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 Afternoon & Evening Thunderstorms Each Day through the Weekend and Early Next Week. Primary concern will be heavy downpours resulting in localized flooding.

- Strong thunderstorm risk will shift inland toward the I-75 corridor this weekend

- Moderate Rip Current Risk Continues at All Area Beaches

NEAR TERM /THROUGH TONIGHT/

Highlights Today and Tonight:

- Heavy rainfall/localized flooding remains the main threat from thunderstorm activity today and tonight

Southwest flow brought early morning showers with isolated storms across the Suwannee Valley and I-75 corridor, with coverage expected to increase area-wide through the afternoon and evening closer to the east coast and across southeast Georgia. Heavier cloud cover in the morning and an early start to convection will leave high temperatures in the mid to upper 80s for most of inland southeast Georgia and the western half of northeast Florida. Closer to the Atlantic coast, temperatures will rise into the lower to mid 90s with the help of a later start to convection. The primary concern again today due to slow storm motion will be locally heavy rainfall potentially causing flooding concerns, especially over areas that are typically flood prone/urban regions. In addition, we can't rule out a few stronger storms producing gusty winds this afternoon through sunset, mainly from boundary collisions. Overall, convection will wane off after sunset, but lingering showers and isolated storms are possible through the night up in southeast Georgia and near the I-75 corridor.

SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/

Main Highlights This Period: (Saturday through Sunday night)

- Strong to possibly severe storm chances in the afternoon and evening hours this weekend

Surface high pressure will build north of the region this weekend as a weakening frontal boundary lingers across southern Georgia, with a secondary cold front extending across northern Georgia. A weak upper trough will move east of the area by midday Saturday, while an upper ridge builds across the Ozarks and Mid-South. By Sunday, surface high pressure will strengthen over the Mid-Atlantic, resulting in increasingly onshore low-level flow and allowing the East Coast sea breeze to penetrate progressively farther inland.

Deep moisture, diurnal heating, and instability associated with the lingering but weakening frontal boundary will support widespread afternoon and evening convection, with PoPs of 50-90 percent across much of the area. Saturday will favor greater storm coverage along and west of I-95, while strengthening onshore flow Sunday will shift the focus farther inland, primarily between U.S. 301 and the I-75 corridor.

Most storms will be pulse-type convection, with the primary threats being frequent lightning, gusty winds, and locally heavy rainfall. A few strong storms are possible, with an isolated severe storm not ruled out where stronger instability overlaps the East Coast sea breeze boundary. High moisture and slow storm motions could also lead to localized flooding, particularly where storms repeatedly move over the same areas.

Temperatures will be near seasonal averages this period.

LONG TERM /MONDAY THROUGH THURSDAY/

Main Highlights This Period: (Monday through Thursday)

- A few strong to severe storms will be possible each afternoon - As the week progresses, increasing heat, with widespread heat indices of 104-109 degrees, particularly inland

A broad upper ridge will expand across the central and southeastern United States while surface high pressure remains established to the north and east. This pattern will support a persistent late-summer heat regime, with temperatures trending above average through the period. Highs will generally reach the lower to middle 90s, with overnight lows in the middle 70s.

Despite the strengthening ridge aloft, abundant moisture, diurnal heating, and persistent onshore flow will support daily afternoon and evening convection. The East Coast sea breeze will push well inland each day, focusing the highest storm coverage across the interior. PoPs will generally range from 40-60 percent well inland, 25 to 40 percent east of Interstate 95, with a gradual decrease in coverage possible all locations toward the latter part of the week.

Most storms will be typical summertime pulse convection across the interior, with locally strong storms capable of gusty winds, frequent lightning, and heavy rainfall. High precipitable water and weak storm motions could also result in localized flooding, particularly where storms repeatedly move over the same areas.

Heat will become the primary concern through the period as strengthening ridging aloft promotes increasing subsidence and a gradual reduction in convective coverage. High humidity and temperatures in the 90s will support widespread heat indices of 105- 109F, especially inland areas. Immediate coastal communities will generally see lower rain chances but warmer overnight temperatures due to persistent onshore flow, with lows likely remaining in the mid to upper 70s.

AVIATION /18Z FRIDAY THROUGH 18Z SATURDAY/

Showers and isolated storms are moving across the area, with TEMPOs in place for moderate showers and gusty conditions with the stronger storms. Convection begins to fade after sunset, with VFR conditions returning by the overnight period, with lower vsbys once again likely for VQQ around 08Z.

MARINE

Coastal showers and thunderstorms will develop this afternoon and evening as offshore winds continue through tonight. A shift to onshore winds over the weekend as high pressure builds to the north over the weekend, then to the northeast and into the western Atlantic early next week. Decreasing chances for showers and storms over the weekend and into next week as onshore flow develops.

Rip Currents: A very low end Moderate Risk of rip currents is expected this afternoon after the sea breeze develops. Prevailing winds turn onshore this weekend, leading to a more solid Moderate risk and increase in surf/breakers to 2 to 3 feet.

FIRE WEATHER

- Patchy Low Inland Dispersions rest of Today and Saturday

Surface high pressure will shift from east-northeast today to over the Mid Atlantic States over the weekend and into next week, turning the low-level flow from southwesterly today to predominantly onshore thereafter. This transition will gradually shift the focus of afternoon convection from coastal areas this afternoon and evening toward the interior beginning this weekend and most of next week.

Fog Potential: Significant fog is unlikely during the next several days. Gusty and erratic winds can be expected in and near thunderstorms.

PRELIMINARY POINT TEMPS/POPS

AMG 88 72 87 72 / 90 50 80 30 SSI 87 76 87 77 / 80 50 40 40 JAX 90 73 89 74 / 70 40 50 30 SGJ 90 75 89 76 / 70 20 30 30 GNV 89 72 91 73 / 50 20 70 30 OCF 90 73 92 73 / 50 20 70 30

JAX WATCHES/WARNINGS/ADVISORIES

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