Marine Weather and Tide Forecast for Merritt Island, FL

DISCUSSION
Issued at 240 AM EDT Mon Aug 17 2026

Today-Tonight...Broad mid-level ridging persists across the area while at the surface, the Atlantic ridge axis drifts southwards as a weakening frontal boundary sags south across the southeastern US. Locally, this will result in weak offshore flow both at the surface and aloft, though the development of the east coast sea breeze later this afternoon will result in winds along the coast becoming more south to southeasterly. A sharp gradient of moisture is forecast across the area today, with moisture out ahead of the frontal boundary pushing towards northern portions of the forecast area while drier air remains in place southward. This will result in better rain chances from Kissimmee to Cape Canaveral and areas northward with PoPs ranging from 20-50%. Storm development will be possible today with this activity thanks to sufficient daytime heating, modest low-level lapse rates, and dry air aloft supporting greater downdraft potential. Storm hazards today will include wind gusts up to 55 mph, frequent lightning strikes, and heavy downpours. Westerly flow aloft will keep activity pushing eastward through today, with showers and storms eventually moving offshore through the evening and overnight hours. Drier conditions are forecast overnight with a return to the prevailing light westerly flow areawide.

Afternoon temperatures will continue to climb into the mid to upper 90s across east central Florida, with showers and storms up north providing some relief from the heat late afternoon and into this evening. Regardless, the heat continues to be a concern as peak heat indices reach well into the triple digits, with yet another Heat Advisory in effect for all ten east central Florida counties between 10 AM and 8 PM. Adequate hydration and breaks in the shade or an air conditioned building will be crucial for those spending extended periods of time outdoors. Residents and visitors alike are encouraged to practice heat safety to help avoid developing heat illness. Muggy conditions continue through the overnight hours will temperatures only falling into the mid 70s to low 80s.

Tuesday-Sunday...The mid-level ridging will continue to broaden through this week as a series of shortwaves travels around the base of a trough situated across the eastern US. The trough is then forecast to deepen and expand farther south towards this weekend. At the surface, the Atlantic ridge axis will remain well south of the Florida peninsula, maintaining persistent offshore flow locally through this week. A return of diurnally-driven showers and storms is anticipated across east central Florida as the plume of moisture expands southwards and keeps the area within a moist airmass through this week. Rain chances return closer to normal values, with PoPs ranging between 40-60% each afternoon.
Any storms that manage to develop will be capable of producing lightning, gusty winds, and heavy downpours, with activity forecast to push offshore due to the persistent westerly flow.
Temperatures and the heat will also remain a focus through this week, with hot conditions persisting through at least Wednesday.
Additional Heat Advisories for portions of the area cannot be ruled out. Towards the end of this week, thanks to the greater rain chances and moisture, temperatures are anticipated to trend slightly closer towards normal.

MARINE
Issued at 240 AM EDT Mon Aug 17 2026

The Atlantic ridge axis slowly shifts southward today and through the rest of this week, with an approaching frontal boundary bringing increasing moisture locally as it stalls and washes out across north Florida. Offshore-moving shower and storm chances increase starting today north of Cape Canaveral but will expand to include all of the waters from Tuesday onward. Storms will be capable of producing lightning strikes, wind gusts in excess of 30 knots, heavy downpours, and locally higher seas. Outside of showers and storms, generally favorable boating conditions are anticipated through this week. West to southwest winds of 5 to 10 knots will persist, becoming more south to southeast each afternoon as the east coast sea breeze develops. Seas remain between 1 to 2 feet, with occasional 3 foot seas across the offshore waters.

AVIATION
(12Z TAFs)
Issued at 630 AM EDT Mon Aug 17 2026

Continued mainly VFR through the TAF period. Dry conditions and light WRLY winds thru the morning hours. Low-level flow a bit stronger WRLY than the previous day and expect the ECSB could be delayed (esp TIX north) on top of not making it toward the interior terminals today. Winds becoming E/SE 8-10 mph where sea breeze passes, else 6-10 mph further west (inland). Higher moisture values northward, thus only have VCTS mention near MLB northward this afternoon/early eve as some CAMs showing a few lightning storms this far south. Potential TEMPO groups later as confidence allows with MVFR in storms. Interior terminals will rely on surface heating/WCSB for aftn convective chances. Boundary collisions early this evening across the eastern peninsula closer toward the coast. Still mainly lower than normal TSRA/SHRA chances overall. Generally quiet conditions resuming mid/late evening thru the overnight.

CLIMATE
Issued at 240 AM EDT Mon Aug 17 2026

Record high temperatures at local climate sites today:

Site Aug 17 Daytona 96 (1990)
Leesburg 98 (2005)
Sanford 97 (2005)
Orlando 99 (1929)
Melbourne 97 (2022)
Vero Beach 98 (2022)
Fort Pierce 97 (2022)

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

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.