Marine Weather and Tide Forecast for Jupiter Island, FL

DISCUSSION
Issued at 204 PM EDT Mon Sep 21 2026

Rest of Today-Wednesday...A stalled upper level low lingers over the Florida peninsula today. This feature is providing enough enhancement to develop scattered to numerous showers and storms along the sea breeze early this afternoon, mainly south of Orlando. Expect this activity to continue westward through this afternoon, clearing into the western half of the peninsula by sunset. Mostly dry conditions then prevail overnight over land areas. However, persistent showers and storms over the Atlantic waters may occasionally drift onshore into coastal areas overnight. The main threats with any storms through this afternoon will be gusty winds to 50 mph, lightning strikes, and locally heavy downpours of 1-3". Low temperatures dip into the lower to mid-70s tonight. Patchy fog will be possible over the interior, especially north of Orlando.

An upper level trough dropping through the central US will push the low NE and merge with it through Wednesday. Deep moisture (PWATs 2-2.3") and the continued unsettled pattern will maintain higher coverage of showers and storms (40-70%) through mid-week. A few strong storms will remain possible. But, 500 mb temperatures warming from around -8 C today to -5 to -6 C by Wednesday will limit the threat overall. Onshore flow becomes increasingly NNE through the period, but remains around 10 mph or less. Winds overnight become light and variable, so will need to monitor the threat for patchy fog each night, especially over the interior.
Otherwise, warm highs continue to reach the upper 80s to lower 90s, which combine with high humidity to produce heat indices 98-102 degrees.

Thursday-Monday...A strong low pressure system develops into Thursday morning offshore from the NE US. Meanwhile, the upper level trough digs into Florida, dragging a cool front southward through the peninsula. High coverage of showers and storms again on Thursday (50-70%), mainly along the weakening front. However, will see progressively lower rain chances from north to south into the weekend, as drier air filters into the area. PWATs fall below 1.5" this weekend, leading to PoPs 20-40% or less, highest across southern portions of the forecast area.

A tightening pressure gradient will produce breezy and gusty NNE winds behind the front beginning on Thursday. Winds build to 10-15 mph Thursday afternoon and 15-20 mph Friday, with gusts 20-30 mph.
The highest winds are forecast along the coast, especially north of the Cape. Breezy conditions linger Saturday, before winds fall to around 10 mph again into early next week. Enhanced onshore flow will lead to poor to hazardous beach conditions this weekend.
Slightly cooler high temperatures in the mid to upper 80s are forecast, though lower humidity will provide relief from heat indices above 100. Inland locations could even see lows in the 60s by the weekend.

MARINE
Issued at 204 PM EDT Mon Sep 21 2026

Scattered to numerous showers and storms, especially overnight, will remain a threat over the local Atlantic waters through Wednesday. Outside of convection, generally favorable boating conditions persist, with NE winds remaining around 10 kts or less.
Seas 1-3 ft.

A nor'easter off of the NE US coast will drag a cool front through the local waters Thursday. NE winds increase to 20-25 kts, progressing farther southward into Friday. Winds then remain breezy around 10-15 kts into the first half of the weekend. Higher coverage of showers and storms lingers Thursday, before drier air reduces chances into the weekend. Hazardous seas up to 6-9 ft are forecast to continue into Sunday.

AVIATION
(00Z TAFs)
Issued at 730 PM EDT Mon Sep 21 2026

Lingering activity along the coast will diminish or push offshore over the next hour or two with activity across the interior earlier having already dissipated or moved out of the area. Have VCTS lingering along the coast through 02Z. Mostly dry overnight, especially across interior sites. Isolated showers and storms may brush across the coast through the overnight. Light and variable winds will become E/NE by late morning to early afternoon and increase to 5-9 KT with the east coast sea breeze. Tuesday, have included VCSH along the coast starting at 15Z and then VCTS starting at 18Z everywhere. Have not included TEMPOs at this time.
Have shower and storm activity diminishing by around 00Z Wednesday for MCO.

PRELIMINARY POINT TEMPS/POPS
DAB 74 88 74 88 / 20 30 10 60 MCO 73 91 74 90 / 20 50 20 70 MLB 74 88 75 88 / 20 40 20 60 VRB 73 88 73 88 / 20 50 30 60 LEE 73 91 74 91 / 20 40 20 60 SFB 73 90 74 89 / 10 50 10 70 ORL 74 90 75 90 / 10 50 20 70 FPR 72 89 73 88 / 30 60 30 70

MLB WATCHES/WARNINGS/ADVISORIES
FL...None.
AM...None.