Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Miami Florida
756 am EDT sun Aug 31 2014
Moderate easterly winds in the 10 to 15 knot range will continue
to dominate across the region today. Patches of cloudiness will
continue to bring passing showers across the Atlantic coast
terminals today with only brief sub-VFR conditions expected from
time to time. For terminal kapf...the easterly flow will result in the
potential for convection late this afternoon with thunderstorms in the vicinity assigned at
21z but the timing may have to be adjusted sooner.
Previous discussion... /issued 323 am EDT sun Aug 31 2014/
* high risk of rip currents Broward, Miami-Dade beaches; moderate
for the Palm beaches
* increasing cloudiness/potentially stormier weather by midweek
with approach of an upper level low
Discussion...high pressure over the deep south continues an
easterly wind flow regime across South Florida. Convergence across the
Atlantic is resulting in some shower and limited tstorm activity
early this morning. Some of this activity will move onshore Southeast
Florida this morning before convection shifts focus towards the
Gulf Coast during the afternoon. Reflected this expected trend in
the pop fields.
The rip current model shows the risk increasing to high across our
southern coast this afternoon. As such, we will hoist a high risk
of rips along the Broward and Miami-Dade coast with a moderate for
the Palm beaches.
GFS and European model (ecmwf) both show an upper level low east of the Bahamas
continuing to move west and into the Bahamas Monday-Tuesday then into
our Atlantic waters and across South Florida Wednesday-Thursday along with a weak
low level reflection/trough. The combination of these features
along with increasing moisture will result in a more unsettled
period by middle week. However, both GFS and European model (ecmwf) show the focus of
convergence/storminess over the Bahamas and out local Atlantic
waters. So it is uncertain just how stormy it could become across
South Florida with this feature. One factor which has our
interest is the cooling middle level temperatures associated with this upper
level low with model consensus showing 500 mb temperatures lowering into the
-8c to -9.5c range Wednesday night-Thursday night...which would be the
coldest 500 mb readings for the first week of September locally.
Increased cloudiness would be a negating factor for active
tstorms, but if we end up with good convergence (especially
Atlantic coast at night...something to watch) then it could
become quite active. Followed close to guidance probability of precipitation through the
week, though did cut probability of precipitation down slightly East Coast Monday-Tuesday before
trending up middle-late week. /Gregoria
Marine...an east southeast wind flow will prevail through week's
end as the Atlantic ridge remains north of the area across North
Florida and the deep south. An inverted trough will move across
the local waters Wednesday night-Thu, bringing the potential for
increased storminess across especially the Atlantic waters then.
Preliminary point temps/pops...
West Palm Beach 91 79 90 78 / 30 20 30 10
Fort Lauderdale 91 81 91 80 / 30 20 30 20
Miami 91 80 90 78 / 30 20 30 20
Naples 92 76 91 77 / 50 10 70 30
Florida...high rip current risk through this evening for flz172-173.
Am...high rip current risk through this evening for amz630.