Area Forecast Discussion
Issued by NWS Miami, FL
Issued by NWS Miami, FL
164 FXUS62 KMFL 181729 AFDMFL Area Forecast Discussion National Weather Service Miami FL 129 PM EDT Sat Oct 18 2025 ...New AVIATION... .SHORT TERM... (Today through Sunday) Issued at 229 AM EDT Sat Oct 18 2025 A continuation of mostly dry weather will be experienced across South Florida today with the exception of a few quick moving isolated showers across the eastern half of the South Florida. 05z Mesoanalysis, ACARS (aircraft) data from local airports, and tonight`s 00z MFL upper air sounding all depict an atmospheric profile that is characteristic of mid-level ridging directly overhead with a stout subsidence inversion at 850mb. The 1.05 inch precipitable water value observed on the 00z MFL sounding remains below the 10% percentile of historical precipitable water for this time of year. The plethora of mid-level dry air remains overtop a shallow layer of low-level surface moisture that may still produce a few vertically-capped quick moving showers along the east coast from time to time today. The breeze will continue across the region today courtesy of expansive surface high pressure gradually pushing eastward into the western Atlantic waters, flow will veer to a more purely easterly direction accordingly. Nocturnal stratification is in full swing early this morning which has resulted in a decoupling of surface winds across most of South Florida with the exception of the immediate coastline. The enhancement of onshore winds later this morning into the afternoon hours will create a notable temperature gradient across the region once again this afternoon with forecasted high temperatures in the low to middle 80s across the eastern half of the region and highs in the upper 80s (even a few locales potentially reaching 90F) across the southwestern half of the region. The mid-level ridging currently situated across South Florida and our local waters will continue to decrease in strength with mid- level flow becoming more zonal in nature later today into tonight. A long-wave trough currently across the central United States will continue to amplify as it pivots eastward into the Great Lakes region tonight. A sprawling frontal boundary connected to distant surface low pressure across the Great Lakes region will sweep eastwards across the southeastern United States (and north and central Florida) during the day on Sunday. Now this is when the local forecast gets slightly more interesting. While the best dynamics are still forecast to remain well to the north of the region, the GFS/European as well as some mesoscale models now show a mid-level shortwave propagating along at the base of the trough across Central Florida during the second half of Sunday into mid Monday morning. The combination of mid-level vorticity and a plume of deeper precipitable water values (2.0 to 2.2 inches) lifting northwards into southeastern Florida may result in higher than previous thought rain chances during the day on Sunday for the eastern half of the region. Uncertainty remains regarding just how much moisture and instability will materialize as the exact phasing of the short-wave and frontal boundary with diurnal heating remains to be seen. That being said, went ahead and upped rain chances on Sunday to the 20- 40% across the eastern half of the region. As winds lessen and veer more southeasterly, temperatures will trend up during the afternoon hours. Forecasted highs will range from the middle to upper 80s along both coasts to temperatures near 90 across inland southwestern Florida. && .LONG TERM... (Sunday night through Friday) Issued at 229 AM EDT Sat Oct 18 2025 As the mid-level trough lifts north across the northeastern United States on Monday, the distant surface low attached to the boundary will lose synoptic forcing. This will result in the previously mentioned frontal boundary stalling out just to the north of South Florida. With our region remaining to the south of the boundary in the warm sector, a residual plume of moisture will remain across the region which may once again allow for a few afternoon showers and isolated storms. The departing mid-level shortwave may provide a second boost in instability during this time frame as 500mb temperatures remain in the -8C to -9C range. With ample sunshine and light winds expected for most of the day, temperatures will remain slightly above average across the region with forecasted highs in the upper 80s to low 90s area-wide. The subtropical jet and upstream waves will remain active across the eastern United States through mid-weel as additional lobes of mid- level vorticity amplify and advect eastward across the Great Lakes. Associated surface lows will also advect from west to east across the Great Lakes dragging sprawling frontal boundaries across most of the eastern half of the country. Temperatures will remain slightly above average for this time of year during this time frame with forecasted afternoon high temperatures each day during the middle to late park of the week remaining in the upper 80s to low 90s each afternoon. && .AVIATION... (18Z TAFS) Issued at 125 PM EDT Sat Oct 18 2025 VFR conditions prevail through the period, with breezy easterly winds this afternoon. Winds will relax overnight, but remain easterly-southeasterly. They will further veer out of the southeast tomorrow, and there will be a slight chance of showers along the East Coast in the afternoon. && .MARINE... Issued at 229 AM EDT Sat Oct 18 2025 East-northeasterly to easterly surface winds will remain fresh across our local waters today and tonight before lessening during the second half of the weekend and veering more southeasterly in direction. Periods of SCEC (Small Craft Exercise Caution) conditions will continue into early Sunday morning across all South Florida waters with the exception of Lake Okeechobee. Seas will remain in the 3-5 feet range across the Atlantic waters today with seas in the 2-3 range across our local Gulf waters. The arrival of more northeasterly swell on Sunday may increase wave heights slightly across the northern Atlantic waters into the 4-6 feet range. The latest forecast now shows the potential of a few showers and perhaps an isolated thunderstorm or two across the local waters on Sunday. If thunderstorm activity does indeed develop over the waters, erratic wind shifts and locally gusty winds could occur near and around any storms. && .BEACHES... Issued at 229 AM EDT Sat Oct 18 2025 A high risk of rip currents will continue across all east coast beaches of South Florida today. With breezy onshore winds and a northeasterly swell arriving along our coast, the high risk of rip currents for the east coast of South Florida will continue through at least Sunday evening. && .HYDROLOGY... Issued at 229 AM EDT Sat Oct 18 2025 The combination of higher than normal tidal levels due to the lunar cycle, enhancing onshore flow, and northeasterly swell will result in the continued potential of minor coastal flooding within 1.5 to 2 hours of high tide along the east coast over the next several days. A Coastal Flood Statement remains in effect for coastal Miami-Dade, Broward, and Palm Beach counties through at least Sunday evening. && .PRELIMINARY POINT TEMPS/POPS... Miami 75 86 75 87 / 0 40 20 30 West Kendall 74 86 74 87 / 0 50 20 30 Opa-Locka 74 87 75 87 / 0 40 20 30 Homestead 75 86 74 86 / 10 50 20 30 Fort Lauderdale 74 86 75 86 / 0 30 20 20 N Ft Lauderdale 74 86 75 87 / 0 30 20 20 Pembroke Pines 75 89 75 89 / 0 40 20 30 West Palm Beach 74 87 74 87 / 0 20 20 20 Boca Raton 74 87 74 87 / 0 30 20 20 Naples 71 89 74 89 / 0 20 10 10 && .MFL WATCHES/WARNINGS/ADVISORIES... FL...High Rip Current Risk through Sunday evening for FLZ168-172-173. AM...None. GM...None. && $$ SHORT TERM...Hadi LONG TERM....Hadi AVIATION...99