Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Miami Florida
238 PM EDT sun Apr 26 2015
Short term (tonight-Tuesday night)...
as of early this afternoon, middle to upper level flow across South
Florida remains zonal with a surface ridge over the Florida Straits
and a stationary frontal boundary over the southeast states with a
weak surface trough in the northeast Gulf of Mexico to the northern
Florida Peninsula. This has placed South Florida under a deep
southwest flow with very little cloud cover in a dry environment as
the precipitable water dropped to less than 1.5" this morning. Diurnal heating is
at its maximum with temperatures climbing into the lower and middle
90s over the interior and along the East Coast metropolitan areas. Some
record highs could be in jeopardy for the day.
Middle level moisture will slowly return on Monday and Tuesday as an
upper level trough deepens across the Southern Plains Monday and
Tuesday with a surface low being induced along the central Gulf
Coast. This will maintain a deep southwest to west flow across South
Florida on Monday with a low level southerly flow developing by
Tuesday. This will also maintain temperatures well above the average
mark for late April with readings once again climbing into at least
the lower 90s along the East Coast and perhaps just one or two
degrees lower on Tuesday afternoon with an increasing amount of
cloud cover by then. The precipitable water will jump back up to the range of 1.6-
1.7" through this period with middle level southwest winds also
increasing in the range of 30-40 knots. This will result in
increasing instability and thus increasing chances for showers and
thunderstorms especially by Tuesday.
Long term (wednesday-sunday)...
the middle level trough will slowly get picked up by a northern stream
trough and shift east through the first half of the extended period.
The GFS has come more in line with the solution depicted by the
European model (ecmwf) and now has a late season cool front pushing across South
Florida late Thursday. Ahead of the front, plenty of moisture and
instability will persist across South Florida on Wednesday into
early Thursday to keep chances for showers and thunderstorms
elevated. There is still some uncertainty as to how strong
thunderstorms may become on Wednesday depending on the exact
position of the surface low pressure and the amount of cloud cover
than could inhibit the diurnal heating cycle. At any rate, it
appears more likely that much drier conditions will push into the
area late in the week and into next weekend.
southwesterly winds will prevail across the regional waters
through Monday generally diminishing to the 10 to 15 knot range. There
will continue to be uncertainty in the wind forecast with a
complex synoptic pattern developing the next several days but will
eventually shift to the northwest behind a cold front late in the
Preliminary point temps/pops...
West Palm Beach 74 91 74 87 / 10 50 40 70
Fort Lauderdale 78 92 78 90 / 10 40 30 60
Miami 78 93 77 92 / 10 30 20 50
Naples 78 89 76 87 / 0 20 20 40