textproduct: Melbourne

KEY MESSAGES

Issued at 250 PM EDT Thu Sep 3 2026

- Locally heavy to excessive rainfall leading to flooding issues will be the main threat from storms this afternoon and early evening. Other storm threats will be gusty winds to around 40 mph and occasional to frequent cloud to ground lightning.

- A wet weather pattern will persist across East Central Florida into the weekend. The main storm hazard through late week will continue to be the potential for locally heavy rainfall that could lead to mostly minor flooding.

- Muggy conditions and seasonably hot temperatures in the upper 80s to low 90s will continue the next couple days, then temperatures increase a couple degrees going into the weekend. Peak afternoon heat indices remain in the triple digits.

DISCUSSION

Issued at 250 PM EDT Thu Sep 3 2026

Currently-Tonight...Showers and storms have been developing near to south of a line from Orlando to Melbourne along the east coast sea breeze and a differential heating boundary created from debris cloud cover over northern portions of east central FL. Showers and storms will continue to increase, especially from near the Orlando metro area southward through Osceola, Okeechobee counties and the Treasure Coast from outflow collisions and the advancing east coast sea breeze. 10Z sounding at the Cape this morning showed a very saturated airmass, with a PW value of 2.5" (a record for the day based off SPC sounding climatology), as well as warm temps aloft (around -4C at 500mb). DCAPE also remains rather low (around 400-500 J/kg) on SPC Mesoscale Analysis. Therefore threat for any stronger wind gusts remains low, but gusts up to 30 to 40 mph and occasional to frequent lightning will still occur. The deep tropical moisture in place will keep locally heavy to excessive rainfall the main threat from storms or heavier showers today. Quick rainfall accumulations of 1-3 inches will be very easy to occur from any storms through this afternoon/evening, leading to mostly minor flooding of roadways and poor drainage areas. However, there remains a low (5-10% chance) for totals of 4+ inches, which may lead to isolated instances of flash flooding. A Marginal Risk for Excessive Rainfall (Level 1 of 4) remains in place across east central Florida for today.

Convection should begin to diminish past sunset with the loss of daytime heating, but a few storms with lingering areas of debris cloud cover rainfall may persist through the evening hours. Drier conditions expected overnight, with low level flow becoming more southerly, which should keep most convection that develops over the waters offshore. Warm and very muggy overnight, with lows in the mid to upper 70s for most locations.

Friday-Saturday...PW values forecast to actually decrease some, but still remain high around 2.0-2.2" through late week and into early weekend, as ridge axis of high pressure across the west Atlantic settles southward across the area. With the continued moist airmass in place and weak steering flow, locally heavy rainfall around 2-4" and mostly minor flooding will continue to be a threat from slow moving or persistent storms and heavier showers. The Weather Prediction Center maintains a Marginal (level 1 of 4) Risk for excessive rainfall through at least Friday. Scattered to numerous showers and storms will develop each day, with increasing coverage from late morning into the afternoon. Low level flow will become more southerly Friday, with boundary collisions favored well inland. Flow then turns south-southwesterly Saturday, shifting the sea breeze collision a little farther east across east central Florida. Rain chances range from 50-70 percent, with highest chances across the interior tomorrow and 70 percent areawide on Saturday. Temperatures increase a tad, but still near to just slightly above normal, with highs in the low 90s and some mid 90s possible across the interior. Peak heat index values will reach 100-107F ahead of any storms. Overnight conditions will remain warm and humid with lows in the 70s.

Sunday-Wednesday...(Previous Discussion) The trough over the eastern seaboard and western Atlantic is forecast to reach just offshore the Southeast seaboard Sunday or so, ushering a weakening front into the Deep South, and possibly reaching Florida Monday or Tuesday. There remains some uncertainty how far south the boundary will make it, and more uncertainty where weak disturbances may develop on the boundary as it stalls. Both impact whether East Central Florida remains in the subtropical soup or if some drier air will finally reach the area, what kinda of support there is for convection, and what flow regime we end up in. Given the uncertainty the official forecast trends towards the ensembles and blends, which call for broad stroked rain chances to remain above normal, but do decrease a bit towards mid-next week. Seasonable temperatures stay on the hotter side through the weekend, then tick down a degree or two for the work week.

MARINE

Issued at 250 PM EDT Thu Sep 3 2026

Tonight-Tuesday...Main hazard for boaters will continue to be above normal coverage of showers and storms, especially during the overnight and morning hours. However, a weak W/SW steering flow may allow for some offshore moving storms in the afternoon and evening from Friday and into the weekend. Otherwise, boating conditions are forecast to remain mostly favorable.

Ridge axis of high pressure over the west Atlantic, currently north of the area, will shift gradually south across the waters through Saturday, and then will shift south of the area by late weekend into early next week. Winds are forecast out of the S/SE through Saturday, before becoming offshore Sunday into Monday. However, the east coast sea breeze will still form into the afternoon on both of these days, with winds turning onshore behind this boundary into the afternoon/evening. A relatively light predominant onshore flow looks to then redevelop into Tue as high pressure builds down toward the Mid-Atlantic coast. Wind speeds are forecast to generally remain below 15 knots, with seas 2-3 feet through Friday, falling to 1-2 feet into the weekend through Monday. Wave heights may then build slightly through Tuesday, up to 2-4 feet.

AVIATION

(18Z TAFs) Issued at 155 PM EDT Thu Sep 3 2026

Mainly a light east wind flow this afternoon, enhanced slightly by the Atlc sea breeze at coastal terminals up to 12 knots. Considerable clouds across northern sections is delaying heating but better heating south of MCO is generating SCT-NMRS SHRA with embedded TSRA. The sea breeze will spark addl convection near the Treasure coast so have upgraded them to a TEMPO to start the 18Z TAF package as storm motion is toward the coast. Additional TSRA will develop later this afternoon assocd with boundary collisions over the interior and better heating as high clouds thin. So maintained MVFR TEMPOs for MCO/SFB. Activity is forecast to gradually diminish beyond 00Z, with light SE winds areawide. CAMs not showing much coastal shower activity for the overnight. On Fri, convective initiation looks a little later than today. Did insert VCTS for MCO aft 18Z Fri.

PRELIMINARY POINT TEMPS/POPS

DAB 76 90 75 91 / 20 50 30 70 MCO 76 93 76 93 / 40 60 40 70 MLB 77 91 76 91 / 30 50 20 70 VRB 75 90 75 90 / 30 50 20 70 LEE 76 92 76 92 / 40 70 40 70 SFB 76 93 76 93 / 30 60 40 70 ORL 77 93 77 93 / 40 60 40 70 FPR 75 90 75 90 / 30 50 20 70

MLB WATCHES/WARNINGS/ADVISORIES

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