Area Forecast Discussion
Issued by NWS Miami, FL
Issued by NWS Miami, FL
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581 FXUS62 KMFL 071859 AFDMFL Area Forecast Discussion National Weather Service Miami FL 259 PM EDT Sun Jul 7 2024 ...New LONG TERM... .SHORT TERM... (Rest of today through Monday) Issued at 1207 PM EDT Sun Jul 7 2024 Beryl in the northwestern Gulf, a frontal boundary stretched across the Appalachians and the southeastern United States, and an Atlantic mid-level low off the Carolinas are the main synoptic scale features for the short term forecast period. Light southerly wind flow with a heavy influence from the diurnal sea breeze is expected. Ample amounts of tropical moisture being transported into the region along the southerly flow should permit healthy convective coverage this afternoon and again on Monday. Hot temperatures and dewpoints in the mid to upper 70s will combine with the lack of breeze to permit heat index values to climb above 105 across the region both today and again on Monday with a Heat Advisory necessary today and one likely needed for Monday. Some pockets of South Florida could see the heat index exceed 110 on late Monday morning into the afternoon hours. Heat illness will remain a threat to anyone conducting outdoor activities or labor. While many of the showers and thunderstorms may not have the environmental profile or support aloft to create hail or severe wind gusts, strong wind gusts and frequent to excessive lightning cannot be ruled out with storms. The slow-moving nature of storms will also provide the potential for excessive rainfall accumulations that could saturate a localized area. && .LONG TERM... (Monday night through next Saturday) Issued at 255 PM EDT Sun Jul 7 2024 Anti-cyclonic flow around the base of weak mid-level ridging situated over the southeastern United States will propagate a weakening cut-off low southwestward towards the Florida Peninsula on Tuesday. Both the deterministic 12z European and GFS indicate that the feature will continue to weaken with a notable degradation in vorticity and cold pool definition being depicted on various model guidance. GEFS and EPS ensemble model "camps" also hint at a similar trajectory and weakening of the cut-off low feature. Even with the cut-off low losing definition, it`s arrival across our region will still cool 500mb temperatures slightly from -4C to -5C down to - 6C to -7C. At the same time, modeling indicates the potential of a plume of Saharan Dust to be in the vicinity of South FLorida. While overall coverage of convection may be suppressed, the influences of S.A.L. (steeper lapse rates, higher DCAPE) combined with the cooler 500mb temperatures could lead to a higher localized strong storm potential on Tuesday afternoon. Examining forecast soundings from Tuesday afternoon hint at this potential with a mid-level dry air signal, mid-level lapse rates of 6-6.5 C/km, and forecasted DCAPE values of 900-1100 J/kg. Differences still exist in model guidance as far as the strength of the cut- off low at that point as well as the Saharan Dust Plume, so the evolution of the forecast for Tuesday could very much change as we move closer in time. By Wednesday, the leftover energy of the cut-off low advects into the Florida Keys as South Florida remains underneath the influences of the mid-level ridge of high pressure situated to the north of the region. The remainder of the extended period is characterized by a weak synoptic regime across the region. Given the meager synoptic pattern aloft, shower and thunderstorms during the first part of the week will be dictated by prevailing background flow and mesoscale driven circulations such as the daily Atlantic and Gulf sea breezes, with convection initiating over the local waters and the coasts each morning, shifting towards the interior and Gulf coast in the afternoon and early evening hours. However by Thursday, the re- establishment of the Bermuda High over the western Atlantic waters will provide just enough of an easterly component to focus afternoon convection across the Gulf coast metro areas with some morning shower activity being possible along the east coast of South Florida. Temperatures throughout the period will remain warm, with high temperatures reaching the lower 90s across most areas and heat indices in the triple digits. && .AVIATION... (18Z TAFS) Issued at 1207 PM EDT Sun Jul 7 2024 Sub-VFR possible with any showers and storms that come near terminals and short-fused AMDs for IFR/LIFR are likely today as the sea breezes advance inland. A lull is possible late evening into the early overnight but an early morning return to the convection is possible on Monday. Southerly flow will be fairly light through the period outside of convective wind gusts. && .MARINE... Issued at 1207 PM EDT Sun Jul 7 2024 Light to moderate southerly winds will prevail across all local waters through Monday. Seas will remain in the 1 to 3 ft range to start the week. Scattered showers and thunderstorms will develop over the local waters each afternoon, and winds and waves could be locally higher in and around showers and storms. && .PRELIMINARY POINT TEMPS/POPS... Miami 81 94 80 90 / 20 40 20 50 West Kendall 80 95 78 91 / 20 40 10 50 Opa-Locka 81 95 80 91 / 30 40 20 50 Homestead 81 93 80 90 / 30 20 10 40 Fort Lauderdale 81 93 80 89 / 30 40 30 50 N Ft Lauderdale 81 93 80 90 / 20 50 20 60 Pembroke Pines 82 96 80 92 / 30 40 20 50 West Palm Beach 80 94 78 90 / 20 60 30 60 Boca Raton 80 94 79 90 / 20 50 30 60 Naples 81 93 80 92 / 30 40 10 50 && .MFL WATCHES/WARNINGS/ADVISORIES... FL...Heat Advisory until 6 PM EDT this evening for FLZ063-066>075-168- 172>174. AM...None. GM...None. && $$ SHORT TERM...RAG LONG TERM....Hadi AVIATION...RAG