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-- Discussion containing changed information from previous version are highlighted. --
000
FXUS65 KVEF 222115
AFDVEF

Area Forecast Discussion
National Weather Service Las Vegas NV
215 PM PDT Tue Aug 22 2017

.SYNOPSIS...
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Isolated thunderstorms will return to much of the
region Wednesday, then moisture decreases and thunderstorm chances
end on Thursday. High pressure regains control Friday, with dry and
hot weather expected through the weekend.
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&&

.DISCUSSION...
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Cumulus clouds over much of the region have produced
even less lightning than was expected today, especially over the
Sierra where zero flashes and strikes had been observed through 2
PM. Reduced PoPs somewhat for the evening there, but spread them a
bit farther south into northern Mohave County where a few strikes
had occurred. Weakening low pressure still expected to move onshore
tomorrow, kicking off a few more storms than today. Any precip
chances Thursday should be limited to Mohave County as the low
weakens and fills. From Friday onward, high pressure building in
will send temperatures 5-10 degrees above late August normals. Heat
Risk grids are showing an outside chance of needing advisories
and/or warnings for the weekend or early next week, while there is
also an outside chance of a record high or two being threatened. The
109F record highs at KLAS on the 26th and 27th are the only two
record highs under 110F in the month of August.
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&&

.AVIATION...
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For McCarran...A light and variable wind, under 8 knots,
will remain through the rest of the afternoon, likely favoring east
southeast direction. Anticipating a shift to a south wind early this
evening between 00z-03z wind and then a drainage wind overnight.
Diurnal winds will set up again Wednesday, however there will be
better chances for thunderstorms in the Mountains and northwest
Arizona, which may direct an outflow boundary toward the terminal.
Few to scattered skies expected with cloud bases between 10-12kft.

For the rest of southern Nevada, northwest Arizona and southeast
California...Typical diurnal winds expected across the region this
evening with mostly clear skies. Wednesday afternoon a southerly
wind will setup and remain through the evening with speeds around 5-
15 knots. Shower and thunderstorm activity will increase Wednesday
afternoon. This activity will be focused over the south Sierra,
northwest Arizona, and Clark County mountains.
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&&

.SPOTTER INFORMATION STATEMENT...Thunderstorm chances will continue
through Wednesday across portions of the area. Spotters are
encouraged to report any significant weather or impacts according to
standard operating procedures.
&&

$$

Discussion...Morgan
Aviation...Boothe

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