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 through Wednesday. High Rip Current Risk through Wednesday at the Northeast FL Beaches. Small Craft Advisories for the Near Shore Atlantic Waters Adjacent to Northeast FL Continue through this Evening.

- Minor Tidal Flooding Continues within the St. Johns River Basin through at least Wednesday Night.

- Isolated Afternoon Thunderstorm Potential through Friday.

- Dense Morning Fog Potential Possible Early on Thursday and Friday Mornings.

NEAR TERM /THROUGH TONIGHT/

Main Highlights:

- Minor Tidal Flooding Continues Within the St. Johns River Basin.

- Rough surf and Dangerous Rip Currents Continue at the Northeast FL Beaches through Wednesday.

- Isolated Thunderstorms Possible Late this Afternoon, Mainly for Locations West of I-75.

Afternoon surface analysis depicts strong high pressure (1031 millibars) centered to the east of Cape Cod and north of Bermuda, with this feature extending its axis southwestward across the southeastern states. Meanwhile, coastal troughing remains situated over our near shore Atlantic waters. Otherwise, a lengthy cold front stretches from Lake Superior southward through the Upper Midwest, the Ozarks, and eastern Texas. Aloft...troughing that was in place over our area during the past few days has split into two cutoff troughs, with one of these features near Bermuda and the other over the far southeast Gulf. Ridging aloft now prevails over the southeastern states, with this feature poised to deflect a potent shortwave trough progressing across the southern Plains states northeastward. Latest GOES-East derived Total Precipitable Water imagery indicates that an unseasonably moist air mass continues to overspread our region from southeast to northwest, with PWATs now in the 1.6 to 1.9 inch range throughout our area. Coastal troughing and deepening southeasterly flow that drove showers onshore from the Atlantic waters early this morning continue to progress inland, with widely scattered activity now extending from around Crescent Lake and Lake George in Putnam/Flagler Counties northwestward across the Suwannee Valley and portions of inland southeast GA. Outside of rain cooled locations, temperatures at 20Z were mostly in the upper 70s and lower 80s, with dewpoints ranging from the mid 60s to the lower 70s.

Deepening southeasterly flow will pin the Gulf coast sea breeze near or just west of Interstate 75 this afternoon, where a potential sea breeze collision could develop an isolated thunderstorm or two, mainly for locations near and west of Interstate 75. Showers or isolated thunderstorms that develop this afternoon should dissipate or push west of the Suwannee and Alapaha Rivers around or shortly after sunset. Mid and high altitude cloud cover may increase after midnight from west to east, while deep southeasterly flow potentially advects isolated showers onshore along the I-95 corridor after midnight. Low stratus cloud cover is also expected to increase at inland locations towards sunrise, with lows only falling to the upper 60s inland and the lower 70s at coastal locations.

SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/

Main Highlights This Period:

- High Risk for Rip Currents Continues at Area Beaches through Midweek.

- Isolated Thunderstorms Possible at Inland Locations, Mostly on Wednesday Afternoon and Evening.

- Areas of Dense Fog Possible on Thursday and Friday Mornings. High pressure along the eastern seaboard will begin to push offshore as a frontal boundary begins to push towards the eastern US due to its parent Low over the Central Plains shifting towards the Great Lakes. Easterly to southeasterly flow will be in place for much of the area midweek as the high pressure begins to move offshore towards the Atlantic. With the approaching frontal boundary, which currently is likely to remain west of the area during the forecast period, will bring a southwesterly shift in winds across inland locations first, then the rest of the area by Thursday Night. Shower and storm activity will be possible during the afternoon hours on Wednesday and Thursday primarily along inland locations near the I- 75 corridor on Wednesday, with activity pushing further eastward on Thursday as southwesterly flow becomes established along the western locations of the area ahead of the front.

Daytime highs will reach into the low to mid 80s across inland locations while the onshore flow will keep coastal locations a bit cooler in the upper 70s to lower 80s. Overnight lows will be around the mid 60s inland and mid to upper 60s along the coast. The light winds and low-level moisture could be enough to bring some fog development during the early morning hours.

LONG TERM /FRIDAY THROUGH TUESDAY/

Main Highlights This Period:

- Isolated Afternoon Thunderstorms Possible on Friday.

- Slightly Cooler and Drier Conditions Expected this Weekend.

- Strong Cold Front Possibly Approaches Our Area on Sunday Night.

As it's parent Low continues to shift towards the NE US, the cold front will begin to push into the area sometime on Friday Night and push south of the area by Sunday Night. Currently scattered chances of showers and isolated storms is forecast on Friday. After the front's passage, drier air filters into the area which will keep conditions on the dry side for the upcoming weekend. Cooler temperatures will begin to build into the area behind the front. Daytime Highs in the 80s on Friday will cool into the lower 70s by Monday. Overnight Lows in the upper 50s across SE GA and Suwannee Valley on Friday will dip to the mid 40s by Monday, while lower 60s across NE FL on Friday dip into the 50s by Monday.

AVIATION /18Z TUESDAY THROUGH 18Z WEDNESDAY/

Showers will continue to move inland and away from the Duval County terminals and SGJ, and VFR conditions will prevail at these terminals and SSI through at least 06Z. Showers may impact the GNV terminal after 19Z, but confidence was only high enough to include a PROB30 group for MVFR conditions during potential heavier downpours through around 23Z. There remains a low probability for a few thunderstorms develop along the Gulf coast sea breeze near or west of I-75 corridor after 20Z, with confidence too low to indicate vicinity thunderstorm coverage at this time. MVFR to possibly IFR conditions are expected to develop at VQQ after 06Z, with confidence currently too low to indicate IFR conditions during the predawn and early morning hours at this time. VFR conditions are then likely to prevail at VQQ after 12Z. Low stratus cloud cover is expected to develop after 09Z at GNV, with low MVFR ceilings have been placed in the TAF through around 14Z. A brief period of MVFR ceilings will be possible at JAX, CRG, SSI, and SGJ around sunrise, but confidence remains too low to include in the TAFs at this time. Easterly surface winds will remain sustained at 10-15 knots and gusty through around 22Z before diminishing to 5-10 knots towards 23Z and then 5 knots or less by 06Z. Southeasterly surface winds of 5-10 knots are expected to prevail at the regional terminals after 14Z Wednesday.

MARINE

Strong high pressure centered off the mid-Atlantic coast will shift further eastward tonight as a coastal trough remains situated over near shore waters. Breezy onshore winds will maintain elevated seas through tonight, with Small Craft Advisory conditions prevailing offshore and continuing through this evening for the near shore waters adjacent to northeast Florida. Another round of overnight showers may develop overnight tonight across our local water. Small Craft Advisory conditions prevail offshore through the overnight hours tonight before diminishing to Caution levels on Wednesday. Meanwhile, a cold front will move into the southeastern states on Wednesday night before slowing its forward progress late this week. Southeasterly winds on Thursday will shift to southerly overnight and then southwesterly on Friday ahead of this front, followed by prevailing northwest to northerly winds this weekend in the wake of the frontal passage. A reinforcing cold front will then cross our local waters on Sunday night and Monday morning, with high pressure building over the lower Mississippi Valley providing a surge of breezy northwesterly winds in the wake of this frontal passage.

Rip Currents / High Surf:

Dangerous surf zone conditions will continue at the northeast FL beaches through Wednesday, where a high rip current risk is forecast, as breakers of 4 to 6 feet this afternoon diminish to the 3-5 foot range on Wednesday. A higher end moderate risk is forecast at the southeast GA beaches on Wednesday, where breakers of 2 to 4 feet are expected. A lingering easterly ocean swell will likely yield a moderate risk at all area beaches on Thursday and Friday.

FIRE WEATHER

Onshore easterly-southeasterly winds remain heading into midweek. An approaching cold front from the west will bring a shift to southwesterly winds during the back half of the week. Fair to Good daytime dispersions midweek will begin to worsen as winds weaken, becoming Poor to Fair by Thursday and Friday. There will continue to be scattered chances of showers and isolated storms over the next couple of days ahead of the cold front. Drier weather is expected behind the front over the upcoming weekend.

FOG POTENTIAL AND OTHER WEATHER REMARKS: Patchy to areas of fog formation are possible for inland locations along and north of the I- 10 corridor. Areas to widespread fog will be possible during the predawn and early morning hours on Thursday and Friday across our area.

TIDES/COASTAL FLOODING

Due to the persistent onshore wind, tidal levels within the St. Johns River basin and it's tributaries have remained steady, reaching minor flood levels at high tide over the last 24 hours. Recent peak water levels in this area have been roughly 1.55 to 1.9 feet MHHW. Minor flooding will likely continue into Wednesday as onshore flow decreases into Thursday allowing water to drain into the Atlantic. A Coastal Flood Advisory remains in effect for the entire middle and lower St. Johns River zones. One caveat is that the recent heavy rainfall over central FL may allow elevated water levels to linger in the St Johns river basin late this week as it drains northward.

PRELIMINARY POINT TEMPS/POPS

AMG 67 84 67 84 / 20 20 40 30 SSI 71 78 67 79 / 20 0 0 10 JAX 68 83 66 84 / 20 10 10 20 SGJ 72 81 68 82 / 20 0 10 10 GNV 69 86 67 86 / 20 30 20 30 OCF 69 86 68 86 / 20 30 20 10

JAX WATCHES/WARNINGS/ADVISORIES

FL...Coastal Flood Advisory until 4 AM EST Thursday for FLZ038-125- 132-137-225-325-633. High Risk for Rip Currents through late Wednesday night for FLZ124- 125-138-233-333. GA...High Risk for Rip Currents through late tonight for GAZ154-166. MARINE...Small Craft Advisory until 10 PM EST this evening for AMZ452- 454-470. Small Craft Advisory until 4 AM EST Wednesday for AMZ472-474.