Area Forecast Discussion
Issued by NWS
FXUS62 KKEY 230858
Area Forecast Discussion
National Weather Service Key West FL
358 AM EST Thu Feb 23 2017
A weakening surface low is nearly stationary over east central
Florida. Meanwhile an upper low is drifting east to southeast
across the southeastern Gulf of Mexico, and is cutoff from the
flow. Scattered showers are moving east - southeastward near 20
knots mainly west and south of the Keys Island Chain. Winds are
out of the southwest to west around 10 knots at the marine
reporting stations around the Keys, and 5 to 10 knots at the
island terminals. Dew points dropped into the mid 50`s before
midnight, and are now near 60 degrees.
.SHORT TERM (TODAY THROUGH SATURDAY)...
The upper low has moved south of the weakening surface low which
would indicate the future demise of the system. The upper low is
on the wrong side of the temperature gradient and is already
showing signs of filling in, down to the surface. The short term
guidance is capturing this rather well. The system will fill in as
the low drift further east, then finally lose continuity by
Saturday afternoon. Have lowered POP`s to a slight chance today
due to the dissipating lift over the area.
.LONG TERM (SUNDAY THROUGH THURSDAY)...
By early Sunday, the low will be absorbed by a clipper system
moving quickly across the Great Lakes, before it retreats
northeastward through Sunday afternoon. A blocking ridge over the
Gulf of Alaska, combined with a nearly stationary upper low over
north central Canada, will disturb the upper level flow across the
United States through much of next week. A series of short wave
lows will dive southward along the Intermountain West, then move
northeast across the Central Plains States. These lows will remain
well north of the Keys area due to a blocking ridge parked over
the southeastern Gulf of Mexico. Seasonal rain chances, with above
normal temperatures are expected Sunday through Thursday.
Until the upper low opens up along the trough Friday, winds will
peak and lull. This upper low will drift eastward today through
Friday while weakening. Advisory or cautionary headlines are not
expected through Tuesday.
A few brief MVFR cigs are possible at the Key West terminals over
the early morning hours. Have that tempoed at both locations. May
need to extend that as pockets of lower clouds rotate around the low
currently over the Florida peninsula. Will also monitor very small
light showers upstream of both locations, but the tendency has been
for those few showers to be short-lived. Expect VFR conditions to
extend through the afternoon with the continuation of moderate west
to northwesterly breezes.
On this date in 1932, 1.71 inches of rain was measured in Key West.
This set the daily rainfall record for February 23rd in the city.
Rainfall records for Key West date back to 1871.
.PRELIMINARY POINT TEMPS/POPS...
Key West 78 68 79 71 / 20 - - 0
Marathon 79 69 81 70 / 20 - - 0
Visit us on the web at weather.gov/key
Follow us on Facebook and Twitter at: