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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

- Extended Duration of Coastal and Marine Hazards Continues this Week. A Coastal Flood Warning has been Extended through Tuesday Morning Along the Southeast GA Coast and through Wednesday Night for Coastal Northeast FL, the Intracoastal Waterway and the St. Johns River Basin. Moderate to Locally Major Flooding around Times of High Tide is Forecast Today, with Minor to Moderate Flooding then Continuing for the Rest of this Work Week.

- Gale Warning for the Atlantic Waters through Early this Afternoon for the Atlantic Waters North of St. Augustine. Gale Warning Extended through Tonight for the Atlantic Waters from St. Augustine Southward.

- High Surf Advisory Extended through Early Wednesday Morning Along the Atlantic Coast. A High Risk for Deadly Rip Currents Continues at All Area Beaches this Week. Major Beach Erosion will be Possible around Times of High Tide this Week.

NEAR TERM /THROUGH TONIGHT/

Main Highlights: Through Tonight

- Moderate to Locally Major Coastal/Tidal Flooding Atlantic Coast, Intracoastal Waterway and the St. Johns River Basin.

- Windy Conditions Prevail along the Atlantic Coast and I-95 Corridor.

Surface high pressure over the mid-Atlantic will gradually weaken today allowing the sharp coastal troughing over the area to slightly relax. Breezy NNE winds are still expected with wind gusts of 25-35 mph. A few spots along the coast may reach 40 mph this afternoon but not enough to warrant continuing the Wind Advisory. A seasonably dry air mass (PWATs < 1 in) in place across SE GA and the Suwannee Valley advects southward later today, which will shift shower activity to mainly south of St Augustine. Showers that shift onshore are anticipated to be light and shouldn't exacerbate the significant tidal flooding during high tide cycles. Below seasonable highs continue with highs in the low 70s along the SE GA coast to the upper 70s/low 80s further inland. A gradual loosening of our local pressure gradient tonight will allow for winds to decouple overnight across inland southeast GA and the Suwannee Valley, where fair skies will allow lows to fall into the upper 40s to mid 50s with onshore winds keeping lows in the 60s for the coast and north- central FL.

SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/

Main Highlights This Period:

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

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

A stagnant weather pattern aloft is expected to continue through midweek, as a cutoff trough remains situated near the Bahamas, while ridging builds across the southeastern states. This ridge will direct a shortwave trough northeastward from the southern Plains on Tuesday morning towards the eastern Great Lakes by Wednesday evening. Meanwhile, a slowly weakening surface high pressure center centered over the Southern Appalachians will shift southward over the southeastern states, followed by a reinforcing and strengthening high pressure center building southeastward from Ontario and Quebec towards the eastern Great Lakes and New England. Otherwise, sharp coastal troughing will remain situated over our local Atlantic waters, keeping a tight local pressure gradient in place across our area.

Breezy northeasterly winds will continue on Tuesday, with this flow advecting marine stratocumulus inland from the Atlantic waters across most of northeast and north central FL. These breezy onshore winds will generate enough low level convergence to create isolated to widely scattered showers over the Atlantic waters that will advect onshore along the northeast FL coast, with a few showers moving inland across southern portions of the St. Johns River basin. Cloud cover and breezy onshore winds will keep highs in the mid to upper 70s for locations along and east of I-95. A seasonably dry air mass over southeast GA and the Suwannee Valley will allow for mostly sunny skies, and rising heights aloft will boost highs to the lower 80s for inland locations west of I-95. Our local pressure gradient will begin tightening on Tuesday night as 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.

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. There may be just enough moisture to combine with the strengthening low level convergence to advect isolated to widely scattered showers onshore from the Atlantic waters, mainly across St. Johns and Flagler Counties. Gusty northeasterly winds will keep highs mostly in the mid to upper 70s for locations along and east of the I-95 corridor on Wednesday, with 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.

LONG TERM /THURSDAY THROUGH SUNDAY/

Main Highlights This Period:

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

- Dangerous and High Surf Conditions Persist, with a High Risk for Deadly Rip Currents and Significant Beach Erosion Continuing at Area Beaches.

Ridging aloft will remain in place across our area late this week, with this feature then flattening during the upcoming weekend as a another shortwave trough progresses north- northeastward from the southern Plains towards the Great Lakes states. Meanwhile, high pressure will weaken as it shifts off the New England and Mid- Atlantic seaboards, with coastal troughing remaining situated over our near shore waters. This coastal trough will combine with veering low and mid level flow to occasionally advect widely scattered showers onshore from the Atlantic waters, mainly for locations along and east of the I-95 corridor in northeast FL. Although multi- layered cloud cover will continue across our region during this time frame, rising heights aloft late this week and warm air advection on the heels of east and southeasterly low level flow will boost highs to the low and mid 80s each afternoon at inland locations. Breezy onshore winds will keep coastal highs in the mid to upper 70s. Lows will generally fall to the lower or mid 60s inland, with coastal lows remaining in the upper 60s to around 70.

AVIATION /06Z MONDAY THROUGH 06Z TUESDAY/

Gusty NNE winds continue through the TAF period with sustained winds 10-20 kts and gusts 18-30 kts. Highest gusts will be in the afternoon for SSI/SGJ. MVFR CIGs will linger over the TAF sites in the early morning. CIGS lift to VFR for JAX and SSI as the orientation of lower CIGS shifts south. A few showers may pass by SGJ this morning but the bulk of the activity should remain south of the local TAF sites.

MARINE

Strong high pressure over the mid-Atlantic and an area of low pressure in the western Atlantic will continue a tight pressure gradient over area waters today into early next week. Frequent gusts to gale force are expected to continue through this evening. Rounds of showers will continue to move over the coastal waters through tonight. The high will weaken slowly to the north this week but winds and waves will remain elevated above headline levels the entire week.

Rip Currents / High Surf: High Surf Advisories have been extended through Tuesday night for our entire Atlantic coastline, with surf peaking today as breakers reach the 8-10 ft range at the northeast FL beaches and 6-8 feet for the southeast GA beaches. High surf conditions will likely continue for the northeast FL beaches through at least Thursday. A high risk of deadly rip currents will continue at all area beaches during the next week, where major beach erosion is likely to occur around times of high tide during this extended duration onshore wind and coastal flooding 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 this week, with a few showers moving inland past the Interstate 95 corridor to around U.S. Highway 301. Otherwise, dry weather will continue during the next several days for southeast Georgia and the Suwannee Valley. A drier air mass moving across inland southeast Georgia may drop humidity values to near critical thresholds for locations north of Waycross on Tuesday afternoon.

Strong northeasterly surface and transport winds will continue along the northeast Florida coastal counties today, with breezy conditions elsewhere yielding 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 at least Thursday. Breezy northeasterly transport winds on Tuesday will create fair to good daytime dispersion values, with a slight increase in speeds on Wednesday yielding good daytime dispersion values area-wide.

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

TIDES/COASTAL FLOODING

Strong north-northeasterly winds will continue to combine with the highest astronomical tides of the year (Hunter's moon) to yield moderate tidal flooding today around times of high tide, with a few spots possibly touching reaching major flooding. Peak water levels are anticipated to be 2.5 to 3.5 feet above Mean Higher High Water (MHHW) during times of high tide today, with water levels then generally reaching 2-3 feet above MHHW from tonight through at least Wednesday night. Northeast winds will remain breezy on Tuesday and will likely increase again on Wednesday and Thursday, with high astronomical tides due to the lunar perigee maintaining 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.

As astronomical tide levels increase, the combination of the high surf and water levels will create significant beach erosion at area beaches. 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 76 50 80 51 / 0 0 0 0 SSI 72 59 75 62 / 0 0 0 0 JAX 74 59 78 62 / 0 0 10 0 SGJ 75 67 79 69 / 20 10 30 0 GNV 78 60 82 62 / 0 0 10 0 OCF 79 61 82 64 / 10 0 10 0

JAX WATCHES/WARNINGS/ADVISORIES

FL...Coastal Flood Warning until 2 AM EDT Thursday for FLZ038-124- 125-132-137-138-225-233-325-333-633. High Risk for Rip Currents through late Wednesday night for FLZ124- 125-138-233-333. High Surf Advisory until 8 AM EDT Wednesday for FLZ124-125-138- 233-333. GA...High Risk for Rip Currents through late Wednesday night for GAZ154- 166. High Surf Advisory until 8 AM EDT Wednesday for GAZ154-166. Coastal Flood Warning until 11 AM EDT Tuesday for GAZ154-166. Coastal Flood Advisory from 11 AM Tuesday to 2 AM EDT Thursday for GAZ154-166. MARINE...Gale Warning until 2 PM EDT this afternoon for AMZ450-452-470- 472. Small Craft Advisory from 2 PM this afternoon to 4 AM EDT Thursday for AMZ450-452-470-472. Gale Warning until 2 AM EDT Tuesday for AMZ454-474.