Area Forecast Discussion
Issued by NWS Melbourne, FL
Issued by NWS Melbourne, FL
466 FXUS62 KMLB 161425 AFDMLB Area Forecast Discussion National Weather Service Melbourne FL 1025 AM EDT Thu May 16 2024 .UPDATE... Issued at 1015 AM EDT Thu May 16 2024 Weak frontal boundary has sagged into central FL and will become stationary across southern sections this afternoon. GOES-16 Total Precip water product shows much drier air has filtered in across northern sections with a band of much higher PWAT across southern FA. Northern sections will experience lower dewpoints/humidity and mostly sunny skies with max temps in the low to mid 90s. Higher moisture across the south will promote scattered to showers and storms this afternoon streaming west to east, primarily affecting Martin/St Lucie counties. Expect a sea breeze to develop this afternoon which will add low level convergence to an already unstable mid levels characterized by steep lapse rates. Expect an increase in convective coverage and intensity this afternoon into the early eve. Isolated strong to severe storms with hail and strong wind gusts will be possible over Okeechobee, St Lucie and Martin counties. The sea breeze will provide locally enhanced helicity in the low levels so a brief tornado/waterspout will be possible in storms along or behind the sea breeze. && .AVIATION... (12Z TAFs) Issued at 1015 AM EDT Thu May 16 2024 A weak frontal boundary will become stationary across central FL this aftn and tonight. Drier air and clearing sky conditions at DAB/LEE/SFB/MCO but scattered SHRA/TSRA will stream eastward and affect SUA/FPR and possibly VRB. Utilizing VC term there but TEMPOs for MVFR/IFR TSRA will be possible later in the day. West wind 10-15 knots will dominate then a wind shift out of the E/SE should occur at coastal terminals (MLB-SUA) aft 18Z. Model trends will be monitored for patchy fog development early Fri morning. && .PREVIOUS DISCUSSION... Issued at 400 AM EDT Thu May 16 2024 Today-Tonight...Activity on radar this morning is largely confined to the adjacent Atlantic waters, where isolated showers and a few storms have developed. Across east-central Florida, mostly dry conditions are present with temperatures in the mid to upper 70s. A weak cold front is now bisecting the area and will continue to meander south toward Lake Okeechobee and the Treasure Coast by this afternoon. North of the front, dry air will be pushing in from the north. It is along and south of the front where the highest rain chances will exist (30-50 PoP), especially this afternoon, along with the chance for a few lightning storms. Some of the high resolution CAMs are lackluster in relation to convective activity later today. Thus, NBM guidance was regarded as too aggressive and high chance PoPs across the Treasure Coast seemed most reasonable for today. With that said, any storm that becomes established will have the potential to produce gusty winds and small hail. The Storm Prediction Center has placed areas near and south of Fort Pierce to Okeechobee under a Marginal Risk for severe storms today. Sky conditions will gradually clear out from north to south behind the front, allowing locations around the Orlando metro and points north to warm into the low 90s. A handful of suburban/urban sites here may even reach the mid 90s by mid to late afternoon. Farther south, remaining clouds and rain chances will keep temperatures in the upper 80s to around 90 degrees. Winds become light and variable tonight, and there are subtle hints in the guidance for some overnight fog into Friday morning. However, more confidence will be needed to add fog into the forecast, so model trends will be monitored through the day. Temperatures late tonight are forecast to fall toward normal mid-May values, into the mid to upper 60s. Friday-Saturday...Low pressure remains in place offshore the mid Atlantic/ northeast coast Friday and Saturday. An associated moisture boundary stretches from the western Atlantic into the northern Gulf, draped across the southern peninsula Friday morning. The boundary gradually lifts northward through the day Friday, washing out as high pressure builds at the surface and aloft. A late afternoon sea breeze collision could support isolated showers and lightning storms on Friday with PoPs only ranging 10-20 percent. Uncertainty exists in the PoP forecast Saturday due to model disagreements in available moisture. The GFS (PWAT ~ 1.6) promotes a drier solution compared to the ECMWF (PWAT ~ 1.9). The current forecast follows closer to a GFS solution and has nudged PoPs down slightly, now ranging 30-40 percent on Saturday. Dry air aloft due to ridging should limit convective growth, keeping any developing activity shallow. Temperatures are forecast above seasonal values through the end of the week. Highs range the low 90s along the immediate coast on Friday, warming into the mid 90s across the interior. A few upper 90s cannot be ruled out in vicinity of Lake Okeechobee. Temperatures warm a degree or two into Saturday. Sunday-Thursday...Mid level troughing and its associated surface feature dig across the southeast U.S. early next week, moving into the western Atlantic. Moisture increases ahead of a cold front passage Sunday night into Monday. Coverage of showers and storms builds on Sunday ahead of the cold front with PoPs increasing to around 60 percent across much of east central Florida. Chances for showers and storms then gradually dwindle each day with only an isolated mention Wednesday and Thursday. Afternoon temperatures are forecast to range the low to mid 90s Sunday and Monday, falling to range the upper 80s to low 90s Tuesday. Highs widely range the 90s again by Thursday. && .MARINE... Issued at 400 AM EDT Thu May 16 2024 Today-Tonight...Favorable boating conditions are forecast outside of scattered showers and lightning storms. A frontal boundary draped across the Atlantic will sink south of Sebastian Inlet later this afternoon, confining higher rain chances to the adjacent Treasure Coast waters. West-northwest winds 10-15 kt decrease and turn out of the east-southeast late afternoon and early evening. Seas 2-3 ft this morning, becoming 1-2 ft this afternoon and evening. Friday-Monday...Coverage of showers and lightning storms increases into the weekend as a cold front approaches the waters on Sunday. Southerly winds around 10-15 kts veer southwest Saturday night, becoming northerly on Monday behind the cold front. Seas of 2-3 ft increase to 4-5 ft offshore Sunday night. && .FIRE WEATHER... Issued at 400 AM EDT Thu May 16 2024 Today...Drier air is forecast to move into northern and interior portions of east central Florida later today. As a result, relative humidity values may fall into the mid to upper 30s. West-northwest winds will remain around or below 10 mph for a majority of the afternoon. Additional fire starts cannot be ruled out from Okeechobee to the Treasure Coast due to a chance for lightning storms. Extended...Moisture and storm chances build into the weekend as a cold front approaches east central Florida on Sunday. Min RH values ranging the upper 30s to low 40s across the interior increase into the upper 40s to mid 50s ahead of the front. Drier air builds early next week, returning interior RHs to the low to mid 40s. Light southwest flow backs south-southeast as the east coast sea breeze develops Friday and Saturday. Winds increase to 10-15 mph on Sunday, veering north-northeast into Monday. && .PRELIMINARY POINT TEMPS/POPS... DAB 90 68 91 73 / 0 0 10 0 MCO 92 69 95 75 / 0 0 20 0 MLB 90 69 91 74 / 10 0 20 10 VRB 91 70 93 73 / 30 0 20 10 LEE 91 70 94 75 / 0 0 10 0 SFB 93 69 95 74 / 0 0 10 0 ORL 92 70 95 75 / 0 0 20 0 FPR 91 69 93 73 / 40 10 20 10 && .MLB WATCHES/WARNINGS/ADVISORIES... FL...None. AM...None. && $$ UPDATE...Kelly