Area Forecast Discussion
Issued by NWS Jacksonville, FL
Issued by NWS Jacksonville, FL
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529 FXUS62 KJAX 171856 AFDJAX Area Forecast Discussion National Weather Service Jacksonville FL 256 PM EDT Wed Jul 17 2024 ...New NEAR TERM, SHORT TERM, LONG TERM, MARINE... .NEAR TERM... Issued at 247 PM EDT Wed Jul 17 2024 For the latest NE FL and SE GA Daily Key Messages please visit: https://www.weather.gov/media/jax/briefings/nws-jax-briefing.pdf Convection is moving east into the Jacksonville Metro area with very little support behind it. Looks like the leading edge of the convection has worked over the atmosphere and stabilized the air mass behind it. Will keep convection going through sunset as any breaks in the mid level convective debris over the inland areas will lead to unequal heating and possible more pulse severe storms. After sunset the convective debris should clear by midnight with just some cirrus around. Not really thinking much fog will form inland overnight. Low temps will be in the mid 70s with yet another humid summer night in the South. && .SHORT TERM... (Thursday through Friday night) Issued at 247 PM EDT Wed Jul 17 2024 Elevated daily rain chances continue through Friday as SW steering flow continues across the local area between the 1000-500 mb ridge axis across south-central FL and weak troughs north of the region. Morning showers and storms will edge inland from the Gulf Coast region, expanding in coverage and progressing toward the Atlantic coast through early afternoon as diurnal instability increases. Additional convection will break across SE GA into the afternoon and linger into the early evening closer to low level trough trough axes and lingering outflow boundaries. Mid level temperatures continue near climo values with -6 to -7 degC at 500 mb with weak upper level shear (< 25 kts) so convective ingredients continue to favor mainly pulse strong to isolated severe storm potential in the afternoon and early evening with boundary mergers. Storm motion of 10-15 kts will somewhat limit the localized flash flood threat, but, storms are dropping 2-4 inches within 2 hours where mergers occur...so a couple days of heavy rainfall could certainly cause localized flood issues. Storms will fade across inland coverage toward midnight with loss of instability, then resurrect toward the Gulf Coast toward sunrise with some inland drift across our Suwannee River Valley zones. Temperatures will trend within a few degrees of climo values with highs in the low-mid 90s and lows in the lower to mid 70s. Peak heat index values near 105 deg each day prior to convective cooling. && .LONG TERM... (Saturday through next Wednesday) Issued at 247 PM EDT Wed Jul 17 2024 The ridge across south-central FL begins to build northward across NE FL Saturday then shifts north of the local area Monday. This will transition prevailing flow from SW over the next couple of days to SSE this weekend then SE early next week, with a more dominant east coast sea breeze pattern. Elevated rain chances with locally heavy rainfall potential will continue through the weekend with high PWAT trapped under the ridge axis and weak storm motion (PWATs 1.9-2.25"). Monday through Wednesday night week, deep layer moisture begins to decrease some into the 1.6-2 inch range favoring more scattered shower and thunderstorm activity for most inland areas (40-50% rain chances), then numerous (50-60%) where sea breezes and boundaries merge during the afternoon and evening near and west of I-75. Temperatures will trend near to above normal with highs in the low-mid 90s and lows in the 70s. && .AVIATION... (18Z TAFS) Issued at 116 PM EDT Wed Jul 17 2024 Convection is racing toward the JAX Metro area and should be on top of the fields about as I issue the TAFS. Have gone with a four hour TEMPO but that will be front loaded at the beginning of the TAF Period. KGNV, due to proximity to the Gulf, went longer with the TEMPO there. && .MARINE... Issued at 247 PM EDT Wed Jul 17 2024 The western periphery of the Bermuda Ridge will be right over our coastal waters and then the ridge axis will ridge west into the Gulf south of us. This will keep a general south to southwest flow pattern over our waters next few days. Will be some breaks in that pattern with a wind shift to the southeast near shore each afternoon and evening as the sea breeze develops. As with most of the peripheral ridge situations will see nocturnal southerly surges briefly bringing winds close to or above Small Craft Exercise Caution during the overnight hours. Some afternoon and evening thunderstorms are possible each day with winds and seas higher in and near thunderstorms. Rip Currents: Moderate rip current risk continues through Friday. && .PRELIMINARY POINT TEMPS/POPS... AMG 74 92 74 91 / 20 60 40 80 SSI 77 91 79 91 / 30 50 40 60 JAX 76 93 76 93 / 20 60 20 70 SGJ 76 92 77 92 / 20 50 20 60 GNV 75 89 74 91 / 20 60 10 70 OCF 74 91 75 91 / 20 50 10 70 && .JAX WATCHES/WARNINGS/ADVISORIES... FL...None. GA...None. AM...None. && $$