Scientific Forecaster Discussion
fxus62 kmfl 271958
Area forecast discussion
National Weather Service Miami Florida
358 PM EDT Tue Jun 27 2017
latest water vapor imagery loop shows a cyclonic spinning low
over New York state with a longwave trough draped along the
the mid-Atlantic. Surface analysis indicates a east- west
oriented stationary boundary sitting stagnant across north-
central Florida. This feature has managed to push the Bermuda high
eastward, away from our region, resulting in near natural flow.
Thus, well established sea breezes have already developed and
continue to push inland, towards the interior. Satellite derived
precipitable water values range from 1.7 inches in the southern peninsula to
near 2.0 inches further north. These values are slightly higher
than climo and more than sufficient for heavy, slow moving storms.
With a modified dcape of 1,400 j/kg, wet microbursts producing
strong wind gusts are also a possibility. Short term model
guidance progs convection to propagating across the interior
through the early evening. After diurnal heating ceases, activity
should begin to wane. Storm Prediction Center has placed a marginal risk of severe
weather from West Palm Beach to Lake Okeechobee, so will continue
to monitor for the remainder of the day. Tomorrow should be a
similar set up, with not much changing synoptically. Light flow
will again lead to sea breeze convergence inland from the coasts.
As the day progresses, outflow boundaries will shift most of the
convection towards the interior. Maximum temperatures tomorrow
are forecast to hover in the upper 80s along the coasts, with
lower 90s inland. These values are around normal to slightly above
normal for this time of year.
Late next week into the weekend: by Thursday, both the GFS and
European model (ecmwf) prog the aforementioned front to wash out and retreat
northward. This will allow surface high near Bermuda to once again
increase in strength. Stronger southeast flow will begin to
concentrate afternoon convection back towards the western
interior, as sea breeze collision shifts west. Friday into this
weekend, a more typical summertime regime reestablishes itself.
Long range models show an elongated high building aloft over the
peninsula with surface high building near Bermuda. This pattern
typically brings persistent southeast flow. Afternoon convection
will most likely occur in the western interior and Gulf Coast with
night showers affecting the East Coast Metro region. Pwats
decrease slightly below climo during this time frame, so not
anticipating much in the way of significant heavy rain events.
winds and seas should remain below Small Craft
Advisory criteria across the local waters through the forecast
period with mainly light southeasterly flow prevailing. Sea
breezes may enhance winds near the coast to 10-15 knots at times
each afternoon. Only exception will be with any thunderstorm that
forms, which will bring brief periods of strong gusty winds and
rough seas. Waterspouts are also possible, especially in the
morning hours, mainly over the Atlantic waters. Seas will be 3
feet or less heading into the weekend.
periods of MVFR will continue at most of the Atlantic terminals
through the rest of this afternoon and early evening as sea
breezes become Focal Point for convection. Brief IFR could is also
possible, but for now tempos are in place for mainly MVFR
conditions under heavy rain and thunderstorms. Showers will linger
in the vicinity of the terminals tonight, with a few
thunderstorms possible in the evening hours. South to southeast
winds will remain light, in the 5-10kt range except becoming gusty
with any thunderstorm that forms. Only exception is apf where sea
breezes will keep onshore flow through the early evening hours.
Preliminary point temps/pops...
West Palm Beach 76 91 78 91 / 50 50 30 50
Fort Lauderdale 78 90 79 91 / 40 50 30 40
Miami 78 92 79 91 / 40 50 30 40
Naples 76 91 76 91 / 20 40 20 50