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

- Breezy conditions & low humidity values may Create An Elevated Wildfire

- Danger on Wednesday Afternoon

- High Risk of Rip Currents at Northeast Florida Beaches this Afternoon

- Near Record High Temperatures on Wednesday Afternoon

- Isolated to Widely Scattered TStorms Late Wednesday through Thursday

- Thunderstorms & Widespread Beneficial Rainfall During the Weekend. Strong to Isolated Severe Storms Possible on Saturday Afternoon & Evening. Potential widespread rainfall totals of 1-3 inches Wednesday through Sunday

UPDATE

Added patchy fog over inland Northeast FL late tonight into early morning Wednesday where more partial clearing and calm winds are expected. Areas of fog most likely over the Ocala national forest, along and west of the St Johns river westward to highway 301 along and south of US highway 100/state road 26. Any fog that combines with smoke from nearby wildfires may create localized superfog conditions where visibility is greatly reduced. Skies will be mostly cloudy from mid to high level clouds along and north of I-10. No rain expected overnight.

With light winds becoming southerly along the coast and then southwesterly by sunrise, lows will be milder over inland locations than past mornings with lows in the low 60s inland and mid 60s along and east of I-95 to the coast.

NEAR TERM /THROUGH WEDNESDAY/

Main Highlights This Period:

- Elevated Risk of Rip Currents at Area Beaches.

Afternoon surface analysis depicts persistently strong high pressure (1026 millibars) situated over the southeastern states. Meanwhile, a cold front extends from the eastern Great Lakes southwestward through the Ohio and Tennessee Valleys to the southern Plains states. Aloft...northwesterly flow prevails locally, as our region lies on the eastern periphery of ridging that was building over the southwestern Gulf (Bay of Campeche). This ridge was steering a potent shortwave trough and associated convection eastward from the Arklatex region and the Ozarks towards the lower Mississippi and Tennessee Valleys, with showers extending east of this convection across central GA and southern portions of SC. Latest GOES-East derived Total Precipitable Water imagery indicates increasing moisture levels across inland portions of southeast GA, where PWATs have climbed to near 1.5 inches for locations north of Waycross, while values were generally in the 1 - 1.25 inches elsewhere. Coastal troughing that developed a few light sprinkles and showers during the early morning hours along the I-95 corridor has since dissipated, leaving behind a cumulus and stratocumulus field across most of our area. High altitude cloudiness emanating from convection and showers to the north and west of our region was beginning to shift southward across southeast GA as well. This increasing cloud cover and some outflow from rainfall north of the Altamaha / Ocmulgee Rivers has cooled temperatures back to the low and mid 70s for locations north of Alma as of 19Z. Temperatures elsewhere have warmed to the upper 70s to mid 80s at inland locations, with temperatures at coastal locations generally in the mid to upper 70s. Dewpoints ranged from the mid 50s to the mid 60s.

Shortwave troughing progressing eastward across the lower Mississippi and Tennessee Valleys will likely keep deeper moisture values in place north of the Altamaha and Ocmulgee Rivers in southeast GA overnight. However, a few showers cannot be ruled out for locations north of Waycross, mainly after midnight tonight. Increasing mainly mid and high altitude cloudiness should prevent fog formation across our region overnight, although some patchy fog may be possible for locations that have clearer skies for a longer period of time, namely north central FL as well as southern portions of the St. Johns River basin. Low level winds will veer from easterly to southerly this evening and then southwesterly overnight, and this veering wind profile and increasing cloud cover should keep lows in the 60-65 degree range at most locations overnight.

SHORT TERM /WEDNESDAY NIGHT THROUGH THURSDAY NIGHT/

Main Highlights This Period:

- HOT Wednesday with breezy SW winds - Transition to a wetter regime begins late Wednesday

Near record heat Wednesday with highs topping out in the lower 90s as breezy SSW steering flow develops with the mean layer ridge across the area shifting to the ESE allowing a surface trough to edge farther across southern GA into late Wednesday afternoon and evening. Enough deep layer moisture combined with daytime heating and an approaching mid level short wave trough could kick off some late afternoon and evening showers and isolated storms mainly near the Altamaha River basin Wednesday evening, with convection increasing in coverage and shifting southward into Wednesday night across parts of southeast GA as the short wave trough passes overhead and the surface front nudges farther south. This will be our first round of needed south GA rainfall into Thursday morning. A few showers may make it as far south as the northeast GA I-10 corridor by Thursday morning. The front lingers across the local area Thursday with elevated moisture and diurnal heating with the sea breezes triggering scattered showers and storms across south GA and northeast FL into Thursday afternoon and evening.

This period will not bring widespread rainfall, but it is the transition time frame as the persistent ridge breaks down and allows fronts and short waves with deeper moisture to finally begin to phase across the local area, all promoting better rain chances but also brining thunderstorm (lightning risk) as the atmosphere becomes more unstable.

LONG TERM /FRIDAY THROUGH TUESDAY/

Main Highlights This Period:

- Unsettled weekend weather but with beneficial rain - Isolated strong/severe storms possible Saturday

A lingering front across the local area on Friday combined with diurnal instability will bring scattered showers and isolated storms to the local area into Friday afternoon. The front begins to lift north as a warm front into Friday evening, with rain chances decreasing south to north through daybreak Saturday morning. A stronger front approaches Saturday and settles across the region into the weekend with rainfall and embedded thunderstorms impacting the area through the day Saturday and into Saturday night with precipitation shifting north to south. Favorable shear and instability ahead of the front could bring a few strong to severe storms, with the general timing of stronger storms north of Interstate 10 Saturday morning, shifting near and south of Interstate 10 into Saturday afternoon and evening. A reinforcing short wave trough slides across the region into Sunday with stratiform rainfall increasing in coverage, with the best rain chances Sunday across northeast FL and lower chances across southeast GA. Isolated storms are possible across north-central FL Sunday near the lingering frontal zone.

Rainfall outlooks are increasingly favorable for all areas to receive a wetting rainfall this weekend. The Long-Range Ensemble Forecast Model (LREF-NH) advertised high probabilities (> 60%) for at least 0.25" Saturday into Saturday night for locations north of a Gainesville to St. Augustine line, with > 80% north of Homerville to Waycross. During the same time period, there's a high chance (> 60%) of locations along and north of Homerville to Waycross to Jesup of heaving at least 0.50 inches. The rainfall is welcomed and needed, but there will be a lightning threat with embedded storms as well, and the potential for locally strong storms Saturday. The main convective hazards in storms Saturday would be strong wind gusts of 40-60 mph and possibly a few rotating cells, especially if a surface low forms along the front as some models suggest.

Drier conditions filter north to south across the area Sunday night into Monday and continued into Tuesday as surface high pressure builds eastward across the deep south. Fog potential increases for inland areas early next week.

Temperatures moderate to above average values Saturday ahead of the front, then cool to near to below average Sunday and Monday trailing the frontal passage. Temperatures moderate back to near to above average Tuesday as a more typical diurnal sea breeze regime develops.

AVIATION /00Z WEDNESDAY THROUGH 00Z THURSDAY/

VFR conditions currently this evening as high pressure extends over the area from the east with southeasterly winds 6-10 knots will decrease and become southerly through 06Z along the coast 5-8 knots and turning calm inland. High level clouds will stream over the terminals downstream of thunderstorms that will remain well to the north and west of the region overnight with enough clear skies over the inland Northeast FL terminals for MVFR fog after 06Z at VQQ and briefly at GNV. Light winds become southwesterly after sunrise with speeds 8-10 knots increasing to 12-15 knots in the afternoon with gusts around 20 knots as a front slowly approaches the region from the northwest and high pressure shifts southeast of the region. Confidence is too low for VCSH, but a quick shower may develop near SSI or along the pinned Atlantic seabreeze that will struggle to move inland of the coast with south southeast winds nearing CRG by 23Z. Skies will trend mostly sunny to sunny Wednesday afternoon.

MARINE

High pressure over the southeastern states will weaken as it shifts offshore this evening allowing for seas to gradually subside offshore tonight. A cold front will enter the southeastern states on Wednesday afternoon, bringing scattered showers and thunderstorms to the Georgia waters Wednesday night and to the northeast Florida waters on Thursday. This front will then stall across the northeast Florida waters on Thursday night and Friday, keeping widely scattered showers and thunderstorms in the forecast. A wave of low pressure will develop over the Gulf by late Friday night or Saturday, with widespread showers and possibly a few strong thunderstorms overspreading our local waters by Saturday afternoon and evening, with activity expected to continue into Sunday across the northeast Florida waters. Small Craft Advisory conditions may develop on Saturday as southwesterly winds increase ahead of this approaching wave of low pressure. The front will shift south of the northeast Florida waters on Sunday, with northerly winds strengthening in wake of departing low pressure by late Saturday night.

Rip Currents:

Breakers of 3-5 feet at the northeast FL beaches will combine with a northeasterly ocean swell of 11-12 seconds to maintain a high risk through early this evening, while surf heights of 2-3 feet at the southeast GA beaches yield a higher end moderate risk. A persistent northeasterly swell will likely result in a high end moderate risk at all area beaches on Wednesday, despite developing breezy offshore winds by late in the morning. The longer period northeasterly swell should continue through at least Friday, keeping a moderate risk in place at the northeast FL beaches.

FIRE WEATHER

ELEVATED FIRE DANGER DAY WEDNESDAY DUE TO BREEZY SOUTHWEST WINDS, - LOWER INLAND HUMIDITY AND HIGH INLAND DAYTIME Dispersion

- Increasing Rain Chances This Weekend

Near record high temperatures Wednesday with lower humidity for locations east of Highway 301 under breezy southwest winds. Gusts will near 20 to 25 mph by the afternoon. The east coast sea breeze will develop and press inland to about the Interstate 95 corridor, trailed by SSE winds near the coast. There a a low (< 20%) of morning showers or a storm near the Altamaha River basin through about 11 am, otherwise mostly dry weather prevails Wednesday. The combination of increasing southwest transport winds and hot temperatures will create very high daytime dispersion Wednesday afternoon.

Rain chances increase across southeast GA through Wednesday night into Thursday as a frontal zone settles southward across the area with isolated thunderstorm potential. The front stalls and lingers over the local area into Thursday afternoon with a chance of showers and isolated storms as the front interacts with diurnal instability and the sea breezes.

Extended outlook: Unsettled weather with high confidence of widespread wetting rainfall this weekend. A chance of strong to isolated severe storms Saturday.

FOG POTENTIAL AND OTHER REMARKS: Patchy fog is possible tonight mainly across inland northeast Florida. Smoke from nearby fires may result in localized visibility reductions, especially during the overnight and early morning hours.

CLIMATE

Record High Temperatures at NE FL/SE GA climate sites:

April 29: KJAX: 93/1991 KGNV: 95/2017 KAMG: 93/2012 KCRG: 91/2021

PRELIMINARY POINT TEMPS/POPS

AMG 64 91 65 83 / 10 10 50 50 SSI 65 86 68 80 / 10 10 40 60 JAX 62 92 67 86 / 0 10 20 60 SGJ 64 89 67 85 / 0 10 10 40 GNV 61 92 65 89 / 0 10 10 40 OCF 62 91 66 89 / 0 10 0 30

JAX WATCHES/WARNINGS/ADVISORIES

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