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 this Weekend. Moderate Tidal Flooding Continues south of Shands Bridge through. High Rip Current Risk and High Surf at all beaches through Sunday. Small Craft Advisories Continue through Sunday. Strong Gusts at the beaches Today and Sunday (around 30-35 mph)

- Heavy Rainfall and Localized Flood Potential for Northeast FL at. Isolated Thunderstorms Possible on Sunday and Sunday Night. Rainfall amounts 1-3 localized amounts up to 4 for Northeast FL

NEAR TERM /THROUGH TONIGHT/

Main Highlights:

- Minor to Moderate tidal flooding continues along the St Johns River basin, NE FL Atlantic Coast, and ICW

- Rough surf and dangerous rip currents continue

Backdoor cold front is currently situated over North Carolina will continue making a southern push into the area through this morning, stalling and weakening almost directly across the area this evening and tonight. A "fresh" high pressure ridge will build down the southeastern seaboard in its wake throughout the day today, tightening the pressure gradient a bit and therefore enhancing the onshore flow once again. Ahead of the front, a diffuse band of showers currently streaming onshore the northeast FL coast is expected to pivot northward this morning, taking advantange of better lift and moisture ahead of the front. This will shift rain chances more so towards coastal I-10 corridor and northward, though a few showers will be possible across much of northeast FL overall with the continued onshore flow and the weakening frontal boundary stalling near northeast FL.

Breezier overall over inland areas today, though only a few mph breezier on average for the coast and St. Johns River where the onshore flow has been persistent. This will keep up/reinforce coastal and beach hazards today and through Sunday, as a high risk for rip currents, elevated surf, and coastal flooding will persist. The good news is astronomical influence continues to subside this weekend, and therefore not expecting a significant increase in tidal flooding potential. Mostly minor flooding is forecast (around 1.5- 2ft above normal dry ground) at times of high tide, with moderate flooding (around or just over 2ft above dry ground) expected in portions of the St. Johns River near Putnam County.

Tonight, scattered showers will persist at times, especially over north FL where the weak boundary settles. Lows will range from the low to mid 60s north to the low 70s south and east, after high temps in the mid 70s to low 80s for most this afternoon.

SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/

Main Highlights This Period:

- Coastal flooding and surf hazards continue.

- Marginal Risk of Flooding due to Excessive Rainfall

Despite the persistent onshore flow in place and coastal hazards continuing through Sunday and early next week, there will be wetter conditions during this period. The primary features will be a diffuse stationary front draped across central FL while an upper shortwave gradually lifts out of the eastern Gulf. Though the trough is trending slightly slower, compared to 24 hours ago, the associated with it is likely to induce a surface wave of low pressure along the stalled frontal zone. Taking the strong ascent, deeper moisture (PWATs up to 1.75"), and enhanced convergence, it's likely that several bouts of heavy rain and coastal banding will develop through the late afternoon Sunday and continuing through the overnight hours into Monday, especially for the NE FL zones. While isolated thunderstorms may develop during the afternoon, especially toward the I-75 corridor, available buoyancy is expected to be marginal and be more conducive to heavy rain showers.

Spread among guidance in terms of how much rain remains a bit wide, but reasonable expectations are around 2-3" with locally higher amounts. As of right now, WPC has an areawide "Marginal Risk" of excessive rainfall and focused "Slight Risk", highlight the heavy rain/flood potential Sunday into Monday. Heavier rainfall may continue along the coast throughout Monday as an inverted coastal trough develops in the wake of the passing wave of low pressure.

Wet and overcast conditions will keep temperature readings in the upper 70s during the days with mild conditions in the 60s overnight.

LONG TERM /TUESDAY THROUGH FRIDAY/

Main Highlights This Period:

- Thunderstorm potential returns Thursday.

- Diminishing onshore flow and improving coastal and surf zone conditions.

Moist, local nor'easter will relent during the first half of next week as trough digs across the southern tier of the CONUS. As the system pushes toward the region steering flow will veer to the southeast helping to alleviate the tidal flooding with the St Johns River. There remains fair agreement among clustered ensembles, deterministic and AI models that the amplified upper trough will push a cold front in from the west around Thursday next week. Trends over the last 24 hours suggest the front may slow or stall across the southeast as the parent trough ejects to the northeast. While the potential for severe thunderstorms appears low, it can't be ruled out entirely. Temperatures will initially warm amid the southeasterly flow but should cool slightly to seasonable readings with the front Friday and into the weekend.

AVIATION /12Z SATURDAY THROUGH 12Z SUNDAY/

The 12Z period will start with restrictions for IFR ceilings at CRG/JAX/VQQ/GNV generally between 0.5-1.0 kft through 14Z with scattered ceilings ranging from 3.0 kft near SGJ and may lower to 1.5 kft at SSI as a front sinks southward and showers approach from the east through 15Z there.

A front moving southward to the area and increasing moisture will bring some potential for showers at the SSI terminals during the afternoon hours, so have placed a PROB30 group for MVFR ceilings and visibilities after 18Z until 00Z. Otherwise, the confidence in placement of showers is less, so have VCSH for all sites this afternoon, with a lull after 00Z. Winds will increase today as high pressure wedges down the southeast coast behind the front moving in from the north and pinching the local pressure gradient. Winds will rise to the about 15 knots gusting to 25 knots at SGJ/SSI/CRG/JAX with 12-15 knots inland gusting to 20-25 knots this afternoon.

Have increasing mid level clouds tonight with VCSH noted at Duval county and SSI terminals as the front weakens as it moves into Northeast FL. Winds will diminish some along the coast after 00Z to 10-12 knots and gusting to 20 knots with just under 10 knots inland overnight. Will ascertain if lower ceilings appear more likely late tonight with subsequent forecast, but for now confidence is too low for mention.

MARINE

A strong high pressure ridge will build southward across area waters today behind a weakening cold front. This ridging will then wedge down the southeastern seaboard this weekend and early next week. A slight surge in northeasterly winds today will return hazards across the coastal waters once again for the weekend. A wavy stationary frontal boundary lifting slowly northward across the Florida peninsula late this weekend will return more numerous showers and a few embedded thunderstorms on Sunday and Monday across our local waters. High pressure will then build more northeast of the region towards mid week before another cold front approaches from the northwest.

Rip Currents / High Surf: High rip current risk continues at all area beaches through this weekend as another surge of onshore flow arrives today. This will also return surf heights of up to 5 to 7 feet by this evening, and hence a High Surf Advisory will begin once again this evening.

FIRE WEATHER

HIGH NIGHTTIME DISPERSIONS FOR THE COAST TONIGHT AND SUNDAY NIGHT..

A cold front will lead to strengthening northeasterly winds through the weekend, especially at the coast with gusts up to 30 mph. Isolated afternoon thunderstorms possible Sunday, primarily along the I-75 corridor with a passing wave of low pressure. Rain chances stick around through early next week, favoring the coast and I-95 corridor. Winds will begin to shift easterly next week then southerly by midweek as speeds diminish. Otherwise, mild and humid conditions continue.

FOG POTENTIAL AND OTHER WEATHER REMARKS: Significant fog formation is not expected through Monday. Locally heavy rain is possible across NE FL Sunday afternoon through Monday.

TIDES/COASTAL FLOODING

Relatively lower astronomical tides will allow for mostly minor coastal flooding along the coast, ICW and portions of the St Johns River through the weekend. Coastal Flood Warning only continues for eastern Putnam County at this time for areas along the St Johns River where localized peaks into moderate flood stage are still anticipated the next couple of high tide cycles. ENE winds increase again today, maintaining reverse flow/trapped tides in the St Johns river and continuing beach erosion along the Atlantic coast. Flood levels may rise back into moderate Sunday into early next week along the St Johns river.

PRELIMINARY POINT TEMPS/POPS

AMG 79 63 76 62 / 10 10 30 40 SSI 76 64 74 63 / 40 40 40 60 JAX 79 66 77 64 / 40 30 60 60 SGJ 79 70 77 67 / 10 20 60 70 GNV 83 69 79 65 / 10 20 50 60 OCF 84 70 80 66 / 20 40 50 60

JAX WATCHES/WARNINGS/ADVISORIES

FL...Coastal Flood Advisory until 5 AM EDT Sunday for FLZ038-124- 125-132-138-225-233-325-333-633. High Risk for Rip Currents through Sunday evening for FLZ124-125- 138-233-333. High Surf Advisory from 5 PM this afternoon to 7 PM EDT Sunday for FLZ124-125-138-233-333. Coastal Flood Warning until 5 AM EDT Sunday for FLZ137. GA...High Risk for Rip Currents through Sunday evening for GAZ154-166. High Surf Advisory from 5 PM this afternoon to 7 PM EDT Sunday for GAZ154-166. MARINE...Small Craft Advisory from 2 PM this afternoon to 7 PM EDT Sunday for AMZ450-452-454. Small Craft Advisory until 7 PM EDT Sunday for AMZ470-472-474.