Area Forecast Discussion
Issued by NWS Jacksonville, FL
Issued by NWS Jacksonville, FL
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636 FXUS62 KJAX 190015 AFDJAX Area Forecast Discussion National Weather Service Jacksonville FL 815 PM EDT Sat May 18 2024 ...New AVIATION... For the latest NE FL and SE GA Daily Key Messages please visit: https://www.weather.gov/media/jax/briefings/nws-jax-briefing.pdf .AVIATION... (00Z TAFS) Issued at 816 PM EDT Sat May 18 2024 VFR conditions will prevail at the regional terminals through at least 03Z. The next round of showers and embedded thunderstorms is expected to push across our region during the overnight hours, mainly from around 04Z through 09Z. Confidence was high enough to include vicinity thunderstorms and an MVFR TEMPO group for heavier showers at SSI from 05Z through 08Z. Confidence was only high enough to include vicinity showers elsewhere overnight. VFR conditions should then prevail by 10Z area-wide. Showers and thunderstorms will redevelop over our region late on Sunday afternoon, mainly for locations along and east of U.S. Highway 301, with activity generally progressing south-southeastward into the early evening hours. A few stronger storms will be possible after 21Z along the I-95 corridor. We included PROB30 groups for gusty winds and MVFR conditions during heavier downpours at all terminals except GNV from 19Z-00Z. Confidence was only high enough for vicinity thunderstorm coverage at GNV. Southerly surface winds sustained at 5-10 knots this evening will shift to southwesterly overnight, with speeds diminishing to around 5 knots by 06Z. Surface winds will continue to veer to westerly after sunrise, with speeds increasing to around 10 knots by 14Z. A pinned Atlantic sea breeze boundary east of I-95 may shift surface winds to southerly at the SSI and SGJ coastal terminals towards 20Z before thunderstorm activity increases on Sunday afternoon and evening. && .NEAR TERM... (Through Tonight) Issued at 310 PM EDT Sat May 18 2024 Numerous showers and storms expected into rest of the afternoon and early evening along and ahead of a weak cool front. The main area of concern for heavy rainfall and potentially severe storms, given the favorable wind fields, is over the central and southeast parts of the area where the airmass has generally been untapped thus far. There appears to be a couple of limiting factors to more robust storm activity, which are frontal forcing closely paralleled to mid to upper level flow and somewhat weak lapse rates aloft. The low level convergence also is not particularly impressive, except where outflow propagates more due to southward. Still, given the effective bulk shear of 40-50 kt and more than ample MLCAPE of about 2500 J/kg, a few briefly severe storms are possible. The main threat is strong to severe wind gusts, and lower probability of isolated large hail and possibly a brief tornado. By the evening hours, scattered shower activity and a couple storms anticipated for southeast GA but scattered to numerous showers and possibly scattered storms expected over northeast FL. Generally anticipate any severe threat is limited and low probability by mid evening with perhaps the stronger storms over the coastal waters. After midnight, chance of showers and slight chances of storms will persist as the remaining low level moisture and shortwave forcing aloft is enough to maintain chances of further convection. Min temps will be muggy in the upper 60s to lower 70s with southwest winds of 5-10 mph. && .SHORT TERM... (Sunday through Monday night) Issued at 310 PM EDT Sat May 18 2024 A cold front will be draped along the southern counties of NE FL on Sunday, with showers and storm chances remaining across the area as another cold front moves in from the north as an upper level trough begins to shift off towards the Atlantic. Most of NE FL is currently under a Marginal Risk (1 out of 5) for Severe Storms on Sunday. Current models are suggesting CAPE values from 1500-2500 J/KG, this along with westerly shear will keep the potential for scattered storms developing mainly along the stalled cold front in NE FL. Main concerns for any storms that do develop will be strong winds, small hail, and low chances for tornadoes. By the evening, activity will begin to dwindle during the overnight hours. High pressure moving into the area from the north-northeast will bring northeasterly winds into the area on Monday. Some showers and isolated storms may develop as the sea breeze moves inland through the afternoon, waning by the evening. Daytime highs on Sunday will primarily rest in the mid 80s in SE GA with warmer temperatures in the upper 80s for NE FL, but cooler temperatures along north central Florida counties. By Monday, most locations will see temperatures get to the mid 80s, as the hot spots will be along the north central Florida counties. && .LONG TERM... (Tuesday through next Friday) Issued at 310 PM EDT Sat May 18 2024 High pressure dominating the area will keep the area mostly dry for most of the upcoming week, save for some showers possibly developing along the north central Florida counties during the afternoon on Tuesday. The next chance of showers and storms looks to be on Friday afternoon as the high pressure will begin to shift off towards the Atlantic. With the high pressure over the area during the upcoming week, daytime temperatures will rise to the low 90s by midweek and eventually near the mid 90s in some locations. && .MARINE... Issued at 310 PM EDT Sat May 18 2024 Breezy south winds this evening will turn to the southwest overnight. West and southwest winds on Sunday before frontal boundary moves north to south, which brings winds around to the north to northeast Sunday night and lasts through Tuesday. At this time, max winds behind the cool front reach to 15-20 kt early Monday and does not appear to be likely meeting small craft advisory conditions. However, additional model guidance does suggest northerly winds may reach advisory levels for the GA waters for at least a few hours during the day on Monday. Stay Tuned! Winds will let up Tuesday night and certainly on Wednesday as high pressure ridge builds over the area, and the low pressure over the west Atlantic moves weakens. Rip Currents: Low Risk of rip currents at all area beaches today and Sunday. Risk goes up Monday and certainly Tuesday given the winds becoming more onshore and building surf. && .PRELIMINARY POINT TEMPS/POPS... AMG 67 86 66 84 / 40 70 10 10 SSI 70 86 70 79 / 70 70 30 10 JAX 69 90 69 82 / 70 70 30 30 SGJ 70 89 71 81 / 70 60 40 30 GNV 68 87 68 85 / 70 60 10 50 OCF 72 87 69 87 / 70 70 20 50 && .JAX WATCHES/WARNINGS/ADVISORIES... FL...None. GA...None. AM...None. && $$