Area Forecast Discussion
Issued by NWS Jacksonville, FL
Issued by NWS Jacksonville, FL
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961 FXUS62 KJAX 190555 AFDJAX Area Forecast Discussion National Weather Service Jacksonville FL 155 AM EDT Sun May 19 2024 ...New AVIATION... .UPDATE... Issued at 1000 PM EDT Sat May 18 2024 Late evening surface analysis depicts a wavy frontal boundary extending across the southeastern states. Aloft...a potent shortwave trough was digging southeastward from the Tennessee Valley towards the Deep South, creating deep west-southwesterly flow across our region. Flow aloft over the northeast Gulf of Mexico is highly diffluent to the south of this potent shortwave trough, with weaker shortwave energy embedded within the flow pattern triggering a large area of convection over the loop current waters of the eastern Gulf of Mexico, with debris cloudiness and lighter shower activity extending northeastward across the FL Panhandle and Big Bend region, with a few showers beginning to develop near the Alapaha River in south Georgia recently. Cirrostratus blowing off from the convection over the Gulf of Mexico was blanketing southeast GA and the Suwannee Valley, with fair skies in place along the I-95 corridor in northeast FL. A warm and humid air mass otherwise prevails across our region late this evening, with temperatures at 02Z generally in the 70-75 degree range, wile dewpoints were in the upper 60s to lower 70s. The aforementioned shortwave trough will continue to dig southeastward towards our area by Sunday evening. This feature will propel weaker shortwave energy currently traversing the northeast Gulf of Mexico across our area overnight, resulting in an increasing area of showers and possibly some low-topped thunderstorms, mainly after midnight. This activity should remain below severe limits, with an uptick in coverage expected for locations along and north of the Interstate 10 corridor during the midnight through 3 AM time frame, with activity then shifting southeastward while gradually weakening as it moves into north central FL during the predawn hours on Monday. Isolated thunderstorms within this activity will be capable of producing heavy downpours and lightning strikes, but a lack of CAPE overnight should keep storms from producing any strong downburst winds. Lows tonight will remain seasonably warm, as values only fall to the upper 60s inland and the lower 70s at coastal locations. A break in convective activity is expected on Sunday morning, with showers and thunderstorms then increasing in coverage and intensity during the afternoon hours, especially along the I-10 and I-95 corridors. The approach of the potent shortwave trough should steepen lapse rates, with morning sunshine boosting highs to the 85-90 degree range for locations from Waycross south and eastward, adding fuel to the atmosphere for strong to potentially isolated severe thunderstorms. Stronger storms late on Sunday afternoon will be capable of producing damaging wind gusts of 40-60 mph, small hail, frequent lightning strikes, and heavy downpours. Activity should push south-southeastward ahead of the approaching frontal boundary towards coastal locations during the late afternoon and early evening hours. && .AVIATION... (06Z TAFS) Issued at 152 AM EDT Sun May 19 2024 A round of showers and embedded thunderstorms streaming in from the Gulf of Mexico will press east through SSI, GNV, VQQ, JAX, and CRG over the next 3 hours, ending by 09Z with VCSH posted for a couple of hours before showers end early this morning. Ceilings will be MVFR aroun 2.0 kft through sunrise during and in the wake of the showers and thunderstorms with variable light winds as the storms will be elevated. Another round of showers and thunderstorms will commence late this afternoon as the cold front stall over northeast florida before a secondary cold front swings south from the Geogia coast with strong thunderstorms that may produce gusty winds to 30 knots and MVFR restrictions after 20Z for SSI and duval terminals and around 00Z for SGJ while GNV coverage should remain VCTS through sunset. WInds this afternoon will be west to west southwesterly with southerly winds at SSI and SGJ this afternoon from the pinned Atlantic seabreeze, then winds shift this evening after 00Z to north and northwest in the wake of the secondary cold front with showers and storms ending after 03-04Z for all sites with lingering mid level clouds and scattered low ceilings. Confidence too low in MVFR ceilings to end the 06Z TAF period. && .MARINE... Issued at 1000 PM EDT Sat May 18 2024 A frontal boundary will remain stalled over our local waters through Sunday night. The next wave of showers and possibly a few embedded thunderstorms will occur after midnight through the predawn hours on Sunday. A break in activity is expected on Sunday morning, followed by the next round of showers and thunderstorms during the afternoon and evening hours on Sunday. Strong to isolated severe thunderstorms will be possible with this activity, with stronger storms being capable of producing damaging wind gusts, frequent lightning strikes, and heavy downpours. Seas of 2-4 feet will prevail both near shore and offshore through Sunday night. High pressure building over New England on Sunday will then wedge down the southeastern seaboard during the predawn and early morning hours on Monday, pushing the frontal boundary south of our local waters. North-northeasterly winds will surge to Caution levels of 15-20 knots throughout our local waters on Monday, with speeds gradually decreasing on Tuesday and Tuesday evening as high pressure begins to settle directly over our waters. Chances for showers and a few embedded thunderstorms will persist on Monday and Monday night. Seas will build to the 3-5 foot range both near shore and offshore from Monday through Tuesday night. High pressure will then shift offshore towards midweek, resulting in prevailing southerly winds across our local waters, with seas diminishing back to the 2-4 foot range throughout our local waters. Rip Currents: Prevailing offshore winds and low wave heights will keep the rip current risk low at all area beaches on Sunday. Strengthening north-northeasterly winds early on Monday will result in a higher end moderate risk at all area beaches that will persist through at least Tuesday, due to building and increasingly choppy surf conditions. && .FIRE WEATHER... Issued at 1000 PM EDT Sat May 18 2024 Westerly transport winds will become breezy after sunrise on Sunday for locations south of Waycross. West southwesterly surface winds will also become breezy for locations along and south of the Interstate 10 corridor by the mid to late morning hours on Sunday. These breezy winds will combine with elevated mixing heights to create good daytime dispersion values for locations south of Waycross, with pockets of high daytime dispersion values possible for locations along and east of U.S. Highway 301 on Sunday afternoon. Strong to isolated severe thunderstorms will be possible for locations along and east of U.S.-301 during the late afternoon and early evening hours, with damaging wind gusts, frequent lightning strikes, and heavy downpours possible within stronger storms. Surface and transport winds will then shift to northeasterly early on Monday morning, with breezy surface winds developing along the I-95 corridor shortly after sunrise, with breezy transport speeds expanding inland during the late morning and early afternoon hours. These breezy conditions will create good daytime dispersion values area-wide on Monday. These breezy northeasterly winds will persist into Tuesday, keeping good daytime dispersion values in the forecast. && .HYDROLOGY... Issued at 1000 PM EDT Sat May 18 2024 Water levels along lower portions of the Santa Fe River near the Three Rivers Estates gauge will rise above flood stage on Sunday morning, with minor flooding expected to then continue during the next several days. Otherwise, minor flooding along upper portions of the Satilla River and also along the Little Satilla River may result in water levels rising above flood stage along lower portions of the Satilla River near the gauge at Atkinson by late in the upcoming week. && .PRELIMINARY POINT TEMPS/POPS... AMG 83 66 81 63 / 70 30 10 0 SSI 87 70 78 69 / 60 70 20 0 JAX 89 69 81 66 / 60 70 30 0 SGJ 89 71 80 68 / 50 60 40 10 GNV 88 68 86 64 / 20 30 50 0 OCF 88 69 89 66 / 20 20 50 10 && .JAX WATCHES/WARNINGS/ADVISORIES... FL...None. GA...None. AM...None. && $$