Area Forecast Discussion
Issued by NWS Miami, FL
Issued by NWS Miami, FL
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881 FXUS62 KMFL 201202 AFDMFL Area Forecast Discussion National Weather Service Miami FL 802 AM EDT Fri Sep 20 2024 ...New AVIATION... .SHORT TERM... (Today through Saturday) Issued at 309 AM EDT Fri Sep 20 2024 Models depict a frontal boundary finally pushing across SoFlo today, with its parent mid level trough lingering across northern FL and the SE CONUS. Deeper NE flow begins to filter in the wake of the FROPA, ushering drier air from the north. Model soundings suggest PWATs decreasing to below 2 inches by this afternoon, and with max POPs in the 50s. But the influence of the decaying boundary and the mid level trough to the north will still provide enough support for scattered showers and thunderstorms this afternoon. And as in previous days, the weak sfc flow will allow for sea breeze boundaries to again become focal points for deeper convection. Main concerns remain with potential for localized flooding, especially over locations with saturated terrain. Ensembles and ECMWF insist in pushing the aforementioned mid-lvl trough further south and through SoFlo on Saturday. In response, deeper ENE flow establishes, although still remaining weak (generally 3-8kt). This will be reinforced by broad high pressure developing over much of the SE CONUS, which will also usher drier air into the mid levels across the state. Nevertheless, hydro models keep at least chances for afternoon scattered showers and isolated thunderstorms, with POPs in the 40-50 percent. Temperatures and heat indices are expected to remain above seasonal climo, but stubborn cloudiness and possible rain activity should help in avoiding advisory criteria through the period. && .LONG TERM... (Saturday night through Thursday) Issued at 309 AM EDT Fri Sep 20 2024 As we wrap up the weekend and move into the new week, an expansive mid-level ridge will stretch across the Gulf of Mexico and into southeastern CONUS as the lingering trough drifts into the Atlantic. With this ridging, dry mid-level air will advect into the region with warm temperatures aloft. Although the mid-level drying is quite evident, with PWATs dipping down into the 1.4-1.7" range over portions of the area, there will be enough moisture remaining in the lower level with the assistance of a stationary surface boundary just to the south of the Keys keeping a sufficient supply of moisture in the southern half of the Peninsula. This will support daily scattered showers and isolated thunderstorms across the region. With the persistent easterly flow regime, the highest chance for rain will be over the western portions of South Florida. The relatively stable airmass will limit the deep convection most likely to the far southern third of the FL Peninsula. Looking further into the extended forecast, confidence is still minimal, as uncertainty increases if a portion of the Central American Gyre may consolidate into a more defined area of surface low pressure over the northwestern Caribbean or southern GOMEX (if forms at all). With the expansive forecast lead times, we will continue to monitor the tropics as the limited model guidance is indecisive and jumbled at the time being. In the upcoming days and as confidence grows, we will be watching the potential for the low`s development and the Gulf of Mexico`s future closely. The latest National Hurricane Center 2AM outlook has a 40% chance of tropical formation in the next 7 days. Temperatures will be near/just above seasonal normals with high temperatures in the upper 80s to low 90 and lows in the 70s. While the heat indices will likely reach the triple digits, the drier air will likely provide a relief from heat advisories due to dew points dropping into the low to mid 70s. && .AVIATION... (12Z TAFS) Issued at 753 AM EDT Fri Sep 20 2024 VFR conditions should prevail through the period. Light northeasterly winds will build into the 5-8 kt range around noon. SCT SHRA/TSRA is once again expected to develop later this afternoon, but coverage is forecast to remain inland of the sites, so no inclusion of TEMPOS or PROB30s at this time. Conditions should improve shortly after sunset, but some light rain could linger overnight. && .MARINE... Issued at 309 AM EDT Fri Sep 20 2024 Generally light winds continue today with a decaying frontal boundary moving across the area. Showers and thunderstorms will begin decreasing today as drier air slowly filters from the north behind the front. But there will be enough leftover moisture for isolated to scattered thunderstorms to develop in the afternoon hours, then the decreasing tend continues into the weekend. Brief periods of rough seas and gusty winds may accompany any thunderstorm that forms. && .BEACHES... Issued at 309 AM EDT Fri Sep 20 2024 Minor to moderate coastal flooding continues during periods of high tide. These elevated tides will continue to affect all coastal areas of South Florida through late this morning, for which a coastal flood advisory remains in effect. For the rest of the weekend, a decrease in northerly swell should help reduce the risk for moderate flooding, but some minor flooding could still be possible through at least late Saturday. Additionally, a moderate risk of rip currents continues for the Palm Beaches during the next couple of days. NAPLES HIGH TIDE TIMES...2:57PM this afternoon LAKE WORTH HIGH TIDE TIMES...10:24 AM this morning && .PRELIMINARY POINT TEMPS/POPS... Miami 89 76 90 76 / 40 20 30 20 West Kendall 91 73 91 74 / 40 20 30 20 Opa-Locka 91 76 91 76 / 40 20 30 20 Homestead 90 75 90 76 / 40 20 30 30 Fort Lauderdale 88 76 88 76 / 30 20 30 20 N Ft Lauderdale 89 76 89 76 / 40 20 40 20 Pembroke Pines 91 76 92 76 / 30 20 30 20 West Palm Beach 89 76 90 76 / 40 10 40 20 Boca Raton 90 76 90 76 / 40 20 40 20 Naples 91 75 91 76 / 20 20 20 10 && .MFL WATCHES/WARNINGS/ADVISORIES... FL...Coastal Flood Advisory until 5 PM EDT this afternoon for FLZ069- 075-168-172>174. AM...None. GM...None. && $$ SHORT TERM...99 LONG TERM....JS AVIATION...ATV