831 FXUS62 KMFL 212249 AFDMFLArea Forecast Discussion National Weather Service Miami FL 649 PM EDT Sun Sep 21 2025
...New AVIATION...
.UPDATE... Issued at 124 PM EDT Sun Sep 21 2025
Main change in the ongoing synoptic scenario is having a decaying frontal boundary near the Bahamas backtracking into the state through tomorrow. This boundary is dragging moisture from the Atlantic into SoFlo today, with model and sounding PWATs now in the 2 inch range. Meanwhile, model and synoptic analyses still show high pressure lingering over the SE CONUS, but being gradually weakened by a frontal feature establishing across the SC/GA region. This will bring a slight shift in wind direction over the area with mainly moderate ENE flow prevailing through Monday.
The increased moisture will push POPs into the 50-60 percent this afternoon and early evening, with even deeper moisture arriving on Monday. Based on latest radar data, POPs/Wx grids for the rest of this afternoon and evening have been updated to better reflect the current trend of increasing shower coverage across the Atlantic metro areas.
By Monday afternoon, max POPs reach the 70-80 percent range, along with better chances for widespread showers and thunderstorms to develop, steeper lapse rates, and daytime heating providing enough lifting. Therefore, Monday since to be the busiest day of the week in terms of active weather.
Despite the increased cloud cover and rain activity, temperatures should remain warm with afternoon highs generally in the upper 80s to lower 90s.
&&
.SHORT TERM... (Today through Monday) Issued at 1247 AM EDT Sun Sep 21 2025
Easterly to northeasterly flow will continue through the period with deeper moisture gradually returning to the area. Coastal showers and storms have persisted for the early portion of the night, and these will likely begin again early this morning and continue into the afternoon. Highest rain chances will remain across southern portions of the area where deep layer moisture is maximized.
Additional chance for overnight and morning coastal showers and isolated thunderstorms on Monday. As the day progresses and daytime heating increases, showers and storms will develop over land and push towards interior and southwest Florida through the evening hours.
High temperatures will reach the upper 80s to low 90s with overnight lows in the 70s.
&&
.LONG TERM... (Monday night through Saturday) Issued at 1247 AM EDT Sun Sep 21 2025
An upper level trough near the Great Lakes is forecast to slowly extend southward towards the southeastern US early next week. By mid to late week, the trough transitions into a cutoff low across the central US where it will slowly drift towards the Ohio and Tennessee Valley areas. This could lead to a weak boundary stalled across central Florida and potentially facilitate additional moisture transport across South Florida through the week. PWATs will remain in the 2.0- 2.2 inch range which is more typical for this time of year. East- northeast flow will prevail across South Florida through this time period which will give the east coast breeze the upper hand in dominating convective initiation, and will keep the area of maximum rain chances across interior and Southwest Florida each afternoon. Partly sunny conditions prevail during the morning hours with isolated coastal showers possible across Southeast Florida. Thunderstorm development is expected across interior areas during the each afternoon as sea breezes push inland and we reach maximum daytime heating. Slightly drier air might move into the region towards the end of the week as the boundary has the potential to pass south of the area. This could drop rain chances for Friday into the upcoming weekend.
High temperatures through the period will reach the lower 90s with overnight lows in the 70s.
&&
.AVIATION... (00Z TAFS) Issued at 700 PM EDT Sun Sep 21 2025
VCSH or even VCTS may still develop near the terminals, although conditions should trend towards VFR through the rest of the evening. Winds are decreasing and should become L/V after 02-03Z. Another round of showers and thunderstorms may result in restrictions after 15Z.
&&
.MARINE... Issued at 1247 AM EDT Sun Sep 21 2025
A moderate east-northeasterly breeze will continue today. Seas across the Atlantic waters will generally remain between 2 to 3 feet while seas across the Gulf waters remain at 1 to 2 feet. Despite lower rain chances this weekend, a few showers and storms may develop across local waters. Periods of rough seas and gusty winds will be possible near the most robust shower and thunderstorm activity.
&&
.PRELIMINARY POINT TEMPS/POPS... Miami 78 89 78 90 / 40 80 40 60 West Kendall 77 89 76 90 / 40 80 40 70 Opa-Locka 77 90 77 90 / 40 80 40 60 Homestead 77 88 76 89 / 50 80 50 50 Fort Lauderdale 77 89 77 89 / 40 80 40 60 N Ft Lauderdale 78 89 78 90 / 40 80 40 60 Pembroke Pines 77 91 77 92 / 40 80 40 60 West Palm Beach 77 89 77 90 / 40 80 40 60 Boca Raton 77 89 77 90 / 40 80 40 60 Naples 77 90 76 90 / 20 70 40 60
&&
.MFL WATCHES/WARNINGS/ADVISORIES... FL...None. AM...None. GM...None. &&
$$
SHORT TERM...GR LONG TERM....GR AVIATION...17
NWS MFL Office Area Forecast Discussion