textproduct: Melbourne

KEY MESSAGES

Issued at 255 AM EDT Tue Aug 18 2026

- A Heat Advisory is in effect for all east central Florida counties between 10 AM and 8 PM for peak heat indices of 108F to 112F. Practice heat safety!

- An active weather pattern is forecast through this week, with daily afternoon showers and thunderstorms anticipated across east central Florida.

- Hot conditions will continue over the next couple of days with temperatures trending closer to normal late this week.

DISCUSSION

Issued at 255 AM EDT Tue Aug 18 2026

Today-Tonight...Surface high pressure will remain just south of the Florida peninsula today, allowing for the continued spread southward of a moist air mass. Westerly flow prevails both at the surface and aloft, resulting in a delayed development of the east coast sea breeze. The sea breeze will struggle to push inland, with guidance suggesting it should move just past the I-95 corridor. With the moist air mass overhead causing PWATs to exceed 2" areawide, a return of scattered shower and storm chances is anticipated across east central Florida today, with timing following the diurnal pattern driven by the sea breezes. Activity will increase this afternoon, with westerly flow aloft supporting offshore-moving showers and storms through late afternoon into the evening hours. Sufficient instability from daytime heating and modest low-level lapse rates supporting vertical growth, dry air above 800 mb enhancing downdraft potential, and PWATs exceeding 2" areawide will support isolated strong storm development across the area today. Storm hazards will include frequent lightning strikes, wind gusts of 45 to 55 mph, and heavy downpours with the potential for quick rainfall accumulations of 1-3" in some spots. Minor, localized flooding cannot be ruled out, especially along the coast. There is a low chance for some broad rotation as well along the sea breeze, with a brief funnel cloud or two not able to be fully ruled out. Activity wanes into the evening and overnight hours across the peninsula, with a return of prevailing light westerly flow and mostly dry conditions.

Hot conditions will persist across east central Florida today, with mostly clear skies through the morning hours supporting effective daytime heating. Afternoon highs will continue to climb into the mid 90s areawide, remaining above normal values. Humid conditions in addition to the highs will result in peak heat indices of 108F to 112F, with another Heat Advisory issued across all ten east central Florida counties between 10 AM and 8 PM. Residents and visitors alike are encouraged to practice heat safety, remain adequately hydrated, and avoid spending extended periods of time in the heat. Limited relief overnight from the muggy conditions, with lows only falling into the mid 70s to low 80s.

Wednesday-Monday...An active pattern will continue across east central Florida through this week and into early next week. Mid- level ridging will weaken across the Florida peninsula, with guidance now favoring a mid-level low developing across the Gulf and lifting across north Florida mid to late week. This low would be absorbed by a trough digging southward across the eastern US this weekend. At the surface, this mid-level pattern would support persistent increasing moisture locally, with a series of decaying frontal boundaries anticipated to approach Florida through late this week while broad high pressure remains situated across the Gulf. Locally, west to southwest winds are forecast to continue areawide, with daytime heating supporting the development of the east coast sea breeze each day. The push inland during the afternoon hours will result in winds becoming more south to southeasterly behind it, with westerly winds aloft preventing too much intrusion inland. Combined with the moist air mass in place, a diurnal pattern of showers and storms will persist, with development driven primarily by the sea breezes each day. Rain and storm chances will remain near normal (40-60%) through the period, with storm hazards including lightning strikes, gusty winds, and heavy downpours that have the potential to produce minor, localized flooding in some spots. With steering flow remaining out of the west, activity will push offshore through the afternoon and evening hours each day, with mostly dry conditions anticipated across the peninsula through the overnight hours.

Temperatures are forecast to remain above normal over the next couple of days, though the persistent moist pattern will lead to a trend closer to normal late this week and into the weekend. The heat will still remain a concern through this week as peak heat indices climb well into triple digits, with continued support from guidance that some locations across east central Florida may near and even exceed Heat Advisory thresholds. This will continue to be closely monitored and additional heat products will be issued as needed.

MARINE

Issued at 255 AM EDT Tue Aug 18 2026

The Atlantic ridge axis will remain south of the waters through most of this week, with boating conditions anticipated to remain generally favorable. West to southwest winds each day become more south to southeasterly during the afternoon hours as the east coast sea breeze develops, with wind speeds around 10 knots anticipated. Seas of 1 to 3 feet persist, highest across the offshore waters.

Offshore-moving showers and storms are forecast across the local waters through this week, primarily during the evening hours. Any storms that develop will be capable of producing lightning strikes, wind gusts exceeding 30 knots, heavy downpours, and locally higher seas. Continued isolated development across the Gulf Stream waters during the overnight hours can't be ruled out, but confidence in this remains low.

AVIATION

(06Z TAFs) Issued at 122 AM EDT Tue Aug 18 2026

Continued mainly VFR through the TAF period. Dry conditions and light WRLY winds thru the morning hours. Low-level WRLY flow, again, will keep the ECSB (delayed) pinned near the coast where it is able to develop later this afternoon. Winds becoming E/SE 8-10 kts where sea breeze passes, else WRLY winds 6-10 kts further inland. Higher moisture values continue northward and PoPs will be highest across the I-4 corridor and toward the Volusia/Brevard coasts later in the day/early evening where a sea breeze collision will occur. TEMPO groups later as confidence allows with generally MVFR in storms. Interior terminals will rely on surface heating/WCSB for aftn convective chances. Entrainment of dry air, however, may allow for elevated DCAPE values to be realized in terms of strong (local) wind gusts at the surface in a few storms. Storm motion favors out of the northwest at 10-15 kts. Generally quiet conditions resuming mid/late evening thru the overnight with WRLY winds becoming light.

PRELIMINARY POINT TEMPS/POPS

DAB 94 78 94 77 / 50 20 60 10 MCO 97 79 95 78 / 50 20 60 20 MLB 96 79 94 78 / 50 30 50 10 VRB 95 77 94 76 / 40 30 50 10 LEE 95 79 95 78 / 60 20 60 20 SFB 95 79 95 78 / 60 20 70 20 ORL 96 80 95 78 / 50 20 70 20 FPR 95 77 93 76 / 40 30 50 10

MLB WATCHES/WARNINGS/ADVISORIES

FL...Heat Advisory from 10 AM this morning to 8 PM EDT this evening for FLZ041-044>046-053-058-141-144-154-159-164-247-254-259- 264-347-447-547-647-747.

AM...None.