Area forecast discussion
National Weather Service Las Vegas Nevada
838 am PDT Thursday may 23 2013
Synopsis...a large area of low pressure will remain over the
Pacific northwest through the coming Holiday weekend with a dry
southwest flow over the southern Great Basin and Mojave Desert.
Winds will not be quite as strong today and will drop off a bit more
on Friday but locally breezy afternoons will continue through the
weekend.
&&
Update...sunny...very dry and locally breezy to windy today.
Temperatures a little below normal. No updates needed this morning.
&&
Aviation...for McCarran...strong southwest winds of 20-30 kts are
expected today before beginning to taper off by middle evening.
Directions favoring configuration #1 are expected through at least
Friday.
For the rest of southern Nevada...northwest Arizona...and southeast
California...south to southwest winds of 15-25 kts with gusts to
25-35 kts will continue through the day with the strongest winds
across the western Mojave Desert and northwest Arizona where gusts
up to 45 kts will be possible. Skies will remain mostly clear.
&&
Previous discussion...
330 am PDT Thursday may 23 2013
Short term...today through Saturday night...the closed low
circulating over the Pacific northwest will continue to bring breezy
to windy conditions across the forecast area today. A fairly strong
surface pressure gradient will remain in place across the western
Mojave Desert and another vorticity lobe swinging through the base of the
system across central Nevada should lead to gusts over 40 miles per hour across
northwest San Bernardino County this afternoon and evening. Another
Wind Advisory was issued from noon until 9 PM PDT. The latest models
all indicate the center of the Pacific low will lift into southwest
Canada and weaken Friday and Saturday which will allow wind speeds
to decrease considerably and temperatures to trend slightly upward
across the forecast area.
Long term...persistent trough over the West Coast is expected to
remain in place through the extended period. There have been some
significant model changes over the past 24 hours starting Monday
afternoon. All models are in good agreement that a fairly strong
piece of energy will drop south along the California coast and
eventually move across southern Nevada Monday and Tuesday. The only
real difference in the models is actual track of the system as it
move across the area. The GFS/Gem models take this system further
inland while the European model (ecmwf) tracks this feature off the coast before
turning inland Tuesday afternoon and Wednesday. Breezy to windy
conditions would be expected Monday and Tuesday afternoons...but the
real question is precipitation. Since the European model (ecmwf) tracks this feature
further off shore it has time to gather Pacific moisture before
turning inland. The 00z run shows a fairly widespread area of light
precipitation over the area from Tuesday afternoon through
Wednesday. The GFS/Gem models are not a wet since the track is
further inland. However...they are both generating some
precipitation further south than previous runs. Did go ahead and up
probability of precipitation to slight chances over the higher elevations for now. As this
system exits east late Wednesday and Thursday another low will push
into the Pacific northwest which in turn will help redevelop a
trough over the West Coast. This will again lead to occasional
breezy conditions. Temperatures will be close to normal Monday and
Tuesday...but drop to potentially several degrees below normal
Wednesday and Thursday before warming back to near normal by Friday.
&&
Fire weather...southwest winds gusting over 35 miles per hour are expected
again today across much of Mohave County so a red flag warning
remains in effect for zone 102 from 10 am this morning to 8 PM MST
this evening. Lighter winds are expected Friday but afternoon gusts
around 25 miles per hour will be common through the Holiday weekend across
northwest Arizona.
&&
Vef watches/warnings/advisories...
Nevada...none.
Arizona...red flag warning from 10 am this morning to 8 PM MST this
evening for azz102.
California...Wind Advisory from noon today to 9 PM PDT this evening for
caz523.
&&
$$
Update...Harrison
aviation...Kennedy
previous discussion...Adair/gorelow
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