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

- Light Freeze & Frost For Inland Areas This Morning

- Patchy Dense Fog North-Central FL Early Monday

NEAR TERM /THROUGH TONIGHT/

Clear skies, light NNW drainage flow and a very dry airmass inland was enabling temperatures to fall quickly into the mid/upper 30s generally north of I-10 to 40s along the coast and toward north- central FL. Still expect a freeze for much of inland southeast GA toward the northeast FL Interstate 10 corridor with frost for most inland locations through sunrise.

Weaker winds today and a a little warmer for inland locations with a continuation of mostly sunny skies. As surface high pressure builds north of the region and a weak coastal trough develops offshore of the local Atlantic coast, NNW this morning become NNE to ENE into the afternoon. As inland highs warm into the 60s, the onshore component near the coast will keep max temperatures chilly in the 50s, especially for locations north of Mayport to near 60 southward down the coast.

Mid and high clouds increase from the north into the evening with the approach of an upper level short wave trough. Despite the clouds, dry low levels and near calm winds will enable temperatures to drop into the mid/upper 30s for inland areas to the low 40s toward the coast. NBM 25-75th percentile range keeps lows above freezing across inland SE GA. With the passing clouds, frost will be less likely to form tonight, however, fog will become possible as low level moisture increases from the east with the onshore flow today. Includes areas of fog after midnight through early Monday morning for portions of northeast Florida including southern Duval, Clay, St. Johns, Flagler, Putnam and Marion counties. Any fog combined with smoke from wildfires could become locally dense.

SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/

Dry conditions continue with a warming trend through mid-week. Surface high pressure over the Carolinas will shift southward into the Atlantic and build off the FL coast by Tuesday as upper ridging builds across the Gulf. This will maintain dry conditions and develop a light low-level southwest flow allowing temperatures to moderate back to seasonable. However, a weak Atlantic sea breeze will shift inland Monday afternoon keeping coastal areas relatively cool. Highs on Monday will range from the low 60s along the coast to the low 70s inland. Temperatures increase to above seasonable on Tuesday with highs in the low-upper 70s. Overnight lows in the 40s Monday night increase to the upper 40s/low 50s Tuesday night.

LONG TERM /WEDNESDAY THROUGH SATURDAY/

Another shortwave trough passes over the region on Wednesday bringing low chances for showers to SE GA. A cold front then sinks southward into the SE US Wednesday into Thursday before stalling just north of the area on Friday. A frontal wave will then move along the Gulf states this weekend. Models continue to differ on how the upper pattern evolves and the strength and placement of the frontal wave. For now, have low chances for showers on Thursday and then increasing chances area-wide for Friday into the weekend. Best chances for beneficial rain will be this weekend with the frontal passage. Above seasonable temperatures continue through Friday as continued southwesterly flow ushers in Gulf air/moisture to the area.

AVIATION /12Z SUNDAY THROUGH 12Z MONDAY/

Prevailing VFR through 06z Monday with increasing mid and high this afternoon into the evening. NNW winds 5-8 kts around 12z will continue to veer NNE through 16z then become more NE through 00z, with winds 5-10 kts inland to 8-12 kts at the coast with coastal afternoon gusts near 15 kts at times.

After 00z, light and variable winds < 5 kts develop through 06z. After 06z Monday morning, NBH probabilities for MVFR ground fog increased between 15-20% at VQQ, GNV and SSI. Advertised prevailing 5SM BR after 07z at GNV and VQQ and kept SSI at 6SM BR. MVFR fog probabilities continued between 10-15% at SGJ, CRG and JAX and advertised 6SM BR at SGJ and CRG where onshore flow will advect more moisture and some shallow fog will be possible, but mid/high cloud cover will temper radiation fog extent through 12z.

MARINE

High pressure will build northeast of the local waters today into Monday. A long period easterly swell arrives today which 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 the Florida peninsula Thursday, then morph into a lifting warm front late Thursday into Friday.

Rip Currents: Moderate rip current risk today and Monday with NNE to ENE winds and elevated combined seas with building easterly swells with periods of 10-11 seconds.

FIRE WEATHER

- Areas Of Low Daytime Dispersions Today And Monday - Low Min Rh Values Inland Today

Dry weather is expected to continue through mid-week. The Atlantic and Gulf sea breezes develop this afternoon and Monday afternoon. Light and variable winds inland will lead to poor to low dispersions today. Surface and transport winds decrease on Monday as high pressure builds into the region leading to poor to low dispersions across the area. Easterly flow will increase moisture to coastal areas today but critically low humidities in the mid-upper 20s expected inland, generally near and west of U.S. Highway 301. Moisture gradually increases through the week. No significant precipitation chances expected until mid-late week when a cold front moves into the area.

FOG POTENTIAL AND OTHER REMARKS: Inland frost and freeze expected this Morning. Patchy dense fog will be possible across north-central FL early Monday morning, especially if it mixes with nearby wildfire smoke.

PRELIMINARY POINT TEMPS/POPS

AMG 61 36 68 41 / 0 0 0 0 SSI 54 42 61 46 / 0 0 0 0 JAX 63 40 69 42 / 0 0 0 0 SGJ 62 44 67 45 / 0 0 0 0 GNV 69 38 72 41 / 0 0 0 0 OCF 69 39 73 41 / 0 0 0 0

JAX WATCHES/WARNINGS/ADVISORIES

FL...Frost Advisory until 8 AM EST this morning for FLZ021-030-031- 035-136-232-236-422-522. Freeze Warning until 8 AM EST this morning for FLZ023-024-120- 220-322-425. GA...Freeze Warning until 8 AM EST this morning for GAZ132>136-149- 151>153-162-163-165-250-264-350-364. MARINE...None.