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 This Week. Coastal Flood Warning - Moderate to Locally Major Flooding around Times of High Tide Along the Atlantic Coast and Within the Intracoastal Waterway and the Entirety of the St. Johns River Basin extended through Tuesday and Wednesday. Wind Advisory for the Atlantic Coastal Counties extended through this Evening. Gale Warning for the Atlantic Waters extended through Monday Night. High Surf Advisory & High Risk for Rip Currents through most of this Week. Major Beach Erosion around Times of High Tide through most of this Week. Locally Heavy Rainfall Possible for Coastal Northeast FL through Tonight

NEAR TERM /THROUGH TONIGHT/

Main Highlights: Through Tonight

- A Coastal Flood Warning for Moderate Tidal Flooding has been Extended through Early Wednesday Morning along the Atlantic Coast and within the Intracoastal Waterway and the Entirety of the St. Johns River Basin.

- Wind Advisory Continues along the Atlantic Coast and St. Johns River through Sunday Evening for Frequent Wind Gusts of around 45 mph.

Sharp coastal troughing remains over the area with strong high pressure centered over the Mid-Atlantic states wedging down the eastern seaboard and weak Atlantic low pressure lingering to the southeast. The Wind Advisory has been extended into this evening for the gusty north-northeasterly winds along the SE GA and NE FL coasts. Wind gusts could reach up to 40-45 mph at times. Breezy conditions linger overnight with the continued tight pressure gradient. Waves of scattered coastal showers will shift onshore through the evening hours mainly for coastal NE FL, St Johns River basin and north-central FL. A few convergent bands may form along the NE FL coast bringing heavier downpours and localized flooding. If these bands coincide with high tide cycles, this could exacerbate the already significant tidal flooding expected. Shower activity wanes overnight with a few coastal showers shifting onshore mainly south of St. Augustine. Meanwhile, a drier airmass (PWATs < 1 in) will keep inland SE GA and Suwannee Valley rain-free. ...Overcast skies and breezy onshore winds will keep highs below seasonable in the low 70s along the coast to around 80 west of I-75. Overnight lows will range from the mid 50s in SE GA to the upper 60s along the NE FL coast.

SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/

Main Highlights This Period:

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

- Wind Advisory Conditions are Likely to Continue through Monday Afternoon at Coastal Locations.

- Gale Warnings Continue for the Atlantic Waters through Monday Night.

- 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.

A highly amplified pattern aloft will continue early this week, with a cutoff trough meandering near Bermuda, while ridging initially extending across the lower Mississippi and Tennessee Valleys shifting slowly eastward across the southeastern states, with this feature directing a series of shortwave troughs northeastward from the Desert Southwest and Rockies towards the northern Plains and the Upper Midwest. Meanwhile, a slowly weakening surface high pressure center centered over the Southern Appalachians will slowly weaken and 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 through Monday.

Wind Advisory criteria will likely continue for coastal locations on Monday, where sustained speeds of 25-30 mph are forecast, with frequent gusts of 35-45 mph possible through Monday evening. This coastal trough will yield enough low level convergence to occasionally drive bands of showers onshore across coastal northeast FL, the I-95 corridor and portions of the St. Johns River basin on Monday before a seasonably dry air mass that will be in place across southeast GA and the Suwannee Valley advects southward on Monday night and Tuesday, which will shift shower activity south of our region. Low stratus cloud cover will persist across most of northeast FL and coastal southeast GA on Monday, where highs will mostly remain in the lower or mid 70s. A drier air mass over interior southeast GA, the Suwannee Valley and north central FL will allow for breaks in the stratus and stratocumulus to develop during the afternoon hours, allowing highs to climb to the mid and upper 70s, with a few lower 80s possible across north central FL. A gradual loosening of our local pressure gradient on Monday night will allow for winds to decouple overnight across inland southeast GA and northern portions of the Suwannee Valley, where fair skies will allow lows to fall into the upper 40s and lower 50s. Lows elsewhere inland will fall into the 50s, except lower 60s for north central FL. Breezy onshore winds keep will lows in the 60s at coastal locations.

Breezy northeasterly winds will continue on Tuesday across northeast and north central FL, but the drier air mass advecting into these areas and rising heights aloft will boost highs to the upper 70s and lower 80s inland, with mid to upper 70s forecast at coastal locations. An isolated brief shower could still advect onshore across coastal northeast FL, but dry weather will otherwise continue into Tuesday night, when our local pressure gradient will begin tightening late 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.

LONG TERM /WEDNESDAY THROUGH SATURDAY/

Main Highlights This Period:

- Coastal Shower Coverage Increases along the I-95 Corridor as Northeasterly Winds Again Surge from late Wednesday through Friday.

Troughing aloft and low surface pressures over the Bahamas on Wednesday will finally shift northeastward and away from our region late in the week. However, reinforcing high pressure centered over New England on Wednesday morning will slowly shift offshore while wedging down the southeastern seaboard, creating another round of gusty northeasterly winds at coastal locations for the duration of the upcoming week as coastal troughing remains situated over our local Atlantic waters. This long duration wind event will maintain significant coastal and marine impacts as high astronomical tides associated with the midweek lunar perigee begin to only gradually subside by Friday and Saturday. A tightening local pressure gradient may result in another round of Wind Advisory conditions, especially for coastal northeast FL by late Wednesday and Thursday.

Coastal troughing will re-sharpen over our local waters on Wednesday, directing another surge of Atlantic moisture towards coastal northeast FL. High pressure wedging down the southeastern seaboard will strengthen low level convergence, which will advect showers occasionally onshore from the Atlantic waters across the I-95 corridor for the balance of the work week. Gusty onshore winds will keep highs mostly in the mid 70s along the I-95 corridor on Wednesday and Thursday, with upper 70s and lower 80s prevailing inland. A slightly drier air mass lingering over inland southeast GA and the Suwannee Valley will allow lows to fall to the upper 50s to near 60, while coastal lows generally remain in the 65-70 degree range.

Ridging aloft developing over the Gulf late this week will begin to build northeastward towards our region, allowing for heights to rise locally. Although multi-layered cloud cover will continue across our region, inland highs should rebound to the low and possibly mid 80s by next weekend, with coastal highs remaining in the 70s due to breezy onshore winds. Lows will trend above late October climatology by Friday and Saturday, with 60s possible area-wide by Friday and Saturday nights.

AVIATION /12Z SUNDAY THROUGH 12Z MONDAY/

MVFR CIGS and gusty NNE winds will dominate through the TAF period. Winds range from 10-15 knots inland and 15-22 knots for the Atlantic Coastal terminals with gusts to 20-25 knots inland and increasing back to around 30 knots through the afternoon hours. Only isolated (VCSH) activity through most of the TAF period for NE FL terminals, but Hi Res models are suggesting another round of heavier showers with at least MVFR VSBYS are possible in the 18-24Z time frame later today so have added PROB30 groups to CRG/SGJ, but will monitor for potential IFR VSBYS in this activity if it develops. NNE winds will slowly fade later tonight after 03Z, returning to 10-15 knots inland, but lower confidence in any lifting of CIGS to VFR late in the TAF period, so have left MVFR CIGS for now.

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 into Monday. 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 and Monday as breakers reach the 8-10 ft range at the northeast FL beaches and 5-7 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.

Rip Currents / High Surf: High Surf Advisories have been extended through Tuesday night for our entire Atlantic coastline, with surf peaking today and Monday as breakers reach the 8-10 ft range at the northeast FL beaches and 5-7 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 CONTINUE FOR PORTIONS OF OUR AREA DURING THE NEXT SEVERAL DAYS.

Scattered to numerous showers will continue to occasionally move onshore from the Atlantic waters through Monday evening, mainly along the northeast Florida coast, with activity extending inland to around the U.S. Highway 301 corridor. Dry weather will otherwise continue during the next several days across most of inland southeast Georgia and the Suwannee Valley. Additional rounds of coastal showers will redevelop towards midweek along the I-95 corridor. Gusty northeasterly surface and transport winds will continue through Monday, creating elevated nighttime dispersion values for coastal southeast Georgia and most of northeast and north central Florida tonight. Good daytime dispersion values will likely prevail during the next several days across our region. Northeasterly surface and transport winds will briefly diminish from Monday night through Tuesday night across inland southeast Georgia and the northern Suwannee Valley, while breezy conditions continue elsewhere. Elevated nighttime dispersion values will continue at coastal locations for much of the upcoming week, as northeasterly surface and transport winds likely re-strengthen by Wednesday and Thursday across our area.

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

HYDROLOGY

Water levels continue to gradually fall along lower portions of the Satilla River in southeast GA. Flood Warnings will be discontinued later this morning as water levels fall below flood stage at the gauge near Atkinson.

TIDES/COASTAL FLOODING

Continued strong north-northeasterly winds combined with the highest astronomical tides of the year (Hunter's moon) will yield water levels reaching moderate flood levels with a few spots reaching major flood levels during the high tide cycles today and Monday. Peak water levels are anticipated to be 2.5 to 3.5 feet above Mean Higher High Water (MHHW) during times of high tide. 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 55 76 51 / 0 0 0 0 SSI 72 60 73 61 / 10 0 0 0 JAX 73 63 76 60 / 20 20 10 0 SGJ 77 68 77 68 / 70 70 50 20 GNV 78 64 79 61 / 10 20 10 0 OCF 80 65 80 62 / 10 20 10 0

JAX WATCHES/WARNINGS/ADVISORIES

FL...Coastal Flood Warning until 5 AM EDT Wednesday for FLZ038-124- 125-132-137-138-225-233-325-333-633. Wind Advisory until 8 PM EDT this evening for FLZ038-124-125- 138-233-333-433-533. High Risk for Rip Currents through late Tuesday night for FLZ124- 125-138-233-333. High Surf Advisory until 2 AM EDT Wednesday for FLZ124-125-138- 233-333. GA...Wind Advisory until 8 PM EDT this evening for GAZ154-166. High Risk for Rip Currents through late Tuesday night for GAZ154- 166. High Surf Advisory until 2 AM EDT Wednesday for GAZ154-166. Coastal Flood Warning until 11 AM EDT Tuesday for GAZ154-166. MARINE...Gale Warning until 2 AM EDT Tuesday for AMZ450-452-454-470-472. Gale Warning until 2 AM EDT Wednesday for AMZ474.