Area Forecast Discussion
Issued by NWS Jacksonville, FL
Issued by NWS Jacksonville, FL
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842 FXUS62 KJAX 270137 AFDJAX Area Forecast Discussion National Weather Service Jacksonville FL 937 PM EDT Sun May 26 2024 ...HOT AND BECOMING BREEZY ON MEMORIAL DAY... ...STRONG TO ISOLATED SEVERE THUNDERSTORMS POSSIBLE ACROSS INLAND SOUTHEAST GA FROM LATE MONDAY AFTERNOON THROUGH EARLY TUESDAY... ...SCATTERED SHOWERS AND THUNDERSTORMS POSSIBLE ON TUESDAY ACROSS NORTHEAST AND NORTH CENTRAL FL... For the latest NE FL and SE GA Daily Key Messages please visit: https://www.weather.gov/media/jax/briefings/nws-jax-briefing.pdf .UPDATE... Issued at 937 PM EDT Sun May 26 2024 Late evening surface analysis depicts weakening Atlantic ridging extending its axis westward across the Florida peninsula. Meanwhile, a cold front extends from Lake Michigan south- southwestward across the Ozarks and the southern Plains states. Aloft...ridging aloft centered over the Bay of Campeche (southwestern Gulf of Mexico) continues to extend its axis east- northeastward across the rest of the Gulf and across the FL peninsula. Otherwise, a series of potent shortwave troughs continue to migrate from the northern Rockies across the Great Lakes states, with fast southwesterly flow in between these troughs and the Gulf of Mexico ridge propelling shortwave energy across the Ozarks and the Mid-Mississippi Valley, resulting in a severe weather outbreak this evening near the confluence of the Ohio and Mississippi Rivers. Closer to home, the Atlantic and Gulf Coast sea breezes collided this evening just east of the U.S. Highway 301 corridor, with subsidence and dry air aloft resulting in only a narrow corridor of towering cumulus clouds, with updrafts unable to sustain themselves for long enough to create showers. Fair skies prevail elsewhere across our region, with temperatures uniformly remaining in the 80-85 degree range throughout our region, with dewpoints ranging from the mid 60s to the mid 70s. Troughing aloft will continue to dig southeastward from the Great Lakes and the Upper Midwest towards the Ohio and Tennessee Valleys on Monday, resulting in ridging aloft over the Gulf of Mexico gradually flattening. This weather pattern will drive the cold front into the southeastern states by Monday evening. Low level west southwesterly flow will slowly increase overnight, which could drive a stratus deck onshore from the northeast Gulf of Mexico into the Suwannee Valley during the predawn and early morning hours on Monday. Strengthening low level flow will likely prevent dense fog formation, but patchy fog may develop beneath the stratus deck along the I-75 corridor. Fair skies will prevail elsewhere, with lows only falling to the 70-75 degree range at most locations. Any fog or low stratus that manages to develop during the predawn and early morning hours on Memorial Day will quickly scour out shortly after sunrise as west-southwesterly winds increase, with breezy conditions expected area-wide by the late morning and early afternoon hours. Multi-layered cloudiness will gradually increase during the afternoon hours downstream of the digging trough and approaching cold front, but plenty of morning sunshine and breezy offshore winds will again boost highs into the low and mid 90s, with the Atlantic sea breeze development delayed until the mid- afternoon hours at coastal locations. Dewpoints will fall to the 60s during the afternoon hours as the dry and subsident air mass holds on along the I-95 corridor, keeping maximum heat index values around or just below 100. Convection developing ahead of the cold front will begin to encroach upon the Ocmulgee/upper Altamaha/Alapaha Rivers during the late afternoon and early evening hours. Although bulk west- southwesterly wind shear values will remain below 40 knots on Monday evening across inland southeast GA, ML CAPE values around 1,000 j/kg may allow for a few storms to pulse and become strong or even briefly severe towards sunset as activity moves into inland portions of southeast GA. The primary threats with any stronger convection will be damaging wind gusts of 40-60 mph, frequent lightning strikes, and briefly heavy downpours. Most activity will remain to the north and west of U.S. Highway 84 in southeast GA during the early evening hours on Monday. && .LONG TERM... (Wednesday through next Sunday) Issued at 235 PM EDT Sun May 26 2024 By Wednesday the front will be sitting over central FL, bringing chances of showers and storms for locations south of the I-10 corridor. On Thursday and Friday, the front looks to lift northward as a warm front, bringing an increase in showers and storms from NE FL and into SE GA during the afternoon each day. A `cooling` trend begins as high pressure builds in from the northwest on Wednesday after the cold front`s passage. Morning lows in the 60s for the latter half of next week. Highs will begin in the 90s across the area on Wednesday and begin to trend downward as Highs will get into the upper 80s for SE GA and the lower 90s in NE FL from Thursday and into next weekend. && .AVIATION... (00Z TAFS) Issued at 809 PM EDT Sun May 26 2024 VFR conditions will prevail through at least 07Z Monday at the regional terminals. Periods of MVFR visibilities are expected during the overnight and predawn hours on Monday at VQQ. Low status ceilings may advect inland from the northeast Gulf of Mexico towards the Interstate 75 corridor during the predawn and early morning hours on Monday, with potential impacts possible at GNV after 09Z through around 13Z. Confidence was too low to indicate anything other than scattered ceilings below 500 feet and MVFR visibilities at this time. A period of low MVFR ceilings of 1,000-2,000 feet will be possible after sunrise at the inland terminals, but confidence remains too low to indicate anything other than scattered ceilings at this time. VFR conditions should then prevail after 16Z at the regional terminals. Southeasterly surface winds of 5-10 knots this evening will shift to southerly while gradually weakening overnight, except at GNV, where west- southwesterly winds of 5-10 knots will continue this evening before diminishing after midnight. West-southwesterly surface winds will increase shortly after sunrise on Monday, with speeds increasing to 10-15 knots at the regional terminals by 17Z. The Atlantic sea breeze boundary will be slower to develop on Monday afternoon, with surface winds shifting to southeasterly at SGJ towards 19Z and southerly at SSI by 20Z. && .MARINE... Issued at 937 PM EDT Sun May 26 2024 Atlantic ridging will continue to extend its axis westward across the Florida peninsula through Memorial Day, with prevailing west southwesterly winds resuming overnight and again on Monday night following afternoon sea breezes and southerly evening wind surges. Speeds should mostly remain below Caution levels during the evening wind surges, although speeds will likely increase to around 15 knots offshore on Monday evening. Seas of 2-3 feet will prevail both near shore and offshore during the next several days. High pressure will slide eastward on Monday afternoon ahead of a frontal boundary that will be entering the southeastern states. This front will stall across our local waters on Tuesday and Tuesday night, bringing increased chances for scattered showers and thunderstorms beginning late Monday night. The front will then gradually weaken and dissipate over the northeast Florida waters on Wednesday and Thursday, with winds becoming onshore by late this week as high pressure builds southeastward from the Great Lakes region. Rip Currents: Breezy onshore winds developing on Monday afternoon will create a lower-end moderate rip current risk at the northeast FL beaches. A low risk is expected to continue at the southeast GA beaches during the next several days. && .FIRE WEATHER... Issued at 937 PM EDT Sun May 26 2024 West-southwesterly transport winds will strengthen early on Monday morning, with these breezy winds combining with elevated mixing heights to create high to very high daytime dispersion values across much of southeast GA and for locations east of Interstate 75 in northeast and north central FL. A hot and dry air mass will result in afternoon relative humidity values falling to around 35 percent for location east of Interstate 75 in northeast and north central FL. Transport winds will shift to west-northwesterly and will remain breezy on Tuesday, with continued elevated mixing heights resulting in high to very high daytime dispersion values area-wide. A drier air mass will filter into inland portions of southeast GA on Tuesday, resulting in minimum relative humidity values falling to the 30-35 percent range for locations north of Waycross during the afternoon hours. Transport winds will then shift to northwesterly by Wednesday, with speeds diminishing slightly. However, elevated mixing heights should create good to marginally high daytime dispersion values nearly area-wide. A drier air mass will continue to filter into our area by midweek, possibly dropping relative humidity values to near critical thresholds across inland southeast GA on Wednesday afternoon, with values elsewhere expected to fall to the 30-35 percent range for locations west of the I-95 corridor. && .HYDROLOGY... Issued at 937 PM EDT Sun May 26 2024 Water levels continue to slowly rise along lower portions of the Santa Fe River due to backwater flooding caused by a wave of minor flooding working its way down the lower Suwannee River. A brief period of moderate flooding may be possible next weekend along the lower Santa Fe River near the Three Rivers Estates gauge. Minor flooding will be possible towards midweek for the lower Santa Fe River near the gauge at Hildreth. Otherwise, water levels have crested along lower portions of the Satilla River near the gauge at Atkinson, where minor flooding is expected to continue into next weekend. && .PRELIMINARY POINT TEMPS/POPS... AMG 71 92 71 90 / 0 50 70 20 SSI 75 91 75 90 / 0 10 40 20 JAX 71 94 73 93 / 10 10 20 40 SGJ 74 92 75 90 / 0 0 30 40 GNV 70 93 73 93 / 0 0 30 50 OCF 70 93 72 92 / 0 0 30 50 && .JAX WATCHES/WARNINGS/ADVISORIES... FL...None. GA...None. AM...None. && $$