Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Miami Florida
744 am EDT Tuesday Apr 21 2015
an approaching cold front will bring more instability to the
atmosphere over South Florida. This will bring continued chances
for showers and thunderstorms through the day. While nothing below
VFR is currently forecast, brief IFR may be possible under heavy
showers and storms. Winds will be tricky today as they will
gradually shift from being generally southwest to northeast this
afternoon. Thus, have a vrb wind group as there will be no
consistency in the direction through the day. Tonight, the winds
will go light and variable.
Previous discussion... /issued 331 am EDT Tuesday Apr 21 2015/
latest radar trends early this morning show a thin line of showers
stretching across the Florida Peninsula around Lake Okeechobee.
These showers are in association with a weak surface trough well
out ahead of an approaching cold front. Latest hi res models
depict some of these showers affecting South Florida over the
next few hours so will keep slight chance to chance pop area wide
through the early morning hours.
The cold front is then expected to push into South Florida later
today with scattered to numerous showers and thunderstorms
developing and pushing into the area ahead of the front beginning
late this morning. The front is still expected to stall across or
just south of the area later this evening. Believe coverage of
showers and thunderstorms should be more extensive over the area
today with the front in the area. Model soundings still depict
precipitable waters near 2 inches across all of South Florida later today. This
combined with weak surface winds and middle level flow roughly
parallel to the frontal boundary will produce showers and
thunderstorms capable of producing heavy rainfall and urban
flooding. Surface to 6 km shear values of around 50 kts could
also initiate a few strong thunderstorms especially with diurnal
heating and added surface forcing along the frontal boundary.
Showers and a few thunderstorms should linger tonight and into
Wednesday as the front remains stalled.
The wet pattern will continue through Wednesday as middle level flow
remains westerly with the quasi-stationary boundary in place over
the area. This will keep the threat for heavy rain and localized
flooding for South Florida through Wednesday.
Coverage of showers and thunderstorms should begin to slowly
decrease toward the end of the week and into the weekend as strong
upper ridging is still expected to build into the eastern Gulf of
Mexico. This will also allow temperatures to increase slightly.
Current mex guidance is depicting high temperatures Saturday in
the low to middle 90s across the East Coast metropolitan areas. For
now...undercut guidance and trended toward the milder ece numbers.
Ridging looks to remain entrenched across the area through the
weekend with limited afternoon convection. Long range models then
hint at another cold front entering the northern Gulf Coast by the
first part of next week.
smoke from interior Miami-Dade wildfire has been present at mia
for several hours, and with the wind direction constant, may
continue through the rest of the night. Cold front dropping into
central Florida and becoming diffuse, will allow showers and storms
regionwide Tuesday afternoon. Coverage may be enough for tempo
MVFR/IFR conds at times. Wind shift/east flow arrives into Tuesday
winds are expected to be variable at 10 knots or less across both
the Atlantic and Gulf waters today as a cold front slowly slides
through the area. This front is then expected to linger across
the area through Wednesday with scattered to numerous showers and
thunderstorms expected. Seas will generally be in the 1 to 3 foot
range with locally higher winds and seas associated with any
Preliminary point temps/pops...
West Palm Beach 85 71 83 72 / 70 50 60 40
Fort Lauderdale 88 73 84 75 / 70 50 70 40
Miami 89 73 86 74 / 70 40 70 40
Naples 87 73 86 72 / 50 20 50 40