Area Forecast Discussion
Issued by NWS Miami, FL
Issued by NWS Miami, FL
993 FXUS62 KMFL 031850 AFDMFL Area Forecast Discussion National Weather Service Miami FL 250 PM EDT Wed Sep 3 2025 ...New UPDATE... .UPDATE... Issued at 240 PM EDT Wed Sep 3 2025 Scattered showers and storms continue to develop this afternoon as South Florida remains to the north of a stalled stationary boundary. Weak westerly flow prevails which will keep showers and storms propagating from west to east across the peninsula through the remainder of the evening. The atmosphere is primed for heavy rainfall, with ample moisture (PWATs of 2.3 inches on the 18Z sounding) and boundary interactions galore, additional showers and storms will continue to develop on and off through the remainder of the diurnal period. Some portions of the Miami Dade metro have already received upwards of 2 inches in the last hour, and the heaviest cells may be capable of dropping a 1-3 inches within an hour which could lead to localized flooding concerns on roadways. Flood advisories may be necessary over the coming hours, and this will be continued to be monitored. && .SHORT TERM... (Today through Friday) Issued at 240 AM EDT Wed Sep 3 2025 Few changes in the synoptic pattern this morning as a frontal boundary remains stalled out just south of South Florida, while a weak surface low continues meandering to our northeast over the Gulf Stream waters. These two surface level features will continue to influence low-level flow patterns, with generally light and variable winds early today gradually veering from the west/southwest this afternoon. This shift will act to inject moisture back into the atmospheric column, which could help enhance convective activity and coverage today, especially along the Atlantic sea breeze boundary, which most models suggest should be able to develop this afternoon. Rainfall totals in the 1-2 inch range could be possible across portions of South Florida, with isolated higher amounts. Thursday and Friday are expected to feature a similar setup as the frontal boundary and surface low remain in the vicinity, once again supporting scattered to numerous showers and thunderstorms with widespread 1-2 inch accumulations possible each day, and 72-hour totals up to 4 inches. Some models show slightly more widespread storm coverage on Thursday afternoon compared to the last couple of days, but run-to-run consistency and inter-model agreement remain somewhat low, resulting in a higher degree of uncertainty regarding that solution. Flash flood guidance (FFG) remains relatively high across South Florida this morning, with 1-hour thresholds generally around 3-4 inches, and 24-hour thresholds exceeding 8 inches. Current probabilities for reaching the 1-hour thresholds on Wednesday remain at or below 10% (or 1 in 10). Given this, and the forecast rainfall amounts, decided to hold off on issuing a Flood Watch today. However, a Marginal Risk (level 1 of 4) of Excessive Rainfall remains in effect for the next several days as the unsettled pattern continues. Highs both days will remain in the low to mid 90s, with overnight lows in the low to mid 70s inland, and mid to upper 70s near the coasts. && .LONG TERM... (Friday night through Tuesday) Issued at 240 AM EDT Wed Sep 3 2025 By Saturday, the upper level trough is forecast to begin lifting northward, but the aforementioned surface front and surface low might still linger, helping to maintain generally southerly/southwesterly flow near the surface and continued rain chances Saturday afternoon. At this time, WPC has placed the East Coast metro under a Marginal Risk (level 1 of 4) of Excessive Rainfall. Come Sunday, ridging may begin to build from the Atlantic as a surface high attempts to set up to the north, shifting winds to a more easterly component and potentially signaling a return to a more typical summertime pattern. However, some uncertainty remains with this solution and confidence in the timing of this transition is low at this point. 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 1243 PM EDT Wed Sep 3 2025 Complex TAF forecast as SHRA/TSRA develops by 18-20z across the region resulting in erratic wind shifts and potentially sub- MVFR cigs/vis at some east coast terminals. Light and variable winds will become westerly although a Atlantic sea-breeze may briefly veer winds onshore before SHRA/TSRA advects into the east coast metro. TEMPOs may need to be adjusted based on trends later today. L/V winds expected once again tonight with additional showers and storms possible Thursday morning. && .MARINE... Issued at 240 AM EDT Wed Sep 3 2025 A weak area of low pressure will remain in place across the Gulf Stream waters today, while a stationary frontal boundary remains stalled out across South Florida through the end of the week. As a result, light northerly/northwesterly flow overnight will become westerly/southwesterly winds later today, and should persist through the end of the week. Seas are expected at 2-4 feet. 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 90 78 90 / 80 90 60 80 West Kendall 76 89 76 89 / 70 90 60 80 Opa-Locka 76 91 77 90 / 80 90 60 80 Homestead 76 89 76 89 / 80 90 70 80 Fort Lauderdale 77 90 77 90 / 80 90 60 80 N Ft Lauderdale 78 90 77 90 / 80 90 60 80 Pembroke Pines 77 91 77 92 / 80 90 60 80 West Palm Beach 76 89 76 90 / 70 90 50 80 Boca Raton 76 91 76 90 / 70 90 60 80 Naples 78 89 78 90 / 70 90 60 70 && .MFL WATCHES/WARNINGS/ADVISORIES... FL...None. AM...None. GM...None. && $$ SHORT TERM...ATV LONG TERM....ATV AVIATION...Rizzuto