Marine Weather and Tide Forecast for St. Augustine South, FL

NEAR TERM /THROUGH SUNDAY/
Main Highlights This Period:

- Another Hot Day with Heat Index peaking around 102-107 degrees

- Scattered to Numerous Afternoon Thunderstorms, a few stronger storms possible

The region will be between high pressure ridging to the south, and a frontal zone to the north Today. The low level flow will be from the west southwest between these features. The flow will not be particularly strong, so the east coast sea breeze will be able to push just past I95 corridor this afternoon. A combination of diurnal heating, ample moisture, and sea breeze interactions will drive convection this afternoon. With the sea breeze interaction happening along or just west of I95, this area will be where the highest convective chances will be focused.

Temperatures will be above normal. Mixing will allow dewpoints to lower this morning, which is expected to be enough to keep heat index values just below advisory levels.

Convection will dissipate this evening, with loss of diurnal heating. Lows in the middle 70s will be common Tonight.

SHORT TERM /SUNDAY NIGHT/
Main Highlights This Period:

- Scattered to numerous thunderstorms, with a few strong to isolated severe storms possible

- Heat indices values will approach Advisory levels each afternoon

Southwest winds continue Sunday and Monday as frontal boundary slowly works its way into the Southeast US, leading to the the Gulf breeze pushing inland each afternoon where it will meet with the Atlantic breeze each afternoon. Showers and storms are expected to develop along the breezes, with the higher focus between US-301 and the I-95 corridor along the mergers of the breezes. Potential hazards for any storms that develop will be locally heavy downpours (with PWATs ~ 1.8" to 2.2"), frequent lightning, and brief wet downburst wind gusts to 40-60 mph.

Hot temperatures into the middle 90s persist Sunday and Monday, with Heat Advisory conditions possible each afternoon, with heat indices topping out in the 103-107F range both day. For now, still expect enough cloud cover and early enough start to convection to prevent the issuance of any Heat Advisory products at this time. Overnight lows will dip to the 70s area-wide, with near 80F low temps along the Atlantic beachfront locations

LONG TERM /MONDAY THROUGH SATURDAY/
Main Highlights This Period:

- Scattered to numerous afternoon and evening thunderstorms each day next week, a few strong to isolated severe thunderstorms possible.

A trough digs south towards the southeastern US into midweek as high pressure sits to the southeast of the area. Southwesterly flow will persist through the upcoming week, continuing to bring tropical moisture into the area. Expect to see scattered to numerous coverage of convective activity due to elevated moisture levels and diurnal heating as the southwesterly flow will allow for the Gulf breeze to push inland during the afternoon hours. By Wednesday, a frontal boundary looks to sink across the SE GA and towards north central FL by Thursday before stalling and dissipating by the end of the week.

Temperatures are expected to remain above average for most of the period with highs into the lower/middle 90s, except for a brief period of highs in the 80s across SE GA on Tuesday and area-wide on Wednesday when the frontal boundary sags into the local area. Heat indices rebound closer to 105F and near Heat Advisory levels by the end of next week and into the following weekend.

AVIATION /00Z SUNDAY THROUGH 00Z MONDAY/
Convection will diminish this evening with loss of heating. VFR conditions are forecast Tonight. Convection will initiate again in the afternoon on Sunday.

MARINE

The region will be between high pressure to the south southeast, and a frontal zone to the north through the early part of next week.
This frontal boundary will move south over area mid week, and stall while it dissipates through the end of the week.

Rip Currents:

Generally low risk of rip currents through the weekend. There will be a slight increase in the risk to a low-end moderate level during the afternoon with the sea breeze, combined with a moderate onshore but low amplitude swell.

FIRE WEATHER
- Areas Of High Afternoon Dispersions Sunday And Monday

Westerly winds during the morning hours will shift to become southwesterly by the afternoon hours and persist through the weekend and the upcoming week, which will keep the East Coast sea breeze pinned close to the Atlantic Coast each day. Scattered to numerous thunderstorms developing during the afternoon and continuing into the evening hours. MinRH levels will continue above critical levels through the weekend and into next week with the continued advection of tropical moisture over the area. Temperatures will rise into the 90s through early next week. Increasing transport winds on Sunday and Monday will bring areas of high afternoon dispersions.

FOG POTENTIAL AND OTHER REMARKS: Significant fog is not expected Tonight. Daily showers and thunderstorms, mainly in the afternoon and evening hours. A few strong to isolated severe thunderstorms will be possible each day.

PRELIMINARY POINT TEMPS/POPS
AMG 77 94 75 93 / 30 70 20 80 SSI 79 92 77 93 / 20 70 30 80 JAX 77 94 75 94 / 30 80 30 80 SGJ 77 93 75 93 / 30 60 30 80 GNV 76 93 75 92 / 40 50 20 70 OCF 77 92 75 91 / 20 20 20 40

JAX WATCHES/WARNINGS/ADVISORIES
FL...None.
GA...None.
MARINE...None.