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

- Minor Tidal Flooding for NE FL Atlantic beachfront and the St. Johns River basin through this evening

- Moderate Risk of Rip Currents at local beaches

- Isolated Thunderstorm Activity Returns Mid to Late Week

UPDATE

Weak surfacing troughing located from coastal GA to the northeast Gulf continues this morning with mid to upper level trough collocated with this area. An upper level jet is bringing in the mostly high clouds across northeast FL that should continue through this evening and slowly thinning out tonight. Made some minor adjustments to the sky for these clouds. Otherwise, still some low chances of showers across northeast FL later today with moisture levels slowly increasing. Some of the showers will be formed by the surface trough and daytime heating. Made slight adjustments down for the POPs based on latest model guidance. Maintained patchy fog in the forecast for late tonight again with good support from the 06z HREF. No other major changes needed.

NEAR TERM /THROUGH TONIGHT/

Main Highlights Today and Tonight:

- Moderate rip current risk at Atlantic beaches

- Minor flooding will continue along the St. Johns River Basin during times of high tide through this evening

Atmospheric moisture levels will continue to slowly increase as the steering flow becomes southerly today and southeasterly tonight with PWATs increasing to 1.5-1.7 inches NE FL and 1.3-1.5 inches for SE GA. This combined with diurnal heating and inland moving East Coast sea breeze should be enough to trigger isolated showers across NE FL this afternoon with PoPs in the 15-25% range, while SE GA should remain mostly dry. Temps will continue at above normal levels with highs around 90F over inland areas and middle 80s along the Atlantic Coast. Any isolated shower activity over inland areas will fade around sunset, then as flow becomes more Southeasterly expect scattered showers and isolated to push into the offshore NE FL coastal waters and may push closer to the NE FL coast towards morning, but overall rainfall chances remain less than 20 percent. Low temps will continue to trend back closer to normal values with lower/middle 60s over inland SE GA and middle/upper 60s over inland NE FL and lower 70s along the Atlantic Coast.

SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/

Main Highlights through Tonight:

- Return to summer like pattern: Scattered thunderstorms Wednesday and Thursday, mainly NE FL, with highs in the upper 80s to low 90s.

A moistening southeasterly flow will lift the old stalled front well to north by Wednesday. A weak inverted low level trough offshore will gradually slide northwestward through Wednesday night, increasing chances to 40-60% across NE FL by Thursday afternoon as precipitable water will push toward 1.8"-2.0". There is some uncertainty in the pace at which deep moisture will push across SE GA and there's potential for thunderstorm coverage to trend to scattered by Thursday with the primary focus for thunderstorm development along the east coast sea breeze.

The faster Atlantic sea breeze and onshore flow will keep the coastal counties cooler by 3-6 degrees each day (mid/upper 80s) while inland areas push toward the 90 degree mark or Wednesday and Thursday afternoon. Lows will be in the upper 60s inland and low 70s at the coast Wednesday night and increase to mid/low 70s areawide as dewpoints increase Thursday night.

LONG TERM /FRIDAY THROUGH MONDAY/

Main Highlights This Period (Friday through Monday):

- Above normal thunderstorm chances with strong to marginally severe storms possible Sunday.

- Local Nor'easter Conditions potential next week.

By the end of the week, stacked upper and lower ridging will decouple as upper ridging retrogrades across the Florida peninsula this weekend. Though there will be enhanced subsidence beneath the ridge, which may mitigate coverage across northeast FL, there will be substantial supply of deep moisture spread across the area by southeasterly flow. Convergence along the Atlantic sea breeze will be the primary focus for scattered to numerous thunderstorms through the weekend. The blocking ridge over the FL appears to breakdown and slide southwestward as a stronger upstream shortwave dive approaches Sunday night and pushing across the area Monday. The timing of the frontal passage may favor an elevated potential for stronger possibly severe convection Monday.

Ensemble guidance is in fair agreement with another strong northeasterly wind surge behind the front through the first half of next week. With the coinciding elevated astronomical tides as the new moon approaches, tidal flooding is to expected again and may linger for several days. Further evaluation on the degree of tidal flooding will come throughout the next week.

Mostly cloudy, diurnal convection, and a gradually lowering sun angle will keep temperatures in the upper 80s to near 90 each day with humidity making it feel like its in the upper 90s to lower 100s each day.

AVIATION /12Z TUESDAY THROUGH 12Z WEDNESDAY/

Outside of some patchy morning fog this morning and late tonight again, VFR conditions prevail. Light south to southwest winds this morning by 14z-15z, with a sea breeze wind shift expected to SSI and SGJ by 17z and CRG and JAX thereafter. Rainfall chances remain quite low at about 10-20 percent and therefore too low for any inclusion in the TAFs.

MARINE

High pressure over the region early this week brings light winds with afternoon onshore breezes developing along nearshore waters due to the Atlantic sea breeze. As the high pressure system shifts northeast mid to late week, a predominant east to southeast wind pattern takes over and persists into the weekend. This onshore flow will draw in higher moisture levels, resulting in scattered showers and embedded thunderstorms Thursday and Friday through the weekend.

Rip Currents: Long period swells and slightly elevated surf heights around 2 ft range today and expect a Moderate Risk of Rip currents through Wednesday.

FIRE WEATHER

- Locally Low Dispersion For Inland Se Ga This Afternoon CRITICALLY LOW AFTERNOON HUMIDITY FOR INLAND SE GA THIS - Afternoon

Light to near absent transport winds and a slow-moving sea breeze will lead to low inland dispersion this afternoon across inland areas, mainly in southeast GA where gradual mixing will drop humidity down to near critical. Elsewhere, conditions will be mostly dry but an isolated shower across north-central FL cannot be ruled out during the late afternoon.

Through the second half of the week, transport flow will shift southeasterly leading to an upward trend in moisture and afternoon dispersions. With the return of moisture over the area, chances of showers and storms increase with highest chances over north central FL as scattered showers and isolated storms will Wednesday and Thursday. By the end of the week, coverage expands but highest thunderstorm chances remain focused across northeast FL.

Fog Potential...Patchy fog over inland locations Tonight, mainly for inland southeast GA where cooler temps, calm conditions, and clear skies are likely.

TIDES/COASTAL FLOODING

Astronomical higher than normal tides will continue into this evening with Minor Flooding occurring during times of high tide within the St. Johns River Basin and along the NE FL Atlantic coast/ICWW. Water levels peak during high tide between 1.5 - 2 feet above Mean Higher High Water (MHHW) through this evening.

PRELIMINARY POINT TEMPS/POPS

AMG 91 65 89 67 / 10 10 20 0 SSI 85 73 84 75 / 10 10 10 0 JAX 90 69 86 69 / 10 10 20 0 SGJ 87 71 84 74 / 10 10 30 10 GNV 89 68 88 67 / 20 10 50 0 OCF 89 68 89 69 / 20 20 50 10

JAX WATCHES/WARNINGS/ADVISORIES

FL...Coastal Flood Advisory until 8 PM EDT this evening for FLZ125- 132-137-138-225-233-325-333-633. GA...None. MARINE...None.