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

- Very Hot & Humid Weather Continues Today: Heat Index 106 - 112. Heat Advisories Possible again Next Week for Portions of Our Area.

- Moderate Rip Current Risk Continues at Area Beaches

- Scattered to Numerous Afternoon & Evening Storms Sat through Mon. Strong Storms, Frequent Lightning Strikes & Locally Heavy Downpours Possible.

NEAR TERM /THROUGH TONIGHT/

Main Highlights through Tonight:

- Strong Storms and Locally Heavy Downpours Possible This Afternoon and Early Evening from I-95 to US Highway 301

- Heat Advisory in effect from Noon to 7PM for Northeast FL and portions of Southeast GA

Higher PWATs have moved into the area as the front slowly sinks into central Georgia, higher precipitation chances are expected today compared to the past few days. Storms are forecast to increase in coverage in the early afternoon, and beginning to dissipate after sunset, although a few isolated storms may linger a few hours after. Impressive DCAPE values are currently present over most of northeast Florida and coastal southeast Georgia, any strong storm development will pose a threat to wind guts of 40-60mph. Highest strong storm chances today will be near US301 to I95 as northwest winds keep the Atlantic sea breeze pretty close to the coast. Slower storm motion and training storms will bring concern for localized flooding over generally flood-prone areas.

Ahead of the storms, temperatures will rise into the mid to upper 90s generally south of Waycross, where a Heat Advisory remains in effect through 7pm due to heat indices reaching 105-110 degrees.

SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/

Main Highlights This Period:

- Numerous Afternoon and Evening Thunderstorms Sunday, Drier for Some Monday

- Strong Storms and Locally Heavy Downpours Possible Each Day

A cool front sagging southward throughout Sunday, stalling and becoming diffuse by Monday, will be the primary feature affecting our weather for Sunday and into Monday. PWATs of 2+ inches ahead of the boundary combined with the frontal boundary and sea breeze/outflow will result in numerous showers and t'storms. Steering flow in the 10-15 knot range from the northwest will help to limit flooding potential somewhat despite the abundance of moisture, though localized slow moving cells and/or training could result in some isolated flooding concerns. Outside of heavy rainfall, temperatures/lapse rates aloft via forecast soundings are not overly impressive, though some lingering pockets of drier air aloft could result in an isolated strong to severe cell, especially towards the I-95 corridor closer to the east coast sea breeze that will be nearly pinned. High temps will remain above normal Sunday, generally in the mid 90s with some readings in the upper 90s possible. Currently forecast to remain just below any heat advisory criteria, though issuance will be possible later this evening or tonight depending on latest guidance and trends.

Monday, a swath of lower PWATs around 1.6 to 1.8 inches will make a push southward along with slightly stronger subsidence aloft, and therefore will limit coverage of convection to an extent, especially the further north and west you go. The highest chances for convection, especially stronger convection, will be generally towards the I-95 corridor and St. Johns River Basin region in northeast FL closer to the nearly pinned developing diurnal Atlantic sea breeze. Similar setup expected regarding temperatures, as highs will be generally in the mid 90s and currently forecast to be just below advisory criteria.

LONG TERM /TUESDAY THROUGH FRIDAY/

Main Highlights This Period:

- Heat Advisory Conditions Possible Across Much of Our Area During the Early to Middle Portions of Next Week

- Drier for Most Tuesday, Higher Shower and Thunderstorm Coverage Likely Wednesday/Thursday

Guidance continues to suggest at least Tuesday being a day with more suppressed convection for many, which will likely allow temps to rise into the mid to upper 90s for much of the area that may last into Wednesday as well. Another frontal boundary looks to drop southward on Wednesday and into Thursday with a modest amount of upper level support as well, returning higher coverage of showers and t'storms for Wednesday but especially Thursday and into Friday before the front stalls almost directly over the area into the end of the week. Guidance varies a fair amount regarding how far southward the front makes it and therefore the amount of drier air that intrudes into the region, though given that we are still well into the swing of summertime, leaning towards a wetter more unsettled solution for now with a front stalled further north. Temperatures will drop closer to normal with the boundary/more active convection for the end of the week.

AVIATION /18Z SATURDAY THROUGH 18Z SUNDAY/

Thunderstorms will develop across the area around 19-20Z, which will likely affect area TAF sites. Restrictions and gusty winds up to 30 knots in and near afternoon storms 21-01Z can be expected. Storms will diminish after 02Z with broken to overcast mid and high level clouds through the end of the period with very light southwest winds.

MARINE

A stationary frontal boundary extending from the Carolina coast westward across the deep south will begin to drift south towards the Georgia waters through Sunday, pushing the axis of Atlantic high pressure southward. This change in the weather pattern will create a prevailing offshore wind flow this weekend and early next week, with scattered to numerous afternoon and evening thunderstorms expected across our local waters each day. A few stronger storms will be possible during the late afternoon hours, with briefly strong wind gusts, frequent lightning strikes, and torrential downpours possible. Another front will approach the waters next week with offshore southwest winds increasing to near advisory levels by midweek.

Rip Currents: A moderate risk of rip currents is expected today through the weekend at Northeast FL and Southeast GA beaches due to onshore winds from the southeast this afternoon with surf heights 2 to 3 feet.

FIRE WEATHER

- Areas Of High Daytime Dispersion Values Inland Sunday

Scattered showers and thunderstorms today will become more numerous on Sunday as more moisture returns to the region. This will be accompanied by a light flow from the west to northwest, except for a sea breeze influence east of about the I-95 corridor. Very efficient mixing will result in good dispersions during the daytime through Sunday, with patchy high dispersions possible over inland areas Sunday. Some drier air will push southward into the area on Monday and into Tuesday as a weakening/dissipating front moves towards the area, which will limit rain potential on these days, especially over southeast GA. A more active pattern looks to return by mid next week.

Fog Potential and Other Remarks: Significant fog development is not expected during the next several mornings. Seasonably hot and humid conditions expected through next week, which will flirt with heat advisory criteria at times.

PRELIMINARY POINT TEMPS/POPS

AMG 94 75 94 73 / 30 20 70 40 SSI 96 78 94 75 / 60 30 70 50 JAX 97 76 95 74 / 60 40 80 60 SGJ 95 77 93 75 / 30 30 70 40 GNV 96 76 95 75 / 50 30 70 40 OCF 96 77 95 75 / 40 20 70 40

JAX WATCHES/WARNINGS/ADVISORIES

FL...Heat Advisory until 7 PM EDT this evening for FLZ021-023-024- 030-031-035-038-120-124-125-132-136>138-140-220-225-232- 233-236-237-240-322-325-333-340-422-425-433-522-533-633. GA...Heat Advisory until 7 PM EDT this evening for GAZ152>154-162- 163-165-166-264-350-364. MARINE...None.