472 
FXUS65 KVEF 180457
AFDVEF

Area Forecast Discussion
National Weather Service Las Vegas NV
857 PM PST Tue Dec 17 2019

.SYNOPSIS...Look for increasing high level cloud cover tonight
ahead of a weak disturbance that will pass by Wednesday. From 
Thursday through Saturday, high pressure will return and bring dry
and warmer weather. A series of Pacific storm systems could bring
recurring rounds of precipitation next week.
&&

.UPDATE...Satellite imagery shows abundant high clouds over the
forecast area this evening with temperatures running within a few
degrees of 9 pm PST temps yesterday. Satellite shows a distinct
clearing between the thick batch of high clouds currently over the
forecast area and the next batch over west central California.
HiRes ensemble forecasts clear this first batch out from west to 
east overnight into early Wednesday morning. Winds overall are
expected to be light overnight. Temperatures in the morning will
continue to run well below normal across much of the region. Made
a few tweaks to the forecast but nothing significant.
&&

.PREV DISCUSSION... /issued at 155 PM PST by National Weather 
Service Flagstaff AZ/

.DISCUSSION...
Todays wind advisory for portions of the Lower Colorado River 
Valley is verifying well this afternoon and will remain in effect
through the early evening. Satellite imagery this afternoon shows
some cirrus has moved east of the Sierra crest and will spread
across all of southern Nevada tonight. These clouds are out ahead
of a weakening trough of low pressure that will cross the area
Wednesday. Precipitation chances are limited to the Sierra crest
with this system. 

From Thursday through Saturday - A broad high pressure system to 
build and slowly cross the desert southwest during this period. 
Expect dry weather with a warming trend.

Sunday through Tuesday - Models are showing a stronger trough of 
low pressure to approach the West coast on Sunday, and then moving
slowly across the forecast area through Tuesday. Forecast precip 
chances start mid day Sunday across the Sierra Nevada mountains, 
and expand eastward to cover all of the forecast area by Monday 
afternoon. Rain and high elevation snow chances continue through 
Tuesday. 
&&

.AVIATION...For McCarran...Generally light winds expected 
through Wednesday. Batches of thicker high clouds with bases AOA 15 
Kft will move into the area this evening through Wednesday. No 
operationally significant weather is forecast at this time.

For the rest of southern Nevada, northwest Arizona and southeast 
California...Gusty north winds will continue down the Colorado River 
Valley through late this evening, with decreasing speeds on 
Wednesday. High clouds with bases AOA 15 Kft will drift over the 
area through Wednesday, with no other significant weather forecast.
&&

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

UPDATE...Salmen

DISCUSSION/AVIATION...NWS FGZ

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