FXUS62 KMFL 180501 AFDMFL Area Forecast Discussion National Weather Service Miami FL 101 AM EDT Mon May 18 2026 ...New LONG TERM... .KEY MESSAGES... Updated at 1257 AM EDT Mon May 18 2026 - High risk of rip currents along the east coast of South Florida will continue through at least Tuesday evening as breezy easterly winds prevail. - Shower and thunderstorm activity will continue this evening as inland activity gradually wanes in intensity and coverage. Rain chances will remain elevated over the next several days. && .SHORT TERM... (Today through Monday) Issued at 224 AM EDT Sun May 17 2026 Increased moisture is expected to filter into the region from the Caribbean through the beginning of the week. Florida will find itself in the middle of two regions of upper-level ridging, one over the southern Gulf and one along the eastern seaboard. Meanwhile a non-tropical disturbance of low pressure will begin to develop over the Atlantic waters just east of the Bahamas. This will serve to increase chances for showers across the Atlantic waters and funnel in more low level moisture towards the peninsula. At the surface, pressure gradients will tighten over the next couple days across the Atlantic as an area of high pressure off the coast of the Carolinas strengthens to around 1026 mb. This will result in stronger easterly flow across the region, with sustained winds of 10 to 15 mph and gusts up to 28 mph. This stronger easterly flow will keep the Gulf breeze pinned further west across southwest Florida during the afternoon on Sunday and even more so on Monday. Spotty showers will develop during the morning hours along the Gulfstream and Florida bay, moving westward across the region. However, most thunderstorm activity will focus along the sea breeze convergence over interior and southwest Florida during the afternoon. THe HRRR performed pretty well for Saturday's activity, and with a similar environment for Sunday, feeling fairly confident that the solution depicting 75% to 80% PoPs across the Gulf coast will play out. However, one factor that continues to be under-modeled by forecast soundings is the amount of dry air in the mid levels. PWATs are expected to climb to near 1.8 inches for Sunday and remain at that level or slightly below for Monday. Due to nearby ridging aloft, would expect some mid-level subsidence to once again suppress thunderstorm growth from becoming strong. Yet, increasing MidRH values should be more conducive for greater coverage of showers and higher rainfall amounts. Once again, steep low level laps rates and plenty of CAPE (near 3000 J/kg) will be favorable for a few stronger storms, with gusty winds and locally heavy downpours being the main concern. Unlike Saturday, there looks to be a little bit better shear available for storms, between 15 to 25 kts, and with 500 mb temperatures cooling down to -9 or -10 C, would not be surprised if a few isolated severe storms develop for both Sunday and Monday. With steering flow aloft being relatively weak and nearly opposite to the low level wind pattern, some of these storms could be slow moving. This would contribute to some heavier localized downpours of 4 to 5 inches. For the most part, HREF ensemble PMMs are depicting 1 to 1.5 inches of rainfall across interior and southwest Florida each afternoon from storm activity. Widespread Moderate HeatRisk (level 2 of 4) is expected for the beginning of the week. With slightly greater relative humidity, heat indices will climb a few degrees area wide. Southwest Florida will see heat indices in the lower 100s, while eastern areas will be in the upper 90s. With storm activity in southwest Florida looking to favor the latter half of the afternoon, temperatures should be able to climbinto the mid 90s for parts of Collier county. Overall, temperatures look to be slightly above average for this time of year. The NWS Prototype Probabilistic HeatRisk tool indicates low chances of 20% to 30% for observing Major (level 3 of 4) heat related impacts for parts of the Dade and Broward metros through Monday. && .LONG TERM... (Tuesday night through Sunday) Issued at 1257 AM EDT Mon May 18 2026 Longwave ridging will be the dominant pattern aloft for the eastern CONUS during the middle portion of the week. Florida will find itself in between an H5 centroid to its west over the southern Gulf and an H5 centroid to its east near Bermuda. Within the overall ridging pattern, ensemble guidance is in pretty good agreement of showing a cut off low meandering around the northern Caribbean just east of the Bahamas. This area of low pressure will provide increased forcing for storms over the Atlantic waters as several lobes of vorticity advect westward near the vicinity of the Florida coastline. Florida will remain under rich moisture through the period, but some deeper pockets look to raise PWATs to near 1.8 inches, which is within the 75th percentile for this time of year. At the surface, winds will remain mostly easterly, but wind speeds will be slightly weaker than in the beginning of the week as pressure gradients relax across the eastern seaboard. As a result of this predominant easterly flow, the Gulf breeze won't be able to advance as far east. This will result in most afternoon thunderstorm activity favoring interior and portions of southwest Florida each day. Overall, PoPs will generally be in the 30% to 40% range across the peninsula each day, with higher 55% to 65% PoPs along the sea breeze convergence zones. Main threats will be frequent lightning, locally heavy downpours, and gusty winds. Despite the cutoff low nearby, 500 mb heights will actually be between 586 to 589 dm across South Florida, which is near to slightly above average for this time of year. This will in turn lead to slightly above normal temperatures area wide, with high temperatures in the upper 80s and low 90s. With moisture staying steady throughout the week, heat indices will remain in the upper 90s and lower 100s through the period as well. Zooming into the forecast a little bit, diurnal heating will drive most of these high temperatures each afternoon. But, with increased chances of showers moving onshore from the Gulfstream during the morning (particularly for the middle part of the week), cloud cover and rain may keep things cooler over certain spots during the day. Conversely, increased cloud cover and rain during the nighttime hours may suppress radiational cooling and keep things slightly warmer overnight. For the most part, widespread Moderate HeatRisk (level 2 of 4) is expected each day. However, long range ensembles are indicating that pressure heights will increase slightly as longwave ridging shifts east and the cut off low dissolves. This will result in warmer temperatures for the weekend, with the NWS Prototype Probabilistic HeatRisk tool showing a 40 to 50 percent chance of Major heat impacts for the east coast metro areas. && .AVIATION... (00Z TAFS) Issued at 631 PM EDT Sun May 17 2026 Inland SHRA/TSRA continues to wane in coverage while new developing scattered SHRA has begun to increase in coverage along the east coast of South Florida once again. Breezy easterly winds will lessen after sunset but remain easterly across the region overnight with SHRA coverage forecast to increase once again along the east coast of South Florida between 10-12z Monday before activity pushes inland by 17-19z. && .MARINE... Issued at 130 AM EDT Sun May 17 2026 Easterly breezes will strengthen through the beginning of the week along the Atlantic, with sustained wind speeds of 10 to 15 kts and gusts up to 25 kts likely. A weaker westerly breeze will be likely along the immediate Gulf each afternoon, but the predominant wind regime shifts easterly over the Gulf as well. These breezier conditions look to create some slightly choppier conditions, but waters are expected to remain below Small Craft Advisory criteria. Sustained winds look to peak near 20 kts on Monday, with only a low 10% chance of winds being greater than 20 kts. Isolated weak showers are possible for the Gulfstream waters through the morning. During the afternoon, thunderstorms will favor the Gulf coast, beginning in the Everglades and shifting northwestward through the early evening. Chances of precipitation are expected to increase across Atlantic waters heading into the middle of the week. Atlantic seas will be 2- 4 feet through the start of the week, while the Gulf will remain 2 feet or less. && .BEACHES... Issued at 130 AM EDT Sun May 17 2026 Breezier conditions will lead to continued high risk of rip currents for all Atlantic beaches to start the week. Guidance continues to show increasing confidence for High Risk of Rip Currents to persist through the middle of the week across the Atlantic coast. && .PRELIMINARY POINT TEMPS/POPS... Miami 88 78 88 77 / 40 30 40 30 West Kendall 89 75 89 74 / 40 30 40 20 Opa-Locka 89 77 89 77 / 30 30 40 30 Homestead 88 77 88 77 / 40 40 40 30 Fort Lauderdale 86 78 86 78 / 30 40 40 30 N Ft Lauderdale 86 77 86 77 / 30 40 40 30 Pembroke Pines 90 78 90 78 / 30 30 40 30 West Palm Beach 86 77 86 77 / 30 30 50 20 Boca Raton 86 78 86 78 / 30 40 50 30 Naples 93 74 93 74 / 60 10 80 20 && .MFL WATCHES/WARNINGS/ADVISORIES... FL...High Rip Current Risk through Tuesday evening for FLZ168-172-173. AM...None. GM...None. && $$ SHORT TERM...NMP LONG TERM....NMP AVIATION...Hadi