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

- Severe to Extreme Drought Continues

- Patchy to Areas of Fog Inland Northeast Florida This Morning

- Cold Front Expected Late in the Weekend. Isolated Thunderstorms & Windy Conditions Possible

NEAR TERM /THROUGH TONIGHT/

Frontal boundary moving across interior GA early this morning will continue to push southward throughout the morning hours, becoming nearly stationary just south of the area by this evening. Through the morning hours, plenty of low clouds are being observed over northeast FL with some moisture pooling thanks to the southwest flow off the Gulf. Depending on how much winds subside towards sunrise just ahead of the front, patchy to areas of fog are quite possible towards the I-75 corridor, especially in Gilchrist/Alachua/Marion Counties in which localized dense fog will also be possible.

Otherwise, isolated showers approaching the FL/GA border as of 06Z are expected to mostly or entirety dissipate moving across northeast FL this morning, with less than 0.1" of rainfall expected in any showers that do hold together. North to northwesterly flow behind the front will quickly shift towards the northeast during the day today as high pressure will be positioned north of the area through tonight. Cold air advection will not be very impressive with this boundary, and combined with increasing sunshine as clearing occurs during the daylight today, high temps will still make it into the upper 60s to mid 70s except by the immediate coast and especially the Southeast GA coast where onshore flow will be strongest. A few isolated showers cannot be ruled out over far southern areas closer to the front this afternoon and evening as well, though would certainly be far from a washout.

Tonight, weaker flow inland will allow for better radiational cooling along with clear to partly cloudy skies, where lows will bottom out in the upper 30s to mid 40s. Upper 40s to near 50 will be expected closer to the coast and St. Johns River Basin where a light onshore breeze persists.

SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/

Friday, mid/upper level trough will lift away from the east coast with ridging aloft in its wake over the appalachians. At the surface high pressure to the north will slowly shift into the Carolina and VA Piedmont with clockwise flow bringing ENE winds to our area. A coastal trough to our east will keep a bit of a pinched gradient over the waters and the coast where breezy winds 10-15 gusting to 20- 25 mph will bring cooler highs to the coast despite sunny skies with low 60s along the SE GA coast and low/mid 60s along the NE FL coast, warming to the mid 70s along I-75.

Friday night, the high will shift to the Outer Banks of NC and allow for light NE winds to keep the coast in the 50-55F degree range while clear skies and calm winds inland will support radiational cooling to bring lows down to the low 40s over much of SE GA and mid/upper 40s over inland NE FL, while in the 50-55F degree range along the immediate coast.

Saturday, the high will shift east of the region into the Atlantic waters as a low pressure system develops near the ArkLaTEx region. The coastal trough will move onshore and merge with a lifting warm front that will rise across the area during the day well ahead of the developing low to the west with isolated to scattered coastal showers developing and moving onshore by late Saturday evening. Clouds will gradually increase, but southerly surface winds and increasing south to southwest winds in the low levels will allow highs to warm into the upper 70s over inland NE FL and low/mid 70s over inland SE GA. The onshore flow will keep coastal SE GA highs to only the mid 60s and coastal NE FL to the upper 60s.

A milder night Saturday is expected with mostly cloudy skies and showers increasing over SE GA towards sunrise. Southeasterly winds will become southerly and increase gradually after midnight as the low pressure system moves into the ArkLaMiss region. Lows will only fall to the upper 50s.

LONG TERM /SUNDAY THROUGH WEDNESDAY/

Sunday, a strengthening mid level southern stream trough will close off and support a dynamic surface low pressure system as it moves east across the deep south. A strong cold front extending south from the low will move eastward along the Gulf coast during the day and into the FL panhandle and SW GA by the afternoon. With high pressure well to the east and increasing low level wind fields, southerly surface winds will become very breezy with rounds of showers and isolated to scattered T'storms arriving by the afternoon and this activity continuing to stream ahead of the cold front as it slowly moves into western portions of the area late Sunday night. Low level (850 mb) jet winds of 30-40 knots, strong 0-6km bulk shear values around 50 knots, and diffluent jet stream will bring potential for strong to severe T'storms. But, instability and lapse rates appear weak given expected cloudy to mostly cloudy conditions ahead of the cold front. Forecasts will continue to monitor the system and it's severe threat which appears more marginal at this time.

However, the heavy showers Sunday afternoon into late Sunday night will bring widespread 1-2 inch amounts with high end potential of 3- 5 inches locally from heavier showers and T'storms. With ongoing drought conditions the rainfall will be welcomed and potential for flooding appears very low.

Monday, winds will back westerly and then northwesterly during the morning hours before becoming more northerly in the afternoon as high pressure builds across the TN and OH valleys. There is some model differences in how quickly the low exits east of the area with the GFS slower with the exit and keeping a low level trough over NE FL until late Monday afternoon while the ECMWF is more progressive with drier conditions arriving. For now, have kept isolated to scattered showers lingering through Monday afternoon for this wrap around moisture potential.

Tuesday, high pressure will become more established over the Mid Atlantic states northeasterly winds and mostly sunny skies. By Wednesday, the high will shift into the Atlantic waters with winds becoming southwesterly under mostly sunny skies. Dry conditions expected both days.

High temperatures will begin the period above normal Sunday, and trend closer to normal along the coast Monday and Tuesday due to onshore flow and cooler shelf waters with above normal highs inland. Then highs will become well above normal on Wednesday. Lows will remain above normal through the period.

AVIATION /06Z THURSDAY THROUGH 06Z FRIDAY/

Tricky forecast early this morning thanks to an approaching frontal boundary currently over interior GA and low level moisture pooling over northeast FL ahead of the front with a southwest wind. Expecting IFR to LIFR ceilings to persist at GNV through at least mid morning, with greater uncertainty further north and east towards Duval terminals and SGJ. For now, have only included TEMPO MVFR ceilings and vsbys at JAX, with the "cut off" expected to be further south towards CRG, VQQ and SGJ in which have included prevailing MVFR with TEMPO IFR as well. Depending on how much winds calm down just ahead of the frontal boundary, low stratus may develop into areas of FG, though confidence only high enough to include this potential at VQQ and GNV at this time towards sunrise. Ceiling/vsby restrictions are mostly expected to occur outside of any SHRA, as this activity over GA is expected to weaken throughout the morning hours. Winds will shift northwesterly from north to south throughout the early morning hours, with sustained winds around or just over 10 kts with gusts approaching 20 kts expected by this afternoon and evening. This breezier and drier flow will also help dissipate any remaining MVFR ceilings later this morning. No other operational concerns expected beyond the 12 hour time frame as winds ease near sunset and cloud cover continues to break.

MARINE

A cold front will move across GA waters and FL waters through this morning before stalling just south of the area by this evening. The front will then remain nearly stationary through Friday Night before lifting back northward Saturday and Saturday Night as a warm front. High pressure riding will persist along the southeastern seaboard through Friday in the meantime, with a northeast to easterly onshore flow. High pressure then moves east of the region Saturday Night and Sunday as a frontal system approaches the area Sunday Night, moving across area waters through Monday. Showers as well as isolated thunderstorms will be expected Sunday Night through Monday as the system moves through. High pressure ridging will then build back down the southeastern coast on Tuesday before weakening by mid week.

Rip Currents: Moderate rip current risk today as easterly swells persist until afternoon with periods of up to 11-13 seconds producing surf/breakers into the 3-4 ft range at local beaches. Easterly swells will diminish into Friday, but a moderate risk of rip currents expected due to breezy onshore north northeast winds.

FIRE WEATHER

- Critically low Relative Humidity Values Today And Friday Across Inland Southeast Georgia

Frontal boundary will exit south of the area this morning as high pressure builds to the northwest. Elevated Onshore flow between the high and weak low pressure over the coastal waters will create breezy northeast winds at the coast 15 mph gusting to 25-30 mph, but decreasing to 10-15 mph gusting to 20-25 mph along I-95 and the St Johns river basin and 5-10 mph further inland. Dry conditions will lower MinRH values across inland SE GA down to 20-25 percent range along and northwest of US-84. Friday, the high shifts north of the area and winds shift more east northeasterly 10-15 mph gusting to 20-25 mph along the coast, but lighter inland 5-10 mph. MinRH values will lower into the 30-35 percent range across inland NE FL and below critical values 22-27 percent over inland SE GA. Dispersions will be in the fair range today and fair to good range Friday due to overall weak transport winds inland, while low mixing heights from cooler temperatures at the coast limit dispersions there despite breezier coastal winds.

This weekend, the high shifts east of the area Saturday as a warm front lifts north of the area by Saturday evening turning winds southeast to southerly and a few showers near the coast. Winds will become southwesterly and breezy to windy Sunday as a strong cold front approaches from the west with rounds of showers increasing through the day. Isolated to scattered T'storms also expected until the cold front exits to the east early Monday. Rainfall totals of 1-2 inches expected Sunday into Sunday night with locally higher amounts of 3-5 inches possible.

FOG POTENTIAL AND OTHER REMARKS: Patchy to areas of dense fog will be possible along and west of the I-75 (including US-129) early this morning mainly south of I-10, then focusing to north central FL by sunrise until mid to late morning as the front exits to the south. Local visibility may fall well below one mile in these areas. Also, localized denser fog may also occur in proximity with wildfire smoke.

PRELIMINARY POINT TEMPS/POPS

AMG 69 38 69 40 / 0 0 0 0 SSI 59 45 60 49 / 0 0 0 0 JAX 67 44 69 47 / 0 0 0 0 SGJ 66 50 67 51 / 10 0 0 0 GNV 74 45 75 48 / 10 0 0 0 OCF 76 47 76 49 / 20 0 10 0

JAX WATCHES/WARNINGS/ADVISORIES

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