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

- Thunderstorm Outlook Today through Saturday. Isolated Strong Storms Possible This Afternoon and Friday. Isolated Severe Storms possible Saturday, including Strong Winds, Heavy

- Widespread Beneficial Rainfall Through the Weekend. Rainfall Totals of 1-2 inches, with Locally Heavier Totals of 2-4 in. Possible. Best Chances for Rain = Saturday. Highest Rainfall Totals Likely Inland SE GA

- Moderate Risk of Rip Currents Today Through Saturday

NEAR TERM /THROUGH TONIGHT/

Main Highlights This Period:

-Isolated to Strong Storms Possible This Afternoon and Evening

A pre-frontal trough and frontal boundary will push southward into north portions of the area today. The first in a series of shortwaves will pass over the area this morning, with additional disturbances pushing in from the west later tonight into Friday morning. The frontal boundary should be sagging southward tonight to about the FL / GA state line or slightly south of that by sunrise Friday. Expect that scattered showers and a few rumbles of thunder will be present this morning from about I-10 northward and then expect a lull in the activity for a few hours. Daytime heating, sufficient moisture with PWATs of about 1.5-1.6 inches, and the front will lead to scattered showers and storms during the afternoon and evening, with a focus over far southeast GA to northeast FL, with the activity in northeast FL mainly near and north of a line from Gainesville to St Augustine. Expect that deep convection could also be triggered by the east coast sea breeze which should be pinned along the coast given the prevailing west or slightly northwest winds. Isolated strong storm possible after about 3 pm with gusty winds to 40-50 mph and small hail during peak heating, especially near the frontal boundary and along the east coast sea breeze. All movement of activity should toward the east about 25-35 mph.

Tonight, the front will linger over far northeast FL/far southeast GA and stall there while scattered showers and a few storms continue until 10 pm or so. The convection should generally be focused around the I-10 corridor. The convective activity should wane by late evening with loss of heating, but anticipate a resurgence of showers/rain well after midnight across parts of southeast GA as the next shortwave approaches leading to increased lift. No thunder anticipated after midnight given most of the lift will be north of the front.

The cloud cover and the west-soutwhest winds lead to a fairly humid and warm day again, but not as warm as Wednesday. Highs in the 80s expected, warmest in the upper 80s over northeast FL. Mild tonight in the 60s to near 70 given cloud cover.

SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/

Main Highlights This Period:

- Unsettled weather brings beneficial rain - Isolated strong/severe storms possible Friday and Saturday

Frontal boundary across north-central FL Friday morning will gradually lift northward as a warm front Friday afternoon and into Friday evening. Stratiform rain with embedded storms will develop across the cool sector in SE GA for much of the day on Friday. South of the lifting warm front across NE FL, warmer conditions and increasing instability will trigger scattered convection along the sea breezes and frontal boundary. An isolated strong storm capable of strong winds 40-50 mph will be possible Friday afternoon and evening along boundary mergers mainly across NE FL. Showers linger Friday night mainly over SE GA.

A stronger cold front then moves through the area on Saturday bringing numerous showers, embedded thunderstorms and beneficial rainfall area-wide. There is high confidence of at least 0.25 to 0.50 inches Saturday through Sunday morning for all of southeast GA and northeast FL, with southeast GA having the better potential of realizing 0.5 to 1 inch with locally higher amounts of 3-4 inches possible. Sufficient shear and instability ahead of the front could bring a few strong to severe storms, with the general timing of stronger storms north of I-10 Saturday morning, shifting near and south of I-10 into Saturday afternoon and evening. The main convective hazards on Saturday would be strong wind gusts of 40-60 mph and possibly a few rotating cells depending on the track of the surface low moving along the front. Convection wanes from north to south Saturday night as the front shifts into central FL.

Due to the front, there will be a north-south temperature gradient with highs ranging from the upper 60s north to around 90 south.

LONG TERM /SUNDAY THROUGH WEDNESDAY/

Main Highlights This Period:

- Drier, Cooler Weather Sunday and Monday

A reinforcing short wave trough slides across the region Sunday potentially triggering a few showers across north-central FL near the lingering frontal zone. Otherwise, drier, cooler airmass filters in from north to south as surface high pressure moves through the SE US Sunday into early next week. Temperatures cool to near to just below seasonable in the wake of the front Sunday into Monday. Temperatures then moderate back to near to above average for mid- week as a more typical diurnal sea breeze regime develops.

AVIATION /12Z THURSDAY THROUGH 12Z FRIDAY/

VFR expected at the outset, but rather rapid increase in low to mid clouds and a chance of showers are anticipated by 12z-15z ahead of a cold front and upper level disturbance. MVFR conditions due to stratus and possible showers may be starting during this time frame for all TAFs except perhaps SGJ, which is possible later in the morning. The cigs may lift back up to VFR the afternoon hours and then scattered showers and thunderstorms expected during the mid to late afternoon and probably into the early evening as the cold front moves in, but exact timing of the convection is a little uncertain. However, will insert PROB30 groups for TSRA with sufficiently high probability and supported by Hi-Res guidance. For sfc winds, mainly west- southwest about 4-8 kt until 13z, then becoming 8-12G20kt more due west and at times northwest through the late afternoon. An exception may be for SSI with a sea breeze pushing through there by around 20z-22z time frame, and possibly around SGJ at 22z-23z. Winds should be diminished around the 00z-03z time frame and become more variable. As frontal boundary sags southward closer to the TAF locations tonight, expect BKN-OVC skies and lowering CIGS to MVFR levels in the 06-12Z time frame at all TAF sites with light winds continuing.

MARINE

A cold front will move into southeast Georgia today and then into northeast Florida late tonight through early Friday. This front will then stall across the northeast Florida waters Friday then begin to lift north as a warm front Friday night. This front will be accompanied by scattered showers and a few thunderstorms at times today through Friday night. A wave of low pressure will then develop over the Gulf by late Friday night or Saturday, with widespread showers and possibly a few strong thunderstorms overspreading our local waters on Saturday, with activity expected to continue into late Saturday night. Small Craft Advisory conditions may develop on Saturday as southwest winds increase. The front will shift south of the northeast Florida waters on Saturday night, resulting in winds shifting to northerly. Breezy northeast winds are then expected on Sunday as high pressure builds into the southeastern states.

Rip Currents:

Preliminary data from buoys suggest the risk is moderate to high right now. For today, winds will mainly be offshore but wind-sea swells and residual southeast winds help to maintain a moderate risk of rip currents for today. Some lower surf conditions will likely bring the risk down a bit further on Friday and Saturday with low to moderate risk. Risk is likely to increase by late Saturday through Monday with a strengthening north to northeast flow expected.

FIRE WEATHER

- High Daytime Dispersions Today And Saturday

- Beneficial Rainfall Expected Into This Weekend

A few lingering showers are expected early this morning especially across southeast Georgia. Scattered showers and embedded thunderstorms are expected area-wide today and Friday as a cold front moves into the area. Breezy westerly transport winds and elevated mixing heights will result in high daytime dispersions today for much of the area. The front over northeast Florida on Friday will lift back northward as a warm front. Breezy southwesterly surface and transport winds will continue across north central Florida on Friday, where high daytime dispersions are expected. Surface and transport winds elsewhere will shift to northeasterly, with poor to fair values for locations north of I-10. A stronger cold front then moves through Saturday into Sunday. Widespread showers and thunderstorms are forecast on Saturday and Saturday night. Strong southwesterly surface and transport winds ahead of the front will result in very high dispersions on Saturday across northeast Florida.

FOG POTENTIAL AND OTHER REMARKS: Isolated strong/severe storms possible Friday and Saturday. Smoke from nearby fires may result in localized visibility reductions, especially during the overnight and early morning hours.

PRELIMINARY POINT TEMPS/POPS

AMG 82 61 75 58 / 60 30 50 60 SSI 82 67 76 64 / 50 30 60 40 JAX 88 66 82 65 / 50 30 50 30 SGJ 87 67 83 66 / 40 30 40 20 GNV 90 65 88 65 / 30 20 40 10 OCF 88 67 88 66 / 20 10 30 10

JAX WATCHES/WARNINGS/ADVISORIES

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