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Area forecast discussion...updated 
National Weather Service Miami Florida
918 am EDT Friday Aug 22 2014

Update...
high pressure over the southeastern United States will allow for a
light northeast to east wind flow over South Florida today. This
will allow for both the east and West Coast sea breezes to develop
and push inland...with the East Coast sea breeze being the main
sea breeze pushing across South Florida.

Scattered to numerous showers and thunderstorms should develop
over the interior and West Coast metropolitan areas this afternoon
where the sea breezes collide. Therefore...the low end chance of
probability of precipitation will remain in place over the East Coast metropolitan areas for
mainly late this morning into early this afternoon...and scattered
to numerous probability of precipitation will remain over the interior and West Coast
metropolitan areas for this afternoon.

A few of the storms could become strong this afternoon over the
interior and West Coast metropolitan areas where the sea breezes
collide as the 500 mb temperatures will be around -7.7c. So will
continue to mention this in the South Florida severe weather potential statement package for
today.

Rest of the forecast looks good at this time and no other changes
are planned at this time.

&&
Update...54/bnb



Previous discussion... /issued 820 am EDT Friday Aug 22 2014/

Aviation...
deep layer high pressure will remain over the southeast
today...and a light northeasterly flow will continue aloft. Light
winds this morning will turn onshore as sea breeze boundaries move
inland. Although most of the shower and storm activity will be to
the west of the East Coast taf sites this afternoon...a few storms
may initially develop near the East Coast along the sea breeze. So
added thunderstorms in the vicinity from 17-21z. Storms are expected to move off to the
west this afternoon...and storms could get near kapf in the
afternoon. VFR conditions and light winds are expected again
overnight.

&&

Previous discussion... /issued 311 am EDT Friday Aug 22 2014/

Discussion...

The main synoptic feature on the weather map is the large area of
high pressure located over the southeastern US. This high will have
an effect on our weather until the middle of next week. This strong
high will provide for a channel in the atmosphere where impulses of
moist air and dry air travel around it reaching our area from the
northeast. Currently, an impulse of moist air is passing through the
Florida Straits enhancing the shower activity over the coastal
waters. At this time winds above the boundary layer are turning
more north/NE in the northern portion of the Atlantic waters
influenced by the flow around this high pressure. These winds are
interacting with easterly flow over the southern portion of the
waters allowing for showers and thunderstorms to develop along
this interface over the Atlantic waters.

Drier air still forecast to affect South Florida over the weekend,
especially on Sunday, which is expected to decrease the coverage of
showers and thunderstorms. However, showers and thunderstorms are
still possible each day mainly focused over the interior. Another
area of moist air rotates around the high and it could possibly
affect South Florida on Monday before much drier air at the middle
levels affects South Florida on Tuesday. There is still very
little confidence with this forecast due to the high amplitude of
the synoptic situation. The 00z mfl sounding shows already a
slight warming in the middle levels compared to previous days. This
trend is forecast to continue during the course of the weekend and
early next week. In addition to the increase in middle level
temperatures, the 500 to 700 mb lapse rate also decreases
substantially.

There is is still considerable uncertainty with the area of
disturbed weather in the Atlantic. However, the GFS and European model (ecmwf) are
now in line and both models move it northward east of Florida following
the western edge of the Atlantic trough before the southeast US ridge moves
to the western Atlantic.

A slight risk of rip currents is in effect for the Atlantic
waters, especially for Miami-Dade and Broward.

Marine...

Winds are forecast to remain easterly across the Atlantic waters
around or below 10 knots and persisting through the weekend. As a
result, seas are forecast to be 2 feet or less through this time
frame.

&&

Preliminary point temps/pops...
West Palm Beach 92 78 91 78 / 20 10 10 10
Fort Lauderdale 91 80 92 80 / 20 0 10 0
Miami 92 80 91 79 / 20 0 10 0
Naples 93 78 91 79 / 50 10 20 10

&&

Mfl watches/warnings/advisories...
Florida...none.
Am...none.
GM...none.
&&

$$

Short term...54/bnb
long term....71/je

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