• Currently

    Reported at Marathon, Marathon Airport, FL
    9:53 AM EST THU JUN 29 2017
  • 90°F32°C
  • Clear
  • Feels Like:103°F39°CDew Point:77°F25°CHumidity:67% Winds:SSE 7 mph 11 kph
    Pressure:30.09 in1019 hPaVisibility:10.00 miles16090.00 meters
  • Area Forecast Discussion

922 AM EDT Thu Jun 29 2017

The morning upper air data reveal plenty of low level moisture and
a favorable vertical wind profile for cloudline develop along the
Keys Island Chain today. The Atlantic ridge axis across the
southeastern United States coast is directing light winds out of
the southeast this morning. Winds across the region are 5 to
10 knots at the marine stations, and 5 knots or less at the
island terminals.

The sounding would indicate that we have an above average
opportunity to witness waterspouts today, and with a similarly
above average chance for cloudlines, will update the hazardous
weather outlook to include this possibility. Cloudlines that form
will slide off the north side of the Keys as they develop, and
showers over the eastern Florida Straits will slide westward
through the day. The Atlantic ridge mentioned above will
gradually move southeastward while gaining strength resulting in
increasing winds out of the east to southeast. Expecting highest
winds over the Florida Straits at around 15 knots this evening and
overnight, with 15 to 20 knots and a caution Friday night and
Saturday night. daytime winds will relax as the thermal gradient
from the heating of the Florida mainland weakens the ridge over
the Keys. Finally, the ridge axis will slide over Central Florida
and the eastern Gulf of Mexico by Sunday, and daytime heating will
continue to break the gradient creating peaks during the nocturnal
cycle, and lulls during the daytime hours through midweek. Rain
chances will remain in the low end chance to high end slight
chance through next week due to the mid to low level ridging.


Atlantic high pressure will is driving the southeast winds today
and will gradually slide to the southeast while gaining strength
through Friday. Expect east to southeast winds will as gradually
increase with the highest breezes over the Florida Straits peaking
during the nighttime. Friday night and Saturday night may require
a cautionary statement for the Florida Straits for east to
southeast winds at 15 to 20 knots. By Sunday night, the gradient
will become slightly weaker as the axis of the high pressure moves
over Central Florida. On Sunday night and after, breezes will
peak during the nighttime, and lull during the day due to the
heating of the Florida Peninsula.


Until 00z/30th, with an increase in moisture below 700 mb and light
and somewhat favorable east winds, wet cloud line genesis will
provide the best chance for sub VFR encounters at the island
terminals from mid afternoon into this evening. Away from any
possible showers or thunderstorms, east to southeast winds of less
than 10 knots can be anticipated.


On this date in Keys Weather History, in 1920 the low temperature
fell to 69 degrees setting the daily record minimum temperature
for Key West for June 29th. Temperature records for Key West date
back to 1872.




Data Collection......DR/JK

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