Area Forecast Discussion
Issued by NWS Tampa Bay Area, FL
Issued by NWS Tampa Bay Area, FL
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779 FXUS62 KTBW 182349 AFDTBW Area Forecast Discussion National Weather Service Tampa Bay Ruskin FL 749 PM EDT Wed Sep 18 2024 ...New UPDATE, AVIATION... .UPDATE... Issued at 747 PM EDT Wed Sep 18 2024 The persistent frontal boundary is finally washing out over N FL, but some residual convection has developed along the remnants of this boundary and is pushing through ECFL. THis is of no factor to our area, however. Locally, the only point of note is a few ongoing showers across central and SWFL. With the sun now setting, much of this activity is waning. However, moisture and instability remain higher over SWFL and the adjacent coastal waters. Cannot completely rule out a few overnight showers reforming off the coast, potentially drifting inland. Thus, keeping 20 to 30% POPs for much of the overnight. Right at the coast through the Tampa Bay area, rain chances increase towards tomorrow morning to around 30 to 40% with a light flow and a weak land breeze circulation to initiate convection. Some may drift onshore during the morning hours, quickly dissipating as they do so as the air becomes more stable. Most of the activity for inland areas is expected to initiate along the sea breeze later in the day as the boundary propagates inland. The best chances are from Manatee/Hardee/Highlands south. The flow looks light, so this will probably be slow to occur. However, overall moisture content remains limited and drier air continues to advect into the area in the mid- levels. This keeps rain chances near zero for the nature coast, with the highest POPs inland and across SWFL (50 to 60%). The main adjustments this evening have been to update the aforementioned POPs to reflect the current trends and expected setup for tomorrow. Otherwise, the forecast remains on track. && .DISCUSSION... Issued at 300 PM EDT Wed Sep 18 2024 Overall forecast is unchanged for the next several days. The upper level low over the southeast U.S. will open up and lift northeast over the next day or so with troughing remaining along the U.S. east coast into the weekend with ridging building over the region early next week. At the surface the weak pressure pattern will persist into Thursday then a weak front will move south through the region late Thursday into Friday with high pressure building in behind it setting up an increasing northeast to east flow through the weekend and into early next week. For tonight into Thursday, we will continue to see a southwest to west flow combined with limited moisture. Isolated to scattered convection will continue into early this evening, then wind down later this evening. However, there could be enough lift with the boundary moving south later tonight to allow a few showers and possibly a thunderstorm to develop near the coast, then the chances shift south during the day with most of the convection over the interior and southwest Florida during the afternoon. On Friday, the wind shift to northeast will bring some drier air into the area, but still should be enough for isolated to scattered afternoon and evening convection, with best chances remaining over the interior and southwest Florida. Over the weekend and into early next week we will continue to see enough moisture for isolated to scattered mainly afternoon and evening showers and thunderstorms in the northeast to east flow. && .AVIATION... (00Z TAFS) Issued at 747 PM EDT Wed Sep 18 2024 Main concern through the TAF period will be for convection. There is the potential for some early morning showers around TPA/PIE in the morning, with a higher probability for showers and eventually thunderstorms at SWFL terminals. KLAL has the least probability of seeing storms. Outside of any convection, no significant concerns exist. Light flow and drier limit any major concerns through the weekend. && .MARINE... Issued at 300 PM EDT Wed Sep 18 2024 The rather light flow will continue into tonight then winds will shift to northwest to north as a weak front moves across the waters during Thursday. Friday through the weekend and into early next week high pressure will build in from the north shifting the flow to northeast to east at around 10 knots with evening surges bumping winds up to around 15 knots, possibly exercise caution levels early next week. Isolated to scattered showers and thunderstorms will remain possible through the period. No headlines are expected through the weekend. && .FIRE WEATHER... Issued at 300 PM EDT Wed Sep 18 2024 Enough moisture will remain across the region for the next few days to allow for isolated to scattered showers and thunderstorms each afternoon and evening. Relative humidity values will remain above critical levels with no fire weather hazards expected. && .PRELIMINARY POINT TEMPS/POPS... TPA 77 90 75 90 / 10 30 10 20 FMY 77 90 75 91 / 30 60 30 50 GIF 74 92 74 93 / 20 40 10 20 SRQ 76 91 75 91 / 30 40 10 30 BKV 72 91 71 91 / 10 20 0 20 SPG 80 91 79 91 / 20 30 10 20 && Sea Breeze Thunderstorm Regime For Thursday: 4 Sea Breeze Thunderstorm Regime For Friday: 8 For additional information on sea breeze regimes, go to: https://www.weather.gov/tbw/ThunderstormClimatology && .TBW WATCHES/WARNINGS/ADVISORIES... FL...None. Gulf waters...None. && $$ UPDATE/AVIATION...Flannery PREVIOUS DISCUSSION...Close