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

- Morning & Late Night Fog Today & Tonight. This Morning St Johns River Basin to Coast. Tuesday Morning Inland NE FL. Superfog Risk near Wildfires

- Moderate Rip Current Risk through Tuesday

NEAR TERM /THROUGH TONIGHT/

Main weather concerns in the near term will be late night and early morning fog, including sea fog, as well as superfog risk near wildfire activity.

Already seeing some observations early this morning of fog near the Atlantic coast where onshore flow advected some shallow moisture yesterday. Through daybreak, anticipate areas to patchy fog mainly impacting coastal locations toward Highway 301. The combination of fog and smoke from smoldering wildfires could also create locally dense superfog. With passing mid and high clouds increasing from the NW through daybreak, dense fog (< 1/4 mile) will likely be intermittent in nature. Min temperatures were trending on the cool side of guidance with dry air in place with lows on track to range from the mid 30s across inland areas to lower 40s toward the coast.

Today, warmer and continued dry under passing mid and high clouds as an upper level trough moves across the eastern US. Surface high pressure north of the region will extend a ridge axis farther southward across the region, which will bring lighter winds and enable weak sea breezes to develop and move inland this afternoon as high temperatures actually warm to near to slightly above average values in the upper 60s to low 70s.

Tonight, the surface ridge settles farther south with a low level ridge axis extending across south FL peninsula by daybreak Tuesday. Fog is expected to form along both the Atlantic and Gulf coasts through the night, with higher confidence of a more persistent and expansive fog bank developing between the Gulf Coast and the Highway 301 corridor of NE FL under light westerly flow that will raise dew points through the day. Locally dense fog and superfog will once again be possible. Continued to lean toward the cooler side of low temperatures tonight with the ridge axis over the area and good radiational cooling conditions, but lows trend a little warmer from the upper 30s to low 40s inland to the mid 40s toward the coast.

SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/

Warm and dry conditions expected on Tuesday with high pressure over the FL peninsula and upper ridging building across the Gulf. Developing deep west-southwesterly flow will gradually increase low level moisture to the region and maintain above seasonable temperatures. Highs on Tuesday will be in the low 70s along the coast to the mid-upper 70s inland. With the increase in moisture, patchy inland fog will be possible early Wednesday morning. On Wednesday, a parade of upper shortwaves will round the ridge and pass across the region as a cold front moves into the SE US. This will bring isolated to scattered showers to mainly SE GA Wednesday into Wednesday night. Lingering dry air will keep rainfall amounts light.

LONG TERM /THURSDAY THROUGH SUNDAY/

Diffused frontal boundary over the FL peninsula on Thursday will move back north as a warm front over the area Thursday night into Friday morning as a frontal wave develops over the Gulf coast states. Models continue to differ on how the upper pattern evolves and the strength and placement of the frontal wave. For now, have slight chance for showers on Friday then increasing chances area- wide Saturday into Sunday. Best chances for beneficial rain will be Sunday with the frontal passage. No thunderstorm potential is noted in the forecast at this time, but a thunderstorm mention could be needed in subsequent forecasts if instability develops more than the current forecast of around 300 J/kg or less. Above seasonable temperatures continue through Friday as continued southwesterly flow ushers in Gulf air/moisture to the area. Temp forecast over the weekend is uncertain given the differing model solutions, but currently we show slightly above normal temps.

AVIATION /12Z MONDAY THROUGH 12Z TUESDAY/

BKN to OVC mid and high clouds limited fog potential this morning and scaled back on IFR to LIFR conditions and adjusted to TEMPO MVFR with TEMPO IFR at VQQ through 12z. Light and variable winds < 6 kts through 12z. After 12z, VFR conditions as ENE winds develop at most terminals with WSW at GNV mid to late afternoon. After 00z, winds become light and near calm once again with higher probability of restrictions near GNV and VQQ after 06z Tuesday morning. Note that some guidance is suggesting sea fog developing today as temperatures, dew point temperatures and sea surface temperatures near equal values, but confidence not high enough to include in TAFs yet.

MARINE

High pressure will build northeast of the region today as a weak coastal trough breaks down over the local waters. A long period easterly swell will maintain elevated combined seas through Tuesday as the surface high builds east of the Florida peninsula. The high will shift southeast of the region Wednesday as a weakening front approaches with increasing westerly winds and a low chance of showers. The front is expected to stall and linger over south Florida Thursday with a brief surge in northeast winds over local waters. The front will morph into a lifting warm front late Friday into Saturday. Rain chances increase this weekend as a stronger cold front approaches from the west late Saturday into Sunday with winds increasing to Small Craft Advisory levels.

Rip Currents: Moderate rip current risk today with northeast winds and elevated combined seas due to easterly swells with periods of 10- 12 seconds. Elevated surf/breakers of 3-4 ft, occasionally up to 5 feet at times, at NE FL beaches today. Tuesday offshore, westerly winds develop with a continuation of long period swells, continuing a moderate rip current risk at local beaches.

FIRE WEATHER

- Low Daytime Dispersions Today - High Dispersions Inland Se Ga Tuesday

Dry weather conditions will prevail through Tuesday. Surface and transport winds remain weak today as high pressure builds into the region leading to poor to low daytime dispersions across the area, especially near the coast. Easterly flow will increase moisture to coastal areas today but critically low humidities in the low-upper 20s are expected inland, generally near and west of U.S. Highway 301. Moisture gradually increases by Wednesday when min RH values are in the 40 to 50 percent range. Weak Atlantic and Gulf sea breezes develop this afternoon. Southwesterly winds increase on Tuesday leading to good and potentially high dispersions. No significant rain chances expected until mid-late week when a cold front moves into the area.

FOG POTENTIAL AND OTHER REMARKS: Patchy to areas of fog will be possible across portions of NE FL early this morning and across inland NE FL and SE GA Tuesday morning, especially if it mixes with nearby wildfire smoke.

PRELIMINARY POINT TEMPS/POPS

AMG 68 40 75 53 / 0 0 0 0 SSI 61 44 69 53 / 0 0 0 0 JAX 70 40 78 51 / 0 0 0 0 SGJ 67 44 75 50 / 0 0 0 0 GNV 73 38 77 48 / 0 0 0 0 OCF 74 37 77 47 / 0 0 0 0

JAX WATCHES/WARNINGS/ADVISORIES

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