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

- Extreme Drought for Inland Areas. Practice Fire Safety & Check for Local Burn Bans

- Strong to Isolated Severe Thunderstorm Risk Tuesday. Tuesday Morning Southeast GA & Suwannee River Valley. Tuesday Midday - Afternoon: Remainder of NE Florida. Main Strong Storm Hazards: Gusty 40-60 mph & Isolated Tornadoes

- Small Craft Advisory Possible early Tuesday to Tuesday Night

- Patchy Frost over Inland Southeast GA, Wednesday and Thursday Mornings

UPDATE

No major updates needed on the forecast for tonight. A light onshore breeze and mostly cloudy skies will keep low temperatures in the low 60s near the northeast Florida Atlantic coast and St. Johns river basin, with lows in the 50s elsewhere.

SHORT TERM /THROUGH TUESDAY NIGHT/

A fairly dynamic time period from Monday through Tuesday night as a cold front that sweeps through today will stall to the south on Monday, only to be forced northward across our area Mon night. This occurs as a surface low develops in a classic manner across the northwest Gulf Monday, translates east to northeast, gradually deepening as a mid level trough moves eastward through the Midwest and the TN valley. The surface low moves across the deep south Monday night into Tuesday morning, likely moving through GA early Tuesday morning. The low will shift northeastward Tuesday and off the Mid Atlantic/NC Outer Banks Tuesday afternoon. An attendant cold front will move across the region Tuesday from northwest to southeast, ending up just southeast of the area Tuesday evening, and continuing to push south of the area Tuesday night.

Considerable cloudy on Monday with an overrunning situation with a chance of showers and areas of rain and a northeast wind flow. The more showery activity may be over the coastal areas initially where a coastal trough is expected to form. As the low level winds veer Monday night, a gradual increase in instability may be realized but probably not until well after midnight, and even then the MUCAPE looks to be only a few hundred J/kg at best.

Ahead of the front on Tuesday, some better instability is expected, with a low level flow from the south and southwest. The better instability with MUCAPE of about 300-600 J/kg is south of US Highway 84, but mainly across northeast FL. This overlap of small CAPE but high shear (50-65 kt) may support a strong or even an isolated severe storm with damaging wind or an isolated tornado. Given the limited instability, the severe threat currently remains low. Overall, the best chance of precipitation will be through about Tuesday mid afternoon, with the dynamics lifting out to the northeast by late Tuesday afternoon and the front sweeps through most of the area.

For temps, mild conditions on Monday with highs in the 70s over northeast FL, but in more cloud cover and the coolest airmass in southeast GA where highs are limited to the 60s and lower 70s. Mild overnight lows Mon night given the cloud cover and the veering winds. Tuesday, highs again limited to the 60s over well inland southeast GA, and 70s elsewhere. We could reach 80 deg briefly for the southeast most zones Tuesday ahead of the front from Marion to Flagler county. Much cooler Tuesday night as the front moves south of the area on northwest flow, with lows ranging from the mid 30s inland southeast GA, to 40s to near 50 over northeast FL.

Rainfall amounts are best over southeast GA at 0.5 to just over 1 inch, and 0.50 inches or less over northeast FL. It's possible some areas in northeast FL east of Highway 301 may barely measure 0.10 inches, unfortunately, in this current drought situation.

LONG TERM /WEDNESDAY THROUGH SUNDAY/

Dry and seasonably cool Wednesday and Thursday with inland frost potential across SE GA both Wednesday morning and Thursday morning with weak high pressure dominating north of the region. The next system will be organizing over the southwest U.S. Thursday which may spread mid or high clouds into the area Thursday through Thursday night.

The current suite remains basically on track with another frontal system, oriented southwest to northeast, coming across the deep south on Friday and Saturday. Moisture and mid level forcing appears more than sufficient for a good chance of showers on Friday and likely into Saturday with this system. This system may also be accompanied by a surface wave of low pressure along the front over the Gulf Coast on Friday and Saturday. At this time, some small potential for a few thunderstorms over the weekend but confidence remains low, with similar amounts of instability to Tuesday's forecast. Main takeaway is that fronts will be moving into the area and accompanied by some much needed rainfall for some locations. Latest climate site rainfall deficits since Sept 1st are 6-9 inches at Alma, Jacksonville and Craig Airfield to 3-4 inches at Gainesville.

AVIATION /00Z MONDAY THROUGH 00Z TUESDAY/

VFR conditions with calm and variable winds expected overnight. Northeast winds will pick up after day break Monday, with a low (<20%) chance of showers at the TAF sites starting in the afternoon. SSI has the highest chance of the sites to reach MVFR ceilings Monday afternoon.

MARINE

Weak high pressure will be located to the northeast this afternoon, with an inverted trough over the coastal waters. A cold front will move south southeast across area Tonight into Monday. The front will lift back north across area as a warm front Monday night, as an area of low pressure lifts northeast out of the Gulf. As this low tracks northeast across the southeastern US, a cold front will move through Tuesday. A round of showers and thunderstorms will accompany this frontal passage. High pressure will build to the northwest Tuesday night into Wednesday. The high will weaken overhead Thursday. Another low pressure area is expected to lift northeast out of the Gulf late in the week.

Rip Currents: SE GA Moderate Monday NE FL High Monday

FIRE WEATHER

Moisture will gradually increase through tonight as a cold front approaches from the north. This front will move through the area later tonight, but stall to the south on Monday, only to move back as a warm front Monday night. There is a chance of showers for the area on Monday due to moisture overlapping the front. A new cold front will then approach from the west early Tuesday, bringing much needed rainfall Tuesday with a chance of a strong thunderstorm capable of gusty winds and lightning. Gusty southwest winds outside of thunderstorms are expected Tuesday mainly in northeast FL. Rainfall will end Tuesday evening as the front presses south of the area. Dry conditions are expected by Wednesday with lower humidity under north winds.

FOG POTENTIAL AND OTHER REMARKS...Gusty and erratic winds will occur from thunderstorm activity Tuesday. Some rainfall is expected, but lightning strikes may cause wildfires due to dry fuels.

PRELIMINARY POINT TEMPS/POPS

AMG 50 67 53 69 / 10 30 80 90 SSI 58 67 60 73 / 10 20 60 70 JAX 58 72 60 76 / 10 30 50 80 SGJ 62 75 65 79 / 10 30 40 70 GNV 58 77 63 79 / 10 20 40 80 OCF 58 79 63 78 / 10 20 30 80

JAX WATCHES/WARNINGS/ADVISORIES

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