Area Forecast Discussion
Issued by NWS Miami, FL
Issued by NWS Miami, FL
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562 FXUS62 KMFL 131534 AFDMFL Area Forecast Discussion National Weather Service Miami FL 1134 AM EDT Sat Jul 13 2024 ...New SHORT TERM, MARINE, BEACHES... .SHORT TERM... (This afternoon through Sunday) Issued at 1112 AM EDT Sat Jul 13 2024 A weak flow convective regime began this morning with scattered showers and thunderstorms slowly arriving from the Atlantic waters. The 12Z sounding supported an moderately unstable environment supportive for scattered activity throughout the day with ML CAPE (2271 J/kg), low-level forcing for ascent, and plentiful moisture (PWATs = 2.14"). There has been minimal pulse-like convective cells this morning, with more likely this afternoon, especially when the Gulf sea breeze kicks in. Any slow moving showers may lead to downpours with the potential for localized flooding. On Sunday, a strong Bermuda High and a mid-level ridge will shift winds to a more easterly flow. Diurnally driven convection will begin early along the eastern coast, with the highest rainfall probabilities expected across southwestern Florida and the interior by the latter part of the day. The presence of a warm air mass and 500mb temperatures remaining in the -5 to -6 degrees C range through the weekend will likely inhibit the development of robust and severe thunderstorms. Temperatures will be seasonable to just above normal. Daily maximum temperatures are expected to reach the upper 80s to mid 90s, with possible heat index values reaching 106-107 degrees over portions of Broward and Miami-Dade counties this afternoon. The heat advisory continues for those two counties today; however, with building cloud coverage and showers, they may luck out and keep cooler, avoiding the intense diurnal heating this afternoon. However, there is potential for another round tomorrow, with the final decision expected tonight. && .LONG TERM... (Sunday night through Friday) Issued at 336 AM EDT Sat Jul 13 2024 An extension of the Subtropical Ridge centered over the Western Atlantic will maintain deep easterly flow across the region. Embedded within this easterly flow is a fast-moving tropical wave near the Windward Islands, forecast to reach the Straits of Florida and the Florida Keys early Monday. This wave will bring deep tropical moisture, with precipitable water values around 2.3 inches (90th percentile) and breezy east-southeast winds of 15-20 mph. The arrival of the tropical wave and associated moisture will result in numerous showers and thunderstorms, supported by sufficient forcing and large-scale ascent. This may lead to atypical convective activity that does not follow the diurnal cycle, potentially causing heavy rainfall in short periods and localized flooding. There exists uncertainty in the forecast regarding the northern extent of the moisture plume as it approaches our CWA. The ECMWF model suggests a more southerly track, resulting in lower PWATs over the area, while the GFS model indicates a more northerly track with higher moisture content. Temperatures are expected to remain near normal throughout the long-term period. Daytime highs will climb into the upper 80s along the east coast and lower 90s across the interior and west coast. Overnight lows will settle into the mid to upper 70s inland and on the west coast, and upper 70s to low 80s on the east coast. && .AVIATION... (12Z TAFS) Issued at 659 AM EDT Sat Jul 13 2024 Light and variable winds will continue at TAF sites until 14Z before increasing to around 10-12 KT from the ESE throughout the day. VCSH/VCTS expected after 13-15Z at TAF sites, starting on the east coast, and will continue until around 00Z. Short-fused MVFR/IFR periods possible with any passing activity. KAPF will likely experience a westerly onshore flow with Gulf breezes during the afternoon hours beginning around 16-18Z through 00Z. Overnight, winds will become light and variable with activity backing off until the morning hours. && .MARINE... Issued at 1112 AM EDT Sat Jul 13 2024 Easterly flow will generally prevail through the weekend as high pressure strengthens over the western Atlantic. Seas and wind speeds will remain well below highlight criteria, ensuring overall benign boating conditions through early next week. The only exception will be near any thunderstorms that form, which could bring brief periods of rough seas and gusty winds. && .BEACHES... Issued at 1112 AM EDT Sat Jul 13 2024 Light easterly winds will lead to a low rip current risk along the Atlantic and Gulf coasts through the weekend and into early next week. && .PRELIMINARY POINT TEMPS/POPS... Miami 92 81 92 81 / 60 40 60 30 West Kendall 92 79 92 79 / 60 40 60 30 Opa-Locka 92 81 93 81 / 60 40 50 30 Homestead 90 81 91 81 / 60 40 60 40 Fort Lauderdale 89 81 90 81 / 60 40 50 30 N Ft Lauderdale 91 81 91 81 / 60 40 50 20 Pembroke Pines 93 81 93 81 / 60 30 50 30 West Palm Beach 92 81 91 80 / 60 30 50 10 Boca Raton 91 81 91 80 / 50 30 50 20 Naples 92 79 93 78 / 70 40 60 30 && .MFL WATCHES/WARNINGS/ADVISORIES... FL...Heat Advisory until 6 PM EDT this evening for FLZ071>074-172>174. AM...None. GM...None. && $$ SHORT TERM...JS LONG TERM....SB AVIATION...JS