Area Forecast Discussion
Issued by NWS Miami, FL

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FXUS62 KMFL 272318
AFDMFL

Area Forecast Discussion
National Weather Service Miami FL
718 PM EDT Tue Sep 27 2016

.UPDATE...
Most shower activity has migrated into Central Florida with
mainly large areas of stratiform rain still lingering around Lake
Okeechobee. Most of the convection generated by the seabreeze-
outflow boundary interactions is now dissipated, although around
7pm EDT radar data was still showing some leftover outflow
boundaries lingering over the Atlantic coastal waters east of
Miami Beach.

A few storms could develop during the rest of the evening hours,
then weather becomes mainly quiet overnight. Current forecast
package remains on track and no significant changes are required
for the evening update.

&&

.PREV DISCUSSION... /issued 339 PM EDT Tue Sep 27 2016/

DISCUSSION...
Short Term (Tonight through Thursday)...deep mid level trough over
the northern states is sending a trough axis into the eastern Gulf
Waters, while low level weak ridging remains over the west
Atlantic. This synoptic setup is keeping an overall southerly flow
aloft over South Florida, with deep tropical moisture streaming
from southwest to north-northeast across the CWA through tonight.
Very heavy rain affected areas over West Palm Beach, and earlier
this afternoon over 4 inches of rain in two hours were reported
over Redland.

Scattered to numerous showers and thunderstorms will continue to affect
most of the area, especially the eastern half of South Florida
through the rest of the afternoon and into the early evening
hours. Coverage should become scattered for the rest of this
evening. However, with deep layer moisture in place and lingering
outflow boundaries across the area, it is possible to still see a
strong cell or two during the late evening hours.

On the short term, models show the aforementioned trough gradually
weakening, but still keeping deep layer southwesterly flow and
streaming moisture across the state. This pattern should keep convective
activity favoring the eastern half of South Florida, mainly in
the afternoon hours. Expect scattered to numerous showers and
thunderstorms each day, with the west coast sea breeze also contributing
convection over the western half of the CWA. Main weather threats
will be very heavy rain at times and lightning strikes.

Long Term (Thursday night through Tuesday)...model solutions show
fair agreement in bringing a weak cold front boundary over
Northern Florida Thursday and gradually stalling it near Central
Florida on the Friday-Saturday timeframe. The front seems to
quickly break down by Sunday.

Assuming the front follows the model scenarios, expect deep moisture
and warm temperatures to prevail over South Florida during the
long term with mainly scattered afternoon convection each day.
Meanwhile, sfc high pressure should strengthen over the west
Atlantic, bringing back a more typical easterly/northeasterly flow
across the area by Sunday, and likely getting moderate or even
breezy at times early next week.

MARINE...
Winds and seas should remain well below highlight criteria through
the weekend. Only exception will be around thunderstorms, which
will produce brief periods of gusty winds and rough seas. A few
waterspouts are also possible. Winds should become more easterly
and northeasterly early next week, possibly breezy at times.

AVIATION...
Widespread showers and thunderstorms will continue to slowly drift
northward through this afternoon, mainly affecting the east coast
TAF sites. Bases of the bkn/ovc cloud deck are between 2000-3000
ft msl. The strongest storms will be capable of lowering vis to
below 2 sm and producing erratic wind gusts between 30-40 kt.
Showers may remain isolated around KAPF. Thunderstorm activity will
begin to dwindle this evening with VCSH continuing to affect the
east coast through tonight.
&&

.PRELIMINARY POINT TEMPS/POPS...
West Palm Beach  73  90  74  90 /  40  50  30  40
Fort Lauderdale  74  89  76  90 /  40  50  30  50
Miami            74  90  76  91 /  40  50  30  50
Naples           74  88  75  89 /  30  40  30  40

&&

.MFL WATCHES/WARNINGS/ADVISORIES...
FL...None.
AM...None.
GM...None.
&&

$$


Update...17/AR



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