textproduct: Melbourne

KEY MESSAGES

Issued at 132 PM EDT Sun Sep 13 2026

- A humid and unsettled pattern persists early this week. Scattered afternoon and evening storms are forecast, particularly over the interior. Locally heavy rain and gusty winds to 40-50 mph are expected in the strongest storms.

- Turning windy, especially at the coast, from late Tuesday through Thursday. The risk of hazardous beach and boating conditions has increased on Wednesday and Thursday, including rough surf/seas and a high risk for life-threatening rip currents.

- Heightened rain chances return to coastal communities on Wednesday and Thursday. Repeated bands of rain and storms over saturated spots may lead to localized flooding in urban areas.

DISCUSSION

Issued at 132 PM EDT Sun Sep 13 2026

-----------Synoptic Overview-----------

In the closing days of summer 2026, there are no signs of autumn on the weather charts yet. Above-normal H5 heights continue to sprawl from the Desert Southwest to the western Atlantic. Jet stream energy is relegated to the northern tier of states this afternoon. At the surface, a dissipating cold front is settling over the southern Appalachians, leaving a high-pressure axis from the Bahamas to the northern Gulf. A reservoir of above-normal moisture is still in place over Florida, characterized by PWATs over 2 inches.

South of a mid-level jet streak passing through the Great Lakes, global ensembles develop another impressive anticyclone over the Tennessee Valley by Tuesday and Wednesday. H5 heights may exceed 600 dam near Great Smoky Mountains NP, which is nearly unheard of for mid-September. Its surface high-pressure reflection will tuck beneath it, freshening easterly flow over Florida and the Carolinas. A sharp moisture gradient is likely to exist over Central Florida by Wednesday and Thursday as deep moisture is shunted toward the southern half of the state.

Cluster analysis of the 13/00Z ensemble suite suggests that pattern retrogression will occur late in the week. As the mid-latitude ridge nudges to the west, an upper-level trough is likely to be forced westward beneath it. This feature should reach Florida by late Thursday and Friday. By next weekend, this disturbance is forecast to push into the Gulf and begin to fill. Surface high pressure and onshore flow are both expected to weaken, and moisture values should return to normal over most of the peninsula.

-------Sensible Weather & Impacts-------

This Afternoon - Monday...

An increase in late-day showers and storms appears on track. Background winds are light WNW, which should limit Atlantic breeze progression while a diffuse Gulf breeze propagates toward the eastern half of the state. Hi-res guidance focuses the highest coverage of storms between now and 9 PM along and especially west of I-95 (50-70%), with a potential collision of the sea breezes roughly near a line extending from Palm Coast to DeLand to Lake Okeechobee. Storms diminish by late evening and into the overnight.

On Monday, high pressure lifts northward a bit, allowing a better push of the Atlantic breeze into the interior. Medium-high (50-60%) coverage of late-day storms is again forecast, particularly from Greater Orlando to along the Kissimmee Basin.

Over the next couple of days, Brief gusty winds to around 40-50 mph, frequent lightning, and torrential rainfall will occur beneath the strongest storms. REFS max-member 6-hour rainfall plots suggest a reasonable worst case of 3-4" rainfall amounts, which may cause localized flooding, particularly if it occurs over urban areas.

Hot and humid conditions continue to dominate. Highs reach the low to mid 90s with heat indices as high as around 105 deg F.

Tuesday - Thursday...

Tuesday marks a transition in our weather pattern. As high pressure strengthens to our north, onshore breezes will steadily increase off the Atlantic. This will disrupt robust sea breeze convergence over the peninsula for much of the work week. With deep moisture still in place on Tuesday, another round of scattered storms is forecast (50-70%) with the highest coverage over the interior by afternoon.

By Wednesday and Thursday, much drier air is expected to infiltrate the northern third to half of the state, but ample moisture may not be scoured out in the lowest 10 kft. Therefore, the setup should transition into onshore-moving showers and a few storms. As the upper-level trough approaches the state by late Thursday, coastal moisture convergence may increase. While it's too early to determine, a localized heavy rain threat may develop, especially on the immediate Space and Treasure Coasts.

Breezy conditions develop beginning Tuesday afternoon, becoming windy on Wednesday into at least early Thursday. Gusts may reach up to around 30-35 mph on Wednesday. The fetch of onshore flow is expected to cause rough surf and a high risk of rip currents at Atlantic beaches beginning Tuesday night.

Highs should still reach the low 90s in most locations on Tuesday. The increasing onshore breezes should then cause high temps to trend into the mid-upper 80s on Wednesday and Thursday. Barrier island communities may struggle to fall below 80 degrees at night as the wind carries in warmth from the Atlantic shelf waters and Gulf Stream.

Friday - Next Weekend...

The upper trough is forecast to be overhead on Friday before pushing westward into the Gulf this weekend. As high pressure weakens, onshore flow and coastal convergence will follow suit. That said, seasonable moisture will continue to support at least scattered showers and storms through this period. High temperatures should run very close to normal in the upper 80s and lower 90s.

MARINE

Issued at 132 PM EDT Sun Sep 13 2026

Weak high pressure near the local waters begins to lift northward on Monday, before strengthening as it pushes well north of Florida by the middle of the week. Onshore flow will increase from late Tuesday and especially into Wednesday, becoming fresh to locally strong. Worsening boating conditions are expected, with Small Craft Advisories likely to be needed for the middle of the week.

Winds becoming light offshore tonight, then E 5-10 kt on Monday. Winds turn NE on Tuesday, 10-15 kt, freshening to 15-25 kt from Wednesday through at least early Thursday. Seas up to 3 ft through early Tuesday, then 2-4 ft on Tuesday afternoon. Seas peak late Wednesday and early Thursday from 5-8 ft, highest north of Cape Canaveral and in the Gulf Stream. Short periods will make for very rough conditions during this time! Seas should then decrease on Friday to 2-4 ft by afternoon.

AVIATION

(18Z TAFs) Issued at 132 PM EDT Sun Sep 13 2026

SHRA/TSRA are approaching LEE/MCO/ISM so will adjust TEMPO groups to account for sooner arrival. Sct TSRA translate closer to the coast as the ECSB collides with the eastward-advancing TSRA/outflow. Gusty winds and brief MVFR/IFR reductions are possible. Activity may linger thru 01-02z before dissipating. SW winds light, variable at times overnight and into the day on Mon.

HYDROLOGY

Issued at 132 PM EDT Sun Sep 13 2026

The St Johns River at Astor may reach Action Stage this week. Locally heavy rain is expected in the middle/upper basin early this week, followed by a period of onshore winds over the lower basin and estuary from late Tuesday through at least Thursday.

PRELIMINARY POINT TEMPS/POPS

DAB 75 90 76 89 / 20 30 30 50 MCO 76 94 76 91 / 30 60 20 60 MLB 75 90 77 90 / 20 30 40 50 VRB 73 90 75 89 / 10 30 50 60 LEE 76 93 76 91 / 20 50 10 50 SFB 75 92 76 90 / 20 60 30 50 ORL 77 93 77 90 / 30 60 20 60 FPR 73 90 75 89 / 10 30 50 60

MLB WATCHES/WARNINGS/ADVISORIES

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