Area forecast discussion
National Weather Service Miami Florida
754 PM EDT Sat may 18 2013
Aviation...
The general thinking for Sunday is that with a slightly stronger
flow from the east the East Coast sea breeze is expected to drift
inland more effectively keeping most activity in the interior and
possibly the West Coast. Vcsh is kept for Naples for Sunday
afternoon and evening. VFR conditions are expected except for some
brief MVFR conditions in thunderstorms near Naples.
&&
Previous discussion... /issued 238 PM EDT Sat may 18 2013/
.Stormier pattern setting up for early next week...
Discussion...
short term...scattered showers and a few thunderstorms developing about
as expected so far this afternoon along the sea breezes and
moving little. Short range models indicate the convection
strengthening and consolidating over the interior of the peninsula
mainly south and west of Lake Okeechobee the remainder of the
afternoon, with metropolitan areas along both coasts mostly dry. Some of
the convection could work its way toward the Gulf Coast early this
evening before dissipating. There is still the potential for a
couple of strong storms this afternoon with gusty winds and small
hail.
The synoptic pattern for the rest of the weekend into early next
week will consist of a low level high pressure area over the
Atlantic with east/southeast flow in the low levels, and a middle/upper level
trough over the eastern United States and western Atlantic,
including Florida. For tonight and Sunday, little change from
today's pattern is expected with night/morning showers along the East
Coast and scattered thunderstorms interior and Gulf Coast.
For Monday and Tuesday, trends point toward an increasingly
unstable and wet/stormy pattern as the low level easterly flow
moistens up and a 500 mb low drops down over Florida. The
combination of moist low levels and cold middle/upper levels (with a
possible boost from a 50-60 knots upper level jet over the southeast Gulf of
mexico) will lead to greater coverage of showers/tstms, including
night/morning along the East Coast and over both Atlantic and Gulf
waters. As a result, raised probability of precipitation into the 30/40 range all areas and
these may have to be increased further in future forecasts if
trends continue. Model soundings show cold middle-levels on Monday
with 500 mb temperatures around -11c, so there's certainly the potential
for strong storms Monday afternoon/evening and perhaps Tuesday as
well.
For the rest of next week...models keep the middle/upper level low
over Florida at least through Wednesday, then temporarily lift the
low north on Florida only to be replaced by another trough
extending south from the eastern United States. At the surface,
the GFS and European model (ecmwf) show a weak low over SW Florida Thursday moving
northeast across the Florida Peninsula. The details of these
features and their effects on our weather are still a little
unclear, but it appears as if a generally unstable pattern may
persist through the entire upcoming week with at least scattered
showers/thunderstorms most days.
Marine...
east/southeast winds increase slightly over the next
couple of days but remain below 15 knots. This will result in
generally good boating conditions (outside of showers/thunderstorms which
will increase over the waters beginning Sunday night) with only a
small northeast swell off the Palm Beach County coast.
Fire weather...
gradually increasing moisture will keep daytime relative humidity
values above critical levels. Some patchy fog isn't out of the
question over the interior the next two nights, but not enough to
mention in forecasts.
&&
Preliminary point temps/pops...
West Palm Beach 74 86 74 86 / 20 20 20 30
Fort Lauderdale 76 86 75 88 / 20 20 20 30
Miami 76 87 75 87 / 20 20 20 30
Naples 72 89 71 88 / 20 30 30 40
&&
Mfl watches/warnings/advisories...
Florida...none.
Am...none.
GM...none.
&&
$$
Discussion/marine/fire...57/dg
aviation/radar...71/je
