Area Forecast Discussion
Issued by NWS Miami, FL
Issued by NWS Miami, FL
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285 FXUS62 KMFL 201908 AFDMFL Area Forecast Discussion National Weather Service Miami FL 308 PM EDT Fri Sep 20 2024 ...New LONG TERM... .SHORT TERM... (Rest of today through Saturday) Issued at 1233 PM EDT Fri Sep 20 2024 With the previously stalled frontal boundary finally pushing south of our area this morning, South Florida should enjoy generally drier conditions for the rest of today and tomorrow! ACARS data at MIA captured the northerly wind shift earlier this morning, along with the drier mid-level air mass and PWATs trending down (down to 1.34 inches as of 12:30PM, near the 10th percentile for this time of year!). Nevertheless, there could still be some isolated showers and storms that develop later this afternoon along sea breeze boundaries, mainly south of Alligator Alley. Some of these showers and storms could be capable of producing heavy rain, with general accumulations of 1-2 inches, and localized amounts up to 2-4 inches possible as some moisture still lingers near the lower levels. This could result in localized flooding, especially if these heavy rain producers sit over areas with already saturated soils. 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 next Thursday) Issued at 234 PM EDT Fri Sep 20 2024 During the second half of the weekend the mid level trough will push into the western Atlantic as mid level ridging over the Gulf of Mexico pushes towards the region. This mid level ridge will be the main synoptic influence in the weather pattern during the early to middle portion of the week as it gradually shifts eastward and centers over South Florida. At the surface, as high pressure strengthens to the north, east northeasterly wind flow will gradually increase during the early to middle portion of next week. This will be the result of the pressure gradient tightening between the area of high pressure to the north, and the stalled out frontal boundary over the Florida Keys. As some mid level drier air works in from the north during this time frame, the PWAT values will fall over the region and could potentially range between 1.5 and 1.9 inches through Tuesday. While this will help to reduce shower and thunderstorm chances each day, the stalled out frontal boundary to the south will keep enough lower level moisture in place to support some convection development along the sea breezes. The best chances of showers and thunderstorms will remain along and south of Alligator Alley during this time frame which will be closest to the weakening boundary. High temperatures during the early to middle portion of the week will range from around 90 along the east coast to the lower to mid 90s over Southwest Florida. During the second half of the week, forecast uncertainty rises significantly and confidence remains low as guidance still remains in disagreement in how it is handling the potential development of a tropical disturbance in the Carribean Sea from the Central American Gyre. As of 2 PM, The National Hurricane Center currently gives a 50 percent chance of development over the northwestern Carribean Sea and southern Gulf of Mexico over the next 7 days. The latest guidance remains in disagreement in its intensity and placement of this feature during this time frame as there is currently no area of low pressure to track. Until an area of low pressure forms, guidance will remain poor in resolving this potential disturbance until something trackable actually develops. This will continue to be monitored as the week progresses. For now, some moisture will try to advect back into the region which will raise daily shower and thunderstorm chances back to a typical late summertime pattern. With east to southeasterly wind flow in place, the highest chances of convection will remain over the interior and west coast each afternoon on Thursday and Friday. High temperatures will generally remain in the upper 80s along the east coast to the lower 90s across Southwest Florida during this time frame. && .AVIATION... (18Z TAFS) Issued at 1233 PM EDT Fri Sep 20 2024 VFR conditions should prevail through the period. Light northerly/northeasterly winds should persist. ISO 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. && .MARINE... Issued at 1233 PM 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 thunderstorms to develop in the afternoon hours, then the decreasing trend continues into the weekend. Brief periods of rough seas and gusty winds may accompany any thunderstorm that forms. && .BEACHES... Issued at 1233 PM EDT Fri Sep 20 2024 Minor to moderate coastal flooding continues during periods of high tide through the short period. 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. Conditions should begin to improve on Sunday as northerly swell and the tidal influence decreases, but we could still see some minor coastal flooding during high tide. 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, 2:15AM tomorrow LAKE WORTH HIGH TIDE TIMES...10:39 PM tonight, 11:18AM tomorrow && .PRELIMINARY POINT TEMPS/POPS... Miami 76 90 76 90 / 20 30 20 30 West Kendall 74 91 74 92 / 20 30 10 30 Opa-Locka 75 91 76 92 / 20 30 10 30 Homestead 75 90 75 90 / 20 30 20 30 Fort Lauderdale 76 89 76 89 / 20 30 20 30 N Ft Lauderdale 76 90 77 90 / 20 30 20 30 Pembroke Pines 76 92 77 92 / 20 30 10 30 West Palm Beach 77 90 76 90 / 10 30 10 30 Boca Raton 76 91 76 91 / 20 30 20 30 Naples 75 91 75 92 / 30 30 10 20 && .MFL WATCHES/WARNINGS/ADVISORIES... FL...Coastal Flood Advisory until 5 PM EDT Saturday for FLZ069-075- 168-172>174. AM...None. GM...None. && $$ SHORT TERM...ATV LONG TERM....CWC AVIATION...ATV