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

- Extended Duration of Coastal and Marine Hazards. Coastal Flood Warning - Moderate to Potentially Major Tidal and Coastal Flooding around Times of High Tide Along the Atlantic Coast and Within the Intracoastal Waterway and the Entirety of the St. Johns River Basin. Wind Advisory for the Atlantic Coastal Counties this Afternoon & Tonight. Windy Conditions Continue at Coastal Locations on Sunday and Monday. Gale Warning for the Atlantic Waters Saturday Afternoon through Monday. High Surf Advisory & High Risk for Rip Currents through most of Next Week. Major Beach Erosion around Times of High Tide through most of Next Week. Locally Heavy Rainfall Possible for Coastal Northeast FL this Afternoon through this evening

NEAR TERM /THROUGH TONIGHT/

Main Highlights: Through Tonight

- Moderate Coastal/Tidal Flooding Atlantic Coast/St. Johns River

- Wind Advisory Atlantic Coast/St. Johns River gusts to 45 mph

- Locally heavy rainfall at times NE FL Atlantic Coast/I-95

The local pressure gradient continues to tighten this afternoon as strong high pressure centered over New England wedges down the eastern seaboard and an area of low pressure develops northeast of the Bahamas. This will develop and sharpen coastal troughing over the nearshore Atlantic waters bringing gusty north-northeasterly winds. A Wind Advisory is in effect for this afternoon into evening where gusts could reach up to 40-45 mph along the SE GA and NE FL coasts. Breezy conditions linger overnight with the continued tight pressure gradient. Waves of numerous coastal showers and a few embedded thunderstorms will shift onshore through the evening hours mainly for coastal NE FL and then into the St Johns River basin. A few convergent bands may form along the northeast FL coast bringing heavier downpours and localized flooding. If these bands coincide with this evening's high tide cycle, this could exacerbate the already significant tidal flooding expected. Shower activity wanes overnight and shifts to the NE FL coastal areas, mainly south of St. Augustine. Overnight lows will range from the mid 50s in SE GA to the upper 60s along the NE FL coast.

SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/

Main Highlights This Period:

- Coastal and Marine Hazards Peak on Sunday and Monday, with Coastal Flood Warnings in Effect Along the Atlantic Coast, Intracoastal Waterway and St. Johns River Basin. Moderate to Possibly Major Tidal Flooding Will Continue Around Times of High Tide.

- Wind Advisory Conditions Likely to Continue at Coastal Locations.

- Gale Warnings Continue for the Atlantic Waters.

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

- Locally Heavy Downpours Possible on Sunday and Sunday Night.

An initially tight pressure gradient situated over the forecast area, between high pressure ridging to the north and a sharp coastal trough to the east and southeast, will act to keep wind speeds of 25 to 30 mph on Sunday, with wind gusts potentially increasing up to 35 to 45 mph on Monday. Rain showers are expected to develop over the region with the onshore flow, with a possibility for heavier downpours capable of causing localized flooding, more likely over northeast Florida with chances dropping by the end of the day on Monday as drier air from out of the north advects southward. High temperatures for the end of the weekend and into the beginning of next week will be in the mid to upper 70s for inland areas and in the lower to mid 70s for areas along the coast. Overnight low temperatures will drop down into the 40s and 50s for southeast Georgia and in the 60s for northeast Florida, with min temps as high as the upper 60s and lower 70s along the shoreline.

LONG TERM /TUESDAY THROUGH SATURDAY/

Main Highlights This Period:

- Coastal and Marine Hazards Continue, with Moderate Tidal Flooding Likely Around Times of High Tide on Tuesday Along the Atlantic Coast, Intracoastal Waterway, and St. Johns River Basin. Minor to Moderate Tidal Flooding May Continue for Much of the Upcoming Week Within the St. Johns River Basin.

- Dangerous and High Surf Conditions Persist, with a High Risk for Deadly Rip Currents and Significant Beach Erosion Possible at Area Beaches throughout the Upcoming Week.

Northeasterly flow will persist through the week into Friday which, along with coastal troughing and astronomical high tides, will result in a continuance of coastal and marine impacts through the week. Drier air over the region will reduce the amount of precipitation for the beginning of the period with chances for showers increasing later in the week as more moist air advects in over the forecast area. Temperatures are expected to rise to be near or slightly above the seasonal average by the end of the week.

AVIATION /18Z SATURDAY THROUGH 18Z SUNDAY/

MVFR area-wide this afternoon after 18Z except for GNV terminal as local Nor'Easter conditions develop, which will include increasing NE winds to 15 to 22 knots with gusts to 25 to 32 knots at times, highest as the Atlantic Coastal terminals of CRG/SGJ. MVFR CIGS will predominate with periods of lower MVFR VSBYS in SHRA activity moving onshore and mostly impacting CRG/SGJ with lesser chances at other inland terminals and will need to include at least PROB30 for the SHRA activity pushing onshore. TSRA chances still remain at 10 percent or less, so will likely keep out of the forecast for now. Strong NE winds will continue through the TAF period at Atlantic Coastal sites but will weaken at inland TAF sites of GNV/VQQ after sunset tonight. MVFR CIGS after sunset this evening will become VFR at SSI/JAX/CRG, but will continue at SGJ as shower activity slowly shifts further southward and likely only impacts SGJ through Sunday morning and the remainder of the TAF period. NE winds will slowly increase again at inland terminals after 15Z back into the 15-20 knot range with gusts to 25 knots or so.

MARINE

A combination of strong high pressure to the north, and an area of low pressure to the southeast will result in a tight pressure gradient over area waters this weekend into early next week. Frequent gusts to gale force this afternoon and evening are expected to continue into Monday. The high will weaken slowly to the north next week but winds and waves will remain elevated above headline levels the entire week.

Rip Currents / High Surf: High Surf Advisories have been issued through Monday for our entire Atlantic coastline, and surf will likely peak from Sunday through Monday, when breakers reach the 8-10 foot range at the northeast FL beaches and 6-8 feet at the southeast GA beaches. High surf conditions may continue for the rest of the upcoming work week at the northeast FL beaches, and a high risk of deadly rip currents will persist at all area beaches, where major beach erosion is likely to occur during this extended duration onshore wind and coastal flooding event.

FIRE WEATHER

- Marginally High Dispersion Values Inland Sunday Afternoon ELEVATED NIGHTTIME DISPERSION VALUES FOR PORTIONS OF OUR AREA - During The Next Several Days

Showers will continue to move onshore along the northeast Florida coast early today, followed by waves of showers throughout the rest of the weekend and into Monday along the I-95 corridor in northeast Florida, with activity occasionally extending to coastal southeast Georgia and for inland locations east of U.S. Highway 301 in northeast and north central Florida. Locally heavy downpours will be possible this weekend along the I-95 corridor in northeast Florida. Otherwise, dry weather will prevail across inland southeast Georgia and the Suwannee Valley during the next several days. Gusty northeasterly surface and transport winds today will create marginally high daytime dispersion values across the Okefenokee Swamp and northern portions of the Suwannee Valley this afternoon, with good values forecast elsewhere. Gusty northeasterly surface and transport winds will continue through Sunday night, creating elevated nighttime dispersion values at most locations this weekend. Northeasterly surface and transport winds will gradually diminish on Monday and Tuesday across inland southeast Georgia and the northern Suwannee Valley, while breezy to windy conditions continue elsewhere, yielding fair to good daytime dispersion values. Elevated nighttime dispersion values will continue at coastal locations for much of next week.

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

TIDES/COASTAL FLOODING

Tidal departures from predicted values continue to increase as the highest astronomical tides of the year arrive. Strengthening north- northeasterly winds this afternoon/evening will combine with the increasingly high astronomical tides to yield water levels reaching moderate flood levels during the evening high tide tonight, with water levels generally climbing to 2-3 feet above MHHW, which has prompted the issuance of Coastal Flood Warnings along the Atlantic Coast and within the Intracoastal Waterway and St. Johns River basin. Peak water levels will likely coincide with the upcoming full moon on Sunday/Monday Oct 25-26, and confidence continues to grow with respect to peak water levels of 2.5-3.5 feet above MHHW during the Sunday and Monday high tide cycles. Northeast winds will only gradually decrease through the week, but high astronomical tides with the lunar perigee on October 28 will maintain minor to moderate tidal flooding from Tuesday onward, with higher chances for moderate flooding continuing within the St. Johns River Basin.

As the astronomical tide levels increase, the combination of the building surf and water levels will lead to significant beach erosion potential. This potential looks higher than the prior northeast wind event around Oct 17-18, and the long duration of this event could produce major erosion during each high tide cycle for much of the upcoming week.

PRELIMINARY POINT TEMPS/POPS

AMG 55 76 55 77 / 0 0 0 0 SSI 63 72 61 72 / 20 10 20 0 JAX 64 74 65 75 / 40 20 30 10 SGJ 68 76 68 76 / 90 70 80 40 GNV 64 78 66 79 / 30 0 30 10 OCF 65 80 66 81 / 30 10 20 10

JAX WATCHES/WARNINGS/ADVISORIES

FL...Coastal Flood Warning until 8 PM EDT Monday for FLZ038-125-132- 137-325-633. Wind Advisory until 1 AM EDT Sunday for FLZ038-124-125-138-233- 333-433-533. Coastal Flood Advisory until 5 PM EDT this afternoon for FLZ124-138-225-233-333. High Risk for Rip Currents through Monday evening for FLZ124-125- 138-233-333. High Surf Advisory until 8 PM EDT Monday for FLZ124-125-138- 233-333. Coastal Flood Warning from 5 PM this afternoon to 8 PM EDT Monday for FLZ124-138-225-233-333. GA...Wind Advisory until 1 AM EDT Sunday for GAZ154-166. Coastal Flood Advisory until 5 PM EDT this afternoon for GAZ154-166. High Risk for Rip Currents through Monday evening for GAZ154-166. High Surf Advisory until 8 PM EDT Monday for GAZ154-166. Coastal Flood Warning from 5 PM this afternoon to 8 PM EDT Monday for GAZ154-166. MARINE...Gale Warning until 8 PM EDT Monday for AMZ450-452-470-472. Small Craft Advisory until 8 PM EDT this evening for AMZ454- 474. Gale Warning from 8 PM this evening to 8 PM EDT Monday for AMZ454-474.