Area Forecast Discussion
Issued by NWS Miami, FL
Issued by NWS Miami, FL
234 FXUS62 KMFL 291651 AFDMFL Area Forecast Discussion National Weather Service Miami FL 1251 PM EDT Fri Aug 29 2025 ...New AVIATION... .KEY MESSAGES... Updated at 1250 PM EDT Fri Aug 29 2025 - Heavy rainfall is forecast for the metro areas of South Florida each afternoon over the next several days. Localized higher rainfall amounts over a short period of time may result in urban flooding. - Scattered to numerous thunderstorms over the next several days may produce frequent to excessive cloud to ground lighting, gusty winds, and small hail. While the greatest coverage of storm activity should be during the afternoon hours, timing may vary from day to day. && .SHORT TERM... (Today through Saturday) Issued at 131 AM EDT Fri Aug 29 2025 One last rinse and repeat type day under this current pattern is expected today as the deep trough covering much of southeastern Canada and the Eastern Seaboard of the U.S. continues to dig further southwards. Nevertheless, latest analysis and ensembles do not have the trough axis pushing into South Florida until later Friday night and into Saturday. Thus, expect today to be more redundant from the last few days with convection being once again driven by diurnal heating and the development of the afternoon sea breezes that push inland from both coasts, as well as any outflow boundaries. Strongest storms will be expected over the interior sections of the region as this will be where convergence is maximized. Primary hazards from storms will be potential for some strong wind gusts with the stronger storm cores as well as heavy downpours. Heading into Saturday, a more active pattern begins to set itself up as the large scale trough axis will extend down into southern Florida. This will result in consistent positive vorticity impulses advecting across the area, providing a source of lift for the abundant moisture in place (PWATs of 1.8-2.2+ inches). In addition, a surface low is expected to develop across the northeastern Gulf. with a frontal boundary in northern Florida that helps keep the moisture pooled in Central and South Florida. The end result will be the potential for increasing widespread coverage of showers and thunderstorms. 24-hour QPF for Saturday is expected to be 0.5-1.5" or so for most of South Florida with highest amounts for the east coast metro areas. The 90th percentile (reasonable worst case and a 10% chance of exceedance) is pretty similar with no more than 1.5-2" region-wide. Therefore, while the overall hydrologic threat is not extremely high, given the pattern setup there will still be chances for isolated localized pockets of flooding, especially since most of the rainfall is anticipated for the east coast metro areas which are more susceptible to flooding. High temperatures for Friday and Saturday are expected in the low to mid 90s with lows Friday night ranging from the low 70s around the Lake O region to the mid and upper 70s for the coastlines and metro areas. && .LONG TERM... (Saturday night through Thursday) Issued at 131 AM EDT Fri Aug 29 2025 The large synoptic trough encompassing most of the central and eastern U.S. will be the primary driver in a much more active pattern setting up for South Florida for the second half of the weekend and extending into the middle of next week. This mammoth trough will provide plenty of forcing for ascent and instability during the long term period, and a stationary frontal boundary is also expected to linger in northern and central Florida which will meander at times. However, the presence of this stagnant boundary will keep abundant moisture (PWATs in excess of 2.0") pooled across the region. We will also see an area of surface low pressure set up over the northeastern Gulf and expanding over the Florida Peninsula and into the western Atlantic. Overall, this setup creates a much more consistently active pattern than we have seen for a lot of the summer. The biggest concern is going to be hydro related as repeated rounds of heavy rainfall each day will increase the risk for flooding, as well as training storms and pockets of heavy steady rain. 24-hour QPF each day through Monday is currently forecast at 0.5-2.0", with 90th percentile (a reasonable worst case scenario) values generally in the 2-3" range. This may not seem like a major problem on the surface, but when you add in the fact that this will be repeated daily it will not take as much rain to cause flooding issues. Current 5-day rainfall potential for a reasonable worst case is currently 8-10+". Furthermore, the fact that the 90th percentile shows widespread 2-3" daily shows how primed the atmosphere is with moisture that localized pockets of significantly higher rainfall are certainly possible. We will continue to assess the situation in each forecast package with the latest information provided as it is received and analyzed. Temperatures during the extended period will start to decrease slightly as we are looking at an increase in rain coverage and cloud cover. High temperatures are expected in the upper 80s to low 90s each day. Overnight lows will range from the low to mid 70s for the Lake O and interior regions to the upper 70s for the coasts. && .AVIATION... (18Z TAFS) Issued at 1250 PM EDT Fri Aug 29 2025 Light and variable winds will veer onshore over the next several hours as SHRA/TSRA will develop and propagate across the region. Sub-MVFR cigs/vis are possible at east coast terminals if shower and storm activity directly impacts terminals. Light and variable winds are expected overnight with another round of SHRA/TSRA expected once again tomorrow. && .MARINE... Issued at 131 AM EDT Fri Aug 29 2025 A light to gentle southeasterly flow is expected across the local waters to end the week and will shift westerly by the second half of the weekend and into early next week. Scattered showers and storms will continue to be possible each day. Showers and storms may result in locally stronger winds and elevated seas. && .PRELIMINARY POINT TEMPS/POPS... Miami 77 91 77 91 / 60 80 40 80 West Kendall 75 91 75 91 / 60 90 40 80 Opa-Locka 76 93 77 92 / 60 80 40 80 Homestead 76 91 76 91 / 60 80 40 80 Fort Lauderdale 77 91 76 91 / 70 80 40 80 N Ft Lauderdale 77 92 77 91 / 60 80 40 80 Pembroke Pines 77 94 76 93 / 60 80 40 80 West Palm Beach 76 92 76 91 / 60 80 40 80 Boca Raton 76 93 75 92 / 60 80 40 80 Naples 77 91 77 91 / 30 60 30 70 && .MFL WATCHES/WARNINGS/ADVISORIES... FL...None. AM...None. GM...None. && $$ SHORT TERM...Redman LONG TERM....Redman AVIATION...Hadi