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 with Minor Tidal Flooding for St. Johns River Basin, High Rip Current Risk and High Surf (Northeast FL Beaches), and Small Craft Advisories (which will end this evening).

- Isolated Afternoon Thunderstorm Potential through Friday

- Locally Dense Morning Fog Possible Wednesday, Thursday, & Friday.

NEAR TERM /THROUGH TONIGHT/

Main Highlights:

- Minor tidal flooding within the St Johns River basin continues

- Rough surf and dangerous rip currents continue

Strong high pressure centered off the mid-Atlantic coast continues to extend its ridge axis into the SE US continuing another day of breezy easterly winds for our area. Light showers continue over north-central FL early this morning and should dissipate by sunrise. A few coastal showers shift onshore mid- morning and then migrate inland and increase in coverage along the I-75 corridor later this afternoon. An isolated embedded thunderstorm cannot be ruled out across north central FL this afternoon. Breezy onshore winds will keep highs in the upper 70s along the immediate coast, while rising heights aloft will boost highs to the low and mid 80s for locations along and west of I-95. Shower activity should wane by sunset. An increasing cirrus shield likely develops from west to east during the predawn and early morning hours on Wednesday. Mild and unseasonably humid conditions should foster low stratus cloud cover to develop at inland locations, with patchy fog possible for inland locations towards sunrise. Lows will only fall to the mid and upper 60s inland and the lower 70s at coastal locations, where an onshore breeze will continue overnight.

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 Wednesday, Thursday and Friday morning.

Onshore flow will begin to shift southeasterly briefly as an upper trough approaches through Wednesday. Warm and humid conditions with an axis of deeper moisture strung along the I-75 corridor will foster enough instability for scattered showers and isolated thunderstorms during the afternoon Wednesday. The cold front associated with the upper wave will encounter resistance by the stubborn ridging to the northeast resulting in the front to slow to a stall to the west. With the front hung up to the west, light southwesterly flow will develop across the area leading to another diurnal afternoon of sea breeze convection with the best chances shifting eastward between the I-75 and US-301 corridors. The stalled front may begin to shift eastward into the inland SE GA zones Thursday night as phasing shortwaves dig across the lower Mississippi valley which may result in a few showers through the overnight hours.

Each day will feature inland high temperatures into the mid 80s and nearing daily record territory. Onshore winds will keep the beaches cooler by about 5 degrees or so each day. Due the boundary layer moisture and light winds, there will be an increasing potential for widespread low stratus and fog potential each night, which may result areas of dense fog during Thursday and Friday morning commutes.

LONG TERM /FRIDAY THROUGH MONDAY/

Main Highlights This Period:

- Warm and Unseasonably Humid Weather Continues through at Least Thursday Night.

- Isolated Afternoon Thunderstorms Possible on Friday.

- Slightly Cooler and Drier Conditions Expected this Weekend.

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

A reinforcing upper trough is expected to sweep across the area Friday night. Before the trough axis sweeps across the area, there may end up being enough moisture pooled along the front to support scattered afternoon thunderstorms along the prefrontal trough as it pushes across the area. There remains uncertainty regarding the amount of moisture, but, as confidence increases, rain changes are likely going to rise on Friday. Though some model discrepancies exist, it does appear that the weekend should be mostly rain free but cloudy under the influence of broad longwave troughing. Behind a second passing cold front and on the backside of the longwave trough, deep northwesterly will advect a much drier and colder airmass into the area next week with below normal temperatures expected.

AVIATION /06Z TUESDAY THROUGH 06Z WEDNESDAY/

Rounds of light showers will move through GNV and SGJ this morning with showers continuing into the afternoon hours for GNV. MVFR CIGs develop early this morning across inland TAF sites with the potential for IFR CIGs at GNV. CIGs lift to VFR by 15Z. ENE winds of 5-10 kts this morning increase to 10-15 kts with gusts up to 20 kts after 15Z.

MARINE

Strong high pressure centered off the mid-Atlantic coast today will shift further into the Atlantic through Thursday as a cold front approaches the area toward the end of the work week. The tight pressure gradient gradually relaxes today into tonight as winds and seas drop below small craft advisory levels. Rounds of showers and heavy downpours will be possible through the middle of the week, especially Today as coastal troughing develops. Winds shift to southwesterly on Friday ahead of the cold front and then to west- northwesterly for the weekend in the wake of the front.

Rip Currents / High Surf:

Dangerous surf zone conditions continue with a High rip current risk at all area beaches today and elevated to high surf for the entire coast. The highest breakers, around 5-7 feet will be from Ponte Vedra south. Conditions gradually improve through the week as onshore winds and surf decrease.

FIRE WEATHER

Easterly winds will prevail through Wednesday before becoming light Thursday as a front stalls to the west. This will translate to fair dispersions, except at the coastal/barrier islands, today and Wednesday. Poor to low dispersion is more likely on Thursday as transport winds diminish. Continued shower chances each day with isolated thunderstorms possible in the afternoon Wednesday and Thursday. The stalled front will weakly push across the area Friday followed by a stronger and drier cold front this weekend setting up a cooler and drier couple of days early next week.

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 81 66 84 66 / 10 0 30 20 SSI 78 68 78 66 / 10 0 10 0 JAX 81 68 82 66 / 10 0 10 0 SGJ 80 71 80 68 / 10 10 20 10 GNV 83 68 85 67 / 30 10 40 10 OCF 84 69 86 68 / 50 10 40 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. High Surf Advisory until 4 AM EST Wednesday for FLZ138-233-333. GA...High Risk for Rip Currents through late tonight for GAZ154-166. MARINE...Small Craft Advisory until 7 PM EST this evening for AMZ452- 454. Small Craft Advisory until 4 AM EST Wednesday for AMZ470-472- 474.