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

- Coastal and Marine Hazards Continue into the Upcoming Weekend. Coastal Flood Warning Widespread Moderate Tidal Flooding along the

- Atlantic Coast, Intracoastal Waterway & St. Johns River Basin through Thursday. Extended Duration of Moderate Tidal Flooding within the St. Johns River Basin. High Surf Advisory through Thursday Night at the Northeast FL Beaches. High Risk for Rip Currents at all Area Beaches through the Upcoming Weekend. Major Beach Erosion around Times of High Tide through Friday. Small Craft Advisory for the Atlantic Waters through at least Friday. Gusty Northeasterly Winds Continue at Coastal Locations through Friday

- Isolated Thunderstorms Possible on Sunday and Sunday Night

NEAR TERM /THROUGH TONIGHT/

Main Highlights: Through Tonight

-Coastal hazards remain in place this period

The region will remain between strong high pressure to the north northeast, and an inverted trough to the south southeast this period. This pattern will continue the elevated onshore flow. Band of showers moving ashore across NE FL this morning, is expected to weaken and dissipate Today. Temperatures will be near average Today. A broad range of temperatures is forecast Tonight due to the onshore flow, with lows over inland SE GA in the lower to middle 50s, and upper 60s to around 70 NE FL coast.

SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/

Main Highlights This Period:

- Coastal and Marine Hazards Continue, with Minor to Moderate Flooding During Times of High Tide Continuing Along the Atlantic Coast and Within the Intracoastal Waterway and the Entirety of the St. Johns River Basin.

- Dangerous and High Surf Conditions Continue, with High Surf Advisories Continuing at the Northeast FL Beaches. A High Risk for Deadly Rip Currents will Persist at All Area Beaches. Pounding Surf During High Tide Cycles Will Cause Major Beach Erosion.

Cutoff troughing situated over the Bahamas on Tuesday will lift slowly northward on Wednesday and will then shift eastward by Thursday as ridging aloft over our region slowly flattens. This ridge will direct a weakening shortwave trough northeastward from the eastern Great Lakes across New England, with this feature moving offshore by Thursday afternoon. Meanwhile, reinforcing surface high pressure will shift offshore from coastal New England and will continue to wedge down the southeastern seaboard. Otherwise, sharp coastal troughing will remain situated over our local Atlantic waters.

High pressure wedging down the southeastern seaboard and a sharpening trough extending from the Bahamas westward across south FL will tighten our local pressure gradient on Wednesday. Northeasterly winds will increase to 20-25 mph with frequent gusts of 30-35 mph across coastal northeast FL, with breezy conditions developing elsewhere during the late morning and early afternoon hours. Strengthening low level convergence will allow a surge of Atlantic moisture located on the northern edge of the surface trough to overspread locations south of the Interstate 10 corridor, where showers will move onshore for coastal locations south of Mayport during the afternoon hours, with activity moving westward across portions of the St. Johns River basin. Gusty onshore winds will keep highs mostly in the mid 70s for locations along and east of the I-95 corridor on Wednesday, with upper 70s and lower 80s prevailing inland. Breezy onshore winds will keep coastal lows on Wednesday night in the upper 60s and lower 70s, while a lighter breeze inland keeps lows in the low to mid 60s.

High pressure will weaken as it shifts slowly southward on Thursday, becoming re-oriented over the Tennessee Valley and the southern Appalachians. Meanwhile, coastal troughing will remain in place over our adjacent Atlantic waters, with a sharp surface trough over south FL lifting slowly northward. Although our local pressure gradient will begin to very gradually loosen, convergent low level east- northeasterly flow will continue to advect scattered showers onshore from the Atlantic waters across coastal northeast FL and the St. Johns River basin. Gusty onshore winds will keep coastal highs in the mid to upper 70s, while inland highs generally climb to the lower 80s, with a few mid 80s possible for north central FL. The loosening pressure gradient will allow winds to decouple at inland locations on Thursday evening, with moist onshore flow likely developing low stratus ceilings at most locations during the predawn and early morning hours on Friday. Lows at inland locations will generally fall to the 60-65 degree range, while an onshore breeze keeps lows in the upper 60s for north central and coastal northeast FL.

LONG TERM /FRIDAY THROUGH MONDAY/

Main Highlights This Period:

- Minor to Moderate Tidal Flooding Continues During Times of High Tide Within the St. Johns River Basin.

- Dangerous Surf Conditions Persist, with an Elevated Rip Current Risk Likely Continuing through the Upcoming Weekend.

- Increasing Chances for Showers and a Few Thunderstorms on Sunday and Sunday Night.

Ridging aloft positioned over Mexico's Yucatan Peninsula and the southern Gulf will expand northeastward over our area. This feature will direct a potent shortwave trough north-northeastward from west Texas on Friday to the Upper Midwest by Sunday morning, with this trough then pivoting slowly eastward across the Great Lakes region. Meanwhile, a southern stream trough will amplify over the lower Mississippi Valley will amplify on Saturday, with this feature continuing to sharpen as it moves eastward, crossing our region on Sunday afternoon and night, moving offshore by Monday afternoon.

Another reinforcing surface high pressure center will build southeastward from the Great Lakes on Friday, with this feature wedging down the southeastern seaboard through Saturday and keeping a stubborn coastal trough in place over our adjacent Atlantic waters. Breezy onshore flow will continue on Friday and Saturday, advecting isolated to widely scattered showers onshore along the Atlantic coastal counties, especially on Saturday, when veering low level flow could shift activity inland during the afternoon hours. This moist flow will likely develop low stratus cloud cover at inland locations during the predawn and early morning hours each day. Breezy onshore winds will highs in the mid to upper 70s for locations along and east of I-95, while low to mid 80s forecast for inland locations west of I-95. Lows will range from the lower and mid 60s inland to the upper 60s to around 70 at coastal locations.

High pressure will shift offshore of coastal New England on Sunday, allowing low level flow to veer to southerly ahead of the approaching shortwave trough by the afternoon hours. Deep moisture will overspread our region ahead of this shortwave's associated surface trough, likely allowing at least scattered showers and isolated thunderstorms to traverse our area from west to east, mainly during the afternoon and evening hours. Forecast trends have been increasing rain chances for our entire area on Sunday and Sunday night, with activity potentially persisting into Monday along the I-95 corridor. Persistent onshore winds will keep highs in the mid to upper 70s for coastal locations, while low to mid 80s remain forecast forecast for inland locations. Lows will only fall to the mid and upper 60s on Saturday night, with 60s likely prevailing again on Sunday night as multi-layered cloudiness overspreads our region.

AVIATION /12Z TUESDAY THROUGH 12Z WEDNESDAY/

The elevated onshore flow will continue this 12z TAF period. Winds will be gusty Today, especially near the coast. With loss of daytime heating, inland sites will have winds diminish Tonight, however the coastal sites will remain gusty. The band of showers moving over northeast FL is expected to weaken early in this TAF period.

MARINE

High pressure to the north and an area of low pressure to the south will maintain breezy northeasterly winds and elevated seas through Thursday. Rounds of showers will continue to move over the coastal waters through the week. The high will weaken slowly to the north this week with winds and waves subsiding below advisory levels by the end of the week.

Rip Currents / High Surf: High Surf Advisories have been extended through Thursday night for the northeast FL beaches, where breakers of 7 to 9 feet today will build slightly to the 8-10 ft range on Wednesday, followed by breakers of 6 to 8 feet on Thursday. Breakers of 4 to 6 feet will prevail at the southeast GA beaches through Thursday. These elevated, rough surf conditions will maintain a high risk of deadly rip currents at all area beaches through the upcoming weekend, and major beach erosion is likely to occur around times of high tide during this extended duration onshore wind event.

FIRE WEATHER

ELEVATED NIGHTTIME DISPERSION VALUES AT COASTAL LOCATIONS AND - Along The I-95 Corridor Through Thursday Night

Isolated to widely scattered showers will continue to occasionally move onshore along the northeast Florida coast through tonight, mainly for locations from St. Augustine to Palatka and points southward. Shower coverage will increase on Wednesday and Thursday for coastal northeast Florida and the St. Johns River basin to the south of Jacksonville. Otherwise, dry weather will continue during the next several days for southeast Georgia and the Suwannee Valley, with a seasonably dry air mass dropping humidity values to around 30 percent on Tuesday afternoon for locations north and west of Waycross in southeast Georgia.

Strong northeasterly surface and transport winds will continue along the northeast Florida coastal counties through Thursday, with breezy conditions elsewhere yielding fair to good daytime dispersion values area-wide. Breezy surface and transport winds during the overnight hours will result in elevated nighttime dispersion values for locations along and east of I-95 each night through Thursday. Surface and transport winds will then shift to east-northeasterly on Friday and easterly on Saturday, with breezy speeds keeping fair to good daytime dispersion values in the forecast area-wide.

FOG POTENTIAL AND OTHER WEATHER REMARKS: Significant fog formation is not expected during the next several days.

TIDES/COASTAL FLOODING

Northeasterly winds will remain breezy and will combine with high astronomical tides due to the lunar perigee to maintain moderate tidal flooding this week within the St. Johns River basin, with minor to moderate flooding continuing during times of high tide along the Atlantic coast and intracoastal. Water levels will generally reach 2-3 feet above Mean Higher High Water (MHHW) during times of high tide. The long duration of this strong onshore wind event will likely produce major beach erosion during each high tide cycle through at least Thursday.

PRELIMINARY POINT TEMPS/POPS

AMG 79 53 79 61 / 0 0 0 0 SSI 74 62 75 64 / 0 0 10 0 JAX 77 64 78 66 / 0 0 10 0 SGJ 78 70 78 71 / 20 10 40 40 GNV 81 64 81 67 / 0 0 10 10 OCF 82 65 82 69 / 10 0 20 10

JAX WATCHES/WARNINGS/ADVISORIES

FL...Coastal Flood Warning until 2 AM EDT Friday for FLZ038-124-125- 132-137-138-225-233-325-333-633. High Risk for Rip Currents through late Thursday night for FLZ124- 125-138-233-333. High Surf Advisory until 2 AM EDT Friday for FLZ124-125-138- 233-333. GA...High Risk for Rip Currents through late Thursday night for GAZ154- 166. Coastal Flood Advisory until 2 AM EDT Friday for GAZ154-166. MARINE...Small Craft Advisory until 6 AM EDT Friday for AMZ450-452-454- 470-472-474.