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

- Elevated Fire Weather Conditions Thursday Afternoon for inland areas of Southeast GA, north of US 82 due to breezy and dry conditions.

- Moderate Rip Current Risk at the Northeast FL Beaches Today

- Small Craft Advisory Conditions from Thurs Afternoon through Sat Morning.

- Patchy to Areas of Frost Inland Southeast GA on Sunday Morning

- Increasing Marine and Coastal Hazards Next Week. Strengthening Northeasterly Winds Expected Beginning Late Monday. Gale Force Wind Gusts Possible on Tuesday. High Risk for Rip Currents Likely at Area Beaches

UPDATE...through Tonight

No substantial forecast changes this evening. The very light rain, but mostly virga, noted in the radar returns will shortly move eastward offshore by 10 PM. Not much rainfall has been measured with the exception of a couple of hundredths here and there. Overcast cirrus will continue to blanket most of the area through the overnight hours as temperatures fall into eh mid and upper 50s tonight.

Given the recent dry conditions over the last few weeks and lack of meaningful precip today, there will be an elevated fire weather risk tomorrow for portions of inland southeast GA generally north of Waycross. Westerly prefrontal winds gusting close to 25 mph and humidity reaching around 30-35% will present a window during the afternoon where wildfire activity could begin to behave erratically and spread rapidly.

SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/

Main Highlights:

- Elevated fire weather conditions for inland SE GA due to breezy and dry conditions. - Strong Cold Front Crosses our Area on Thursday Night, Ushering in Colder and Drier Air Mass. - Wind Chills Drop into the 30s Late Friday Night and Early Saturday Morning.

Deep troughing will dig over the eastern half of the nation on Friday, driving a couple of dry cold fronts across our area from Thursday evening through Friday night. Deeper moisture will remain confined to locations along and south of the Interstate 4 corridor, with multi-layered cloud cover increasing across our area by Thursday afternoon and evening along and ahead of the initial approaching cold front, mainly for northeast and north central FL. Meanwhile, a surface low pressure center migrating across the Mid- Atlantic states will quickly tighten our local pressure gradient after sunrise, with breezy conditions and warm air advection ahead of the front boosting highs to the upper 70s to around 80 area-wide. These values are around 5 degrees above mid-November climatology.

A strong but dry cold front will cross southeast GA and the Suwannee Valley on Thursday evening and the rest of our area around or just after midnight. Skies will clear across for locations along and north of I-10 during the overnight and predawn hours, while a developing 140 knot jet streak at 250 millibars (around 35,000 feet) that will be shifting off the southeastern seaboard will keep a veil of mid and high altitude cloud cover in place through around sunrise on Friday elsewhere. A northwesterly breeze in the wake of the frontal passage will usher in a colder and drier air mass, with clearing skies and cold air advection dropping lows to the mid and upper 40s by sunrise across inland southeast GA and the Suwannee Valley, ranging to the low and mid 50s elsewhere.

Skies will clear out shortly after sunrise on Friday across the rest of our area, with breezy northwesterly winds countering full sunshine as high pressure builds southward from Hudson Bay, Canada through the Upper Midwest. Highs on Friday afternoon will generally top out in the 65-70 degree range, which will be about 4-8 degrees below mid-November climatology. Low pressure over coastal New England will gradually strengthen on Friday night, and a reinforcing, dry frontal boundary crossing our area overnight will renew a cold northwesterly breeze during the predawn and early morning hours on Saturday. Otherwise, fair skies and cold air advection will drop lows to the upper 30s by early Saturday morning for inland southeast GA and the Suwannee Valley, ranging to the low and mid 40s elsewhere inland and the upper 40s for coastal northeast FL. The strengthening northwesterly breeze during the predawn and early morning hours on Saturday will drop wind chills into the 30s at most locations.

LONG TERM /SATURDAY THROUGH WEDNESDAY/

Main Highlights This Period:

- Seasonably Cool and Dry Weather this Weekend. - Inland Frost Potential for Southeast GA and the Suwannee Valley Early on Sunday Morning. - Increasing Coastal and Marine Hazards Forecast Next Week.

Deep troughing will remain in place over the eastern third of the nation on Saturday as strong high pressure shifts southeastward from the Upper Midwest towards the Ohio and Tennessee Valleys, while a significant coastal storm initially over New England lifts northeastward across Atlantic Canada. This weather pattern will allow breezy northwesterly winds on Saturday morning to shift to northerly during the afternoon hours. Cold air advection will again be countered by full sunshine and a dry air mass, which should allow highs to reach the 60-65 degree range at most locations by Saturday afternoon. These values will be about 10 degrees below mid-November climatology. Although flow aloft will become more zonal by Saturday night across the Deep South, decoupling winds and fair skies should allow for radiational cooling, especially for inland southeast GA and the Suwannee Valley, where lows will likely fall to the mid and upper 30s, creating the first frost of the season for many of these inland locations. Lows elsewhere inland will fall to the 40s, while a northerly breeze keeps coastal temperatures closer to 50.

A southern stream trough will emerge from the lee side of the Rocky Mountains on Saturday night, with this feature migrating across the Southern Plains and the Ozarks on Sunday and Sunday night. High cloud cover will gradually increase downstream of this trough on Sunday afternoon and evening, with weak cyclogenesis likely along the northern Gulf by Monday. Meanwhile, strong high pressure positioned over the Great Lakes and Ohio Valley will wedge down the southeastern seaboard, which will gradually tighten our local pressure gradient, creating breezy northeasterly winds along the I- 95 corridor by Sunday afternoon. Highs on Sunday will remain in the 60s, except lower 70s for portions of north central FL. Thickening mid and high altitude cloud cover on Sunday night will keep inland lows in the 40s, while a persistent northeasterly breeze keeps lows in the 50s at coastal locations as well as north central FL.

Weak low pressure developing along the northern Gulf on Monday should progress quickly eastward across the FL peninsula or north central FL on Monday night, with this feature potentially strengthening off the southeastern seaboard on Tuesday. Strengthening isentropic lift may develop a few showers across our region by Monday afternoon, followed by rain chances increasing on Monday night and Tuesday, especially across north central and coastal northeast FL. A tightening local pressure gradient may result in an extended period of breezy to possibly windy conditions from Monday night onward along the I-95 corridor, with near Gale conditions possible across our adjacent Atlantic coastal waters. Highs on Monday and Tuesday will likely remain in the 60s at most locations, ranging to the lower or mid 70s for north central FL, ultimately depending on the track of weak low pressure. Strong onshore winds will create a large temperature gradient across our area at night, with lows in the 40s across inland southeast GA and the Suwannee Valley, ranging to the upper 50s and lower 60s for coastal northeast FL.

AVIATION /00Z THURSDAY THROUGH 00Z FRIDAY/

Moisture and a fast-moving disturbance moving overhead will continue to produce virga, which will gradually shift offshore through 02z. High clouds will continue as west winds fall to or below 5 knots. A weak surface front will trail the disturbance tonight, mitigating any fog potential tonight. VFR conditions persist through Thursday with increasing westerly winds ahead of stronger cold front that will pass through the region Thursday night. Westerly winds will increase to 10-15 knots around 15z-16z with gusts 20-25 knots possible through around 22z.

MARINE

Weak frontal boundary crosses the local waters today with a shift to offshore winds and bringing a low chance of showers. Westerly winds increase Thursday ahead of a cold front. This strong cold front will cross the waters Thursday night, bringing strong northwest winds and building seas through Saturday morning. Small Craft Advisory conditions are expected to develop by Thursday evening in association with the strong front, with advisory conditions lasting through at least Saturday morning over the local waters. Winds and seas will briefly subside on Saturday as surface high pressure builds into the region, before breezy northeast winds develop Sunday as another high builds from the north.

Rip Currents: Moderate risk in place at all area beaches Today. Strong offshore winds from Thursday through Saturday should yield a low risk. Breezy northeasterly winds developing by Sunday will likely create a moderate risk.

FIRE WEATHER

HIGH DAYTIME DISPERSIONS FOR INLAND SOUTHEAST GEORGIA ON - Thursday ELEVATED NIGHTTIME DISPERSION VALUES AT COASTAL LOCATIONS ON - Thursday And Friday Nights

Isolated to widely scattered light showers will move across our region this afternoon and evening, with chances for measurable rainfall mostly for locations along and north of Interstate 10. Otherwise, dry weather is expected through at least Sunday night. Westerly surface and transport winds will become breezy after sunrise on Thursday, creating high daytime dispersion values for most of inland southeast Georgia, with good values forecast elsewhere on Thursday afternoon. Surface and transport winds will shift to northwesterly on Thursday night, with breezy conditions developing at coastal locations creating elevated nighttime dispersion values. A much cooler and drier air mass will then overspread our area for Friday and Saturday. Breezy northwesterly surface and transport winds on Friday will yield good daytime dispersion values nearly area-wide, with breezy transport speeds persisting on Friday night at coastal locations, where elevated nighttime dispersion values are again forecast. Surface and transport winds will then shift to northerly on Saturday and northeasterly by Sunday. Fair to good daytime dispersion values are expected this weekend region-wide.

FOG POTENTIAL AND OTHER WEATHER REMARKS: Significant fog expected through the weekend. Patchy to areas of frost formation are possible late Saturday night and early Sunday morning across inland portions of southeast GA, the Suwannee Valley, and portions of inland northeast Florida.

PRELIMINARY POINT TEMPS/POPS

AMG 55 78 46 64 / 10 0 0 0 SSI 57 80 50 66 / 20 0 0 0 JAX 56 80 50 68 / 0 0 0 0 SGJ 58 80 55 69 / 10 0 0 0 GNV 57 79 50 69 / 10 0 0 0 OCF 59 79 53 70 / 0 0 0 0

JAX WATCHES/WARNINGS/ADVISORIES

FL...None. GA...None. MARINE...None.