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 to Scattered Strong/Severe TStorms & Beneficial Rainfall Sunday. Localized Heavy Downpours, Especially Along & North of I-10. Gusty Non-TStorm Winds Sunday Afternoon/Evening

- Extreme Drought Expanding Across our Region. Moderate Wildfire Danger Throughout the Region. Lightning from Storms on Sunday Could Cause Ignitions

- Small Craft Advisory Sunday-Monday Offshore Waters

- Moderate Rip Current Risk at Area Beaches Through Sunday

NEAR TERM /THROUGH TONIGHT/

After a cool start especially away from the coast, a very similar pattern to the previous few days is expected across the region today as the area remains under the influence of high pressure ridging from the north and east. The main difference will be the fact that the high pressure center will start to slowly drift southeastward off the coast of the Carolinas throughout the day today and through tonight, which will veer winds more east to southeasterly as compared to a northeast flow. In addition, higher clouds will start to move into the region throughout the day today, especially north and west. Despite more cloud cover for many, the veering winds as well as ridging building a bit aloft will allow for high temps a few degrees higher today, especially away from the coast where widespread 70s are expected and perhaps a few readings at 80 near the Suwannee River Valley. Further north and east and towards the coast, we will still hang on to the 60s for the most part.

Tonight, higher clouds will start to thicken as low pressure and associated frontal system start to approach the area from the northwest. Expecting the area to remain dry through early Sunday Morning at this time, though a warm front lifting northeast overnight Sunday may bring a few isolated showers with it. Min temps will be milder accordingly, with readings in the 50s being most common.

SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/

On Sunday, a positive tilt mid to upper level trough will swing through the eastern U.S. with a sfc low around 1000-1004 mb moving across the southern U.S. A strong cold front will be moving quickly eastward from the lower MS valley east to our local area by the late evening. The forecast area will be in the warm sector on Sunday with breezy and warm conditions ahead of the front. Breezy/windy southerly winds of 15-25 mph gusting to near 40 mph are anticipated, with a possible need for a wind advisory, for gusts near the 40-45 mph range. A good swath of moisture moves out ahead and the cold front with instability reaching upwards of 300-500 J and bulk shear of about 50 kt. CAM model guidance shows the main squall line approaching the area, moving into western zones by about the 1-4 pm time frame but some prefrontal scattered convection may also develop ahead of this feature. The line should continue to move east, possibly merging with prefrontal convection by late aftn, with potentially for a few damaging wind gusts and an isolated embedded tornado within the line. Latest HRRR shows some indications of this isolated tornado threat from inland northeast FL to parts of inland southeast GA. Sunday night, the weakening squall line looks to be located roughly from near the GA nearshore waters southwest to northeast FL, continuing to move east. However, timing of the line still a little in question given the differences between HRRR and other guidance. While the threat is still there for a severe storm, the threat should be waning Sunday night after about 8-9 PM as the airmass stabilizes overnight and front moves in from the west. SPC has highlighted the forecast area in a marginal to slight risk of severe storms. The front should push into the area Sunday night while the associated sfc low moves offshore of the southeast coast. Precip chances should diminish considerably overnight and lows will drop to the 50s.

On Monday, post-frontal trough extends from the low offshore and across our area and so we continue to have a chance of showers in the morning, but would assume the chances will diminish further in the aftn. Northwest to north winds and drier conditions will make for a more pleasant day with highs in the lower 70s south zones to 60s coast and nrn zones as weak cold advection is anticipated behind the departing system. Not too cold on Monday night with lows in the 40s for nrn zones and lower 50s further south. Some patchy fog can't be ruled out.

LONG TERM /TUESDAY THROUGH FRIDAY/

Surface high pressure system around 1025 mb will be positioned over the SC/NC coast Tuesday morning and will move southward through mid to late week and so return flow will develop eventually by mid week. Airmass looks dry for the long term but the model blend shows some low chance for showers on Friday but confidence at this point remains low given the low amount of QPF in the output and what looks like weak forcing aloft. The return flow suggests moderation in high temps and then above normal temps with high of around 80 and then lower 80s by Thursday into Friday. Overall, lows will be above average during the long term. The pattern may favor some occasional late night and early morning fog/stratus.

AVIATION /12Z SATURDAY THROUGH 12Z SUNDAY/

VFR conditions are expected to persist today and into later tonight. FEW to SCT cumulus expected to develop in the afternoon as mean layer low-level flow through 5 kft turns east and then southeast with a moisture increase. Some chance of MVFR late tonight, but confidence is on the low side. Very isolated showers/sprinkles will also be possible towards the end of the forecast period, though coverage/impacts expected to be very minimal.

MARINE

High pressure ridging persists through today, with the high center drifting towards east of the region by tonight. A warm front will lift northward across the area tonight as a low pressure system approaches from the west. Isolated shower and thunderstorm chances will increase tonight over area waters, but especially through Sunday as the low and associated cold front move across the region through Sunday Night. A few storms may be strong to severe Sunday afternoon and Evening as a squall line moves across the region. South-southwesterly winds also increase ahead of the front on Sunday, with small craft advisory conditions likely for all waters Sunday Afternoon/Evening and persisting offshore Sunday Night. High pressure ridging will then build back down the southeastern coast on Tuesday before weakening and shifting east of the Florida Peninsula once again mid week.

Rip Currents: Moderate rip current risk today for all beaches with a persistent onshore flow. Stronger more southerly winds along shore Sunday will persist a moderate rip current risk for the end of the weekend.

FIRE WEATHER

- CRITICALLY LOW HUMIDITY ACROSS INLAND SOUTHEAST GEORGIA THIS AFTERNOON - HIGH DAYTIME DISPERSIONS ON SUNDAY...

Long durations of critically low relative humidity values are forecast this afternoon for inland portions of southeast Georgia. However, low-level moisture gradually increases tonight and early Sunday morning as a cold front approaches.

Increasing cloud cover is expected later tonight into Sunday ahead of cold front, with high chances for showers and embedded thunderstorms, some of which could be strong or briefly severe. This activity will overspread the area Sunday, possibly continuing into late Sunday night. Strong transport winds, breezy surface speeds, and elevated mixing heights will create high daytime dispersion values on Sunday throughout most of the area. Beneficial rainfall overspreads the region Sunday into Monday. Rainfall amounts of around 1 inch are possible, with locally higher totals possible. Linger shower chances on Monday but will decrease in the afternoon as drier air will filter in.

FOG POTENTIAL AND OTHER REMARKS: Significant fog formation is not expected during the next several days but some localized visibility reductions are possible during the predawn and early morning hours for locations near active or ongoing wildfires or prescribed burns.

PRELIMINARY POINT TEMPS/POPS

AMG 70 50 76 55 / 0 10 90 90 SSI 63 53 71 55 / 0 10 80 100 JAX 71 53 81 57 / 0 10 70 90 SGJ 71 55 79 58 / 0 10 60 90 GNV 78 56 82 58 / 0 0 70 90 OCF 79 57 82 58 / 0 0 60 90

JAX WATCHES/WARNINGS/ADVISORIES

FL...None. GA...None. MARINE...Small Craft Advisory from 10 AM Sunday to 7 AM EST Monday for AMZ470-472-474.