800 
FXUS65 KVEF 040143
AFDVEF

Area Forecast Discussion
National Weather Service Las Vegas NV
643 PM PDT Fri Sep 3 2021

.SYNOPSIS...Expect dry weather with a warming trend, peaking early 
next week as high pressure builds overhead. Excessive Heat Watches 
are in effect for parts of the Mojave Desert for Labor Day and 
Tuesday. A low-grade push of moisture will bring isolated 
thunderstorms to the area in the second half of next week.
&&

.UPDATE...No changes needed to the evening and overnight forecast. 
Clear skies and dry weather will continue through the night. 
Afternoon breezes of 20-25MPH will continue to diminish, with light 
winds likely in most locations after sunset. Low temperatures will 
be comparable to last night's temperatures. 
&&

.PREVIOUS DISCUSSION...111 PM PDT Fri Sep 3 2021
.SHORT TERM...through tonight. Satellite loop showed cumulus 
developing over the higher terrain of Mohave and Lincoln counties, 
with clear skies elsewhere as of noon. The only spot of concern for 
thunderstorm development looks like the Mount Trumbull area, and 
there's only a very small chance there. Nudged up NBM output to show 
10-15 PoPs there. Otherwise, haze and smoke in the Owens Valley is 
about the only impactful weather expected today. Heat becomes a 
problem by Labor Day - more on that in the long term section.

.LONG TERM...Saturday through Thursday.

High pressure will build into the region through early next week, 
which will result in climbing temperatures. Above normal 
temperatures are expected Sunday through at least Tuesday. ECMWF 
EFIs do hint at anomalous max and min temperatures Monday and 
Tuesday of next week, and this will likely be the hottest stretch of 
the period. High heat risk is noted in spots early next week, 
especially through southern Nevada through Inyo County. Hoisted an 
Excessive Heat Watch for a considerable portion of the lower 
elevations of the Mojave Desert for Monday and Tuesday.

Dry weather is likely through Tuesday as westerly flow and building 
heights keep the area free of precipitation chances. By midweek, 
models hint that the area of high pressure will retreat east and set 
up in a more favorable setup for increasing moisture and monsoonal 
thunderstorms. Ensemble meteograms show many members bringing higher 
PWATs around 1 inch to areas of Arizona and southern Nevada, though 
with each new model run the moisture is slower to arrive. The 
monsoonal set up may be short-lived though as another trough 
swinging into the West Coast later in the week, so it could be a 
short window for an uptick in thunderstorm activity and monsoonal 
impacts.
&&

.AVIATION...For McCarran...Southwest winds will continue through 
the evening hours  gusting from 15-20 kts. After sunset, wind will 
decrease but remain southwesterly overnight. Light and variable 
winds will return Saturday morning. No operationally significant 
cloud cover expected through the TAF period.

For the rest of southern Nevada, northwest Arizona and southeast 
California...Wind will generally follow diurnal trends. Gusts up to 
20 kts possible for the Las Vegas Valley and Owens Valley TAF sites 
from the southwest and southeast, respectively, that will fall off 
around sunset. No operationally significant cloud cover expected 
through the TAF period.
&&

.SPOTTER INFORMATION STATEMENT...Spotters are encouraged to report
any significant weather or impacts according to standard operating
procedures.
&&

$$ UPDATE...Nickerson
SHORT TERM...Morgan 
LONG TERM...Nickerson/Morgan 
AVIATION...Berc

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