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

- Scattered to Numerous Thunderstorms this afternoon and evening. Main Hazards: Wind gusts up to 50 mph, frequent lightning, locally heavy rainfall.

- Hot and Humid Conditions Continue into Next Week. Heat Advisory headlines possible.

NEAR TERM /THROUGH TONIGHT/

Main Highlights Today and Tonight:

- Hot Conditions with Heat Index in the 102-108 Degree Range - Scattered strong and Isolated Severe Storms late afternoon/evening

Latest models are suggesting frontal boundary over the SE US states will make a bit further progression than expected later today into tonight and will push into SE GA by tonight. This will lead to better chances of scattered to numerous pre-frontal showers and storms late this afternoon and evening along the FL/GA border and I- 10 corridor, which will move offshore into the Atlantic waters after sunset. A stronger belt of westerlies aloft along with cooler mid level temps will support better chances for strong to isolated severe storms with gusty winds to 40-60 mph as the main threat, along with locally heavy rainfall, frequent lightning and small hail. Timing of storms generally in the 3pm-9pm time frame.

Breezy westerly winds will develop ahead of the approaching frontal boundary with sustained winds around 15 mph with frequent gusts to 25 to 30 mph at times. This will push Max temps into the lower to middle 90s for SE GA with heat indices of 102-106F and into the mid to upper 90s for NE FL with heat indices into the 104-108F range, the breezy westerly winds should keep the low level mixed enough to keep dew point temps low enough to prevent Heat Advisory headlines.

Skies become mostly clear later tonight as the frontal boundary stalls near the FL/GA border and much drier airmass aloft pushes into the region and prevents any overnight rainfall chances along the boundary. Light Northwest winds develop overnight and low temps fall into the upper 60s inland SE GA and lower/middle 70s for coastal SE GA and NE FL.

SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/

Main Highlights This Period:

- Lower storm coverage Tuesday & Wednesday

Showers and storms shift north to south Tuesday afternoon into the evening mainly impacting the middle section of the local forecast area between Waycross to the FL I-10 corridor where deeper moisture plume coincides along a southward moving washed-out frontal zone and passing upper level short wave trough. A few stronger storms and locally heavy rainfall are possible where sea breezes and frontal activity converges. Tuesday night, the front shifts farther south and begins to stall and linger across central FL. Wednesday, much drier air with PWAT < 10th percentile brings rain chances < 15% across inland southeast GA with the higher chances of afternoon and evening showers and storms south of Gainesville to St. Augustine southward and toward the Atlantic coast, with storm motion from the northwest to the southeast into the evening and clearing skies for much of the area by 8 pm.

Highs will range in the low/mid 90s with daily heat index values 95- 100 across most of southeast GA to around 105 degF across northeast FL. Muggy overnight lows will range in the 70s.

LONG TERM /FRIDAY THROUGH MONDAY/

Main Highlights This Period:

- Daily heat indices 105-108 degF - Daily thunderstorm risk

Pattern for diurnal showers and thunderstorms will continue on through the week and into Monday. Daily high temperatures temperatures are expected to consistently rise to above average levels with max temps potentially rising into the mid to upper 90s by the end of the weekend and into the beginning of next week. Heat Advisory conditions may occur through the long term period as heat index values rise to levels of over 100.

AVIATION /06Z TUESDAY THROUGH 06Z WEDNESDAY/

VFR conds expected through the night with just low chances of MVFR stratus towards sunrise, and with probs less than 20% will leave out of the current forecast for now. West winds increase to 12-13 knots for all locations by 13-14Z with gusts to 18-20 knots at times. Pre frontal scattered showers and storms develop in the 20-24Z time frame and will continue PROB30 groups of MVFR CIGS/VSBYS and gusty winds for all TAF sites with this TAF package. Shower/storm chances end by the end of the TAF period and expect a return to VFR conds with diminishing winds after 03Z.

MARINE

Prevailing offshore winds will keep seas low and maritime conditions fair. Offshore flow and unstable airmass will lead to daily potential for scattered thunderstorms during the afternoon and evening hours. A front will press into the waters and stall through Wednesday which lead to a break in the offshore flow pattern through Thursday before returning this weekend. While winds will be generally less than ten knots during the daytime, nightly southerly wind surges may lead to Exercise Caution Conditions offshore during periods of offshore flow.

Rip Currents:

Rip current risk is expected to remain on the low side with the predominant offshore flow and surf/breakers 1-2 ft through this week.

FIRE WEATHER

AREAS OF HIGH DAYTIME DISPERSION INLAND TUESDAY & WEDNESDAY...

Breezy westerly winds near 10 to 15 mph with gust potential to 25 mph for today, ahead of a front that slowly edges southward across the area with the best coverage of storms between Waycross and the I- 10 corridor. Wednesday, the front begins to stall across north- central FL with much drier conditions across southeast GA but continued mainly afternoon showers and storms across northeast Florida, especially near the St. Johns river basin under northwest winds, with an afternoon east coast sea breeze pushing inland toward the I-95 corridor and St. Johns River basin. Thunderstorm hazards include lightning, gusty winds and locally heavy rainfall.

FOG POTENTIAL AND OTHER REMARKS: Late night and early morning patchy fog are possible, especially where recent heavy rainfall occurred. Gusty and erratic winds will occur near thunderstorms.

HYDROLOGY

Minor flooding on the Satilla River Basin will continue to move downstream and impact the forecast points at Waycross and Atkinson this week.

PRELIMINARY POINT TEMPS/POPS

AMG 91 73 91 73 / 20 0 10 20 SSI 94 76 91 78 / 30 10 20 10 JAX 96 76 95 76 / 40 20 40 30 SGJ 97 77 93 76 / 20 20 50 30 GNV 95 75 95 74 / 20 30 30 20 OCF 95 76 93 75 / 0 30 40 20

JAX WATCHES/WARNINGS/ADVISORIES

FL...None. GA...None. MARINE...None.