Area Forecast Discussion
Issued by NWS Miami, FL

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FXUS62 KMFL 191541

Area Forecast Discussion
National Weather Service Miami FL
1041 AM EST Sun Feb 19 2017

Fog has lifted this morning as gusty SW winds have developed. This
trend should allow for east coast metropolitan areas to reach mid
80s this afternoon. Guidance continues to hint at /and 12Z RAOB
supports/ isolated to perhaps scattered afternoon shower coverage
over eastern Palm Beach County and coastal sections of Miami-Dade
and Broward counties. Can`t totally rule out a thunderstorm over
Atlantic waters. Updated forecast grids reflect slightly raising
maxima and reducing shower chances over NW CWA.


.PREV DISCUSSION... /issued 606 AM EST Sun Feb 19 2017/


Patchy fog with some dense fog possible is across portions of the
interior peninsula early this morning but thus far not affecting
the terminals. However, terminals KAPF and KTMB are experiencing
fog/low stratus with KTMB possibly having periods of MVFR to near
IFR conditions around 12z and could start clearing around 13-14z.
Otherwise, mid-level disturbance will continue across Central
Florida today, with VCSH assigned Atlantic terminals at 18Z.
Isolated thunderstorms forecast across the Atlantic waters after
18z, but low confidence and not expected to impact terminals.
Westerly to northwesterly winds forecast through at least 21z.


PREV DISCUSSION... /issued 252 AM EST Sun Feb 19 2017/

Weather remains pretty quiet this morning as showers associated
with a mid-level disturbance push across Central Florida. The
ample amounts of low level moisture across South Florida have led
to fog development in low-lying, fog-prone areas this
morning...have included a mention of patchy dense fog with the
pre-dawn grids. As the fog dissipates, some showers will be
possible over northern portions of the forecast area around Lake
Okeechobee and Palm Beach County. The best chances for
thunderstorms today appear to exist over the Atlantic waters where
the warmer waters of the Gulf stream and the potential mid and
upper level support from the trough are potential ingredients.

High pressure will build in across the area to start the week.
This will usher in a relatively drier pattern and help limit some
of the fog potential. The dry period will be short lived as a
mid-level cutoff low pushes into the Gulf Tuesday into Wednesday
and moves eastward towards the state. Guidance has become slightly
less consistent over the last couple of runs with the solution of
this event. This is particularly true with the latest GFS which
has weakened the system considerably as it moves past Florida late
on Wednesday through Thursday before it exits into the Atlantic on

The 00z ECMWF, which has been consistent with this system for
several days, continues to hold firm with the idea that a decently
well-defined cutoff low will push between southern Florida and
Cuba later this week. While the timing between both solutions is
similar, the GFS points to a case where even thunderstorms may be
an ambitious forecast. While the threat of strong to severe storms
appears to be much lower in this forecast cycle compared to a few
nights ago, caution should still be urged and the coming forecast
evolution of the event should be monitored.

The 00z GFS seems to be an outlier again like it was in the early
days of this event, but the ECMWF consistency does not guarantee
a better forecast either. We will have to keep an eye on the
upstream development of this system earlier in the week to see its
potential impacts on us. Have re-added slight chance of thunder
areawide as the risk is high enough to warrant mentioning it in
the forecast. The uncertainty with this system`s track and
intensity is still great enough that eliminating thunder
completely from the forecast is not something I`m comfortable with
at this point. Have lowered PoPs a bit to match the lower
confidence along with the potential for a weaker system pushing
through the region.

To clear things out at the end of the period, a front associated
with a system pushing through the Great Lakes will move through
the state next weekend and help push the remnants of the mid-week
system out into the Atlantic. Temperatures through the period will
stay on the warmer side of seasonal averages.

Marine conditions should remain relatively quiet through the
holiday on Monday with just a few showers and thunderstorms
possible over the waters. Conditions will start to deteriorate
ahead of the next system mid into late week.

West Palm Beach  83  67  80  64 /  30  10   0  10
Fort Lauderdale  85  70  80  67 /  30  10   0   0
Miami            86  68  80  66 /  20  10   0   0
Naples           81  63  82  62 /  10   0   0   0



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