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

- Dangerously Hot & Humid Weather Continues Through Mid-Week. Heat Advisories in Effect Today and Tuesday. Heat Indices up to 112 Possible. Heat Advisories Likely and Extreme Heat Watches Possible for Wed

- Widely Scattered TStorms this Afternoon and Evening. Isolated Strong/Severe Storms Expected this Afternoon/Evening. Brief Gusty Winds, Frequent Lightning Strikes & Heavy Downpours Possible

- Isolated to Widely Scattered Afternoon & Evening TStorms Tuesday

- Strong to Severe TStorms are Possible on Wed Afternoon & Evening

NEAR TERM /UNTIL 6 AM TUESDAY MORNING/

Main Highlights For Tonight:

- Thunderstorm potential to continue into the overnight

A few thunderstorms will possible through around 2 AM Tonight, as an upper wave moves southeast across the area. A few strong storms will still be possible this evening.

Lows in the upper 70s along the coast, and mid 70s inland.

SHORT TERM /6 AM TUESDAY MORNING THROUGH WEDNESDAY NIGHT/

Main Highlights This Period:

- Reduced Thunderstorm Coverage Tuesday, Higher Storm Chances Return Wednesday - Potential for Isolated Strong to Severe Storms, Especially Wednesday - Heat Advisory Tuesday, Likely Needed Wednesday As Well

A cool front will drop southward throughout Tuesday and into Tuesday Night, stalling over southeast GA for Wednesday and likely beyond as well. Guidance is in good agreement with respect to some drier air remaining in place aloft on Tuesday as seen on forecast soundings, which will overall reduce convective chances, especially for southeast GA. Therefore highest PoPs (generally in the 30-40% range) will be found south of I-10 in northeast FL. Given the pockets of drier air, localized stronger downbursts will be possible, especially where the best lift from the east coast sea breeze and/or mergers/boundary collisions occur. Though some drier air will allow afternoon dew points to mix down slightly below normal for this time of year, widespread high temperatures in the 90s to near 100 has already prompted a Heat Advisory area-wide Tuesday, with forecast heat indices generally in the 107-112 range. It is also worth noting that Tuesday Night is expected to be quite mild as well, with widespread upper 70s forecast and some areas possibly not dropping below 80F. Along with near record high max temps, some climate sites may also flirt with record high min temps Wednesday Morning.

The above mentioned front will drop even further south on Wednesday as some energy from a mid/upper trough also drops southward with it. These factors combined with the return of more robust moisture will result in more numerous to widespread showers and thunderstorms across the area, some of which could be strong to isolated severe. The Storm Prediction Center (SPC) has already highlighted much of our area in a marginal (level 1/5) risk for severe storms, which will likely be adjusted over the next 24-36 hours. Along with very heavy downpours and flooding potential as PWATs exceed 2 inches, strong downbursts up to 40-60mph are forecast to be the other primary hazard as temps aloft look to be on the warmer side for any hail development. More updates to be narrowed down through Tuesday. Wednesday will be another very hot one prior to the onset of any convection as well, with Heat Advisories being likely once again with widespread high temps in the upper 90s and forecast heat indices around 108-113F.

LONG TERM /THURSDAY THROUGH MONDAY/

Main Highlights This Period:

_ Daily rounds of mainly afternoon and evening thunderstorms, which may become strong to severe

The above mentioned front looks to remain nearly stationary across southeast GA late in the week as some shortwave energy aloft also continues to come in waves at times as an upper trough slowly moves east into the Atlantic. The front will start to lift back northward a bit this upcoming weekend in response. This pattern will persist higher chances for showers and t'storms for much of the long term period. This setup will likely come with continuing chances for strong to isolated severe storms given abundant moisture/lift and some upper support. A more active pattern will drop temperatures closer to normal for this period overall.

AVIATION /00Z TUESDAY THROUGH 00Z WEDNESDAY/

The potential for isolated storms will continue through around 06z, then dry weather is forecast for much of the overnight into Tuesday morning. Convection is expected Tuesday afternoon, but coverage will be below average.

Prob30 groups have been included for this evening, and again Tuesday afternoon for locations and times when storms are most favorable.

MARINE

A slow moving frontal boundary approaching the Georgia waters will stall tonight and will dissipate on Tuesday. Light northwest to northerly winds will prevail across our local waters today, with only isolated afternoon showers and thunderstorms, mostly across the northeast Florida waters. Winds will become onshore over the near shore waters towards noon, followed by southerly winds briefly surging throughout our local waters this evening, with speeds generally remaining below Caution levels. Light prevailing westerly winds are forecast on Tuesday, with the afternoon sea breeze potentially triggering isolated to widely scattered showers and thunderstorms through Tuesday evening, mainly for the northeast Florida waters.

Another frontal boundary will sink into the Deep South late this week, with this feature becoming stationary during the weekend. Strong to severe thunderstorms will be possible well in advance of this front on Wednesday afternoon and evening across our local waters. Scattered to numerous thunderstorms will continue across the northeast Florida waters on Thursday and Friday, with less coverage currently forecast for the Georgia waters. Waves of showers and thunderstorms will then overspread all of our local waters during the upcoming weekend. Outside of expected thunderstorm activity, southwesterly winds will prevail and will strengthen ahead of the approaching front beginning towards midweek, with Caution conditions likely through the upcoming weekend and periods of Small Craft Advisory conditions possible.

Rip Currents: A low end moderate risk of rip currents is expected today and Tuesday at Northeast FL and Southeast GA beaches due to an afternoon sea breeze and surf/breakers of 1-2 feet.

FIRE WEATHER

-Heat Indices in the advisory range for much of the area Today through Wednesday.

-Patchy high daytime dispersions this week.

Some drier air will have impacts to shower and thunderstorm chances both today and Tuesday, ahead of a frontal boundary that will drop southward Tuesday and Tuesday Night. Through Tuesday, areas south of I-10 in northeast FL will have the highest chances for these showers and storms. Outside of these chances, hot and humid conditions will be expected with heat advisories for almost all counties today, and for the entirety of the area Tuesday. Good dispersions are also forecast for all but the immediate coast through mid week, with some patchy high dispersions possible north of about I-10 by Wednesday. Chances for showers and storms also increase by Wednesday as the same frontal boundary stalls over southeast GA.

Fog Potential: Significant fog development is not expected during the next several mornings. Heat Advisories are in effect for this afternoon as well as Tuesday afternoon, and may be needed Wednesday as well. Daily thunderstorm chances this week, with greatest chances beginning mid week. Gusty and erratic winds can be expected in and near storms.

PRELIMINARY POINT TEMPS/POPS

AMG 76 99 78 98 / 30 0 0 50 SSI 79 99 82 99 / 10 10 0 70 JAX 77 98 79 98 / 30 20 0 70 SGJ 78 96 79 97 / 20 30 10 50 GNV 78 97 79 95 / 30 30 10 40 OCF 78 95 79 94 / 20 40 10 20

JAX WATCHES/WARNINGS/ADVISORIES

FL...Heat Advisory until 8 PM EDT this evening for FLZ021-023-024- 030-031-035-120-124-125-132-136-220-225-232-233-236-322- 325-333-422-425-433-522-533-633. Heat Advisory from 11 AM to 8 PM EDT Tuesday 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 8 PM EDT this evening for GAZ136-151>154- 162-163-165-166-250-264-350-364. Heat Advisory from 11 AM to 8 PM EDT Tuesday for GAZ132>136- 149-151>154-162-163-165-166-250-264-350-364. MARINE...None.