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

- Flood Watch Through This Evening for Inland Southeast GA. Mainly for areas from Waycross Northward. Areas that received heavy rain Friday will be prone to flooding today.

- Numerous to Widespread T'storms This Afternoon and Evening. Main Hazards Wind gusts 40 to 60 mph, frequent lightning, locally heavy rainfall

- Hot and Humid Conditions Continue into Next Week. Heat Index Values 102 to 106 degrees Today and Sunday for Northeast FL. Dangerous Heat Index Values of 105 to 110 degrees Possible Next Week.

NEAR TERM /THROUGH TONIGHT/

Main Highlights Today and Tonight:

- Numerous Showers and T'storms through late evening - Potential for Flooding across portions of inland Southeast GA - Scattered strong, isolated severe storms with a damaging wind threat possible through this evening.

A frontal boundary is across central GA this afternoon and will shift a bit southward into this evening near the Altamaha River Basin. Visible satellite imagery at 145 pm showed at lot of the area have not developed cumulus owing to somewhat lower moisture values, except across the south zones. We should see more development near and south of Gainesville to Bunnell over the course of the next couple of hours due to higher amounts of moisture through 700 mb and the west coast sea breeze. In all areas though, satellite data shows PWATs of about 2 inches.

Models are in fair agreement showing a couple of mid to upper level disturbances moving toward and into our region through this evening. This combined with the weak cool front pressing toward the area should yield numerous showers and thunderstorms, which looks to peak in intensity between about 5 pm and 11 pm. With sufficient downdraft CAPE of about 650-800 J/kg and a motion of about 15-20 mph, isolated storms may be briefly severe with localized damaging wind threat with winds of 40-60 mph. In addition, near boundary parallel flow to upper levels and high PWATS will bring a threat of localized flooding concerns, especially over inland southeast GA where flooding rains of 5-10 inches occurred yesterday in a swath from Coffee county to Pierce and Brantley counties. For the moment, it appears the heavier rainfall totals today will be along or just east of the where the flood watch remains in effect which is good news so any remaining water could recede. In any of these storms some localized totals of 2-4 inches looks possible, mainly where training of cells occurs.

Scattered showers and a few t-storms may linger past midnight, but should dissipate during the overnight hours. With a weakened pressure gradient giving light to calm winds late tonight, somewhat lower min temps in the lower 70s or around 70, and wet grounds, low stratus and some patchy fog are placed in the forecast.

SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/

Main Highlights This Period:

- Lower rainfall coverage on Sunday - Heat Indices may near advisory conditions Monday

Lower coverage of showers and storms through the forecast period moisture levels will be relatively lower compared to the past couple of days. With westerly winds remaining the predominant flow, the Gulf breeze is expected to push inland each afternoon, with scattered showers and storms along the breezes with most activity likely along inland locations towards the I-95 and US-17 corridors. Even with lower chances of precipitation, for any showers or storms that do develop the potential for isolated strong to severe storms remain along with locally heavy downpours.

Temperatures will continue to warm through the end of the week and into the upcoming week. Highs on Sunday will be in the upper 80s to lower 90s area-wide. By Monday, Highs are expected to be in the 90s area-wide, with mid 90s in northeast Florida, possibly upper 90s for some locations of inland northeast Florida, with heat index values currently forecast to range near Heat Advisory criteria during the afternoon hours.

LONG TERM /TUESDAY THROUGH SATURDAY/

Main Highlights This Period:

- Heat Advisory conditions expected Tuesday and Wednesday - Return to at least scattered afternoon storms mid to late week

Scattered showers and storms through much of the upcoming week as high pressure sits over the region. Warm temperatures will persist across the area as highs will continue in the mid 90s. Daily heat index values near and above heat advisory criteria will likely result in issuance of Heat Advisory each day during the first half of the upcoming week. An approaching frontal boundary is expected to begin to slow and to stall north of the Altamaha river after midweek. But with it remaining north the area, westerly flow is expected to persists through the remainder of the week, with the Gulf breeze remaining the dominant breeze and continuing to direct most convective towards the eastern portions of the local area.

AVIATION /18Z SATURDAY THROUGH 18Z SUNDAY/

A round of showers and storms expected this afternoon and evening time. We have a TEMPO group for at least MVFR conditions if not IFR. Strong wind gusts potential to 30 knots also included for gusty, erratic winds in T'storms. May still be some storms around in the 23z-03z time frame. Sfc winds will be westerly outside of T'storms 6-10 knots, though variable or east-southeast for SSI and SGJ, but wind will diminish tonight. West- northwest flow about 5 kt expected Sunday morning by 14z.

T'storms will end and move off the Atlantic coast later this evening, probably not until after 03z/04z. Later tonight, some broken MVFR ceilings and potentially IFR cigs may develop toward 09Z- 12Z from near JAX to SSI, but should lift/disperse by 14z.

MARINE

A frontal boundary will move toward the area waters tonight but then shift back north. This front will help bring a round of thunderstorms to area waters through tonight. Some of these storms may produce strong gusty winds, frequent lightning and very heavy rain. A good chance of thunderstorms is expected again Sunday afternoon and evening. Weak high pressure ridge will slowly build in over the area waters early Monday and into Tuesday with isolated to scattered thunderstorms returning by midweek as another front moves in from the north. Stronger offshore winds with exercise caution level winds looks possible for offshore waters Monday into Tuesday.

Rip Currents:

Surf cams and wave guidance show surf about 1 foot, or maybe 2 ft at the most. Some wind sea swells, from the southeast at with 1 foot with periods of 6-8 seconds. Probably looking at low risk Sunday and into Monday as well. Noted NWPS rip current probability guidance is generally under 30 percent. Offshore flow is also dominant.

FIRE WEATHER

Lingering showers and storms will push offshore through the early to mid evening hours Tonight. Relatively drier air filters into the region as ridging builds across the FL peninsula, with scattered showers and isolated T'storms expected on Sunday and through midweek. Winds will continue to generally be from the west to southwest through midweek.

Good dispersions expected Sunday afternoon through as clouds limit mixing heights. Higher dispersions develop on Monday and Tuesday mainly over southeast Georgia and portions of northeast Florida.

Temperatures will rise next week as drier conditions will limit chances for T'storms. A return of potential heat advisory conditions on Monday and Tuesday for portions of northeast Florida.

FOG POTENTIAL AND OTHER REMARKS: Areas that receive heavier rainfall may also experience patchy late-night and early-morning fog. T'storms will produce locally gusty winds, frequent lightning, and locally heavy downpours.

EQUIPMENT

The WSR-88D Radar located near the Moody AFB near Valdosta remains offline due to technical problems. Technicians are awaiting critical parts to restore functionality. During the outage please utilize other area radars...KJAX, KTLH, or KJGX.

PRELIMINARY POINT TEMPS/POPS

AMG 70 89 73 91 / 50 20 10 30 SSI 74 90 77 93 / 70 20 10 30 JAX 71 92 75 95 / 60 40 10 30 SGJ 73 91 76 95 / 60 30 10 30 GNV 72 92 73 95 / 30 40 20 10 OCF 72 92 74 94 / 20 40 10 10

JAX WATCHES/WARNINGS/ADVISORIES

FL...None. GA...Flood Watch until 11 PM EDT this evening for GAZ132>136-149- 151-152-250. MARINE...None.