textproduct: Melbourne

KEY MESSAGES

Issued at 245 AM EDT Mon Sep 21 2026

- A nearly stationary disturbance aloft will help generate scattered to numerous showers and storms across the area the next few days.

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

- A cool front is forecast to cross the area Thursday with lower rain chances and slight cooling late week and into the weekend.

DISCUSSION

Issued at 245 AM EDT Mon Sep 21 2026

Today-Tue...An upper level (cut-off) low will continue to spin over the western FL peninsula today then open up into a trough and lift NE on Tue. Deep moisture (PWATs 2-2.2") will support scattered to numerous (50-70%) showers and storms both afternoons over land. Overnight/early morning showers and storms will continue over the Atlc, sparked this morning by a land breeze slowly pushing offshore. As diurnal heating develops, convection should develop along the sea breeze by early afternoon, then drift inland into the evening hours. Temps aloft remain cool today (-8C at 500mb) so a few strong storms are possible containing gusty winds to 50 mph, frequent lightning and locally heavy rainfall 1-3". Temps are forecast to warm to -6C Tue as the upper low weakens/fills so risk of strong storms will decrease. Highs in the upper 80s to lower 90s and high humidity will support peak afternoon heat indices in the upper 90s to near 100 degrees.

Wed-Sun...An upper level trough drops SE out of the Great Lakes region Wed, then deepens into a strong cut-off low just off the mid Atlc coast late week with an assocd sfc low deepening near 990mb. This stacked low pressure system will not move much as high pressure to the north will create a blocking pattern into the weekend. In the low levels, a cool front will get driven southward into the Florida peninsula Wednesday with a secondary surge pushing the front south of the area by Friday.

Deep moisture (PWATs 2-2.3") will persist over the area Wed esp southern sections while the presence of the front maintains enough lift for numerous (60-70%) showers and storms, especially in the afternoons. N/NE winds are forecast to increase Thu as pressure gradient tightens supporting 10-15 mph and gusts 20-25 mph spreading southward from Volusia into Brevard during Thu. Gusts near 30 mph are possible along the immediate Volusia coast Thursday aftn-eve. Max temperatures in the upper 80s to lower 90s continue.

Drier air will filter down into central FL beginning Fri, lowering PoPs to 20-40% this weekend. Breezy NE flow continues, especially along the coast on Friday then decreasing slightly this weekend. Drier air and onshore flow will allow for high temperatures to drop a few degrees to the mid to upper 80s. However, min temps will remain quite mild holding in the 70s due to the onshore flow. But as that onshore flow decreases, inland sections should drop into the mid and upper 60s Sat night/Sunday morning.

MARINE

Issued at 245 AM EDT Mon Sep 21 2026

Generally favorable boating conditions persist into mid-week as NE to E winds remain around 10 kts or less during the afternoon, becoming light and variable overnight and early morning. However, will see scattered to numerous showers and storms persist each day, especially overnight. A few strong storms will be possible, capable of wind gusts near 40 kts and lightning strikes. Seas 1-3 ft. A cool front is forecast to cross the local Atlantic waters Thursday, bringing a surge of N/NE winds increasing to 20-25 kts north of Cape Canaveral in the afternoon. Conditions look to deteriorate southward into Friday, with seas building to 6-9 ft.

AVIATION

(12Z TAFs) Issued at 655 AM EDT Mon Sep 21 2026

Small patch of LIFR stratus/fog near ISM is quickly lifting and is expected to diminish near 12Z. Isolated showers and possibly a storm may also brush northward along the Treasure Coast this morning, producing brief IFR/MVFR conditions. Scattered to numerous showers and storms then forecast into the afternoon with the inland moving east coast sea breeze. Have maintained VCTS starting at 17Z, with PROB30/TEMPO groups for most sites running from 18-21Z for most sites, excluding KDAB. Convection will then mostly diminish and push W/SW of the area by 00Z, but could still see some lingering areas of light rain and isolated storms into the evening.

Light and variable winds this morning will pick up slightly out of the E/NE around 5-9 knots into the afternoon as sea breeze develops and shifts inland. Gusty and variable winds will be possible near any storms or heavier showers.

PRELIMINARY POINT TEMPS/POPS

DAB 87 74 88 74 / 30 10 40 10 MCO 89 73 90 74 / 60 20 60 10 MLB 87 74 88 75 / 50 20 60 30 VRB 87 73 88 73 / 50 20 60 30 LEE 90 73 90 74 / 50 20 50 20 SFB 88 73 90 74 / 50 10 60 10 ORL 88 74 90 75 / 50 10 60 10 FPR 87 72 88 73 / 60 20 70 30

MLB WATCHES/WARNINGS/ADVISORIES

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