textproduct: Key West

KEY MESSAGES

- Scattered showers and thunderstorms are expected to wax and wane across the forecast area today and tonight.

- Bouts of wet weather will continue through at least Wednesday or Wednesday night, with less confidence in rainfall coverage for Thursday.

- Near the end of the week, breezy to possibly windy conditions may return, and last through the weekend.

DISCUSSION

Issued at 1100 AM EDT Tue Apr 7 2026 It has been a messy morning along the Keys, particularly for the Upper Keys! Our proximity to the stalled frontal boundary over the Florida peninsula is making for unsettled weather. Our KBYX radar reflectivity suggests that most of the shower activity is light to modestly moderate, but embedded pockets of stronger thunderstorms have occurred this morning. Around 7 AM, a hefty thunderstorm over Florida Bay crossed over the Key Largo area. Automated surface observations reported wind gusts near 25 mph, and just over an inch of rainfall in the hour between 7 AM and 8 AM. MRMS 12-hour totals estimate that most of the island chain has seen at least a few hundredths of an inch of rain since showers first developed early this morning, but the highest totals are limited to the Upper Keys with totals up to almost 3 inches. Of note, MRMS also suggests that some of the heaviest showers occurred over the waters around the Upper Keys with estimated totals of almost 6 inches.

12Z SPC upper air analysis shows a deep trough extending into the eastern Gulf and Florida area coupled with a low level low over South Florida. The low level confluence is visible on the satellite and radar overlay as showers associated with the low level clouds across the area are moving from south to north, but showers associated with mid level clouds are moving from west to east. This is also a testament to the veering wind profile observed on the 12Z KKEY sounding this morning. All of this is to say that there is plenty of lift available for showers, and occasionally thunderstorms, The caveat is determining coverage. Closer to the boundary, coverage tends to be uniform. Current radar loops show our coverage broken up, and this will likely remain the case. Expect an on and off pattern with this activity.

The forecast is unfolding as expected, and no adjustments or changes are needed at this time.

MARINE

Issued at 1100 AM EDT Tue Apr 7 2026 There are no watches, warnings, or advisories in effect for the Florida Keys local waters. From synopsis, a frontal boundary stalled north of the Florida Keys will be responsible for light to variable breezes, and scattered to numerous showers across the nearshore waters. However, seas will be elevated across western marine zones due to a northwest swell. Thunderstorm chances are expected to decrease Wednesday. Breezes are forecast to freshen late in the week to the weekend, but confidence is low with regard to timing due to uncertainty in where and when the frontal boundary moves south of the Keys.

AVIATION

(15Z TAFS) Issued at 1100 AM EDT Tue Apr 7 2026 EYW will continue to see VFR conditions through the beginning of the TAF period, but a mix of VFR and MVFR CIGs will prevail at MTH due to SCT to BKN decks at, and above, FL015. Opting to keep the prevailing flight category at MTH as MVFR. ON and off showers may bring some light rainfall to either terminal throughout the period, we will keep VCSH in the TAFs unless a more uniform shield forms. Even though any individual shower may bring modestly gusty conditions, surfaces winds will continue to be generally light and variable. Cross wind concerns are at a minimum.

PREV DISCUSSION

Issued at 430 AM EDT Tue Apr 7 2026 Low to medium confidence defines the forecast through Friday to Saturday. Shower coverage depends on the location and intensity of the frontal system and any adjacent low pressure centers. However, there are a few points of confidence. A secondary low developing east of the Florida Peninsula will support fresh to strong breezes north of the Outer Gulf waters, so there is high confidence in stronger than normal north swell in the western waters. The location of this low would also delay the onset of breezy to windy conditions over the Keys. Finally, the lower to mid level winds will keep directing moisture-laden air across the island chain. Dew points are forecast to linger near 70 for the rest of the week. Brace for waxing and waning showers for most of the work week, which given the drier conditions, is a relief.

Once the frontal boundary moves away from the Keys, there is increasing confidence in a prolonged period of breezy to windy conditions this weekend. Exactly when breezes will freshen is not certain, and numerical guidance indicates a nearly 20 mph spread between the 10th and 90th percentiles on Friday. In terms of showers, once the frontal system moves away from the coastline, more drier air will move towards the Keys. All we can say with confidence is that weather this week will be active.

PRELIMINARY POINT TEMPS/POPS

Key West 81 70 80 71 / 50 40 40 30 Marathon 80 71 81 72 / 50 40 40 40

KEY WATCHES/WARNINGS/ADVISORIES

FL...None. GM...None.