textproduct: Key West

KEY MESSAGES

- Heat will be the primary weather concern over the next seven days. Heat indices may creep towards 109 this afternoon.

- A Saharan Air Layer will linger across the Keys through the remainder of the weekend into next week, keeping rain and thunder chances slight at best.

- As we approach closer to the new moon, tide levels will rise but should remain below Coastal Flood Statement levels at this time.

DISCUSSION

Issued at 1032 AM EDT Sun Jul 12 2026

A nearly rinse and repeat start to the day as yesterday. We have a Saharan Air Layer (SAL) rooted in the lower levels between 900 mb and about 600 mb. Above this layer we continue to have a thin layer of moisture trapped around 500 mb which has been stubborn to move out of the region. This has resulted in a layer of altostratus that has been muting the sun the last 24 hours. This moisture is finally eroding and we are beginning to see more in the way of sunshine. Meanwhile, low level ridging remains in place and as such, we continue to see our winds out of the east to southeast.

The decreasing cloud trend will continue through the afternoon and evening and we should see a fair amount of sunshine before it sets. Made only very minor changes to the going forecast to account for a slightly weaker wind. Otherwise, SAL will limit rain chances to near nil for the next several days or so.

MARINE

Issued at 1032 AM EDT Sun Jul 12 2026

Gentle to occasionally moderate east to southeast breezes this morning will continue into the afternoon. Expect the cycle of daytime lulls and overnight peaks to occur high pressure remains situated over the southwestern North Atlantic and Florida Peninsula. In addition, a large area of Saharan dust will remain in place across the area for several days and this will result in a rain-free forecast through at least the middle of next week.

AVIATION

(15Z TAFS) Issued at 1032 AM EDT Sun Jul 12 2026

VFR conditions will prevail at both island terminals through the remainder of the forecast period. High level stratus will gradually erode through the afternoon. Near-surface winds will hold out of the east to southeast.

PREV DISCUSSION

Issued at 306 AM EDT Sun Jul 12 2026

Recent Nighttime Microphysics Satellite imagery shows the stubborn mid and upper level cloud deck that has been in place for much of this weekend so far is starting to gradually erode. This gradual clearing of the cloud cover is to be expected given the influence of the SAL in the area but moisture aloft has been slow to completely scour out due to the close proximity of a TUTT analyzed at 250mb near eastern Cuba. This TUTT will make slow westward progress over the coming days across the northern Caribbean/Cuba before eventually drifting northwestward into the northern Gulf coast later in the upcoming week. Meanwhile, the SAL that is currently in place is forecast to linger well into the new week over the region based on the latest analysis of atmospheric particle movement from the NASA GEOS product. This suggests that rain chances in the week ahead will be minimal at best with PoPs generally less than 15%. Thus, a rather dry week is in store for mid July standards in the Florida Keys. The one caveat to this is whether or not some synoptic forcing from the TUTT can overcome the limiting factors from the exceptionally dry air mass that will have full control over the area. One day in particular that may have at least some rainfall potential could be on Wednesday as the TUTT will be drifting across the southern Gulf waters near western Cuba and this may provide some upper divergence aloft with a strengthening upper level jet. The NBM is not too enthusiastic about this scenario at this time but the idea is supported by some ensemble guidance, notably the EPS. Given there remains uncertainty in the positioning of the TUTT and thus where the better forcing for ascent will materialize, will hold off on adding measurable PoPs at this time but this will be something to monitor as the week progresses. Otherwise, in addition to the mostly dry week ahead, highs will be around climatological normal values each day with highs reaching around 90 and overnight lows in the low to mid 80s. In addition, heat indices will generally range from 103- 108 each day and may approach heat advisory criteria at times, but overall coverage of locations may be too low to consider any heat related products at this time.

PRELIMINARY POINT TEMPS/POPS

Key West 92 83 92 83 / 0 0 0 0 Marathon 90 83 89 83 / 0 0 0 0

KEY WATCHES/WARNINGS/ADVISORIES

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