NEAR TERM
Issued at 155 PM EDT Thu Sep 12 2024

For the latest NE FL and SE GA Daily Key Messages please visit: https:// www.weather.gov/media/jax/briefings/nws-jax-briefing.pdf

Persistent frontal zone will remain across area through Tonight.
Over inland areas it will lift as a warm front, as remnants of Francine moves north into central US. The combination of the moist onshore flow, and lift from the warm front will keep above average chances for showers in the forecast. A few embedded thunderstorms will be possible.

Convergent bands in the onshore flow will continue to bring the potential for localized flooding in coastal counties. Further inland, the rainfall will be more broad in coverage, but generally lighter and moving, as compared to the persistent banding at the coast.

Flood watch to continue along the coast due to potential for the dominant bands. Coastal Flood Advisory will continue along St Johns basin from Jacksonville south, as the river remains elevated due to runoff from recent rains, with onshore flow helping to trap tides.

Lows in the lower to mid 70s will be common.

SHORT TERM
(Friday through Saturday night)
Issued at 155 PM EDT Thu Sep 12 2024

Frontal zone will run from along the Gulf coast of FL and across central FL Friday, while high pressure remains to the north northeast. This pattern will continue the moist onshore flow, with proximity of the front adding another source for convergence. As a result, another day with above normal precipitation chances is expected.

Flood Watch for coastal counties extended through the day Friday, as any significant rainfall over these areas could quickly result in flooding. The most troublesome scenario under these conditions is dominant rain bands that develop in convergent onshore flow.
Have seen a few of these develop this morning, and expect this potential through at least Friday.

An inverted trough is expected to develop on this front over the coastal waters Friday night through Saturday night. The development of the low will help to pull the frontal zone back into northern FL, while the high remains centered to the north northeast. Once again, moist onshore flow and frontal convergence expected, so the wet pattern continues through Saturday night.

Temperatures will trend near normal this period.

LONG TERM
(Sunday through next Thursday)
Issued at 155 PM EDT Thu Sep 12 2024

Increasing uncertainty in this forecast period, as the trough over the coastal waters may wrap up into a closed low late this weekend into early next week. Meanwhile, the frontal zone will remain parked over northern FL. There is a chance for this low to then strengthen into a tropical system, and move west into the Carolinas. Longer range models are inconsistent with this outcome though.

Due to uncertainty related to the low, and what will happen with frontal boundary, will keep the fairly wet trend going throughout this period. The two most likely scenarios: If the low wraps up and moves inland to the north, it would likely break the front down, and possibly wrap drier air around the backside of it, resulting in lower precipitation chances across our area for the later portions of this period. However, if it does not wrap up, and it stays more of an inverted trough, then boundary largely stays in place, along with continued wet pattern.

Temperatures will remain around seasonal averages this period.

AVIATION
(00Z TAFS)
Issued at 644 PM EDT Thu Sep 12 2024

MVFR conds as rainfall ends at TAF sites this evening by 02Z, followed by some partial clearing and temporary VFR conds before LIFR CIGS develop towards sunrise in the 07-10Z time frame and lingering until 13-14Z. Conds should become MVFR to VFR in diurnal heating during the morning hours prior to a round of SHRA/TSRA during the 18-00Z time frame and will introduce PROB30 groups at all TAF sites with MVFR conds and gusty winds.

MARINE
Issued at 155 PM EDT Thu Sep 12 2024

A frontal zone will remain over the area through the weekend into early next week. An area of low pressure will develop on this front early next week, which may then strengthen and move into the Carolinas.

Rip Currents: High Risk through Tonight

PRELIMINARY POINT TEMPS/POPS
AMG 71 86 71 84 / 20 80 40 70 SSI 75 84 74 83 / 40 50 50 70 JAX 73 87 73 86 / 40 80 50 80 SGJ 75 88 74 88 / 60 80 40 70 GNV 72 88 73 89 / 60 90 30 80 OCF 73 89 74 90 / 70 80 30 70

JAX WATCHES/WARNINGS/ADVISORIES
FL...Flood Watch through Friday evening for FLZ024-033-038-124-125- 133-138-225-325-425.

Coastal Flood Advisory until 8 PM EDT Friday for FLZ033-038-132- 137-325.

High Rip Current Risk until 5 AM EDT Friday for FLZ124-125-133- 138.

GA...Flood Watch through Friday evening for GAZ153-154-165-166.

High Rip Current Risk until 5 AM EDT Friday for GAZ154-166.

AM...Small Craft Advisory until 10 PM EDT this evening for AMZ470-472.