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

- High Risk for Rip Currents Today Most Local Beaches. High Risk Wednesday All Local Beaches. Elevated Rip Current Risk through Thursday

- Daily Afternoon & Evening Thunderstorms Tuesday to Sunday. Main Hazards: Locally Heavy Rain, Lightning & Gusty Winds to 40 mph

NEAR TERM /THROUGH TONIGHT/

Highlights Through Tonight:

- Breezy onshore/easterly winds today

- Passing gusty showers & inland mainly afternoon storms

- High Risk for Rip Currents Southeast GA and most Northeast FL Beaches & Elevated Tides

High pressure to the north will shift to the NC/VA coast through this afternoon and early evening as a coastal trough continues to develop to the east. Still expecting showers to gradually increase in coverage to more scattered coverage through the course of the afternoon as moist low level onshore flow and lift due to the trough and coastal convergence combine and produce some thin bands of showers that will shift onshore the SE GA and NE FL coast inland WSW to I-75. Strong heating will allow low level instability with CAPE exceeding more than 2,000 J/kg of CAPE across Northeast FL south of I-10 and near I-75. Breezy ENE flow will interact with a pinned Gulf seabreeze along the nature coast and a lingering front near to just south of north central FL, producing scattered thunderstorms coverage from Gainesville to St Augustine southward into Marion county.

Breezy winds 10-15 mph with gusts to 25 mph expected along the coast into the St Johns river while further inland decreasing to 8-12 mph with gusts to 20 mph. A mix of sun and clouds from the occasional onshore moving coastal showers will limit highs to the mid 80s along the coast, upper 80s along I-95, and the low 90s well inland near I- 75 and inland SE GA.

Tonight, showers will continue off and on along the SE GA coast with scattered coastal showers moving onshore the immeidate Northeast FL coast. Lows will fall to the low/mid 70s inland and the upper 70s to near 80 along the coast. Winds will become easterly as the coastal trough shifts to the SE GA coast and the high to the north moves to the northeast off the VA/NC coast.

SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/

Main Highlights This Period:

- Daily Thunderstorms Chances

The stalled front over central Florida will weaken and lift northward, behind it, steering flow will shift southerly, bringing in higher PWAT values above 2.0". The southeasterly winds will allow the Atlantic sea breeze to push inland and interact with the Gulf sea breeze further inland, with numerous showers and storms forecast for Wednesday afternoons and evening. The stronger onshore surface winds on Wednesday will bring in showers and isolated storms near the coast, spreading inland throughout the day. Thursday, the Gulf sea breeze will be able to dominate a little more, enhancing storm potential closer to I-95 and the east coast. Both days there will be an isolated strong storm threat with boundary collisions, gusty winds as the primary hazard, but we will also continue to see the heavy rainfall/localized flooding potential. Highs will generally be in the mid to upper 80s along the Atlantic coast, and lower 90s inland.

LONG TERM /FRIDAY THROUGH TUESDAY/

Main Highlights This Period:

- Daily Thunderstorms Chances and Locally Heavy Rainfall Potential

Southwesterly flow strengthens Friday and Saturday ahead of an incoming cold front from the north that is forecast to stall and fizzle out over central Georgia this weekend. Precipitation chances remain high (50-75%) over the region Friday and Saturday, again prompting the isolated flooding risk as well. Storm chances trend downward Sunday and Monday, with the highest coverage expected over north central Florida both days. High temperatures will be the mid to upper 80s along the Atlantic coast, and lower 90s inland.

AVIATION /18Z TUESDAY THROUGH 18Z WEDNESDAY/

A mix of MVFR and VFR ceilings are expected through the afternoon hours and again tonight as a coastal trough to the east brings in periodic showers onshore with chances for thunderstorms inland at GNV. East northeast winds 12-15 knots will prevail at the coast and JAX sites with gusts to 20-25 knots while less breezy inland 10-12 knots with gusts to near 20 knots. Have VCSH for all sites this afternoon with some MVFR ceilings as times as the coastal showers move onshore. Have PROB30 groups for TSRA now only at at GNV and SGJ while PROB30 groups for SHRA in place through 23-24Z at all other sites. A lull in showers is expected after 23Z inland, but enough probability for SHRA and MVFR ceilings along the coast for portions of the late overnight hours as winds become more easterly 5-10 knots st the coast and trend light and variable inland under 5 knots.

Expect SHRA to prevail at SSI after 13Z Wednesday morning with VCSH coverage elsewhere except further inland GNV as the coastal trough moves onshore the Southeast Georgia coast before weakening later Wednesday. Easterly winds will resume around 10 knots at the coast and 5-8 knots inland.

MARINE

A coastal trough developing today will persists through this evening into Wednesday morning with waves of gusty showers and isolated thunderstorms. Elevated winds and seas will bring Exercise caution conditions to the waters north of St Augustine through this late this evening. Winds will become easterly Wednesday morning and gradually lessen as the trough begins to weaken by late Wednesday Night as high pressure builds northeast of the region. The high will then extend across the Florida peninsula Thursday with southerly winds and a return of southwest winds Friday into the weekend with the afternoon east coast sea breeze.

Rip Currents: Onshore ENE winds strengthen today with building surf. With elevated ENE wind surge over the waters, the high rip current risk includes southeast GA and northeast FL beaches down the St. Johns county coast. Flagler county remains under a Moderate rip current risk today. Surf heights increase to 2-4 ft through the evening. High rip current risk likely for all local beaches Wednesday due to persistent onshore flow and elevated surf.

FIRE WEATHER

Aside from thunderstorm outflow influence, there is no significant fire weather forecasted at this time.

A stalled front over southern Florida will lift north through NE FL and SE GA through Thursday. Easterly winds will be favored through Wednesday, shift southerly Thursday, and then southwesterly by Friday. There will be higher chances for rain and thunderstorms inland through Thursday before the end-of-the-week wind shift focuses scattered to numerous thunderstorms along and east of Highway 301. Moderate to Good Dispersion is expected each day.

Fog Potential: Breezy to gusty outflow winds possible beneath and in the vicinity of passing thunderstorms. Significant fog development is not expected.

HYDROLOGY

Coastal water levels begin to increase this week with the approach of the New Moon on Sept 11th and breezy onshore easterly winds late Tonight through Wednesday, with the peak winds across the local waters and coast this afternoon and early evening. Guidance and observations show that water levels will be near and just above the action stage through Wednesday both along the local Atlantic coast and within the St. Johns River basin.

PRELIMINARY POINT TEMPS/POPS

AMG 73 90 72 91 / 10 60 20 60 SSI 79 87 78 89 / 60 60 30 50 JAX 75 89 75 91 / 40 40 10 70 SGJ 77 88 76 89 / 40 30 10 60 GNV 74 91 73 91 / 10 70 30 80 OCF 74 91 74 91 / 10 70 30 70

JAX WATCHES/WARNINGS/ADVISORIES

FL...High Risk for Rip Currents through late tonight for FLZ124-125-233- 333. GA...High Risk for Rip Currents through late tonight for GAZ154-166. MARINE...None.