Area Forecast Discussion
Issued by NWS Melbourne, FL
Issued by NWS Melbourne, FL
014 FXUS62 KMLB 050908 AFDMLB Area Forecast Discussion National Weather Service Melbourne FL 508 AM EDT Sun May 5 2024 .DISCUSSION... Issued at 506 AM EDT Sun May 5 2024 Key Messages: -Isolated to Scattered Showers and Lightning Storms Possible This Afternoon and Evening, One or Two Could Become Strong. -Early season heat wave mid to late next week with highs well into the 90s. Today-Tonight...A series of mid-level shortwave troughs and ridges cycle over Florida through the broad ridging pattern along eastern seaboard and adjacent Atlantic waters, with the trough currently overhead ejecting the the northeast later this evening. At the surface, attendant high pressure to the ridging over the Atlantic seaboard continues to build, and also get reinforced by high pressure over the eastern US. Relatively high moisture (PWATs 1.4- 1.6" around 75-90th climatological percentile) plus the energy aloft will support scattered showers and lightning storms today (i.e. higher coverage than yesterday). Onshore moving showers will be possible through the morning (20 pct PoPs), then rain chances shift inland with daytime heating and the sea breeze (30-50 pct PoPs). Most CAMs clustering towards majority of convection developing well inland, but the ARW is a little more aggressive starting showers by late morning closer to the coast, and was a little closer to how yesterday panned out. Given that, have PoPs 20 pct from the coast to just west of I-95, increasing inland through the afternoon to 40-50 pct across the interior between 5 PM and 8 PM, including the Orlando Metro Area. Most locations clear out by 8 PM, but a few showers and lightning storms could linger from near Leesburg to Clermont, and maybe even Kissimmee until around 10 PM. 500mb temperatures will have warmed a bit to around -9C as the shortwave starts to eject, but the higher moisture near the surface should make up for it, with the RAP and NAM 3km calling for SBCAPE 1,000-1,500 J/kg early in the afternoon, potentially peaking as high as 2,000 J/kg in the late afternoon and evening. A little bit of variability in DCAPE, but general consensus seems to be 600-900 J/kg. Overall, the environment looks supportive of a few stronger lightning storms, capable of gusty winds around 40 mph, frequent cloud to ground lightning, and locally heavy downpours that could deliver a quick 1-2" of rain. Steering flow is virtually non- existent, so while convection will progress westward/inland with the sea breeze, individual storm motion will be slow and erratic again, potentially leading to minor flooding if a storm becomes stationary. As for the rest of the forecast, warm again inland with highs in the U80s-90. Near the coast highs will be closer to normal in the M80s thanks to the onshore flow and sea breeze, but a degree or two warmer than the last couple days as flow becomes more southeasterly (more parts of the barrier islands could reach the M80s). Generally southeasterly winds 5-10 mph in the morning pick up to around 10 mph inland and 10-15 mph with gusts as high as 25 mph along the coast in the afternoon behind the sea breeze, under partly cloudy skies, then settle back down to 5-10 mph overnight as skies clear. Overnight lows in the M60 in the cooler inland spots, otherwise in the U60- L70s. Mon...Low level high pressure ridge will settle south across north FL maintaining a SE wind flow. Some drier air is forecast to move in across southern sections around the southern periphery of the ridge but sufficient moisture across the north should generate isolated to scattered showers/storms late in the day assocd with a sea breeze collision roughly over Lake county. Highs ranging from the mid 80s along the coast with a warming trend continuing over the interior, reaching near 90/lower 90s. Tue-Sat...A mid-level (500 mb) ridge builds over the FL peninsula and the resulting subsidence will increase the hot and dry conditions. Temperatures warming through the period reaching the mid 90s as early as Tue across the interior becoming widespread mid 90s Thu and Fri. Along the immediate coast (barrier islands), daily sea breezes will hold max temps to the mid 80s Tue, then upper 80s Wed-Fri. But inland portions of the coastal counties (west of I-95) will reach the low 90s. Fri continues to look like the hottest day as the ridge axis slips farther south and resulting breezy/gusty offshore (SW) flow causes a much delayed sea breeze. This should allow max temps to reach the low 90s even at the coast and possibly mid 90s if the sea breeze does not develop at all. Model guidance shows a frontal passage Sat bringing a 20-30 percent chance of showers and storms and lower temps esp across the north in the mid to upper 80s. Still hot across the south though with low to mid 90s. Although dewpoints and humidities will not be oppressive due to drier air, wet bulb globe temps indicate a Moderate to High heat risk. && .AVIATION... (06Z TAFs) Issued at 506 AM EDT Sun May 5 2024 Generally VFR conditions through the TAF period, with summer-like diurnal SH/TS impacts possible at ECFL terminals. Chances for onshore moving SH INVOF the coastal terminals sufficient for VCSH from 10Z-11Z (14Z for KDAB) until 18-19Z when the ECSB pushes well inland and subsidence behind the circulation limits SH chances. ISO SH possible inland ahead of ECSB, so have VCSH starting at KMCO/KSFB/KISM 16Z, then SH/TS becoming ISO-SCT as the ECSB pushes through. VCTS at inland terminals starting 18Z-19Z running through 22Z-23Z at KMCO/KSFB/KISM, and 04Z at KLEE due ECSB/WCSB collision just to the west. Coverage too low for TEMPOs, except perhaps KLEE. Will reevaluate at 06Z package. Winds SE 5-10 kts pick up to 10-15 kts with gusts to 20 kts in the afternoon behind the ECSB. && .MARINE... Issued at 506 AM EDT Sun May 5 2024 Today-Tonight...High pressure building along the eastern seaboard is reinforced by another area of high pressure over the eastern US. Winds and seas remain favorable for boating, but isolated to scattered lightning storms, especially those over the inland lakes in the afternoon and evening, could produce wind gusts to 35 kts and occasional to frequent cloud to water lightning. While convective development will progress inland along the sea breeze, individual storm motion will be slow and erratic. Outside of storms, winds generally SSE-SE 10-15 kts back a bit to SE-ESE in the afternoon after the sea breeze develops, then settle back to the SSE-SE late tonight. Seas 2-3 ft. Mon-Thu...Overall favorable boating conditions expected with surface ridge axis gradually slipping south across the waters. This will promote a SE wind flow to start, veering S then SW as the ridge axis reaches S FL Thu. Daily sea breezes of SE 10-15 knots will develop near the coast each aftn but onset will become gradually delayed each day due to increasing offshore flow. Winds will veer south Mon night, and S to SW Tue-Wed nights as the sea breeze circulation diminishes. Seas of 2-3 ft persist through the period, building to 4 feet offshore Wed night as pressure gradient should support 15-20 knots. && .FIRE WEATHER... Issued at 506 AM EDT Sun May 5 2024 Increasing heat and slightly drier conditions this week will produce min RH values falling to 30-35% for much of the interior by mid-week. ISOLD lightning storms will be possible this evening inland and again on Mon over the interior late day/early evening. Isold showers near the coast in the mornings but widespread wetting rainfall is not forecast through the next 7 days, so further fuel drying is expected. Temperatures will gradually warm each day, reaching the mid 90s across the interior by Wed and continue Thu. && .PRELIMINARY POINT TEMPS/POPS... DAB 86 68 86 68 / 20 10 20 10 MCO 89 69 90 69 / 40 20 30 10 MLB 85 70 85 69 / 20 10 10 10 VRB 86 68 86 67 / 20 10 10 10 LEE 89 70 90 70 / 50 40 30 10 SFB 89 68 90 69 / 40 10 20 10 ORL 89 70 90 69 / 40 20 30 10 FPR 86 68 85 66 / 20 10 10 10 && .MLB WATCHES/WARNINGS/ADVISORIES... FL...None. AM...None. && $$ SHORT TERM...Haley LONG TERM...Kelly AVIATION...Haley