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

- Daily Mainly Afternoon & Evening Thunderstorms. Today Thu: Mainly Inland Northeast Florida (between HWY 301 & I-75). Fri Weekend: Increasing chances including Southeast GA

- Moderate Rip Current Risk SE GA & NE FL Beaches Today

- Minor River Flooding for Satilla River

UPDATE

Breezy onshore flow today with drier air infiltrating from the ENE through the day. This will bring morning coastal showers, with rain chances shifting inland across northeast FL into the afternoon. With more mid and upper level dry air across the area today, vertical convective growth will be challenged until boundary mergers occur with higher CAPE toward inland northeast FL into the afternoon. Thunderstorm potential is low today so adjusted the forecast for only isolated inland thunderstorms into the afternoon across northeast FL. If a storm can form, DCAPE will be high so localized strong wind gusts will be the main convective hazard.

Mostly dry conditions will prevail across southeast GA where high temperatures will warm into the mid 90s under more sun, while onshore flow brings highs near 90 to the beaches this afternoon to lower 90s across inland northeast where higher afternoon shower and isolated thunderstorm chances exist. With drier air invading through the day and a good mixing profile, drier dew pts will mix down into the afternoon. Dew pts in the 60s with highs in the 90s across southeast GA will create heat index values 'cooler' than recent days with peak heat index values in the mid 90s while dew pts in the lower 70s across northeast FL will bring peak heat index values in the upper 90s to around 100.

SHORT TERM /THROUGH FRIDAY NIGHT/

Main Highlights This Period:

- Gradual Increases in Convective Coverage Each Day - Elevated Rip Current Risk at Area Beaches

Drier air aloft will continue to have an influence of chances for showers and t'storms again Thursday, with overall expecting similar coverage compared to Wednesday. Chances will remain mainly confined to north central FL where the highest available moisture will be and less subsidence aloft, with the main focus area for stronger storm potential being generally towards and west of the I-75 corridor where the northeast flow reaches the Gulf Sea Breeze. High temps will once again be mainly in the low to mid 90s, except for some upper 80s closer to the immediate coastline. A few coastal showers will remain possible both Thursday Morning and overnight Thursday Night into Friday Morning as a weak coastal trough lingers, with min temps in the 70s.

Stacked high pressure weakens a bit and shifts towards more northeast of the region on Friday, which will result in more of a east to southeasterly flow at the surface and higher layer moisture/PWATs starting to return to the area. This will shift the "axis" of diurnal convection a bit closer to central areas with more of a Gulf Sea Breeze influence, with the highest PoPs still residing over northeast FL. The flow shift will result in high temps a few degrees warmer close to the coast where more readings in the low 90s are expected. Inland, mid 90s will be most common. A few coastal showers are likely to continue for Friday Night as well, with similar low temps mainly in the mid to upper 70s.

LONG TERM /SATURDAY THROUGH TUESDAY/

Main Highlights This Period:

- Higher Storm Chances Return for Much of the Area - Building Heat for Southeast GA

High pressure will shift increasingly east of the area this weekend and into early next week, returning low level flow towards more south to southwesterly and more numerous shower and thunderstorm coverage. This will also result in temperatures leaning above normal, and combined with the increasing low level moisture and humidity may also return potential for heat headlines for at least some of the area.

AVIATION /12Z WEDNESDAY THROUGH 12Z THURSDAY/

VFR to tempo MVFR this morning as coastal showers move onshore. Breezy easterly increase late morning and continue through early afternoon, with peak gusts 20-25 kts at the coast to 18-22 kts inland. Included tempo MVFR this morning with showers at SGJ, then into the afternoon given limited TS potential removed the TEMPO at GNV for TS and replaced with a PROB30. Will include TEMPO for convection as needed based on radar trends. Drier conditions into the evening. With drier air and weak winds overnight at inland terminals, patchy shallow ground fog will be possible especially VQQ and GNV if rainfall occurs today.

MARINE

Gusty easterly winds today between high pressure northeast of the region and an inverted trough offshore of the southeast coast. Morning showers will shift inland into the afternoon. The trough lingers but weakens Thursday into Friday with a dominant east coast sea breeze regime shifting morning showers inland into the afternoon each day. High pressure builds across central and south Florida this weekend into early next week with a transition to south to southwest flow over the local waters and high afternoon and evening thunderstorm chances over the local waters and nightly wind surges near exercise caution levels.

Rip Currents:

Onshore winds and surf increasing to 3 to 4 feet will result in a high end Moderate risk for rip currents this afternoon. Moderate risk continues for Thursday in the onshore flow.

FIRE WEATHER

- Areas Of High Dispersions Over Interior Se Georgia Today

Onshore flow will continue today as strong high pressure remains to our north. The high pressure and drier airmass will limit shower and t'storm chances towards north central FL as the Atlantic sea breeze quickly pushes inland. Stronger than normal winds above the surface for this time of year will result in fair to good dispersions across northeast FL and the coasts, with areas of high dispersions over inland GA with less maritime influence and better mixing. With the drier air and sufficient mixing, minRH values will fall into the 35 to 40% range for these areas both today and Thursday afternoon/evening. Shower and t'storm chances gradually return further north and west Thursday and into Friday, but especially for the upcoming holiday weekend. Dispersions overall look to be on a downward trend for the rest of the week after today.

Fog Potential: Significant fog development is not anticipated through the period. Any stronger thunderstorms will be capable of producing frequent lightning, heavy rainfall, and strong, erratic wind gusts, particularly during the afternoon and evening hours.

HYDROLOGY

Satilla River at Atkinson will remain in Minor Flood through the weekend with a gradual fall.

PRELIMINARY POINT TEMPS/POPS

AMG 94 69 94 72 / 10 10 0 0 SSI 88 76 89 79 / 20 10 10 10 JAX 90 72 91 75 / 20 10 10 10 SGJ 89 76 90 77 / 40 10 20 10 GNV 92 70 93 73 / 30 10 30 0 OCF 91 72 92 74 / 40 10 20 10

JAX WATCHES/WARNINGS/ADVISORIES

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