Area Forecast Discussion
Issued by NWS Jacksonville, FL
Issued by NWS Jacksonville, FL
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565 FXUS62 KJAX 122248 AFDJAX Area Forecast Discussion National Weather Service Jacksonville FL 648 PM EDT Sun May 12 2024 ...New AVIATION... .NEAR TERM... Issued at 245 PM EDT Sun May 12 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 Weak high pressure ridging is still the dominant feature today allowing the Atlantic seabreeze to make its way inland shifting coastal winds to easterly. The sea-breeze will continue to make its way inland to around the US 301 corridor, bringing with it winds around 10-15 mph before calming down after sunset. Ample cloud cover has kept temperatures down into the mid 80s this afternoon. SE GA has a slight chance (10-20%) of some light showers blowing through early this evening and again early Monday morning. Overnight temperatures will be in the 60s inland with coastal temperatures hanging around the upper 60s to low 70s. && .SHORT TERM... (Monday through Tuesday night) Issued at 245 PM EDT Sun May 12 2024 An active weather pattern starts Monday with a warm front lifting up across the area Monday through Monday night. Forcing associated with shortwave perturbations expected to move across parts of the southeast states, but by and large most of this synoptic forcing will extend just to our west and over parts of GA, including southeast GA. However, the best low level forcing Monday afternoon appears to be along a sfc trough across the inland northeast FL zones due to breezy southeast flow over eastern FL zones of near 15-20 mph up against west coast sea breeze that pushes to I-75 corridor. Here, we expect scattered to possibly numerous showers and storms to break out and continue into the early evening hours. Further north into southeast GA, the instability will tend to be weaker so more scattered shower activity and a few thunderstorms. The overlap of moderate bulk shear of about 55 kt amid MLCAPE of up to 1000-1500 J/kg could easily support a couple of stronger storms in northeast FL as well as parts of southeast GA, with gusty winds, hail, and localized heavy rainfall. SPC has parts of our area in a marginal risk of severe storms. Stay tuned! More southerly flow over northeast FL will give support for max temps in the mid 80s to 90 deg and then generally mid 80s over southeast GA. Monday night, with diurnal cooling, any thunderstorm activity will tend to weaken and probably become more isolated. However, breezy southerly flow, upper level divergence and plenty of moisture will support scattered to numerous areas of rain/shower activity. Some locally heavy rainfall remains possible mainly over southeast GA. Patchy fog is possible but winds will tend to be too mixed to support any dense fog. Meanwhile to our west, a cold front will be marching eastward over the lower MS Valley where stronger forcing and thunderstorm activity will be. Min temps will be very mild in the upper 60s to lower 70s. Tuesday, the warm front looks to be across southeast GA and continue to lift north-northeast while the cold front will moving across the FL panhandle and over southwest GA. Generally looks like a better setup for isolated to scattered strong or severe storms given the wind fields and available instability ahead of the cold front. SPC has placed most of our forecast area in a marginal risk of severe storms. Inhibiting factors for strong and severe storms will be cloud cover and areas/widespread rain. In addition to the severe storm threat, heavy rainfall is likely in some locations given parallel flow to the front and higher than moisture (fcst PWATs near 1.8 inches vs climatology of about 1.3 inches). Tuesday night, the cold front appears to be located across south central GA to the western FL panhandle. With the expected relatively slow progress of the cold front, lingering isolated severe storm threat and locally heavy rainfall threat will persist. For now, it appears this will primarily be southern 2/3rds of the area. Once again, warmer than average overnight lows are anticipated. && .LONG TERM... (Wednesday through next Sunday) Issued at 245 PM EDT Sun May 12 2024 The cold front is located over northeast FL Wednesday morning, only gradually moving southward. The GFS shows the bulk of the moisture along the front over northeast FL so continued moderate to heavy rainfall threat persists in the morning there and could last until mid aftn. Drier air will arrive finally be late afternoon into the evening as the mean mid level trough axis will move through bringing some subsidence to the area. The front looks to settle just south of the region Wednesday night, with more fair weather during this same period. Subsidence and dry air prevails on Thursday as upper level ridge will be over the area. The next mid/upper level trough approaches from the west Thursday night and will allow a weak warm front to lift up into the region. Rain chances may increase again during the Fri-Sat time frame as increased ascent and moisture ratchets up. && .AVIATION... (00Z TAFS) Issued at 648 PM EDT Sun May 12 2024 VFR conditions prevail through the period. Light and variable winds tonight will become southeasterly and increase to sustained 10-15 kt with gusts 18-22 kts possible after 15Z. Highest winds will be along the coast. Showers and storms will move in from the west Monday afternoon into evening. Since convection is expected toward the end of the period, only VCSH was included at this time. && .MARINE... Issued at 245 PM EDT Sun May 12 2024 Weak high pressure is still the dominating feature today with some slight chances (10-20%) of some light rain occurring over SE GA local waters later this afternoon. Winds for the onshore sea- breeze have picked up a bit with winds 8-10 mph. Onshore winds will strengthen Monday afternoon as a warm front lifts northward. Showers and storms will spread out over our local waters Monday afternoon and into the evening as the warm front lifts through the local waters. Tuesday, The front stalls just north over the local waters as several rounds of heavy showers and storms push across the area through Wednesday. Improving conditions are expected on Thursday as offshore flow develops along with lower rainfall chances. Rip Currents: Moderate rip current risk today and into the beginning of the week for all area beaches. && .HYDROLOGY... Issued at 240 PM EDT Sun May 12 2024 From Monday to Wednesday, forecast storm total rainfall amounts are from 2 to 3 inches for southeast GA to about 1 to 2 inches for northeast FL. This may be enough to raise river levels a bit but for now no minor river flooding is forecast. The high- end potential total rain is over 5 inches in some locations, mainly favoring nrn half of the area, so we will need to monitor trends in the guidance for further updates to the forecast rainfall. && .PRELIMINARY POINT TEMPS/POPS... AMG 62 83 67 85 / 30 70 80 90 SSI 68 81 70 85 / 20 60 80 90 JAX 65 85 70 90 / 10 60 60 80 SGJ 68 84 72 90 / 10 50 50 70 GNV 66 88 69 89 / 0 70 40 80 OCF 68 91 70 92 / 0 60 30 60 && .JAX WATCHES/WARNINGS/ADVISORIES... FL...None. GA...None. AM...None. && $$