Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Miami Florida
744 PM EDT Wednesday Jul 27 2016
conditions have abated for the day. VFR conditions expected to
prevail at all terminals overnight with light easterly breezes.
For tomorrow, guidance indicates the potential for a slight surge
of moisture along southern East Coast terminals mid/late morning
to early/mid afternoon before activity transitions to the interior
and West Coast (apf) mid afternoon into the early evening. But
overall activity should remain below normal as area remains under
influence of strong ridge at low/mid levels. VFR conditions
should prevail although a slight chance of MVFR or even IFR brief
conditions at apf in the afternoon and early evening associated
with storms cannot be ruled out tomorrow. But given nature and
expected durations handled it with thunderstorms in the vicinity for now. Easterly breezes
will increase to 10 to 15 mph tomorrow during the day with West
Coast c-breeze of 5 to 10 mph at apf around 18z or so.
Previous discussion... /issued 437 PM EDT Wednesday Jul 27 2016/
high pressure centered northeast of the region will keep
southeasterly winds in place. Rain chances will be fairly low over
eastern portions of the region, but relatively high over western
portions of the region, especially during the afternoons.
Short term /tonight through Friday night/...
dry air aloft and warm ocean temperatures (minimal East Coast
sea-breeze development) have precluded much in the way of
convection this afternoon. The only activity is isolated in
nature, and mainly confined to the Naples metropolitan area. These
showers and thunderstorms will persist through mid-evening and may
impact portions of Hendry and Glades counties as well. Thereafter,
most of the night should be precipitation-free.
Synoptically, powerful Bermuda ridge will be the dominant feature
impacting South Florida weather through the short term. 800 mb-6 dry
layer, hints of sal, overhead will keep pwats closer to 1.5 inches
and limit overall convective coverage, particularly Thursday.
Thunderstorms will be focused over the interior and west, where
subtle Atlantic sea breeze will collide with more defined Gulf
Breeze during the afternoons. Slight moisture surge will impact
far southwest Florida Thursday, and this may enhance convection
somewhat over The Everglades.
Temperatures will remain warm, particularly overnight lows which
will run as much as 5 degrees above normal. High temperatures will
be at average levels for julys end, with lower 90s most locations.
Heat indices could approach 105 degrees. The easterly wind will
maintain moderate rip current risk on the Atlantic coast.
Long term /Saturday through Tuesday/...
although overall weather pattern is not expected to change through
the extended, several features moving westward around the base of
the deep-layer ridge will influence South Florida weather. The
first will be TUTT that will cross the region over the weekend.
Typically, these can bring increased convection to the region, but
relatively dry atmosphere will accompany this one, thus overall
forecast pop regime for now will change little this weekend. Thus,
scattered mainly afternoon showers and thunderstorms, away from
the East Coast, are expected.
Second feature on the horizon is a tropical wave that may approach
the region early next week. Although the waves timing and location
is quite uncertain, both GFS and European model (ecmwf) depict increased moisture
by Tuesday, which forecast rain chances also increase.
Temperatures this weekend into early next week will be near to
slightly above normal for this time of year.
with afternoon/evening convection expected mainly western
interior, mainly VFR conditions expected to prevail for Atlantic
coast terminals. For terminal kapf, currently there are showers in
the vicinity with vcsh assigned at 18z. Onset of the West Coast
sea breeze could be delayed until 19-20z with 19z in taf for kapf
and thunderstorms in the vicinity assigned at that time. There may be brief periods of MVFR
to near IFR conditions at kapf with occurrence of showers and
east and southeast wind flow at speeds of 10 to 15 knots will
prevail through the weekend. There is a chance of showers and
thunderstorms at any time, but the best chances will be afternoon
and evening over Lake Okeechobee and along the Gulf Coast. In
addition to dangerous lightning, gusty and erratic winds will
accompany the stronger thunderstorms.
Preliminary point temps/pops...
West Palm Beach 81 92 81 92 / 10 0 10 20
Fort Lauderdale 82 90 81 90 / 10 10 20 20
Miami 81 91 81 92 / 10 20 20 20
Naples 78 93 78 91 / 20 30 20 40