Area Forecast Discussion
Issued by NWS Miami, FL
Issued by NWS Miami, FL
786 FXUS62 KMFL 311754 AFDMFL Area Forecast Discussion National Weather Service Miami FL 154 PM EDT Sun Aug 31 2025 ...New UPDATE, AVIATION... .UPDATE... Issued at 152 PM EDT Sun Aug 31 2025 A deep trough remains over the E CONUS, while a decaying stationary sfc boundary stretches across the northern half of the Florida peninsula and the northern Gulf waters. 18Z MFL sounding data was showing deep moisture over SoFlo with PWAT values above 2 inches, with model soundings also estimating PWAts around 2.0-2.5 inches for this afternoon, which is around the 80th percentile for the season. Deep tropical moisture will remain blocked to the north by the frontal boundary, supporting scattered to numerous showers and thunderstorms this afternoon. The overall synoptic flow will continue to be driven by a westerly component dominating the 2-10 km atmospheric column. At the sfc, pressure gradients remain weak enough to keep a prevailing south-southwesterly weak flow in place, even becoming calm at times. Therefore, storm motion will be west-to- east, and placing the best chances for deep convection over the eastern half of SoFlo. POPs will be in the 70-75% range, with another round of weather expected today. Main lifting mechanism will again be sea breezes and outflow boundary collisions, resulting in lines of heavy showers and embedded thunderstorms. Rainfall accumulations could reach the 2-3 inches range (isolated higher amounts possible) with the heaviest downpours, especially slow-moving cells. Therefore, main concern will be the potential for urban flooding over some of the Atlantic metro areas. Much of southeast Florida remains under a Marginal Risk (level 1 of 4) for excessive rainfall each day through the rest of the long weekend. Expect high temps in the upper 80s to low 90s before cloud cover increases, while lows will again dip into the low-mid 70s overnight. && .SHORT TERM... (Today through Monday) Issued at 149 AM EDT Sun Aug 31 2025 A prolonged period of unsettled weather will continue across South Florida as deep upper-level troughing remains established over the Eastern Seaboard. Satellite imagery early this morning shows the trough axis has ejected over the western Atlantic, while a corresponding surface boundary gradually drifts southward along the Florida peninsula. This should help enhance moisture advection along the column today. With this improved moisture profile and westerly flow in place, scattered to numerous showers and thunderstorms will once again be possible this afternoon, with activity starting to develop inland in the early afternoon hours, then progressing east towards the East Coast metro. Guidance suggests generally up to 1 inch across much of South Florida could be possible, with pockets of 1-2 inches along the East Coast metro, and up to 3 inches in isolated spots. One potential limiting factor to keep in mind will be the potential that the prevailing westerly flow could preclude the development of the Atlantic sea breeze this afternoon, which would reduce the possibility for convection to become pinned over the metro areas for prolonged periods, and thus limit the potential for higher rainfall accumulations. That being said, high-res models have shown spotty run-to-run consistency over the past several days, so confidence regarding the finer-scale details of this solution remains low. Nevertheless, given this discussion, and recent rainfall over the last few days, localized flooding concerns cannot be ruled out, and WPC is keeping much of South Florida under a Marginal Risk (level 1 of 4) for excessive rainfall today, but widespread impacts appear unlikely at this time. On Monday, chances for widespread rainfall have trended downward, with scattered showers and a few thunderstorms still forecast to develop, but concerns over flash flooding somewhat diminished. Highs this weekend will remain in the low-mid 90s, while lows could dip to the low-mid 70s overnight. && .LONG TERM... (Monday night through Saturday) Issued at 149 AM EDT Sun Aug 31 2025 The period of unsettled weather looks to persist through much of the upcoming week as the upper-level trough lingers over the Eastern Seaboard, with several shortwave impulses moving through the flow. Repeated rounds of rainfall through mid-week will keep at least a marginal risk for localized flooding, especially along the East Coast metro where westerly flow will continue to focus activity. A weak surface low may develop and move across South FL on Tuesday, which could bring a temporary uptick in shower and thunderstorm coverage. By late week, the upper trough is expected to gradually lift northward, which should begin to shift the pattern into next weekend. High temperatures through the extended period will generally range from the low to mid 90s, with overnight lows in the low-mid 70s across the interior and up to the upper 70s along the coasts. && .AVIATION... (18Z TAFS) Issued at 152 PM EDT Sun Aug 31 2025 Westerly 7-10 kts through around 01Z, then light and variable flow prevails tonight. Lingering showers or thunderstorms until around 01Z may still result in brief periods of MVFR/IFR, especially over the Atl terminals. Then VFR should prevail after 01Z. && .MARINE... Issued at 149 AM EDT Sun Aug 31 2025 Light westerly to southwesterly winds develop today across all local waters. Seas are expected at 2 feet or less across all local waters. Scattered to numerous showers and thunderstorms remain possible each day, which may cause periods of locally gusty winds and rough seas. && .PRELIMINARY POINT TEMPS/POPS... Miami 77 92 77 91 / 70 80 60 80 West Kendall 76 91 76 91 / 60 80 60 80 Opa-Locka 76 93 77 92 / 70 80 50 80 Homestead 76 91 76 91 / 70 80 60 80 Fort Lauderdale 76 91 77 91 / 70 80 60 80 N Ft Lauderdale 77 92 77 92 / 70 80 50 80 Pembroke Pines 76 93 77 93 / 70 80 50 80 West Palm Beach 76 91 77 91 / 70 80 50 80 Boca Raton 76 93 76 92 / 70 80 50 80 Naples 78 91 77 91 / 60 70 50 70 && .MFL WATCHES/WARNINGS/ADVISORIES... FL...None. AM...None. GM...None. && $$ SHORT TERM...ATV LONG TERM....ATV AVIATION...17