textproduct: Melbourne

KEY MESSAGES

Issued at 155 PM EDT Fri Sep 18 2026

- A passing disturbance aloft will help generate scattered to numerous showers and storms across the area through this weekend and into next week.

- A few stronger storms will be possible this afternoon and evening, with the main threats being strong wind gusts up to 50 mph, frequent lightning, small hail and locally heavy downpours of 1-3 inches.

- Seasonable temperatures will continue across the area over the next several days.

DISCUSSION

Issued at 155 PM EDT Fri Sep 18 2026

Through Tonight...A mid/upper level low drifting westward towards the Florida peninsula from the Atlantic has made it to east central Florida, with GOES19 visible satellite imagery showing a broad counter-clockwise rotation of some upper level clouds. This is further supported by SPC upper level analysis, with the 12Z analysis indicating the center of the upper level low was just offshore. This set-up has brought increasing moisture to the area, with the dry air mass in the mid-levels slowly being eroded away as seen in the observed sounding. Temperatures aloft have also cooled a few degrees down to around -10C today as a result of the low, as indicated by the 10Z XMR sounding. This set-up combined with persistent east- northeast flow at the surface has allowed for isolated to scattered showers and storms to develop across the Atlantic waters this morning and into the early afternoon hours, with the diffuse east coast sea breeze supporting further development across parts of the Florida peninsula this afternoon. Continued development of showers and storms is forecast through the remainder of this afternoon, though lingering dry air between 800-500mb has served as a limiting factor for more robust development across the area. This trend will likely continue, with hi-res guidance continuing to favor lower coverage of activity through the rest of today. Trended rain and storm chances slightly below NBM through this afternoon, with the highest coverage of activity anticipated across the Treasure Coast and near Lake Okeechobee over the next few hours (40-50%). Given the cold temperatures aloft and pocket of lingering dry air in the mid- levels, some isolated stronger storms cannot be ruled out across east central Florida this afternoon. Storm hazards will include frequent lightning strikes, wind gusts up to 50 mph, small hail, and heavy rainfall that leads to quick accumulations of 1-3". While activity is anticipated to wane into the overnight hours, the increasing moisture combined with persistent onshore flow will continue to support isolated shower and storm development across the local Atlantic waters through the overnight hours, with some activity potentially moving onshore along the east coast.

Afternoon high temperatures remain on track to range between the mid 80s to low 90s, with the warmest temperatures anticipated across the far interior northwest of I-4. Tonight, temperatures will remain near normal values for this time of year, falling into the low to mid 70s. A moderate rip current risk persists at the local beaches.

Saturday-Sunday...The mid/upper level low will continue to drift westward from east central Florida towards the western Florida peninsula and the eastern Gulf through Saturday, with the feature becoming quasi-stationary on Sunday. This set-up will help keep a moist air mass overhead through the weekend, with PWATs forecast to range between 1.8-2" on Saturday and exceed 2" areawide on Sunday. This moisture combined with persistent northeast flow will support isolated shower development early in the mornings across the local Atlantic waters, with activity drifting onshore. Coverage is then anticipated to increase into the afternoon hours as a diffuse east coast sea breeze develops and moves inland, with scattered to numerous showers and storms each day. Some drier air aloft may help limit coverage on Saturday, so have continued to trend slightly below NBM values based on hi-res guidance. Sunday, higher coverage of showers is anticipated due to the increasing moisture. Isolated to scattered storm development is anticipated with activity, especially during the afternoon hours. The low overhead combined with daytime heating will create sufficient instability across east central Florida, further supported by cold -8C to -7C 500 mb temperatures. These parameters combined with the 1.8-2.0"+ PWATs indicate that primary storm hazards will include frequent lightning strikes, wind gusts up to 50 mph, and heavy downpours producing quick rainfall accumulations of 1-3". Small hail also cannot be fully ruled out given the cooler temperatures aloft, but there remains some uncertainty with this. Shower and storm activity will gradually diminish across the peninsula each evening into the overnight hours, with the potential for continued westward-moving shower and storm development across the local Atlantic waters. Temperatures are forecast to remain seasonable in the upper 80s to low 90s each day, with lows in the low to mid 70s each night.

Monday-Thursday...The mid/upper level low will meander across the eastern Gulf into early next week before lifting northeastward and weakening as it is absorbed by a trough pushing across the eastern US. Moist air will remain in place across the Florida peninsula, with higher rain and storm chances persisting through next week, especially given an approaching cold front that is anticipated to drift towards east central Florida mid to late week. Stronger storms cannot be ruled out at times with this activity, with lightning, gusty winds, and heavy downpours all possible. Each night, activity will gradually diminish across the Florida peninsula with ongoing development across the local Atlantic waters. Temperatures are forecast to remain near to slightly above normal through the extended forecast period, with humid conditions potentially pushing heat indices above 100F once again in some spots early next week.

MARINE

Issued at 155 PM EDT Fri Sep 18 2026

Broad, weak surface high pressure will overspread the local Atlantic waters through this weekend, resulting in east-northeast winds remaining around 10 knots this weekend into next week. Seas are anticipated to continue a gradual decline, starting around 3 to 4 feet through the remainder of today and tonight and then subsiding to around 2 to 3 feet through the remainder of the forecast period. While boating conditions are forecast to remain favorable through the period, the primary hazard to mariners will be rounds of showers and storms. A moist air mass will promote continued development of isolated to scattered showers and storms, with storms capable of producing lightning strikes, wind gusts in excess of 30 knots, and heavy downpours. Small hail also cannot be ruled out in stronger storms, though confidence in this remains low. Activity is anticipated to be persistent, continuing through the daytime and nighttime hours most days.

AVIATION

(18Z TAFs) Issued at 146 PM EDT Fri Sep 18 2026

VFR conditions are forecast outside of showers/lightning storms with onshore flow. TAFs begin with VCTS at KMCO/KISM/KFPR/KSUA with TEMPO groups for TSRA between 18Z-22Z at KFPR and KSUA, as well as TEMPO groups for MVFR CIGs at KTIX between 18Z-20Z. VCTS and TEMPO groups for TSRA are forecast at KMCO at 16Z SAT. Breezy ENE winds are expected to weaken tonight before increasing SAT AM.

PRELIMINARY POINT TEMPS/POPS

DAB 75 88 74 88 / 10 30 30 50 MCO 73 90 73 90 / 10 50 10 70 MLB 76 88 75 87 / 20 40 30 70 VRB 73 87 72 87 / 20 50 20 70 LEE 73 90 73 89 / 10 30 10 70 SFB 73 88 73 88 / 10 40 20 70 ORL 74 89 74 89 / 10 40 10 70 FPR 73 88 72 87 / 20 50 20 70

MLB WATCHES/WARNINGS/ADVISORIES

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