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

- Isolated Thunderstorms through Early Afternoon. Isolated Strong Storms with gusty winds and locally heavy rainfall

- Improving Coastal & Marine Hazards Today into Monday. Small Craft Advisory Offshore through This Afternoon. Moderate Rip Current Risk at All Beaches

- Minor Tidal Flooding St. Johns Basin

UPDATE

Morning showers with isolated storms will continue to edge gradually to the east across coastal SE GA over the next couple of hours and northeast Florida through late morning, with rainfall ending by mid afternoon for most locations. Drier and sunnier weather returns from west to east through the day trailing the cold front passage. High temperatures will peak in the lower 80s to upper 70s with breezy post-frontal wind gusts of 15-20 mph at times by afternoon across parts of southeast GA and the Suwannee River Valley where more sunshine is expected.

Best chances of t'storms through mid-afternoon will focus from Marion county toward St. Augustine, southward, where better surface instability resides with dew pts in the upper 70s. Main hazards will be gusty winds of up to 30 mph, lightning and periods of localized heavier rainfall. Most rainfall will be light.

Much more stable conditions ushering in behind the cold front now across our far NW GA zones where the Douglas dew pts just dropped to 63 deg.

NEAR TERM /THROUGH TONIGHT/

Main Highlights Today and Tonight:

- Isolated T'storm Potential Through This Morning

- Coastal and Marine Impacts Continue, but Improve Sunday

Scattered showers with some isolated embedded thunderstorms continue to stream from southwest to northeast across the area this evening, ahead of a frontal boundary pushing from west to east through the area through this morning associated with the extratropical low to our north associated with formerly Isaias. Not expecting much in the way of strong to severe storm potential with any of this activity due to the mostly nighttime passage, though with forecast CAPE in the 1000-1500 J/kg range and effective shear around 25-30 knots, certainly cannot rule out an isolated strong to marginally severe t'storm through the rest of the morning hours, though it will likely take a rather robust updraft/tall storm for any strong to severe winds to reach the ground given the timing. Otherwise, mostly cloudy outside of any showers with some clearing for western areas towards morning as drier air starts to fill in. Lows will be mild mainly in the 70s, with some upper 60s possible for far western areas.

Cold front and associated convection ahead of it will continue to shift eastward throughout the morning as mentioned above, with most if not all of the region expected to start drying out by the afternoon hours. Depending on the exact timing, some slight diurnal enhancement could occur the further south and east you go late morning and towards about midday, though Hi Res guidance is not very excited about this idea and given the time of year/sun angle etc., I'm not really either. In fact, most of today will likely turn out to be a pretty nice day as drier westerly flow on the southwest side of departing low pressure will clear out most cloud cover from west to east and lower dew points into the 60s for most with afternoon mixing. As this occurs, also expecting coastal marine and river flooding hazards to overall improve, though have still kept a Coastal Flood Advisory for the entirety of the St. Johns River through high tide this evening to cover lingering trapped tides. Have also dropped high risk for rip currents at area beaches today with a developing offshore flow, but certainly a moderate risk continues. High temps today will be generally in the 80-85 degree range, warmest south and east.

Generally just a few lingering clouds tonight as well as a persistent light west to northwesterly breeze around 5-10 mph, with a bit more comfortable temperatures in the 60s.

SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/

Main Highlights This Period:

- Convection will clear out by end of Sunday

- Dry weather conditions following the frontal passage, on Monday

The dry stable air mass will settle in over the forecast area on Monday and Tuesday as the frontal boundary presses southward over the Florida peninsula, bringing clear skies and dry weather conditions through the period. Initially northwesterly winds will shift about to become more out of the northeast by Tuesday evening as the remnants of Isaias move eastward and prevailing flow veers to a more northeasterly onshore flow over the region. High temperatures for the beginning of the week will rise into the mid to upper 80s for inland areas and in the mid to lower 80s along the coastline. Overnight low temperatures will drop down into the lower 60s for inland areas and in the mid to upper 60s for areas along the coast and near the St Johns River.

LONG TERM /WEDNESDAY THROUGH SATURDAY/

Main Highlights This Period:

- Dry and warm weather Wednesday and Thursday

- Increased chances for Showers on Friday and Saturday

Dry weather conditions will continue on through midweek with chances for showers increasing on Friday and Saturday as prevailing flow shifts about to become more out of the southwest ahead of an advancing cold front pressing in from out of the northwest. Surface winds are anticipated to shift to be out of the north and northeast following the frontal passage, however current models show some disparity on the timing and placement of the front at this time. Above average temperatures will be in place for midweek with max and min temps dropping down to below average levels by the weekend.

AVIATION /12Z SUNDAY THROUGH 12Z MONDAY/

Showers and isolated storms will eastward across the terminals this morning where prevailing SHRA and VCTS where included with brief 2-3 hr TEMPO groups for gusty TS winds up to 25 kts and restrictions of IFR to MVFR. Drier air and clearing skies into the afternoon with cold front passage, with wind shift from SW this morning to WSW to W after 18z with post-frontal gusts of 15-20 kts at times. VFR conditions expected at all terminals after 18z.

MARINE

A cool front will approach the area waters today, moving across the waters this afternoon and evening. This will continue Small Craft Advisory conditions of elevated south to southwest winds and seas for the offshore waters through tonight. A few rounds of showers and thunderstorms will move through the waters this morning and into early this afternoon. Winds will become westerly tonight and gradually decrease as the cold front moves through and exits east of the waters. High pressure will then build in from the west tonight and remain the main feature across the waters for much of the upcoming week.

Rip Currents: Rip current risk improves slightly to moderate today flow shifts to west-southwesterly, but some lingering longer period swells will keep risk from dropping significantly. This moderate risk is likely to continue into the start of the work week as well.

FIRE WEATHER

- Patchy High Dispersions Inland Se Ga Sunday

Showers and possible thunderstorms associated with the frontal passage will diminish and move offshore by this afternoon with breezy diurnal westerly winds dropping off before this evening. Drier weather conditions will build in over the region overnight and into next week resulting in clearing skies and westerly to northwesterly winds. Dry weather will continue through midweek with winds shifting to be more out of the east northeast.

FOG POTENTIAL AND OTHER WEATHER REMARKS: Significant fog developments are not expected for the next few days.

HYDROLOGY

River flood warnings continues for the Satilla at Atkinson which is cresting in lower-end Minor flood stage today and the St. Marys River at Macclenny which is hovering just above Minor flood stage. The Satilla at Waycross is forecast to crest below Minor flood stage early this week.

Some tributaries of the St. Johns will remain high as heavy rainfall from last week's rainfall drains. Locations include Julington Creek, Thomas Creek, and Pottsburg Creek.

TIDES/COASTAL FLOODING

Adjusted the coastal flood advisory to focus between downtown JAX southward to Welaka and Crescent Lake areas where Minor tidal flooding is expected to continue through tomorrow. Peak high tides will gradually dampen with lowering peak amplitudes. Northerly winds return Monday and become more northeast to east toward the end of the week, with the higher water level departures continuing for locations generally south of the Shands bridge with an extended duration of Minor flooding possible for some locations.

PRELIMINARY POINT TEMPS/POPS

AMG 79 63 84 62 / 0 0 0 0 SSI 82 66 85 67 / 40 0 0 0 JAX 83 63 86 64 / 40 0 0 0 SGJ 84 66 85 66 / 50 0 0 0 GNV 82 62 85 62 / 40 0 0 0 OCF 82 64 83 63 / 60 0 0 0

JAX WATCHES/WARNINGS/ADVISORIES

FL...Coastal Flood Advisory until 8 AM EDT Monday for FLZ038-132- 137-325-633. GA...None. MARINE...Small Craft Advisory until 2 PM EDT this afternoon for AMZ470- 472-474.