Scientific Forecaster Discussion
000 FXUS62 KMFL 281926 AFDMFL Area Forecast Discussion National Weather Service Miami FL 326 PM EDT Wed Jun 28 2017 .DISCUSSION... THIS AFTERNOON AND TONIGHT: Remainder of the afternoon is expected to pan out similarly to yesterday with scattered showers and storms now ongoing along the seabreezes as well as other boundaries across the region. A special 15Z sounding shows that steering flow remains non-existent over the region, so storms that develop will move very little. New development will trend further inland with the seabreezes as we move through the afternoon, though outflow boundaries may initiate additional storms back towards the coasts. Best chances will be late afternoon/early evening with the seabreeze collision over the interior. Lightning will remain the main hazard with storms, though slow storm movement will also bring locally heavy rainfall and boundary collisions may produce stronger storms with gusty winds and small hail. Storms are expected to wind down by midnight, with scattered activity over the open waters overnight occasionally brushing the coasts. THURSDAY: This will be a transitional day, as we lose the influence of the weak front currently across North Central Florida as high pressure begins to build in from the east. The overall drier, and slightly more subsident airmass will keep coverage of showers and storms right around seasonal norms. Isolated showers and storms will likely get going along both seabreezes as they develop and move inland early in the afternoon, with the east coast seabreeze moving more quickly and afternoon coverage generally favoring the western interior. With temps aloft near normal and no significant synoptic features, the biggest hazard with storms will remain lightning. The light southeasterly wind profile is also favorable for waterspout development over the local waters, especially in the morning. FRIDAY THROUGH FOURTH OF JULY HOLIDAY: Somewhat stagnant, and fairly typical summertime pattern will be in place across the region for this weekend through the upcoming holiday. The axis of the western Atlantic ridge, both at the surface and aloft, will extend across the Florida peninsula bringing prevailing easterly flow. Both seabreezes will develop each afternoon, with the Atlantic seabreeze dominating and convection favoring the Gulf coast and western interior. Best rain chances along the east coast will be during the overnights and mornings. Warm and muggy temperatures will continue with highs in the lower 90s, leading to afternoon heat indices around 100F. Overnight lows will be in the mid-upper 70s, with east coast locations potentially remaining above 80F for many nights. && .MARINE...Generally good boating conditions will continue across the local waters into the weekend and early next week. Prevailing winds will generally be southeasterly at 10kts or less, with local sea breezes briefly enhancing winds near the coast to 10-15 knots during the afternoon. Overall coverage of showers and storms will be on the decrease as we go into the weekend, with the best coverage over the open waters during the nights and mornings. Inland waterways, as well as the Gulf coast will see better chances during the afternoons and evenings. Erratic winds and higher seas, along with lightning will be possible in and around thunderstorms. && .AVIATION...Both the Atlantic and Gulf sea breezes have developed and are currently moving across the peninsula around 10 KT. Scattered thunderstorms in the western portion of the east coast metro area may push an outflow boundary or two across the TAF sites, but less than 25 KT. Winds and shower activity should diminish aft 29/0000Z. Light and variable winds are expected tonight with mostly dry conditions. The Gulf and Atlantic sea breezes will push inland again aft 29/1700Z with more shower/storm activity developing inland. && .PRELIMINARY POINT TEMPS/POPS... West Palm Beach 78 91 78 91 / 20 30 20 40 Fort Lauderdale 79 91 79 90 / 20 30 30 30 Miami 79 92 79 90 / 20 30 30 30 Naples 76 91 76 91 / 20 40 40 40 && .MFL WATCHES/WARNINGS/ADVISORIES... FL...None. AM...None. GM...None.