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 Marginally severe thunderstorms late this afternoon and early evening north of I-10. Primary threat is strong wind gusts, up to 60 mph.

- Strong storms, with isolated severe storms on Monday fallowed by daily scattered to numerous afternoon thunderstorms each day this week.

- Moderate Afternoon Rip Current Risk through the middle of the week.

NEAR TERM /THROUGH TONIGHT/

Highlights through Tonight:

- Scattered to numerous thunderstorms south of I-10 this afternoon

- Isolated strong to marginally severe thunderstorm this evening for southeast GA.

The early morning satellite analysis shows the predominant upper level trough axis shifting offshore this morning, with dry northwesterly upstream pushing edging south of the Altamaha river. Derived precipitable water in the drier airmass is ranging from about 1.25-1.5" which equates to about the 10th-25th percentile. As that dry air pushes southward, deeper moisture will be pooled south of I-10 this afternoon. Scattered to numerous showers and thunderstorms will develop within and along the edge of the moisture axis during the late morning hours (after 10 AM) with additional waves of convection through the afternoon. Some warming air aloft will keep instability in check this afternoon across NE FL but a few stronger storms, capable of strong gusts, may develop along the pinned Atlantic sea breeze in St Johns and Flagler counties this afternoon. Some training may occur but generally southwesterly storm motion of around 10-15 mph should limit the potential for substantial flooding.

Though the dry air will limit much convection throughout the afternoon north of I-10, the latest HiRes ensemble guidance indicates leftover moisture from an ongoing MCS over the lower Mississippi river valley may be enveloped by the westerly flow aloft and transported into SE GA early this evening. This will give a late day window for isolated convection to develop despite the lower level dryness. The interplay between the increase instability and dry air may support strong to severe microburst activity (winds 40- 60 mph) with isolated convection in the SE GA vicinity this evening. The Storm Prediction Center has kept a "Marginal Risk" of severe storms north of I-10 given this potential wind threat this evening. Activity will wane by midnight with dry conditions through the early morning hours Monday.

Temperatures will soar into the mid and upper 90s across SE GA this afternoon but drier air will keep heat index generally in the upper 90s and low 100s this afternoon. Though temperatures will be a few degrees lower in NE FL, the moisture in the air will make it feel like 100-106F this afternoon.

SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/

Main Highlights This Period:

- Increase in showers and storms with return of moisture, higher chances heading into midweek.

Moisture steadily increases across the area as a trough digs across the southeastern CONUS. PWATs will trend upwards, with values near or above 2", as the mid to upper level trough brings a frontal boundary to skim north of the area over central GA. Light southwesterly flow will persist through the forecast period, with the Gulf breeze steering convective activity from southwest to northeast. With the increase in moisture and forecasted DCAPE values >=1000 J/kg, there will be the potential for some wet downbursts with any storm that develops during the afternoon to evening hours on Monday and Tuesday. Chances of showers and storms increase on Tuesday as coverage of higher PWATs spreads across the area.

A bit warmer temperatures on Monday as daytime highs will sit near the mid 90s for most locations. Tuesday, with higher chances of precipitation and cloud cover, a bit 'cooler' temperatures as highs sit in the lower 90s. Overnight lows in the lower 70s.

LONG TERM /WEDNESDAY THROUGH SATURDAY/

Main Highlights This Period:

- Active weather continues past midweek of the upcoming week

Southwesterly flow persists through midweek as a trough remains across the area, with chances of showers and storms in the 25% to 65% each afternoon as shortwaves along the trough will likely bring the chances for stronger convective activity. Will continue to see the Gulf breeze push inland each afternoon, and increase activity near the I-95 corridor as the breezes meet. Highs each afternoon will rise into the 90s.

Tropics Outlook: NHC has a 40% chance of tropical cyclone formation mid to late week across the central Atlantic. Locally, rip current activity could become more enhanced late week depending on the evolution of this system.

AVIATION /06Z SUNDAY THROUGH 06Z MONDAY/

Predominantly VFR conditions persist with localized light fog possible at inland terminals, especially in the northern Suwannee Valley and southeast GA. A weak stalled front will be across southern GA today, keeping prevailing winds around 5-10 from the West-southwest. Westerly flow will be strong enough to keep the sea breeze from reaching the I-95 corridor this afternoon. Drier air will initially limit shower and thunderstorm potential along and north of I-10 this afternoon. Scattered showers and thunderstorms are still possible (30-40%) chance at KGNV and KSGJ from around 15z this morning to 21z this afternoon. There may be a short window for VCTS at KSSI this evening but confidence is low of direct TSRA impacts. Fair, VFR conditions after 02z-03z this evening.

MARINE

A stalled front near the Georgia coastal waters will linger through Monday before dissolving through the week. Main maritime concern will be increasing potential for afternoon and evening thunderstorms each day during the upcoming week. The steering winds will generally move thunderstorms from the shoreline toward the offshore waters during the evening hours. Outside of thunderstorm influences, low to calm seas and light offshore winds persist.

Rip Currents: Surf/breakers will remain 1 to 2 feet through early next week in the mainly offshore flow with overall low rip current risk, but brief periods of moderate risk will exist during the afternoon hours as local onshore sea breeze develops each day.

FIRE WEATHER

West to southwesterly flow continues Today and into midweek across most locations, with east to southeast winds across coastal locations during the afternoon hours as the Atlantic sea breeze pushes inland.

Drier air will bring lower humidity and mostly dry weather during the morning to early afternoon hours across southeast Georgia Today, with showers and storms possible during the late afternoon to early hours, while scattered to isolated afternoon showers and storms will continue across northeast FL. Moisture levels begin to increase next week, with chances of showers and storms increasing through the week. Hotter temperatures Today and Monday will increase mixing heights across southeast GA, with locally high dispersion Monday afternoon.

Fog Potential: Significant fog is unlikely, and any strong wind will be associated with nearby thunderstorm activity.

PRELIMINARY POINT TEMPS/POPS

AMG 97 72 96 73 / 10 20 20 20 SSI 94 76 95 76 / 20 10 20 20 JAX 94 74 96 74 / 30 10 30 20 SGJ 93 75 95 76 / 30 10 10 10 GNV 93 73 95 73 / 30 10 20 10 OCF 92 73 95 73 / 40 10 20 10

JAX WATCHES/WARNINGS/ADVISORIES

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