Small Craft Advisory 28, NWS Key West, FL

Area Forecast Discussion
National Weather Service Key West FL
206 PM EDT Tue Jun 3 2025

...New DISCUSSION, PREV DISCUSSION...

.AVIATION...
(18Z TAFS)
Issued at 205 PM EDT Tue Jun 3 2025

Brief LIFR occurred earlier at KMTH as thunderstorms with heavy
rain propagated southward over Vaca Key. Expect gradual
improvement in the next few hours. Meanwhile, MVFR ceilings have
moved in as a cold pool of rain-cooled air from showers and
thunderstorms north and east of KEYW work south and west into the
vicinity. Period disruptions to the southeast winds will occur due
to convection, otherwise resumption of southeast winds near 15
knots with frequent gusts 20 to 25 knots are expected this evening
through much of the overnight. Otherwise, showers and
thunderstorms are likely this evening and overnight with activity
already developing and entering the Straits of Florida from Cuba.
Expect temporary IFR ceilings and IFR to LIFR visibilities with
heavy rain. Coverage of showers and thunderstorms is expected to
begin declining after 04/06Z, with a possible longer lull in the
activity Wednesday morning. Southeast winds will gradualy decrease
as well, however gusts near 20 knots remain likely even after
sunrise Wednesday.

&&

.PREV DISCUSSION...
Issued at 1040 AM EDT Tue Jun 3 2025

Several short convective lines and clusters have moved slowly northward
across the Keys this morning, with a couple locations where
differing outflow-driven boundaries have intersected, resulting in
transient rotation. Presently two solid bands of convection were
located over the offshore Gulf waters to waters near and just off
the Content Keys, through Florida Bay, to the Key Largo/Ocean Reef
area. Despite several radar indications of wind gusts 40 to 45 mph
here and there, no reliable reports of such winds have been
measured thus far with this round. After an hour or two of
stabilization, indications are once again southerlies are mixing
downward with sustained winds 13 to 18 knots along the reef where
cloud-filtured insolation has restarted. Radar trends indicate
there is hardly any inhibition other than in the immediate wake of
existing convection.

Synoptically, it is a tale of three major systems. A noticeable
cyclonic circulation roughly 700-500 mb over the northeast Gulf
supplyiing deep upper cyclonic flow, a stationary front analyzed
over central Florida, and the deep layer ridging displaced just
enough to the east to escort deep tropical moisture northward from
the western Caribbean. Indeed CIMMS MIMIC water vapor estimated
were north of 2.5 inches over the Straits south of the middle
Keys, and what wasn't cloud-shadowed on GOES showed significant
areas of 2.2 inches flanking our Straits district. Morning
soundings across central and north Florida indicated subtle height
rises 850-700mb, thus the north Atlantic ridge is holding position
for now. Water vapor imagery shows the upper trough in the eastern
Gulf continuing to dig with a narrow dry slot on the southeast
flank edging closer to our offshore Gulf waters.

For the afternoon and evening, little yielding between the upper
trough and mid-level circulation over the eastern Gulf and the
ridge is expected, with guidance varying on the strength of
southerlies between the two systems, the regional NAM most
aggressive. Interestingly there is a suggestion the deepness of
the Gulf trough may152 be allowing the lower tropospheric ridge
to edge northward, and enough to cause backing of surface/low
level winds. Mean winds in the 925-700 mb layer may be in the
25-35 knot range this evening and overnight, with 1-3 km storm
relative helicity in the 100-200 m^2/s^2 range. Global numerical
guidance also indicates the possibility of mid-level dry air
pockets rotating in from the west with the digging trough.
Convection- allowing models suggest a rapid increase in
development after a buoyancy recharge this afternoon, with the
HRRR aggressive in showing a large cold pool driving against the
deep southerly flow this evening.

All to say the slight risk of excessive rainfall is definitely
warranted through tonight, and with a possibility of locally
strong convection with a wind and a few violent waterspouts
possible later today and tonight.

&&

.MARINE...
Issued at 1040 AM EDT Tue Jun 3 2025

South winds were resuming along the reef at 13 to 18 knots with
gusts over 20 knots, but affected by showers and thunderstorms
across the Gulf and Bay waters at thsi time. Seas at Satan Shoal
were near 2 feet with a period of 5 seconds.

A stalled front across the central Florida Peninsula
will continue to encourage a very active weather pattern across
our area, and is expected to remain through at least Wednesday
evening. Expect strong gusty winds and locally rough and confused
seas with the stronger activity. Southeast to south breezes are
expected to freshen this afternoon and evening as a surface high
pressure system moves eastward through the eastern U.S. and
eventually links up with an Atlantic ridge. This high will move
out into the Atlantic later this week, resulting in a return to
gentle to moderate east to southeast breezes.

&&

.CLIMATE...

On this day in Keys Weather History, the daily record
rainfall of 2.99 inches was recorded in Key West set back in 2020.
Rainfall records for Key West date back to 1871.

Also, the daily record rainfall of 5.47 inches was recorded in
Marathon set back on this date in 2022. This is also the wettest
June day ever recorded for the Marathon area. Rainfall records for
Marathon date back to June 1950.

In 1982, Tropical Storm Alberto intensified into a category one
Hurricane, with maximum sustained winds of 85 mph, about 120 miles
west-southwest of Key West. The maximum wind measured at the Dry
Tortugas was 60 knots, or about 70 mph, at 600 pm when the center
of Hurricane Alberto was less than 25 miles west of the Dry
Tortugas. An F1-rated tornado spawned by Hurricane Alberto
produced $250k in damage on Stock Island, with another tornado
reported on Cudjoe Key. A 24-hour rainfall amount of 16.47 inches
was recorded in Tavernier. 6.25 inches fell at Key West during a
24-hour period ending at noon the next day.

&&

.PRELIMINARY POINT TEMPS/POPS...
Key West  77  88  82  89 /  70  60  50  30
Marathon  77  88  82  89 /  70  60  40  30

&&

.KEY WATCHES/WARNINGS/ADVISORIES...
FL...None.
GM...None.
&&

Public/Marine........JR
Aviation.............JR
Warnings/Nowcasts....AJP/CLR
Data Acquisition.....AJP

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