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

- High Risk for Rip Currents & Rough Surf Today through Thursday. Breezy Onshore Winds Overspread Coastal Locations. Wind Gusts at Area Beaches around 35 mph Today through Thursday. Small Craft Advisories Through Thursday, with Wind Advisories Possible. Waves of Showers & Thunderstorms Today, Thursday & Friday, Mainly Along the I-95 Corridor

NEAR TERM /THROUGH TONIGHT/

Main Highlights through Tonight:

- Breezy Onshore Winds Today, mainly along the coast

- Dangerous surf conditions and a high rip current risk

Cold front currently over central FL will continue to shift southward down the peninsula early this morning before stalling over south FL by this afternoon. Meanwhile, high pressure centered over New England will wedge down the eastern seaboard maintaining local breezy ENE flow. Highest wind gusts will be along the coast in the 30-35 mph range. Moist airmass quickly gets replaced by drier air (PWATs ~ 1 in.) filtering in from the NE. Drier air and increasing subsidence will squash convection on land today. However, waves of isolated showers will develop over the coastal Atlantic waters with a few shifting onshore before quickly dissipating. An east-west temperature gradient develops with the onshore flow with highs ranging in the mid 80s along the coast to low 90s inland. Overnight lows will be in the mid 70s along the coast to upper 60s in inland SE GA.

SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/

Main Highlights This Period:

- High rip current risk remains over the area beaches - Isolated to scattered showers expected - Breezy northeast to east winds continue on Thursday, trending down for Friday.

For Thursday, strong 1027 mb high pressure system located over the Carolinas and broad low pressure in the Caribbean will continue to produce breezy northeast to east winds. Gusts of about 35 mph are expected for the coastal counties. Cannot rule out isolated gust of 40 mph, which would be more probable in a shower. An inverted trough feature will work toward the area from the Atlantic Thursday night. Aloft, strong ridge in the mid levels will be over the TN valley to the lower MS valley close to 600dam, while a sharp mid/upper level trough and an embedded 500 mb low is located from the FL straits northeastward into the Atlantic. These features aloft will retrograde through Friday. While the airmass remains pretty dry, especially above 8-10 kft, the low level airmass remains relatively moist and enough boundary layer convergence to generate isolated to scattered shower activity for Thursday and Thursday night. These showers will mostly be noted along coastal counties and the marine waters, while well inland have near zero rain chances. Some lingering isolated showers are expected at the coast Thursday night.

Friday, the mid/upper level trough and 500 mb low from the Atlantic will move across the FL peninsula with an associated surface trough moving west through the marine waters and the land zones, and then probably into the far eastern Gulf by late Friday night. Weak sfc ridge remains across central GA and east into the Atlantic. Mean low level flow becomes more easterly with a weaker pressure gradient expected, and leading to less breezy winds. A much weaker subsidence inversion and increasing moisture is noted in the model guidance so looks like a better chance for diurnal shower and isolated thunderstorm activity. Will advertise isolated to scattered showers and storms for northeast FL. Highest chances probably going to be at the coastal counties and the St Johns River Basin. Only about 10 percent chance for most of southeast GA. Going into Friday night, it seems reasonable to see isolated shower activity but primarily for the coastal areas due to onshore flow.

Near seasonable temps are forecast. On Thursday, max temperatures forecast in the mid 80s coast to near 90 deg, and then max temps trend up 1-2 degrees on Friday. Lows are forecast in the upper 60s to lower 70s, but the mid 70s coast due east flow off the Atlantic.

LONG TERM /SATURDAY THROUGH TUESDAY/

Main Highlights This Period:

- Daily chances for showers and thunderstorms with locally heavy rainfall possible - Elevated rip current risk and rough surf for area beaches is likely for at least the weekend

The mid/upper level trough and embedded 500 mb low will be near the FL west coast Saturday morning, and slowly track westward. Models diverge on the evolution of this feature with the GFS moving it faster west than the ECMWF, which throws some uncertainty into the longer range forecast. At the surface, weak high pressure ridging north of the area continues for the weekend with weak, broad troughing over the local forecast area. Mean low level flow is easterly for the weekend with a more moist and unstable airmass expected. Model guidance continues to suggest shows scattered showers and embedded storms especially for northeast Florida coast, and lowering to about 20 percent for southeast GA where drier air is expected. More veered flow expected on Sunday and moisture will be continue to be pumped into the area from the prevailing deep layer southeast flow. For the rest of the period from Sunday onward: High airmass moisture is forecast in current model output with PWATs of about 2 inches. Deep layer flow will transition from east and southeast, to southerly by Tuesday. The combination of the moisture and weak surface troughing will lead to diurnally- driven scattered and numerous showers and scattered storms each day, and fostered partly by sea breeze boundaries. If the remnants of the mid/upper level low over the eastern Gulf ends up stalling and drifts north late in the weekend, then we may be looking at a better chance of locally heavy rainfall.

Overall, high temperatures will be in the mid 80s to lower 90s and lows in the lower 70s.

AVIATION /12Z WEDNESDAY THROUGH 12Z THURSDAY/

A few coastal showers could cause brief restrictions this afternoon, but the chance is too low to mention in TAFs at this time. So, prevailing VFR conditions are forecast.

Winds will become elevated and gusty this morning. These winds will subiside away from the coast after sunset.

MARINE

Local pressure gradient remains tight as high pressure ridging builds down the eastern seaboard in the wake of a cool front. Small Craft Advisory conditions with breezy northeast winds and elevated seas will continue across area waters through Thursday. Waves of isolated to scattered showers and a few thunderstorms will move over the area waters through much of the week. Improving conditions are expected by Friday as onshore winds weaken and seas gradually lower.

Rip Currents: Continued breezy northeast winds and building surf combine to lead to dangerous surf and a high rip current risk for area beaches through Thursday.

FIRE WEATHER

- Patchy To Areas Of High Daytime Dispersions Today And Thursday

Elevated onshore winds remain in place for today and possibly into Thursday, especially at the coast where wind gusts of 30-35 mph are expected. Isolated showers and storms are forecast for today through Friday, mainly at the northeast Florida coast. Strong surface and transport winds will lead to areas of high daytime dispersion today and Thursday, and may still remain somewhat elevated on Friday. Higher precipitation chances return this weekend through early next week.

Fog Potential...No significant fog expected.

PRELIMINARY POINT TEMPS/POPS

AMG 90 68 90 67 / 0 0 0 0 SSI 86 76 86 75 / 20 0 20 0 JAX 87 74 87 71 / 20 10 20 0 SGJ 86 76 86 75 / 20 20 20 20 GNV 90 72 89 70 / 10 10 10 0 OCF 90 72 90 71 / 10 10 10 0

JAX WATCHES/WARNINGS/ADVISORIES

FL...High Risk for Rip Currents through late Thursday night for FLZ124- 125-138-233-333. GA...High Risk for Rip Currents through late Thursday night for GAZ154- 166. MARINE...Small Craft Advisory until 5 AM EDT Thursday for AMZ450-452- 454-470-472-474.