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

- Scattered to Numerous Afternoon & Evening TStorms Each Day through the Weekend and Early Next Week. Primary Concern will be Lightning and Heavy Downpours resulting in Localized Flooding.

- Moderate Rip Current Risk Continues at All Area Beaches

NEAR TERM /THROUGH TONIGHT/

Highlights through Tonight:

- Waves of heavy downpours may lead to localized minor flooding this afternoon

Skies have trended mostly clear with convection persisting well offshore this morning. In the scope of the broader weather pattern, there will be on subtle changes today. The primary change will be a strengthening southwesterly steering flow owing to the sharpening of mean layer troughing across the Appalachians and into the Deep South. A broader blanket of deep moisture, sourced from the Gulf, will channeled south of a decaying frontal zone situated across central GA. This will keep "high grade" (near the 90th percentile) across NE FL and SE GA today, fueling waves of scattered to numerous showers and convection this morning and afternoon. This pattern will favor an initial late morning bout of scattered thunderstorms moving from the Big Bend northeastward as morning heating erodes the "cap" by 10-11 AM. That activity is expected to reach the Atlantic coast around 1-3 PM followed by additional waves through the afternoon.

Given the increase in the offshore steering winds and potential for earlier showers and thunderstorms, the Atlantic sea breeze may not be able to establish or push inland this afternoon. Poor lapse rates aloft and the Atlantic sea breeze being potentially pinned over the coastal waters will minimize the potential of stronger thunderstorm this afternoon. The main focus with storms will be the potential for waves of heavy downpours over areas that have already received a few inches during the last few days.

Similar to last few evenings, a decline in thunderstorm coverage will occur with the loss of heating with minimal, if any, leftover shower activity after 10 PM. There will be another prefrontal boundary approaching Friday morning and this may help initiate predawn showers along the Big Bend which could push toward portions of the lower Suwannee Valley through sunrise.

Near normal afternoon temperatures are expected today, with highs again in the low 90s and peak heat index in the upper 90s and lower 100s. Temperatures tonight will be similar to low this morning, generally in the low 70s inland and mid 70s at the coast.

SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/

Main Highlights This Period: ( Friday through Saturday night )

- Strong storms are expected each day, with a few severe storms possible

Surface high pressure will be centered to the northeast this period, with a frontal zone nearly stationary across GA. The region will also be under a weak upper trough.

A combination of ample moisture, instability under upper trough, frontal convergence, diurnal instability and sea breeze interactions will result in above average coverage of mainly afternoon and evening showers and thunderstorms. A few strong to severe thunderstorms will be possible each day.

Temperatures will trend a little above average this period.

LONG TERM /SUNDAY THROUGH WEDNESDAY/

Main Highlights This Period: ( Sunday through Wednesday )

- A few strong to severe thunderstorms possible each afternoon and evening

Surface high pressure will remain centered to the northeast of the region this period, while the persistent frontal zone over southern GA gradually dissipates. A ridge of high pressure will build overhead this period.

Daily convection will largely be driven by diurnal instability this period. The upper high will help to limit activity somewhat, but a few strong to severe storms can not be ruled out each afternoon.

Temperatures will trend near seasonal levels this period.

AVIATION /12Z THURSDAY THROUGH 12Z FRIDAY/

Southwesterly flow will bring waves of showers during the late morning, then scattered thunderstorms during the afternoon. Thunderstorms will bring the potential for flight category reductions, primarily due to visibility for short durations during the afternoon hours (18-00z) with activity generally, moving eastward off the coast or decreasing in strength and coverage after 00z. For now, maintained PROB30s for most of the TAF sites, but TEMPOs may be necessary to add later on. VFR conditions with leftover cloud debris is expected through the evening with light southerly winds.

MARINE

A stalled front to the north will be replaced by another front which is also expected to stall just to the north of the local waters this weekend. Offshore winds will prevail through Friday night, then shift onshore over the weekend as high pressure builds to the north over the weekend, then to the northeast and into the western Atlantic early next week. Afternoon thunderstorms remain possible today and Friday due the prevailing offshore winds, followed by decreasing chances this weekend into next week as onshore flow develops.

Rip Currents: A very low end Moderate Risk of rip currents is expected this afternoon after the sea breeze develops. Similar expectation on Friday. Prevailing winds turn onshore this weekend, leading to a more solid Moderate risk.

FIRE WEATHER

High pressure will be located to the northeast throughout this period. A frontal zone will be nearly stationary over southern GA through Sunday. Daily rounds of showers and thunderstorms each day, mainly in the afternoon and evening hours.

Fog Potential: Significant fog is unlikely over the next several days. Gusty and erratic winds can be expected in and near thunderstorms.

PRELIMINARY POINT TEMPS/POPS

AMG 92 72 91 71 / 60 50 80 40 SSI 89 76 89 76 / 50 30 50 60 JAX 91 72 91 72 / 50 20 70 40 SGJ 91 74 90 74 / 50 20 60 40 GNV 90 72 89 72 / 60 20 50 20 OCF 90 72 90 72 / 60 10 60 30

JAX WATCHES/WARNINGS/ADVISORIES

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