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

- Widely Scattered Thunderstorms Late this Afternoon and Early this Evening. Isolated Strong Storms Possible. Main Thunderstorm Hazards: Strong Wind Gusts of 40-55 mph, Small Hail, and Frequent Lightning Strikes.

- Strengthening Northeasterly Winds are Expected Across the Atlantic Waters North of St. Augustine Late Tonight and Early Tuesday Morning. Small Craft Advisories Will Begin After Midnight Tonight for the Georgia Waters. High Rip Current Risks Expected at Area Beaches on Tuesday and Wednesday.

- Beneficial Rainfall Expected to Overspread Northeast and North Central FL Late Tonight through Tuesday Night.

- Exceptional to Extreme Drought Continues across Most of Our Region.

NEAR TERM /THROUGH TONIGHT/

Main Highlights This Period:

- Widely Scattered Thunderstorms Late this Afternoon and Early this Evening. Isolated Strong Storms Possible. Main Thunderstorm Hazards: Strong Wind Gusts of 40-55 mph, Small Hail, and Frequent Lightning Strikes.

- Strengthening Northeasterly Winds are Expected Across the Atlantic Waters North of St. Augustine Late Tonight and Early Tuesday Morning. Small Craft Advisories Will Begin After Midnight Tonight for the Georgia Waters. High Rip Current Risks Expected at Area Beaches on Tuesday and Wednesday.

- Beneficial Rainfall Expected to Overspread Northeast and North Central FL Late Tonight.

Patchy to areas of fog and stratus early this morning will dissipate by the mid morning hours. A cold front will be located across inland SC to far southeast LA at sunrise with a pre-frontal trough bisecting part of the forecast area oriented sw-ne. Mean layer flow becomes more westerly today, but low to mid wind speeds are not as strong as the weekend, while moisture levels remain sufficient, somewhat lower than the weekend, for convection with PWAT values generally 1.4 to 1.7 inches.

The forecast for today calls for scattered showers and thunderstorms which should be developing during the afternoon and evening from the peak heating. Not much impressive dynamics aloft initially today with weak to neutral height falls going through the mid afternoon hours, but this begins to change by this evening and into tonight. Shortwave energy will be approaching from the northwest and west tonight with gradual height falls occurring. At the sfc, the aforementioned cold front will be pressing southward this evening with possible frontal wave development over southeast GA. We expect rain chances to increase tonight with the approach of shortwave and front. The front will sweep in from the north over southeast GA during the evening, shifting southward into northeast FL just after midnight, and likely ending up in north central FL by sunrise Tuesday morning.

The forecast area is covered in a Marginal (level 1 of 5) risk for severe weather based on the SPC outlook. Main threat will be strong to damaging wind gusts, hail, and a brief tornado. The tornado risk is mainly focused near the east coast sea breeze where the low level shear is best as the westerly flow is up against the slow moving east coast sea breeze. Model soundings depict MLCAPE of around 1400- 1800 J/kg and 0-6 km shear of 30-40 kt later today.

Thunderstorms chances exist this evening, but are expected to diminish overnight as the airmass stabilizes more.

Max temps today forecast in the 85 to 90 deg range, and lows tonight mid 60s for southeast GA and upper 60s to around 70 for northeast FL.

SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/

Main Highlights This Period:

- Scattered to numerous showers and isolated T'storms Tuesday and Tuesday Night Across Northeast and North Central FL. - Breezy Northeasterly Winds on Tuesday and Tuesday Evening, with Hazardous Beach Conditions and Small Craft Advisories.

- Widely Scattered T'storms Wednesday along the Atlantic Seabreeze.

Tuesday, mid to upper level trough axis will swing east off the SE coast with a lingering southern stream shortwave along the central Gulf coast shifting east to southeastward across the FL panhandle, Northeast and north central FL during the afternoon. This feature will provide instability aloft while a surface front sinks from northern central FL into central FL as high pressure builds in from the north. Despite the north to northeasterly breezy flow, Gulf and Atlantic seabreeze boundaries will shift inland and combined with moist low level airmass remaining will develop scattered to numerous showers with isolated to scattered T'storms. The increasing north to NE winds 15-20 mph gusting to 30 mph along the coast and diminishing with inland extent to 10-15 mph gusting to 25 mph over inland areas west of US-17 will bring slightly drier air over inland SE GA. Highs will be cooler than Monday with mid to upper 70s across much of SE GA, low 80s over inland NE FL and mid 80s south of a Palatka to Gainesville to Trenton line with upper 70s to near 80 along the NE FL coast.

Drier air will allow showers and lingering isolated T'storms to sag into central FL Tuesday evening and the FL coastal waters as an inverted trough forms north of the front offshore. Lows will range from the upper 50s over Altamaha river basin in SE GA to the low 60s to I-10 and mid/upper 60s over north central FL and the SE GA coast with milder lows in the low 70s over NE FL beaches.

Wednesday, ridging aloft and the associated surface high will move off the Mid Atlantic coast as a compact trough moves southeastward from the Upper Midwest into the OH valley and Great Lakes. Weak ridging will remain over the coastal southeast. Light winds from the east southeast will turn westerly in the afternoon with easterly winds behind the Atlantic seabreeze as it moves towards US-17. Isolated to widely scattered T'storms will form mostly along the convergence of the Atlantic and St Johns river breeze where lift will be maximized and overcome the dry air in the mid levels. Strong to severe potential appears low with weak shear. Highs will be in the mid to upper 80s inland and the low 80s at the coast.

LONG TERM /THURSDAY THROUGH SUNDAY/

Main Highlights This Period:

- Dry Conditions late this week into the Weekend.

Thursday, a cold front will drop southward through the area, but should remain dry as high pressure builds to the north through Friday, then settles over the region Friday night into early Saturday. An overall weak pressure gradient pattern and abundant sunshine will allow for daily seabreeze circulations, but no showers expected.

Saturday and Sunday, high pressure will move eastward into the Atlantic with prevailing dry conditions until Sunday afternoon when increasing moisture around the high to the east and inland moving seabreezes kick off widely isolated T'storms.

Temperatures during the period will be near normal Thursday and Friday afternoon with slightly drier air behind the front bringing cool mornings inland in the upper 50s to low 60s while warmer in the mid to upper 60s at the coast Friday and Saturday mornings.

Temperatures will rise above normal this weekend with highs reaching into the low 90s away from the coast and the mid/upper 80s at the beaches with lows in the mid/upper 60s inland to the low 70s at the coast.

AVIATION /12Z MONDAY THROUGH 12Z TUESDAY/

IFR conditions at SSI will improve to MVFR by 14Z and then VFR by 16Z. MVFR ceilings at SGJ should lift to VFR towards 15Z. Otherwise, VFR conditions will prevail at the regional terminals through at least 19Z. Confidence in afternoon and evening showers and thunderstorms developing near the regional terminals has decreased, and we have removed PROB30 groups and vicinity thunderstorm mentions this afternoon and evening at the regional terminals for this TAF cycle. We will continue to monitor forecast trends and could re- introduce VCTS and/or TEMPO groups for restrictions due to heavier showers in the 18Z TAFs, especially at the Duval County terminals and SGJ. Shower activity will briefly diminish after 01Z Tuesday, with increasing confidence in lowering ceilings and shower development during the predawn and early morning hours. IFR ceilings may develop as soon as 07Z at SSI, with MVFR ceilings likely to develop at the northeast FL terminals before 09Z and IFR possible towards the end of this TAF period. Westerly surface winds sustained at 5-10 knots will develop towards 15Z, with the Atlantic sea breeze boundary pushing onshore after 17Z, shifting surface winds to southeasterly around 10 knots at SGJ and southerly around 10 knots at SSI by 19Z. Surface winds will shift back to westerly around 5 knots after 00Z before shifting to northwesterly and northerly after 06Z, with speeds at SSI increasing to around 10 knots by 09Z.

MARINE

A strong cold front will approach the region today with scattered thunderstorms likely late this afternoon into tonight with a couple of strong storms possible. The cold front will then push across the local waters tonight. Northwest to north winds will strengthen tonight in the wake of the frontal passage, with conditions likely reaching Small Craft Advisory levels for portions of the area waters tonight through Tuesday. Weak high pressure will briefly build over the area Wednesday before a dry cold front moves through on Thursday.

Rip Currents:

A low to moderate rip current risk is expected today, with surf heights generally below 2 feet. The risk will be locally higher within a few hours of low tide, especially near sandbars. The next potential for higher risk expected Tuesday and likely Wednesday due to strengthening onshore winds and increasing surf conditions.

FIRE WEATHER

- High Dispersions Over Southeast Georgia Today

- High Afternoon Dispersions Wednesday And Thursday - Near Critically Low Humidity Values on Thursday and Friday for Inland Southeast Georgia.

Cold front will move southeast across the area through Tonight with scattered showers and storms developing along the Atlantic seabreeze this afternoon with breezy westerly winds 8-15 mph with gusts 20-25 mph. An isolated strong to severe thunderstorm may develop near I-95 with main impacts gusty winds 40-60 mph, small hail, lightning and heavy downpours. Increasing transport winds and mixing heights will create high dispersions over Southeast GA. High pressure will shift to the northeast Wednesday with isolated showers/storms developing along the Atlantic seabreezes over the US-17 and I-95 corridors. Dry cold front moves through Thursday, high pressure will build overhead Friday and Saturday. Dispersions will be in the good range despite breezy winds due to low cloud cover, but increase Wednesday from higher mixing heights. Drier airmass arriving on Thursday and increasing transport winds ahead of and behind the dry cold front will create widespread high afternoon dispersions. MinRH values will fall to near critical levels Thursday and Friday over inland Southeast Georgia.

FOG POTENTIAL AND OTHER REMARKS: Gusty and erratic winds expected in and near thunderstorms.

PRELIMINARY POINT TEMPS/POPS

AMG 90 64 79 59 / 10 40 0 0 SSI 88 69 76 69 / 10 40 30 10 JAX 91 70 79 66 / 20 50 60 10 SGJ 89 72 81 70 / 30 60 60 30 GNV 91 70 85 66 / 20 60 60 10 OCF 91 70 86 67 / 20 30 60 10

JAX WATCHES/WARNINGS/ADVISORIES

FL...None. GA...None. MARINE...Small Craft Advisory from 2 AM to 9 PM EDT Tuesday for AMZ450- 470. Small Craft Advisory from 6 AM to 9 PM EDT Tuesday for AMZ452- 472.