Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Miami Florida
250 PM EDT Thursday Aug 21 2014
the subtropical ridge is driving the East Coast sea breeze this
afternoon. Showers and thunderstorms continue to develop over the
interior and western forecast areas. Sounding data indicated
decent 850 to 500 lapse rates at 6 to 6.5 c/km. However the well
mixed layer shows only moderately unstable atmosphere. Currently
showers and thunderstorms are producing good outflow booundaries
push through the weak easterly flow.
For the remainder of today and tonight expect the convective
activity to pulse mainly to the western edge of the forecast area.
Some of the outflows may initiate new showers and thunderstorms
over the eatern sections of the area especially over northwest
Miami Dade and Broward counties. Showers and thunderstorms will
move off shore after sunset.
A ridge will build over the southeast states late Friday while a
tropical low develops near the Leeward Islands. The East Coast sea
breeze will dominate the movement of showers and thunderstorms,
keeping most of the action over the interior and western areas. As
the ridge strengthens Friday night and Saturday, winds will turn
northeast. Some drier air will be introduced over South Florida,
which will reduce the coverage of afternoon showers and
thunderstorms through the weekend.
Model guidanace has the tropical low turning north over the
eastern Bahamas leaving South Florida in the subsidence on the
perifery of the system, which will add to the dry air from the
ridging to our north. Winds may increase a bit on Sunday due to
the location of the low, but uncertainty in the forecast will make
no changes to the forecast at this time.
east flow has initiated sea breeze-anchored thunderstorms inland of
kmia and early this afternoon...with a few remaining in the vicinity
of kpbi at present. Convection should drift west and increase in
coverage toward the Gulf Coast with tempo MVFR indicated for
kapf...although brief IFR visibility is possible with thunderstorms.
Expect convection to dissipate a couple hours after sunset over land
with a slight chance for a shower along the East Coast late tonight.
gentle to light east winds around 10 knots or less will continue
through at least Saturday night, with seas of 2 feet or less. A
weak low may develop near the Leeward Islands and move toward the
Bahamas Saturday night and Sunday. Winds will turn northeast
Saturday night and Sunday, and possibly increase depending on the
placement and intensity of the low.
Preliminary point temps/pops...
West Palm Beach 79 90 78 90 / 10 30 0 10
Fort Lauderdale 81 91 80 91 / 20 20 - 10
Miami 80 90 80 90 / 10 20 - 20
Naples 78 91 79 91 / 20 40 20 30