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

- Increasing Daily Thunderstorm and Heavy Downpour Coverage. Waves of Heavy Downpours May Increase the Threat for Localized Flooding this Weekend and into Next Week

- Moderate Rip Current Risk all Area Beaches through Monday

- Coastal and Marine Hazards Increase Next Week. Strong & Gusty Northeast Winds Arrive Monday Night. Gale Conditions Likely for the Atlantic Waters Tuesday through Wednesday. Deadly Rip Currents, Rough Surf & Substantial Beach Erosion Likely. Moderate Tidal Flooding Risk Tuesday through Thursday Along the Atlantic Coast, Intracoastal Waterway & Tidal Tributaries of the St. Johns & St. Marys River Basins

NEAR TERM /THROUGH TONIGHT/

Main Highlights Today and Tonight:

- Numerous showers and scattered thunderstorms this afternoon and into the evening; Highest coverage inland areas along the Suwannee river and interior Southeast GA.

- Localized heavy downpours may lead to brief periods of flooding, especially for inland areas.

Deep moisture, with PWATs 2-2.3", will fuel showers and thunderstorms along the Atlantic sea breeze as it pushes during the early afternoon. Meanwhile, another embedded impulse will track northeastward across the northern Gulf coast and toward the Suwannee River valley and inland SE GA during the afternoon into evening hours. Highest coverage will likely be inland areas along the Suwannee river and interior Southeast GA due to interactions with the passing impulses and sea breeze boundaries. While numerous showers are expected inland, the potential for locally heavy rain remains a bit too spotty to warrant a Flood Watch for this afternoon's activity. Like yesterday, there is potential for heavy downpours to train locally and lead to 2-4" of rain and localized flooding. Highest concern for isolated flooding will be across the Suwannee Valley and interior areas of southeast GA.

Overcast skies and convection will limit afternoon highs to the mid- upper 80s. Another seasonably mild night in the low to mid 70s is expected once again. Cloud cover will limit fog development but patchy light fog may form, especially over soggy grounds in inland areas.

SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/

Main Highlights This Period:

- Localized heavy downpours and flooding possible.

South/southwesterly flow ahead of a frontal passage will continue to bring high PWATs across the area, increasing precipitation chances area-wide. Waves of showers with embedded thunderstorms will move across the area Sunday and Monday, including during the overnight hours. The main concern during this period will be localized flooding, especially over normal flood prone and urban areas.

With the passing showers and cloud cover over the area, daytime highs in the upper 80s is forecast for much of the area on Sunday with locations across north central FL possibly reaching into the lower 90s. By Monday, the sinking cold front and continued showers and cloud cover will bring cooler temperatures across the area with upper 70s to mid 80s from SE GA and south towards the I-10 corridor in NE FL, with mid to upper 80s across north central FL.

LONG TERM /TUESDAY THROUGH SATURDAY/

Main Highlights This Period:

- Strong northeast flow pattern through Thursday, with potential for Minor to Moderate Tidal Flooding, Rough Surf, and Gusty Coastal Conditions.

- Potential for rounds of heavy rainfall, and a few strong to severe thunderstorms can not be ruled out

A local nor'easter is expected to develop Tuesday as an area of low pressure develops along the stalled frontal boundary northeast of the area. With a tight gradient between the low pressure to the northeast of the area and high pressure over the Great Lakes region, strong onshore winds are expected to develop, bring a slew of hazards. Waves of showers and isolated embedded thunderstorms will move onshore through the period, with highest rainfall totals and flooding concerns mainly along the Atlantic coast. From Tuesday through Friday, drier air will slowly inch into southeast Georgia, lowering precipitation chances a little bit each day. Breezy winds will bring peak wind gusts of 30-40 mph along the coast and St. Johns river basin, a Wind Advisory may be needed for Tuesday afternoon for the beaches. Dangerous beach and marine conditions are expected, including coastal erosion, high rip current risk, high surf, and Small Craft Advisory and/or Gale conditions over the local waters. In addition, we will likely see minor to moderate tidal flooding along the northeast Florida and southeast Georgia coasts, the ICWW, and St. Johns river basin. With the forecast rainfall amounts being highest near these same areas as tidal flooding, flooding may be enhanced further around times of high tide.

High cloud cover, enhanced precipitation chances, and northerly flow will keep temperatures below normal Tuesday through Friday, with highs in the mid 70s to low 80s.

AVIATION /18Z SATURDAY THROUGH 18Z SUNDAY/

Isolated showers and storms will pass in the vicinity of SSI between now and 19Z. A few showers will move through SGJ, CRG and JAX as the Atlantic sea breeze shifts inland. Coverage increases for more inland sites like VQQ and GNV. Heavy downpours with thunderstorms could lower VSBYs to IFR/MVFR. Patchy fog and low stratus may develop at GNV/VQQ between 09-12Z. Outside of shower and storm influence winds will favor an east-southeasterly direction around 5- 10 knots.

MARINE

Southeasterly wind continues over the weekend with waves of showers and thunderstorms moving from south to north. Outside of thunderstorm activity, winds and seas are expected to remain below Caution levels through at least Monday afternoon.

Deteriorating conditions are expected Tuesday as cold front enters and stalls over the area waters. Following the front, a strong high pressure building will wedge down the southeastern seaboard, initiating a prolonged surge of strong northeasterly winds and high seas across our local waters. Small Craft Advisory conditions are likely by Tuesday, with the potential for wind gusts near Gale force through Thursday. Northeasterly winds are expected to gradually decrease through Friday, allowing seas to lower thereafter.

Rip Currents: Persistent onshore winds and 2 to 3 foot breakers will maintain a higher end moderate risk at all area beaches through Monday. Dangerous surf conditions are expected to develop on Tuesday as northeasterly winds strengthen, with the likelihood for very rough surf and deadly rip currents from Tuesday through the end of next week, with breakers potentially building to 8-10 feet at the northeast FL beaches and 6-8 feet at the southeast GA beaches by midweek.

FIRE WEATHER

- Areas Of Low Daytime Dispersions Through Tuesday

Waves of rain with embedded thunderstorms are expected over the weekend and through next week, due to an inverted trough over the Gulf, and its associated frontal boundary which will gradually sink south across the area. Lower mixing heights across much of the area will lead to poor dispersions to develop through the weekend and into Monday for the entire forecast area, and low dispersion continues for portions of northeast Florida Tuesday. An area of low pressure is expected to develop just to the northeast Tuesday, bringing elevated northeasterly winds to the area, especially along coastal locations.

Fog Potential...Significant fog is not expected tonight. Gusty and erratic winds in and near thunderstorms. Locally heavy rainfall with localized flooding possible each day this period.

PRELIMINARY POINT TEMPS/POPS

AMG 71 83 70 76 / 30 90 90 90 SSI 74 84 72 80 / 40 70 80 100 JAX 72 86 73 81 / 20 70 80 90 SGJ 75 87 74 83 / 20 60 60 90 GNV 72 88 73 83 / 50 60 50 90 OCF 73 90 74 86 / 60 50 40 80

JAX WATCHES/WARNINGS/ADVISORIES

FL...None. GA...None. MARINE...None.