Area Forecast Discussion
Issued by NWS Melbourne, FL
Issued by NWS Melbourne, FL
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802 FXUS62 KMLB 220153 AFDMLB Area Forecast Discussion National Weather Service Melbourne FL 953 PM EDT Fri Jun 21 2024 ...New UPDATE, MARINE... .UPDATE... (Through Saturday) Issued at 953 PM EDT Fri Jun 21 2024 KEY MESSAGES: - Rich tropical moisture remains overhead through the weekend, sparking scattered to numerous (50-70%) showers and storms, especially in the afternoon and evening hours. There is a Marginal Risk for locally excessive rainfall. - High temperatures ranging from 88-94F, yielding max heat indices of 100-107F this weekend. - Scattered to numerous showers and storms (50-70%) are also expected early to mid next week. Tonight... Downpours are still percolating out there this evening, particularly in a zone from Tampa Bay to Daytona Beach, clipping the western Orlando suburbs. This is near a surface trough axis emanating from weak low pressure just NE of Jacksonville (Invest 92L). Deep moisture convergence is occurring in an uncapped environment with PW`s ~ 2.25". Guidance isn`t handling this activity particularly well, but the trend should be for lessening coverage overnight. However, localized pockets of heavy rain and isolated lightning strikes are possible in this area through around midnight. South of Orlando to Titusville, shower chances are quite low (20%) through the night. Overnight low temps will remain balmy, in the mid 70s. Saturday... Mid-level ridging over the ArkLaTex will act to hold this axis of deeper moisture over the state through the weekend. Only isolated morning showers are expected, however the latest HREF guidance remains bullish on sea-breeze driven showers and storms over the interior by afternoon and early evening. Tall, skinny CAPE profiles and warm cloud depths to above 16 KFT will support very efficient rain processes. Localized flooding of poor-draining and urban areas is possible where storms recur. A marginal risk (5%) of excessive rainfall is in place for the interior, and HREF members indicate a 20-40% chance of 2"+ / 6HR rain potential. This includes the Greater Orlando area. Storm chances range from 70% from Lake/Orange Co`s south to Lake O, decreasing to around 50% along the coast. Before the storms pop, highs will reach the 89-94F range, hottest near Greater Orlando to Clermont where heat indices from 102-107F are expected due to the intense humidity. While just below our "Heat Advisory" criteria, folks working or enjoying the day outdoors should seek frequent water breaks in the shade. && .MARINE... Issued at 953 PM EDT Fri Jun 21 2024 Overnight... Showers are ongoing to the north of Cape Canaveral, and this trend should continue over the next few hours as we reside just south of weak low pressure. Winds will remain SE from 8-15 KT, with seas 3-4 FT nearshore, 4-5 FT in the Gulf Stream. Sat-Tue (previous discussion)... Improving boating conditions this weekend into early next week, with south to southeast winds remaining under 15 kts this weekend, then veering more SW early next week. A sea breeze near the coast should develop each aftn, however. Seas 3-4 ft becoming 2-3 ft through the period. Greater daily shower and thunderstorm coverage is expected, especially early next week, with increasing chances for offshore- moving convection each afternoon and evening. && .PREVIOUS DISCUSSION... (Sunday-Thursday) Issued at 334 PM EDT Fri Jun 21 2024 Patchy fog is forecast Sunday morning mainly between 5am and 8am. Patchy ground fog will have the potential to reduce visibility to a half mile or less at times mainly over the Treasure Coast before dissipating into the mid morning hours. Upper level ridging stays in place across the southern tier of the U.S., weakly influencing the overall pattern here in Florida. H500 falls across the southeast and Mid Atlantic are expected Sunday into Monday as a low pressure system moves across the Great Lakes region. Surface flow will remain southerly, backing southeast during the afternoon as the sea breeze forms. Light flow becomes increasingly SSW through midweek next week. With PW around 2"+ through much of this period, expect at least scattered to perhaps numerous showers and storms each afternoon and evening as sea breeze and storm-scale boundary collisions occur over the peninsula. PoPs go up to 60-70 percent later in the weekend and next week. The NBM remains too high with PoPs (a common bias at least here in FL) so we continue to cap forecast values. Regardless, this stretch of days could provide some additional much needed rain for parts of the area. Temperatures through the extended stay warm, generally in the low 90s. Heat indices approach 100-107 Sunday and then the 102-110 range Monday and into midweek. Nighttime temperatures will stay in the mid to upper 70s. && .AVIATION... (00Z TAFs) Issued at 645 PM EDT Fri Jun 21 2024 VFR conditions expected outside of showers/storms. Showers near the Orlando terminals slowly diminish through this evening, with rain chances around 20% overnight through the morning hours. Plentiful moisture and a return to a more typical sea breeze circulation should promote another round of storms, most prevalent near and west of MCO, tomorrow afternoon. This necessitates TS TEMPOs for a few of our inland terminals after 22/19-20Z. && .PRELIMINARY POINT TEMPS/POPS... DAB 76 90 74 91 / 50 60 50 70 MCO 76 92 75 91 / 30 70 50 70 MLB 77 89 75 89 / 20 50 30 60 VRB 77 90 75 90 / 20 50 30 50 LEE 77 93 76 92 / 40 70 60 70 SFB 76 92 75 92 / 40 60 50 70 ORL 77 92 76 92 / 30 70 50 70 FPR 76 90 74 90 / 20 50 30 50 && .MLB WATCHES/WARNINGS/ADVISORIES... FL...None. AM...None. && $$ UPDATE...Heil AVIATION...Heil