On Top of the World, FL Weather

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, 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 through Thursday Night. A High Risk for Deadly Rip Currents will Persist at All Area Beaches into the Upcoming Weekend. Pounding Surf During High Tide Cycles Will Cause Major Beach Erosion through Friday.

- Gusty Onshore Winds Will Continue at Coastal Locations through Friday, with Frequent 30-35 mph Gusts Expected on Wednesday and Wednesday Night.

- Isolated Thunderstorms Possible on Sunday and Sunday Night.

Near Term

Main Highlights:

- Coastal Hazards Continue, with Coastal Flood Warnings Remaining in Effect along the NE FL Atlantic Coast, Intracoastal Waterway and St. Johns River Basin. Moderate Tidal Flooding Will Continue Around Times of High Tide for these Locations.

Waves of coastal showers will continue to shift onshore in the NE flow to coastal NE FL mainly south of St Augustine through the late morning hours. The local pressure gradient weakens slightly as high pressure to the north weakens but gusts could still reach up to 30 mph along the coast. A drier airmass (PWATs < 1 in) in place will keep much of the area rain-free today. With lighter onshore winds and clearer skies, highs will rise to the mid/upper 70s along the coast to the low 80s inland. The local pressure gradient will tighten slightly late tonight as a reinforcing strong high pressure begins to wedge down the southeastern seaboard once again. Lows will fall into the 50s for inland southeast GA and the Suwannee Valley, with 60s expected elsewhere.

Short Term

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

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.