Area Forecast Discussion
Issued by NWS Jacksonville, FL
Issued by NWS Jacksonville, FL
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816 FXUS62 KJAX 130710 AFDJAX Area Forecast Discussion National Weather Service Jacksonville FL 310 AM EDT Mon May 13 2024 ...New NEAR TERM, SHORT TERM, LONG TERM, MARINE... .NEAR TERM... Issued at 300 AM EDT Mon May 13 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 A few sprinkles are moving across the region as of 06-07Z, in response mainly to a pseudo warm front passing overhead as weak high pressure moves northeastward. This is setting the stage for the start of an active few days, as a more robust warm front approaches the region this afternoon and evening. The timing of this also coincides with the diurnal heating cycle and therefore an onshore sea breeze, which should help to induce convection over northeast FL. At the same time, shortwave energy/diffluence aloft associated with a larger upper trough over the south/central US streams east/northeast along the Gulf coast and across southeast GA. The combination of all these features will result in increasing shower and t`storm coverage throughout the afternoon and evening, likely continuing into at least the first half of tonight. Although plentiful ingredients are in place, the main limiting factor will be instability, as SB/MUCAPE is expected to be generally around 1000 J/kg, decreasing further north and east and especially over southeast GA. Despite this, with the modest dynamics and frontal boundary, the SPC still places the entirety of the CWA in a "marginal" risk for severe storms. The main threats will be gusty winds, hail, and heavy rainfall - though an isolated tornado cannot be ruled out as well. Looking like the best "overlap" of ingredients will be around I-10 southward, though southeast GA certainly cannot be totally overlooked as well. Temps today will be a bit tricky due to the amount of cloud cover likely to be in place (which also will play a big factor in the amount of buoyancy available). However, expecting mid 80s to low 90s south of about I-10 and low 80s and some upper 70s over southeast GA. Expecting a break for most about after midnight through the morning hours, with a mild night of upper 60s to low/mid 70s. && .SHORT TERM... (Tuesday through Wednesday night) Issued at 300 AM EDT Mon May 13 2024 Tuesday...Warm frontal boundary still on track to be somewhere near the FL/GA border early in the day with likely ongoing convective complex along this boundary close to/or just west of the local area and expect this feature to push across the entire area at some point during this time frame with heavy rainfall and isolated strong to severe storms expected. Rainfall totals still expect to be highest along and to the north of the warm frontal boundary with localized 2-4 inch amounts across SE GA and 1-2 inch amounts across NE FL. Damaging winds will remain the main storm threat, but large hail and/or isolated tornadoes cannot be ruled out. Max temp forecast a bit tricky due to possible timing issues with storm activity but widespread highs in the 80s expected, with some lower 90s possible across NE FL south of a line from Ocala to St. Augustine. Even without storm activity expect the gradient wind flow to be out of the Southwest from 15-25 mph with gusts to 35 mph at times, strongest in the warm sector across NE FL. Tuesday Night...Mid to upper level trough sweeps into SE GA through the night with dry slot of air aloft pushing the frontal boundary with numerous showers and isolated strong/severe storms with heavy rainfall from SE GA during the evening hours slowly southward into NE FL during the overnight hours with waves of storms moving along this boundary during this time frame. Training of storms over already wet soils in some areas from this pattern set up may require the issuance of a Flood Watch for some areas on Tuesday ahead of this event. Low temps generally near 70 with gusty Southwest winds continuing at 10-20 mph with gusts to 30 mph at times. Wednesday...Models trending towards dry slot aloft pushing in faster and driving trailing frontal boundary with showers/storms and heavy rainfall south of the region quicker than previous model runs, but for now have kept rainfall chances mainly during the morning hours across all areas, then shifting southward through NE FL during the early to mid afternoon hours with some partial clearing by the end of the day as frontal boundary pushes into Central Florida. Max temps generally in the mid/upper 80s with winds shifting to the West at 15-20 mph with gusts to 30 mph at times. Wednesday Night...Drier airmass overspreads the local area with mainly dry conditions after sunset and skies becoming mostly clear and temps falling into the 60s area-wide behind the frontal passage. && .LONG TERM... (Thursday through Sunday) Issued at 300 AM EDT Mon May 13 2024 Thursday...Lingering dry airmass in place between weather systems will continue mainly dry conditions with above normal temps reaching into the upper 80s/lower 90s over inland areas with West- Northwest winds at 10-15 mph and East Coast sea breeze remains pinned closer to the Atlantic Coast along the I-95 corridor. Friday/Saturday...Another similar scenario with warm frontal boundary lifting back northward on Friday and trailing frontal boundary pushing southward through the region on Saturday with heavy rainfall and isolated strong to severe storm potential area- wide and rainfall chances already in the 50-70% range. Above normal temps will continue. Sunday...Lots of long range model uncertainty as some models push drier air into the region, while some stall the frontal boundary in the vicinity so for now the model blends are just placing normal diurnal scattered convection due to local sea breeze activity as above normal temps continue. && .AVIATION... (06Z TAFS) Issued at 130 AM EDT Mon May 13 2024 VFR prevails at all terminals through at least the morning hours. A stray SHRA is possible over the next few hours, though not expected to affect any operations. Winds pick up at all terminals later today, with gusts into the 20s expected for all. Chances for convection also increase by the afternoon and through the remainder of the forecast period. Confidence is high enough for TSRA chances to include PROB30 for all terminals, with MVFR likely and IFR also possible at times, as well as gusty winds. && .MARINE... Issued at 300 AM EDT Mon May 13 2024 Southeasterly winds increase through today as a warm front lifts northward toward the coastal waters. This will result in Small Craft Advisory conditions this evening and overnight tonight. Showers and storms will spread over our local waters this afternoon and into the evening ahead of the aforementioned warm front. Tuesday, the front stalls just north of the local waters as several rounds of heavy showers and storms push across the area through Wednesday. Conditions improve on Thursday as weak high pressure and offshore flow develops. Rip Currents: Rip current risk will be low to moderate given the offshore or along shore wind developing today and into Tuesday. && .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 81 68 83 69 / 80 80 100 70 SSI 81 71 84 72 / 60 60 90 70 JAX 85 70 89 71 / 60 60 90 70 SGJ 83 71 91 71 / 60 50 80 60 GNV 88 68 89 71 / 60 50 80 70 OCF 90 71 92 71 / 60 50 70 60 && .JAX WATCHES/WARNINGS/ADVISORIES... FL...None. GA...None. AM...Small Craft Advisory from 5 PM this afternoon to 11 AM EDT Tuesday for AMZ450-452-454. Small Craft Advisory from 5 PM this afternoon to 2 PM EDT Tuesday for AMZ470-472-474. && $$