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

- Isolated Strong to Severe Storms Thursday and Friday

- Hot and Humid Thursday into the Weekend

- Heat Advisory Possible Thursday for portions of NE FL

NEAR TERM /UNTIL 7 AM THURSDAY MORNING/

Main Highlights Today and Tonight:

- Numerous showers and scattered thunderstorms through the early evening. Minor flooding is the primary concern; Gusty winds around 40 mph are also possible. - Hot and humid for north-central FL with Heat Index peaking around 100-106 degrees

As we have seen the past few days, southwest flow has allowed for an earlier start to convection, with showers and isolated storms already moving through the area. There will be an uptick in coverage this afternoon through the early evening, with convection nearly gone by sunset. With a fairly quick storm motion today, localized flooding concerns will come from training storms over already saturated grounds, mainly near the I-10 corridor region. Can't rule out a few isolated strong storms producing gusty winds again given the faster storm motion it won't take much instability to see gusts of 30-40 mph.

Higher cloud cover this morning is keeping high temperatures in the mid 80s for most of southeast Georgia, warmer over northeast Florida where they have seen more sunshine today. Very mild low temperatures expected tonight, in the mid to upper 70s.

SHORT TERM /7 AM THURSDAY MORNING THROUGH FRIDAY NIGHT/

- Daily rounds of Afternoon and Evening T'storms - Elevated Heat and Possible Heat Advisory Conditions Thursday for most areas and Friday south of Jacksonville

Pattern for daily bouts of showers and storms will continue through into Thursday and Friday as the moist southwesterly flow pattern persists over the forecast area between the stalled frontal boundary to the north and an area of high pressure rotation east of the Florida peninsula over the Gulf. Scattered to numerous are expected through this period with a potential for strong storms capable of producing destructive winds, frequent lightning, and a potential for localized flooding with training storms as PWAT values measure upwards of 2.4 inches over the region. High temperatures for the end of the week will rise into the upper 80s and lower to mid 90s with overnight low temperatures dropping down into the lower to mid 70s over inland areas and in the upper 70s along the coastline. Heat index values rise to values of over 100 Fahrenheit with conditions potentially reaching Heat Advisory levels over portions of southeast Georgia and northeast Florida.

LONG TERM /SATURDAY THROUGH WEDNESDAY/

Main Highlights This Period:

- Numerous to Widespread Showers and T'storms Saturday - Hot and Humid through the Weekend, increasing to near Heat Advisory levels early next week - Increasing Rip Current Risk to moderate levels by Sunday - Decreasing chances for showers Afternoon and Evening T'storms early next week

Drier air will filter in over the region by end of Sunday and into Monday as the frontal boundary to the north dips southward and high pressure over the Gulf extends in over the forecast area resulting in more inhibited convection for the beginning of next week, with the prevailing flow shifting about to become more out of the northwest. Temperatures will experience a warming trend through the weekend and into next week with max temps rising into the mid to upper 90s before midweek. Heat index values are expected to rise to be 100 and higher for portions of southeast Georgia and northeast Florida.

AVIATION /00Z THURSDAY THROUGH 00Z FRIDAY/

VFR conditions expected tonight as SW winds decrease to less than 5 kts. SW winds increase again after 15Z to around 10 kts with gusts 15-20 kts. Another round of scattered showers and storms will move in from the west and interact with the pinned Atlantic sea breeze pinned along the I-95 corridor between 18-23Z. A few of these storms could be strong to severe. Storms may quickly lower visibilities and bring strong erratic winds.

MARINE

Breezy offshore winds will continue through the end of the week as a remnant wave of low pressure tracks north of the waters through Friday. A weak front trailing the low pressure will stall north of the waters and weaken the offshore flow this weekend. After a day or two of onshore flow, offshore flow pattern will return as another broader front approaches from the north around the Tuesday or Wednesday next week. During the period of offshore winds, elevated chances of daily scattered to numerous showers and afternoon thunderstorms will be possible.

Rip Currents:

A general low risk of rip currents continues today and likely through the end of the week as surf remains only in the 1-2 ft range in offshore flow. Some slight increase in east-southeast wind-sea is possible Thursday and Friday, but still looks relatively weak.

FIRE WEATHER

- High Daytime Dispersion Values for North-Central FL Today - High Dispersion for inland locations just west of I-95 Thursday

Moist and unstable airmass will continue through this afternoon and early evening with scattered to numerous thunderstorms this week as west to southwest winds allow the Gulf seabreeze to move quickly eastward to the Atlantic coast before interacting with the pinned Atlantic seabreeze near the Atlantic coast. Thunderstorms will include locally heavy rainfall, frequent lightning, and gusty winds with isolated strong to severe storms on Thursday. A front will sink towards the area by the end of the week and move through Northeast Florida on Saturday with widespread showers and storms. The front will stall near north central or central Florida Sunday with slightly drier air aloft and only widely scattered afternoon storms.

Favorable transport winds and mixing heights will lead to areas of high afternoon dispersion values today over north central Florida. Temperatures are expected to remain near to slightly above seasonal normals throughout this week into this weekend accompanied by elevated humidity levels.

FOG POTENTIAL AND OTHER REMARKS: Areas that receive heavier rainfall may also experience patchy late-night and early-morning fog. Potential Heat advisory conditions for much of the area on Thursday.

PRELIMINARY POINT TEMPS/POPS

AMG 74 89 74 84 / 20 70 70 90 SSI 79 92 78 90 / 20 70 40 80 JAX 77 95 77 91 / 20 50 30 70 SGJ 78 95 77 93 / 10 50 20 60 GNV 77 94 77 91 / 10 20 30 50 OCF 78 94 78 90 / 0 30 20 30

JAX WATCHES/WARNINGS/ADVISORIES

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