textproduct: Melbourne

KEY MESSAGES

Issued at 303 AM EDT Tue Jun 23 2026

- Lower than normal rain chances today, but storms that manage for form could produce strong to locally damaging winds, small hail, and torrential downpours.

- Above normal heat today with high temperatures in the mid to upper 90s resulting in peak afternoon heat indices 103-107 and widespread Major HeatRisk impacts.

- Confidence in rain chances and heat impacts Wednesday and Thursday are lower than normal, and residents and visitors should monitor the forecast for changes. Regardless, heat and rain are expected to return going into the weekend and next week.

DISCUSSION

Issued at 303 AM EDT Tue Jun 23 2026

Today-Tonight...Troughing builds over the eastern US in response to a ridge over the Desert Southwest. Guidance now favors the upper level pattern becoming more amplified than previously forecast, with the base of the trough now dropping into North to possibly Central Florida, shunting weak riding over Florida south and east. At the surface, the ridge axis from the Atlantic high is pushed further south towards the Straits of Florida by the trough aloft and an associated surface front, now forecast to drop near North Florida tonight. A slight tightening of the pressure gradient is expected to enhance the offshore (WSW-SW) flow a bit to around 10 mph in the afternoon, slowing inland progression of the east coast sea breeze, which could end up pinned near the coast north of the Cape. Drier air filtering across central Florida knocks rain chances down to just 20% near the coast from the Cape north where the sea breezes may be able to get a shower or storm going, up to 20-40% to the south where higher moisture resides, with the highest chances focused on the sea breeze collision over the interior in the late afternoon and evening. The trough pushing south farther and faster cools the mid-level (T500 M9-M8C), marginally increasing instability (MUCAPE 2,000-3,000 J/kg), and offering a better environment for hail growth. Low- level lapse rates remain steep (7-9 C/km) and mid-level lapse rates have improved from previous days (6-7 C/km). Shear remains non-existent (20 kts or less) favoring a pulse storm mode. While dry air aloft could enhance downdrafts (800-1,100 J/kg), it will also cause significant entertainment and be a hurdle for deep convection. Overall, there is a conditional threat for storms that manage to develop to become strong to marginally severe, capable of wind gusts 40-55 mph and isolated damaging gusts to 60 mph (less than 5% chance), hail up to 1", frequent to excessive lightning, and torrential downpours. Storm motion could again become slow/erratic due to light steering winds and chaotic boundary interactions, and storms/heavy showers that become stationary could deliver a quick 2-3" of rainfall leading to minor flooding of low-lying and poor drainage areas. With all the boundary interactions, a brief funnel cloud or waterspout can't be ruled out.

Above normal heat with high temperatures in the M-U90s combined with humidity will result in peak afternoon heat indices 103-107, and widespread Major HeatRisk impacts. Coastal areas where the sea breeze is slow or fails to develop will be subjected to more prolonged heat impacts. There is potential for settling of smoke on portions of Highway 520 in rural Orange County near Nova Road tonight into early morning that could reduce visibility. Chances for fog development elsewhere has dropped to 20% or less, and only very patchy fog was seen Monday morning, thus fog has not been mentioned in the official forecast.

Wednesday-Thursday...The base of the aforementioned trough aloft drops down most if not all the Florida peninsula Wednesday, pushing a weakening surface front into Florida. Model agreement is improving and moving towards the GFS/ECM-AIFS solutions, which call for the front and very dry air to drop into North Florida and towards Central Florida. PWATS Wednesday are forecast to drop as low as 1.4" (0.5" below normal) to the north, with GFS soundings very dry from 850-300mb, nearly a death sentence for deep convection. To the south, PWATs remain around 1.8" (near normal), but soundings show considerable dry air persisting between 850-600mb which will be a hurdle for deep convection. Even drier conditions are forecast Thursday, with PWATs potentially crashing to 1.1-1.5" across the north and 1.5-1.8" across the south. Have knocked back rain chances both days a fair amount to 30-50% Wednesday and 20-50% Thursday, but don't want to over correct as CAMs are still calling for scattered to numerous showers and storms, but they may need a cycle or two to catch up. If the current model trends hold rain chances could come down a few more points in the next couple forecast cycles. Not enough confidence in the storm environment for a detailed assessment, but at the moment there is again conditional potential for storms that manage to develop to again become strong. Cloud cover associated with the trough knocks high temperatures back a couple degrees to the L-M90s, resulting in peak afternoon heat indices 100-106, and Moderate to Major HeatRisk impacts.

Friday-Monday...A trough moving into the Pacific Northwest flattens the ridge over the Desert Southwest across Mexico, Texas, and towards the Gulf, causing the ridge over the eastern US to retreat north as an additional weak upper level ridge slides over Florida from the Atlantic. The front lifts back north as the associated low pressure system ejects, and the ridge axis of the Atlantic high slides north towards Central Florida. Flow generally remains light offshore, but could be more southerly at times, allowing the east coast sea breeze to push further inland and a collision over the interior. Moisture quickly recovers, and near to slightly above normal rain chances forecast, with the highest chances focused over the interior in the late afternoon-evening on the sea breeze collision. Above normal heat continues, especially early next week when dangerous heat may make a return.

MARINE

Issued at 303 AM EDT Tue Jun 23 2026

Today-Saturday...Generally favorable albeit hot boating conditions through the week and into the weekend as the Atlantic high weakly extends towards Florida. A weakening front that may drop near to into Central Florida will keep the surface ridge axis suppressed over South Florida to the Straits of Florida through Thursday, continuing offshore (WSW-SW) flow. The front departs and the ridge lifts north towards Central Florida Friday into the weekend, shifting flow more southerly at times but generally remaining offshore. Winds back onshore (SE-E) from the afternoons into the early overnights as the east coast sea breeze develops, which will be able to gradually push farther inland each day as offshore flow weakens. Wind speeds 5-15 kts, occasionally pushing over 15 kts offshore in the overnights. Seas 1-2 ft. Most showers and lightning storms expected to stay inland, but a few could move offshore in the evenings, and isolated overnight showers and storms can't be ruled out.

AVIATION

(06Z TAFs) Issued at 154 AM EDT Tue Jun 23 2026

VFR conditions forecast through much of today into tonight. Below normal rain chances again expected today (~20-30%). Greatest potential for convection and brief IFR/MVFR conditions in isolated to scattered showers/storms will be southeast of the I-4 corridor from mid afternoon through early evening. Have kept PROB30 groups for MVFR TSRA impacts at KMLB-KSUA. Have also added VCTS for KMCO/KISM as hi-res guidance is indicating some isolated storm activity developing just east of the terminals between 21-01Z. Farther north of KMCO, rain chances look even more limited.

Low level offshore flow strengthens slightly today with W/SW winds at the sfc increasing to 5-10 knots. Strongest winds will be across northern portions of east central FL, which will likely pin the east coast sea breeze right at the coast north of KMLB. From KMLB south, the east coast sea breeze will push far enough inland to switch winds the E/SE around 10 knots.

PRELIMINARY POINT TEMPS/POPS

DAB 95 76 91 74 / 20 20 40 20 MCO 97 77 93 76 / 20 20 50 20 MLB 93 76 91 76 / 30 30 40 40 VRB 94 76 93 75 / 30 30 30 40 LEE 95 77 93 76 / 0 30 30 10 SFB 97 77 93 75 / 20 20 50 20 ORL 97 78 93 76 / 10 10 50 20 FPR 94 75 93 75 / 30 30 30 40

MLB WATCHES/WARNINGS/ADVISORIES

FL...None. AM...None.