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

- High Risk for Rip Currents At All Beaches this afternoon and Memorial Day

- Isolated Strong to Marginally Severe Thunderstorms Across Inland SE GA. Primary Thunderstorm Hazards: Localized Flooding & Gusty Winds \. Daily Afternoon Thunderstorms Expected through the week ahead

- Hot and Humid - Daily Heat Index 95-100F through the Week

- Historic Drought & Elevated Wildfire Danger Continues

UPDATE

Shower and storm activity is currently remaining offshore, but a few showers will begin to drift along the NE FL coast in the next few hours as we head into the afternoon hours ahead of the inland push of the sea breezes. Current Satellite Obs show PWATs in the 1.65" to 1.75" range and expected to increase closer to the 1.9" range this afternoon. With the inland push of the sea breezes this afternoon, any showers or storms that develop could have heavy downpours supported by the moisture aloft, with any slow moving storms bringing the potential for localized flooding as the storms creep along.

NEAR TERM /THROUGH TONIGHT/

Main Highlights This Period:

- Scattered thunderstorms capable of gusty winds and localized flooding this evening for inland counties, west of I-95.

- High Risk of Rip Currents Continues at all area beaches this afternoon.

A slight change to the pattern today as upper ridging near Cuba lifts northward and phases with the stronger Bermuda ridge. Convective potential will not be entirely subdued by the increased subsidence and warming aloft but it will decrease the potential for strong to severe thunderstorm development this afternoon.

A light low level southerly steering flow continues, allowing sea breezes from the Gulf and Atlantic to push inland this afternoon, acting as the primary focus for scattered convection. Weak flow through the lower half of the atmosphere will lead to slow-moving thunderstorms, which will be fed by anomalous deep moisture (PWAT 1.75-1.9"). Heavy rain rates and slow storm motion could lead to localized flooding this afternoon and evening, especially as the sea breezes collide between the I-75 and US 301 corridors between 7-9 PM.

Overall, convection will decrease in coverage during the late evening but a grazing shortwave impulse lifting across western GA may continue scattered showers and isolated storms across portions of SE GA through the early morning hours Monday.

Temperatures will follow a similar diurnal trend today, rising into the upper 80s and low 90s once again this afternoon with heat index values pushing into the upper 90s and be followed by mild, muggy conditions tonight with lows in the low 70s inland and mid 70s at the coast.

SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/

Main Highlights This Period:

- Daily afternoon/evening thunderstorms - Hot and humid conditions

Bermuda ridging extending across the SE US will gradually shift southward early next week maintaining low level SSE flow. Meanwhile, the parade of shortwaves continue to round the ridge and move across SE GA in the upper SW flow. Slightly drier air (PWATS 1.5-1.8 in) begins to filter in from the SSE Monday afternoon into Tuesday. This will lower convective coverage to scattered over NE FL and along the coast early next week as the sea breezes shift inland. Better coverage will be over the Suwannee Valley of NE FL and inland SE GA where PWATs will be closer to 1.8-2.0 inches and potentially enhanced by passing shortwaves.

Highs will be above seasonable in the mid 80s to low 90s with max heat indices in the mid 90s to around 100. Overnight lows will be in the upper 60s to upper 70s.

LONG TERM /WEDNESDAY THROUGH SATURDAY/

Thursday through Sunday...

- Daily Thunderstorm Chances - Slight Risk of Heavy Rainfall Late Next Weekend

The 1000-500 mb mean layer Bermuda Ridge axis begins to shift farther east and south of the local region with a transition to a more unsettled, wetter southwest steering flow pattern into next weekend. Above average precipitable water content is forecast to range between 1.65 - 2 inches (average for early June is 1.4 to 1.5 inches). This general pattern indicates a dominant west coast sea breeze regime Thu & Fri with higher afternoon and evening storm coverage east of Highway 301 toward the Atlantic coast. Then, not a classic diurnal pattern into next weekend with more widespread periods of rainfall as the upper trough moves across the deep south with upper level lift, a weak surface front, and daily sea breezes interacting with deep layer moisture to bring periods of heavy rainfall and a localized flooding rain risk where grounds may become briefly saturated. The CPC US Week 2 Hazard Outlook does have much of the FL peninsula and coastal SE GA flagged in a "Slight Risk" of heavy rainfall. Still too far out for specific rainfall amounts, but given the long term drought, rain over the next week will be welcomed by most.

With increased cloud cover and storminess, high temperatures will trend below average generally in the 80s with muggy lows in the 70s to mid 60s for parts of inland SE GA early next week on the northern side of the lingering front.

AVIATION /12Z SUNDAY THROUGH 12Z MONDAY/

Southeasterly winds persists into the afternoon hours ahead of the inland push of the Atlantic sea breeze, shifting winds to be from the ESE. Some isolated to scattered storms will be likely along sea breeze, with occasional TSRA impacts along the I-95 corridor. Inland push of the sea breeze will bring possible activity near KGNV with highest TSRA chance between 21z-02z this evening. With convection, anticipate brief heavy downpours that may lead IFR to LIFR visibility.

MARINE

Influence of Bermuda high pressure will continue a south to southeasterly wind over the waters through the upcoming week. Daily afternoon and evening surges are expected with winds increasing to 15 to 20 knots. Widely scattered showers and offshore thunderstorms are possible this morning, with activity then becoming more isolated on Memorial Day and Tuesday. Atlantic high pressure will then shift southward around Thursday this week,increasing chances for showers and thunderstorms across our area as prevailing winds become southerly.

Rip Currents:

Due to breezy onshore winds this afternoon, and surf around 3-4 feet, there will be a High Risk at all area beaches this afternoon and evening. High risk is likely to continue into Monday due the afternoon southeasterly wind surge.

FIRE WEATHER

- Patchy High Dispersions Monday And Tuesday

Numerous showers and storms will limit dispersions this afternoon into the fair to good range. Showers and storms develop along the inland moving sea breezes each afternoon. Generally southerly flow will result in the sea breeze merger occurring between the I-75 and US 301 corridors in the late afternoon into early evening today. Isolated strong thunderstorms are also possible along the merger in the late afternoon into early evening. Potential hazards still expected to be strong wind gusts, heavy downpours, localized flooding, and frequent lightning. Some drier air aloft then moves in from the east early next week leading to lower storm coverage to scattered for most of the area except over portions of Southeast Georgia north of US-82. Elevated mixing heights and slightly increasing transport winds early next week will lead to good to patchy high dispersions Monday and Tuesday.

FOG POTENTIAL AND OTHER REMARKS: Significant fog is not expected into early next week. Erratic winds during periods of thunderstorms.

PRELIMINARY POINT TEMPS/POPS

AMG 87 68 87 69 / 80 70 80 60 SSI 86 76 86 77 / 40 40 20 30 JAX 89 74 89 75 / 70 30 30 20 SGJ 89 76 89 77 / 50 20 30 10 GNV 90 72 91 73 / 70 40 50 50 OCF 90 73 91 74 / 60 40 40 40

JAX WATCHES/WARNINGS/ADVISORIES

FL...High Risk for Rip Currents through late tonight for FLZ124-125-138- 233-333. GA...High Risk for Rip Currents through late tonight for GAZ154-166. MARINE...None.