approaching cold front to possibly develop a few thunderstorms on Friday afternoon and night. Highs will climb well into the 70s on Thursday despite increasing cloud cover, with lower 80s possible across north central FL. Warm air advection should keep lows in the 50s region-wide on Thursday night. Some cool air advection, widespread cloud cover, and scattered to numerous showers may keep highs in the upper 60s and lower 70s for most of southeast GA, while highs elsewhere generally reach the 75-80 degree range. Lows on Friday night will fall back into the 40s for southeast GA in the wake of the frontal passage, with 50s forecast elsewhere as the front likely slows its forward progress.

Broad troughing is expected to prevail next weekend over the southeastern states, keeping chances for scattered showers in the forecast. Surface ridging will strengthen along the Mid-Atlantic coast as the frontal boundary potentially stalls over north central FL, resulting in an onshore wind pattern. Highs will likely remain in the 70s for most locations on Saturday, with lower 80s possible for north central FL and upper 60s for coastal southeast GA. Lows should remain in the 50s throughout our area on Saturday night.

AVIATION /12Z SUNDAY THROUGH 12Z MONDAY/

Prevailing MVFR ceilings are likely at all of the TAF sites through mid-morning as a cold front approaches from the northwest. GNV has the highest potential for dropping to IFR ceilings for a few hours in the early morning.

Sunday, VFR levels resume as the front will exit to the southeast with skies clearing by midday to early afternoon. Northwest winds will increase from 15 knots gusting to 25 knots in the late morning to up to 20 knots gusting to around 30 knots through the reminder of the afternoon as a low strengthens quickly to the northeast and high pressure builds in from the northwest.

MARINE

Northwesterly winds will quickly strengthen in the wake of a frontal passage on Sunday with Small Craft Advisory conditions quickly changing to Gale conditions Sunday afternoon. A Gale Warning is in effect Sunday afternoon through Monday afternoon for frequent gusts to Gale Force as low pressure rapidly strengthens near the Mid- Atlantic and New England coasts through Monday night. Arctic high pressure will then build along the northern Gulf coast on Tuesday and then shift across the Florida peninsula on Tuesday night, allowing for winds and seas to diminish across our local waters. The high will move offshore by midweek ahead of another approaching cold front that should impact our local waters late this week, with south to southwesterly winds prevailing ahead of the front.

Rip Currents: Moderate rip current risk today for the northeast Florida and southeast Georgia beaches.

FIRE WEATHER

- Red Flag Conditions This Afternoon From Waycross Southward

- Red Flag Conditions Likely On Monday For Portions Of Our Area

- High Daytime Dispersion Values Today, Monday, And Wednesday

- Elevated Nighttime Dispersion Values Tonight

- Long Durations Of Critically Low Humidity On Tuesday Inland

A Red Flag Warning is in effect this afternoon for all of northeast and north central Florida and for portions of southeast Georgia.

Showers and a few embedded thunderstorms will exit our area before noon, with strong northwesterly surface and transport winds then overspreading our region late this morning through this afternoon. A very dry air mass will plunge into our area this afternoon, resulting in critically low humidity values for locations from Waycross southward in southeast Georgia and across all of northeast and north central Florida, where Red Flag Warnings have been issued. Strong northwesterly transport winds and breezy surface speeds will continue tonight and Monday, creating Elevated Nighttime Dispersion values tonight.

A Fire Weather Watch has been maintained throughout our entire region on Monday, as minimum relative humidity values and soil moisture levels following Saturday night and Sunday morning's rainfall amounts remain in question. Red Flag conditions appear likely across most of northeast and north central Florida, with an Elevated Fire Danger likely elsewhere, with high daytime dispersion values expected at most locations as well. Northwesterly surface and transport winds will gradually diminish on Monday night and will shift to westerly on Tuesday. Long durations of critically low humidity values are forecast at all inland locations on Tuesday, with fair to good daytime dispersion values expected. Southwesterly surface and transport winds are forecast to increase on Wednesday, creating high daytime dispersion values inland, with good values expected at coastal locations.

FOG POTENTIAL AND OTHER REMARKS: A light freeze is expected tonight for all of inland southeast Georgia and for inland locations along and north of the Interstate 10 corridor in northeast Florida. Widespread subfreezing temperatures are forecast area-wide late on Monday night through early Tuesday morning, with a hard freeze expected for inland southeast Georgia, the Suwannee Valley, and for portions of inland northeast Florida. widespread frost and a possible light freeze are forecast on Tuesday night and early Wednesday morning.

PRELIMINARY POINT TEMPS/POPS

AMG 61 30 49 25 / 10 0 0 0 SSI 66 34 50 31 / 40 0 0 0 JAX 70 33 53 28 / 40 0 0 0 SGJ 73 36 54 33 / 50 0 0 0 GNV 70 34 55 27 / 30 0 0 0 OCF 71 34 55 27 / 40 0 0 0

JAX WATCHES/WARNINGS/ADVISORIES

FL...Red Flag Warning from 1 PM this afternoon to 9 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. Fire Weather Watch from Monday afternoon through Monday 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 Watch from late Monday night through Tuesday 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. Wind Advisory until 6 PM EST this evening for FLZ023-024-120- 124-125-220-225-322-325-425. Freeze Warning from midnight tonight to 9 AM EST Monday for FLZ023-024-120-220-322. GA...Red Flag Warning from 1 PM this afternoon to 9 PM EST this evening for GAZ151-152-162-163-165-166-250-264-350-364. Fire Weather Watch from Monday afternoon through Monday evening for GAZ132>136-149-151>154-162-163-165-166-250- 264-350-364. Freeze Watch from late Monday night through Tuesday morning for GAZ132>136-149-151>154-162-163-165-166-250-264-350- 364. Wind Advisory until 6 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 Monday for GAZ132>136-149-151>154-162-163-165-166-250-264-350-364. MARINE...Small Craft Advisory until 3 PM EST this afternoon for AMZ450- 452-454. Gale Warning from 3 PM this afternoon to 10 AM EST Monday for AMZ450-452-454. Small Craft Advisory until 1 PM EST this afternoon for AMZ470- 472-474. Gale Warning from 1 PM this afternoon to 10 AM EST Monday for AMZ470-472-474.