Area Forecast Discussion
Issued by NWS Las Vegas, NV
FXUS65 KVEF 301030
Area Forecast Discussion
National Weather Service Las Vegas NV
330 AM PDT TUE AUG 30 2016
.SYNOPSIS...Dry conditions and slightly warmer temperatures are
in store across the area today before slight chances of
thunderstorms return to southeast Nevada and northwest Arizona
Wednesday through Friday. Dry weather and temperatures cooling a
little below normal can be expected over the weekend and early next
.SHORT TERM...Today through Thursday night.
The main forecast problem will be determining how far west moisture
and resulting chances for showers and thunderstorms will spread
across southeast California and southern Nevada as it is pulled up
from Mexico late Wednesday through Thursday. Satellite loops showed
an inverted trough and substantial moisture associated with it
moving up toward northwest Mexico. The area of high pressure over
the forecast area today will give way to a deepening trough
currently off the Pacific Northwest coast. As this trough digs along
the west coast Wednesday and Thursday, it will produce an increasing
southerly flow below 700 mb up through northwest Arizona and
southwest Utah with the moisture boundary setting up near bordering
zones in Nevada and California. Broad ascent associated with the
leading edge of the trough will increase across the same area
leading to at least a slight chance of showers and thunderstorms as
early as Wednesday afternoon across the higher terrain of San
Bernardino, Clark and eastern Lincoln counties. Models are beginning
to show better agreement at the potential for isolated showers and
thunderstorms continuing over the same areas Wednesday night then
focusing over the mountains of Clark, Lincoln and Mohave counties.
Increasing shear may help sustain thunderstorms as they move off the
Spring mountains and Sheep Range and impact the northwest Las Vegas
Valley and other zones to the northeast of higher terrain.
Confidence is still low to moderate in this scenario, but
probability of precipitation values were increased into the 15-20
percent range. Temperatures will peak today then lower 3-5 degrees
by Thursday under the influence of the trough and rising dewpoints.
.LONG TERM...Friday through Tuesday.
There is good agreement that the incoming trough will bring
increasingly dry southwest flow to the region Friday and especially
Saturday through early next week. This pattern will keep a dry
southwest flow over the region with a slight cooling trend and
.AVIATION...For McCarran...Light winds favoring typical diurnal
trends are expected today and tonight. No significant weather is
For the rest of southern Nevada...northwest Arizona...and southeast
California...Light winds favoring typical diurnal trends are
expected today and tonight across most of the region. Gusty south-
southeast winds of 15-20 knots will develop up the Owens Valley this
afternoon. Otherwise, no significant weather is expected.
.SPOTTER INFORMATION STATEMENT...Spotters are encouraged to report
significant weather according to standard operating procedures.
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