Forecast Discussions mentioning any of "ACARS" "MDCRS" "AIRCRAFT" "TAMDAR" "AMDAR" "WVSS" received at GSD on 08/24/19

Area Forecast Discussion

National Weather Service Key West FL

 1042 PM EDT Fri Aug 23 2019

.DISCUSSION...
A broad area of low pressure has moved west over southeast
Florida with a rotation still noted near Miami. Radar imagery from
both the Miami and Key West radars show that most of the
convection from earlier in the day has dissipated with the
exception along and just offshore of Miami proper. Surface
observations show that the trough axis lies over Florida Bay and
the Middle Keys. Middle Keys/Upper Keys and surrounding waters,
the winds have become southwest, while the Lower Keys and
surrounding waters winds remain from the northwest to north. This
area of low pressure will continue to slowly trek northwestward
for the overnight and winds will eventually shift to the southwest
across the entire island chain. Best chances for precipitation
will remain in the Upper Keys and surrounding coastal waters. Only
minor changes were made to the wording in the coastal forecast
for the overnight period, otherwise forecast remains on track.

&&

.MARINE...
A disorganized low pressure system will continue to track
northwestward across South Florida through the overnight and into
Saturday. This feature will then lift out northeastward late in
the weekend into early next week. As a result, winds will start
out light and wrapping cyclonically around the low then become a
more uniform light to gentle south to southwesterly through the
weekend. Thereafter, ridging will lift northward towards the Keys,
behind the departing low, but then break down. This will leave
light and variable winds across the area.

&&

.AVIATION...
VFR will prevail at the EYW and MTH terminals overnight as a broad
and disorganized low pressure system lumbers northwest from near
South Florida. Variable low-level steering will become confluent and
southwesterly Saturday. Given the lower pressure, ample moisture,
and vertical profile favorable for congestus along the island chain,
there are good chances for afternoon thunderstorm impacts at both
terminals. For now we have only included vicinity mentions, although
periods of MVFR CIGS/IFR VIS will be possible with convective wind
gusts near 25 knots.

&&

.TROPICAL...
A broad area of low pressure located near the coast of southeastern
Florida continues to produce a large area of showers and
thunderstorms that extend eastward over the northern Bahamas and the
adjacent western Atlantic waters.  The system has changed little in
organization since this afternoon, but environmental conditions are
expected to be conducive for gradual development, and a tropical
depression is likely to form over the weekend.  The low is forecast
to move generally northwestward near or over southeastern Florida
through tonight, and then move northward to northeastward over the
Atlantic near the east coast of central Florida on Saturday.  After
that, the system is expected to move northeastward offshore of the
southeastern United States coast. Regardless of development, locally
heavy rains are possible over the northwestern Bahamas and the
southern and central Florida peninsula through the weekend.
Interests in the northwestern Bahamas, the Florida peninsula, and
the southeast coast of the United States should monitor the progress
of this system.  An Air Force Reserve Hurricane Hunter aircraft is
scheduled to investigate the system on Saturday, if necessary.
Formation chance through 48 hours...high...70 percent. Formation
chance through 5 days...high...90 percent.

Satellite imagery suggests that the circulation associated with an
area of low pressure located about 1100 miles east-southeast of
the Windward Islands has become better defined, but the thunderstorm
activity is limited at this time.  Environmental conditions appear
conducive for additional development, and a tropical depression is
likely to form over the weekend or early next week while it moves
generally westward to west-northwestward near 15 mph. Formation
chance through 48 hours...medium...60 percent. Formation chance
through 5 days...high...70 percent.

&&

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

$$

Public/Marine/Fire...LIW
Aviation/Nowcasts....CLR
Data Collection......SD

Visit us on the web at weather.gov/key

Follow us on Facebook and Twitter at:
www.facebook.com/nwskeywest
www.twitter.com/nwskeywest