Area Forecast Discussion
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Issued by NWS
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495 FXUS62 KTAE 090851 AFDTAE Area Forecast Discussion National Weather Service Tallahassee FL 451 AM EDT Thu May 9 2024 ...New NEAR TERM, SHORT TERM, LONG TERM, AVIATION, MARINE, FIRE WEATHER, HYDROLOGY... .NEAR TERM... (Today and tonight) Issued at 431 AM EDT Thu May 9 2024 An active next 36 hours is upon us with 2 rounds of severe thunderstorms, the first round arriving early this afternoon across our northern counties and working south into the evening hours. Round two will arrive in the overnight hours from west to east and this second round appears to be the more significant of the two rounds. All modes of severe weather will be possible with damaging to destructive winds as the highest threat. SPC for today has expanded the enhanced risk (level 3 of 5) further south to the Florida state line with the slight risk (level 2 of 5) also expanded further south to include all our coastal sections. SPC continues the marginal risk for Friday (level 1 of 5) across our entire area with the exception from Albany to Bainbridge to Tallahassee and points eastward have been upgraded to a slight risk. Mid level flow will become more zonal today as a mid level high retrogrades into Mexico and an upper low retrogrades towards the Great Basin. A shortwave trough is supporting widespread development of storms currently in the Mid-South and Tennessee Valley which will gradually move southeast today. The atmosphere will remain unstable this afternoon with SBCAPE 2000-3000 J/kg, MLCAPE 1000-2000 J/kg, and DCAPE of 1000-1500 J/kg. Coupled that with bulk shear around 40 knots and mid level lapse rates of 7-8 C/km and severe thunderstorms will be likely with both rounds this afternoon and overnight. Latest CAMs have the first round making it south into the Big Bend into the early evening hours which is a slight change from a few runs ago and have increased pop chances here through 00Z. Round 1 Timing will begin around 12pm ET in our northern and northwestern sections in AL and GA, moving south through the day, arriving into the Florida Big later this afternoon into early evening. && .SHORT TERM... (Friday through Saturday night) Issued at 431 AM EDT Thu May 9 2024 Throughout Friday the ridge slides eastward as a trough looks to move across eastern CONUS. A fast moving shortwave coming off the Rockies zooms eastward merging with another shortwave rounding the base of the developing trough. As these two features merge, over the southeast, early Friday morning into Friday afternoon, our risk for severe weather increases. This correlates with why the SPC has our region, north of I-10, under a Enhanced Risk (level 3 of 5) for severe weather through 8am ET Friday. Areas east of a line from Albany, GA to Tallahassee, FL are under a Slight Risk (level 2 of 5) through the rest of Friday. With low-level winds possibly around 30- 45 kts, PWATs around 2 inches and a defined shortwave providing forcing for ascent via PVA, the ingredients for severe would be present. All hazard types are possible, with hi-res guidance indicating a preference towards QLCS solutions, strong damaging winds would be our primary hazard of concern. Depending on how far south the first round of severe weather gets today (Thursday) will determine where our second round ends up as it seeks out higher instability. How late into the day on Friday the front decides to move across the region will also determine if we see diurnal instability aid in forcing for ascent for additional showers and storms throughout Friday afternoon. With higher PWATs comes an increased risk of torrential downpours leading to localized flash flooding issues. Which is why we`re under a slight and marginal risk for excessive rainfall from WPC. The front is expected to clear the region by Friday night. Clear and dry conditions are in store through the rest of the weekend. Expect daytime highs generally in the low to mid 80s with overnight lows generally in the low 70s tonight before frontal passage. Overnight lows will then be in the low 60s Saturday morning after frontal passage. && .LONG TERM... (Sunday through Wednesday) Issued at 431 AM EDT Thu May 9 2024 Being post-frontal will lead to relatively cooler temps and a decrease in moisture as northerly flow prevails through Monday morning. Although surface winds will be southerly during the afternoon hours due to the sea breeze, high pressure will lead to large-scale subsidence. Limiting development to fair weather Cu or developing towers that fizzle away. On Monday another shortwave looks to move across the northern Gulf states with our region possibly being impacted on Tuesday as winds turn to being southeasterly. With this shortwave possibly moving overhead, a stationary boundary to our south, left behind from the previous system, and a low-level wind field again around 30-45 kts, the potential for severe is once again present. We`ll have to see how this progresses over the next few days to have better confidence, be sure to come back for updates. Expect relatively cooler temps to what we`ve been experiencing as of late. Daytime highs will generally be in the low to mid 80s with overnight lows generally in the upper 50s to mid 60s until Tuesday morning. Beyond Tuesday morning, overnight lows look to rebound into the mid and upper 60s. && .AVIATION... (06Z TAFS) Issued at 431 AM EDT Thu May 9 2024 Low cigs are developing from south to north off the Gulf into our western half of the CWA with an overall expansion north and east will take place overnight. Cig heights will lower to low MVFR or IFR across all TAF sites through mid morning. Surface winds will be slightly elevated so vsbys may not be too much of an issue. Will return to VFR by mid morning. Into the afternoon, will be watching a line of TSRA moving south from central Alabama/Georgia which is progged to move into our area. Have used high res guidance to time the line into DHN/ABY 19-23Z. Less confidence further south into VLD/TLH and have PROB30 22-02Z. Will need to watch future model runs for possible increase in confidence if the line can hold together towards the coast. Outside of convection, winds will be from the southwest and breezy with gusts 18-23 knots from mid morning through the afternoon hours. Winds could be stronger as the line arrives. && .MARINE... Issued at 431 AM EDT Thu May 9 2024 An Atlantic ridge axis across the southern Florida Peninsula will retreat southward on Thursday. A cold front will slowly approach from the north on Friday, preceded by strong to severe thunderstorms over the waters. Cautionary conditions could be possible. The front will limp across the waters on Friday night. It will be followed by moderate to occasionally fresh northerly breezes on Saturday morning. Surface high pressure over the southern Plains on Saturday will move across the Southeast States on Sunday, causing winds to clock around. High pressure will move east into the Atlantic on Monday, brining a return to south- southeasterly flow. && .FIRE WEATHER... Issued at 431 AM EDT Thu May 9 2024 Several rounds of wetting rains and possible severe thunderstorms are on tap through Friday afternoon. The first round will arrive into our southeast Alabama and southwest Georgia area early this afternoon then move south into our Florida counties by mid to late afternoon. There appears to be a lull this evening ahead of the second round of storms in the overnight into Friday morning hours moving from west to east. All modes of severe weather will be possible with the storms with damaging to destructive winds as the highest threat. Outside of rain and storms, high dispersions are possible today along the I-75 corridor westward towards the Apalachicola river. Conditions improve behind these rounds of storms heading into this weekend. && .HYDROLOGY... Issued at 431 AM EDT Thu May 9 2024 A slight risk of excessive rainfall exists for the northern half of our area today, with a marginal risk for most of the area on Friday as a frontal system looks to push through the region. The primary risk here being torrential downpours or training within any thunderstorm(s) leading to a localized flash flooding risk. Otherwise, area rivers are expected to remain below flood stage. In the extended period the WPC is forecasting 3-5 inches by midweek next week. This could introduce some riverine concerns, however, it`s too far out to say with any degree of confidence. && .SPOTTER INFORMATION STATEMENT... Spotter activation is requested. Spotters should safely report significant weather conditions and/or damage by calling the office or tweeting us @NWSTallahassee. && .PRELIMINARY POINT TEMPS/POPS... Tallahassee 91 73 84 63 / 60 30 90 10 Panama City 85 73 83 64 / 20 20 60 0 Dothan 89 71 85 59 / 60 50 80 0 Albany 89 70 85 59 / 80 50 70 0 Valdosta 92 71 83 62 / 60 40 90 10 Cross City 88 72 85 64 / 50 20 80 30 Apalachicola 83 75 82 66 / 10 20 50 10 && .TAE WATCHES/WARNINGS/ADVISORIES... FL...High Rip Current Risk through Saturday morning for FLZ108-112- 114-115. GA...None. AL...None. GM...None. && $$ NEAR TERM...Scholl SHORT TERM...Oliver LONG TERM....Oliver AVIATION...Scholl MARINE...Oliver FIRE WEATHER...Scholl HYDROLOGY...Oliver