Scientific Forecaster Discussion
fxus62 kmfl 181151
Area forecast discussion
National Weather Service Miami Florida
651 am EST Sat Nov 18 2017
high pressure is forecast to keep the weather quiet through the
taf period with VFR conditions. The light and variable wind should
pick up out of the east by late morning, then go light and
variable again tonight. The exception is kapf, where the Gulf sea
breeze looks to bring the wind around to the west this afternoon.
Previous discussion... /issued 349 am EST Sat Nov 18 2017/
Short term (today through monday)
quiet weather with seasonably warm temperatures has continued
overnight, with most areas early this morning in the 60s, with
some 50s over the interior. High pressure will remain dominant
this weekend, bringing lessening winds and dry conditions. Maxima
will reach low 80s with minima in the 60s.
Synoptically, changes in the weather pattern will commence this
weekend as an upper-level longwave trough begins to deepen over
the eastern Continental U.S.. a moisture-starved and weakening cold front
will cross the region Sunday night, perhaps inducing a few showers
over Atlantic waters and immediate East Coast, but more likely
precipitation will hold off until Monday as the front stalls over
the Florida straights and low-level moisture increases on gusty
northeast winds. Temperatures behind the front, which will
reinforce the relatively low sfc dewpoints across the region,
will only be a few degrees cooler.
Long term (monday night through friday)
Moisture will increase further Monday night and into Tuesday, as
flow aloft turns southwesterly as shortwave trough digs into the
Gulf Coast states. There may be enough instability to induce a few
thunderstorms Tuesday afternoon. By Wednesday, the aforementioned
stalled front over the Florida straights will have retreated
northward into central Florida as a developing warm front. Winds
will turn southerly and more humid conditions are expected. The
pattern becomes fairly complex and models are in high disagreement
on how low-pressure and subsequent cold front will impact South
Florida. The GFS solution depicts a southern jet branch shortwave
trough interacting with the northern stream to close off and
deepen an upper-level lopres over the Gulf states, moving it
across Georgia and the Carolinas by Friday. This solution would induce
cyclogenesis over the east/NE Gulf of Mexico and track a reasonably
strong surface low across north/c Florida Wednesday night through
Thanksgiving night, bringing a good chance of showers and possibly
some thunderstorms to South Florida, before a cold front brings
noticeably cooler air and drier air into the region for Friday.
ECMWF, however, keep the jet interaction limited, and projects an
open, highly positively tilted trough cross the region through
the end of the period. In this scenario, surface low pressure
development would be questionable, and precipitation would be
focused along a much weaker cold front that would likely stall
over central and South Florida through the end of the week,
keeping warm, humid, and potential wet weather over our region.
high pressure will dominate this weekend, bringing lighter winds
and dry conditions. Sunday night a cold front will move through
the waters, bringing gusty winds and higher seas through Monday
night, and small craft advisories may be needed. Shower chances,
especially over Atlantic waters, will increase behind this Front.
a moderate risk of rip currents exists on Atlantic beaches today
due to moderate easterly winds and a small northeasterly swell.
This swell may persist into Sunday. By Monday, a cold front will
have passed through the region, bringing NE wind of 20 to 25 mph.
This will increase the Atlantic coast rip current risk through at
Preliminary point temps/pops...
West Palm Beach 81 65 83 65 / 0 0 0 20
Fort Lauderdale 81 67 83 67 / 0 0 0 20
Miami 83 68 83 67 / 0 0 0 10
Naples 82 64 81 61 / 0 0 0 0