textproduct: Key West

KEY MESSAGES

- Heat will be the primary weather concern over the next seven days. Heat indices may creep towards 110 beginning this weekend.

- A Saharan Air Layer will begin spreading across the Keys over the weekend into next week, keeping rain and thunder chances slight at best.

DISCUSSION

Issued at 1055 AM EDT Sat Jul 11 2026

An extensive layer of altostratus has been left behind in the wake of last night's rain/thunder event. Meanwhile, below this altostratus deck, the next SAL Plume has already begun moving in. It has made for quite the interesting sounding with a mixed layer and steep lapse rates between 850 mb to around 650 mb with a nearly fully saturated layer above it. We may actually have a rare mostly cloudy July day for the Keys if the altostratus is not able to mix out with the drier SAL air below. Otherwise, winds have certainly calmed down and are generally 10 to 15 mph. In fact, if these clouds do not mix out we may struggle to leave the mid to upper 80s. As such, made a downward adjustment of temperatures for the rest of today. No other changes made at this time.

MARINE

Issued at 1055 AM EDT Sat Jul 11 2026

Gentle to moderate east to southeast breezes are expected to prevail through this afternoon and evening. Some additional brief shower activity may occur today, mainly this morning and early afternoon, however, much drier air associated with the next round of Saharan dust will build into the region. This will maintain rain- free conditions through at least early week next week.

AVIATION

(15Z TAFS) Issued at 1055 AM EDT Sat Jul 11 2026

VFR conditions will prevail under an extensive altostratus deck across the region. East to southeast breezes will remain gentle to occasionally moderate through the forecast period.

PREV DISCUSSION

Issued at 255 AM EDT Sat Jul 11 2026

After multiple rounds of convection brought numerous reports of 45-50 mph wind gusts to the Florida Keys last night, the conditions this morning have been much less intense with just lingering stratiform precipitation in place and much lower winds as a result at this time. This activity was driven by a variety of factors such as a TUTT analyzed at 250mb centered just west of the central Bahamas, a lower level inverted trough feature advancing across the Straits ahead of the TUTT, and outflow boundaries originating from Cuban convection. The lingering stratiform precipitation activity should continue through around sunrise and will mostly taper off thereafter with the departure of the inverted trough and the initial arrival of the next round of Saharan dust. Thus, it should be mostly dry today after the morning precipitation activity tapers off with highs reaching the low 90s.

The next round of the SAL looks to be rather robust with the initial push of dust arriving later today as previously mentioned, though the dust concentrations will not peak until Sunday or early next week. In fact, models show PWATs in the coming days falling to values around 1.50" or possibly a bit less at times, which would be around the 10th to 25th percentile per SPC sounding climatology. As to be expected, the nature of this very dry air mass will yield low to virtually non-existent rain chances in the coming days with PoPs less than 15% through at least early next week. Meanwhile, the aforementioned TUTT will make slow westward progress across Cuba into next week and eventually drift northward towards the northern Gulf coast by mid week. In the low to mid levels, high pressure in the western Atlantic will remain in control throughout this time and this will maintain the east-southeast wind flow regime across the Keys. Overall, it will be a warm and rather dry week for mid July standards given the exceptionally low moisture depth associated with the robust signal with this next SAL event.

PRELIMINARY POINT TEMPS/POPS

Key West 93 83 92 83 / 10 10 0 0 Marathon 90 84 90 83 / 10 0 0 0

KEY WATCHES/WARNINGS/ADVISORIES

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