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fxus65 kvef 051028 
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Area forecast discussion 
National Weather Service Las Vegas Nevada 
328 am PDT Sat Jul 5 2008 


Synopsis...a weak trough will continue to move east through the 
area today...bringing drier air to southern Nevada and much of 
southeast California. Moisture will linger over northwest Arizona 
today...with a slight chance of thunderstorms this afternoon. Drier 
air will then push in Sunday...ending the thunderstorm chances. Hot 
weather will continue through next week...with temperatures possibly 
approaching excessive heat warning criteria by the middle of the 
week. 
&& 


Short term...interesting scenario unfolded overnight...leading to 
short lived thunderstorms near the Colorado River from Cottonwood 
Cove to Needles. A strong outflow boundary from evening 
thunderstorms over Arizona rolled in from the east...producing 
southeast winds over 30 miles per hour in Kingman at 9 PM. Around 11 PM...it 
reached the Colorado River and met up with some weak synoptic scale 
lifting associated with the trough coming in from the west. The 
coupled lift was enough to overcome the cap which had been in place 
during the day Friday...and thunderstorms broke out in The Needles 
vicinity just after midnight. The majority of the storms occurred 
between Laughlin and Needles...and the last lightning strike was 
recorded just after 1 am. Since then...the boundary has continued 
west over Clark and San Bernardino counties...producing bands of 
clouds and weak radar returns but no lightning or measurable precipitation. 
Meanwhile...the aforementioned trough has continued to progress 
east...with much drier air noted on satellite northwest of a line 
from Barstow to Mount Charleston to Rachel. This drying/clearing 
should make further eastward progress today...limiting afternoon 
thunder chances to Mohave County again. The westerly flow aloft is 
expected to strengthen a little tomorrow as ridging noses in from 
the Pacific...which should reduce thunderstorm chances below 15 
percent in Mohave County. The moisture will linger near the 
southeast corner of our County warning forecast area through the remainder of the short term 
as the middle level flow weakens. Temperatures will be interesting 
today...as overnight clouds/storms have left a disorganized pattern 
in their wake. Expect most areas to clear out and warm without any 
problems...but small areas near Mohave Valley may be less warm due 
to residual cold pools and soil moisture from thunderstorms. 


Long term...not too much change from previous forecast. Tuesday 
through Thursday will be very warm as ridge holds sway over the 
western Continental U.S.. temperatures will be close to record highs then and 
will be flirting with the excessive heat warning criteria...112 
degrees at Las Vegas...around midweek on. A change is expect to 
start Friday as a trough is expected to be approaching the pacnw 
then. Might see a degree or two of cooling. Uncertainty exists here 
as models differ on timing and depth with the European model (ecmwf) being the 
fastest and deepest. Concur with day shift about the depiction being 
a bit deep for this time of year. Flow changes look favorable Friday 
on for some moisture to be pulled into the southeast part of the 
forecast area and have kept the 20 percent chance for thunderstorms 
Friday in Mohave County. 
&& 


Aviation...for McCarran...pretty much a diurnal wind pattern with 
light and variable this morning becoming south this afternoon and 
then southwest Saturday evening on into Sunday. Cloud cover will be 
minimal. Afternoon thunderstorm are possible in the Peach Springs 
corridor today. 


For the rest of southern Nevada...northwest Arizona...and southeast 
California...in the Sierra and Owens Valley areas smoke layers aloft 
are expected through the weekend. Other item of note is 
thunderstorms are expected again this afternoon in northwest 
Arizona...primarily higher terrain south of Interstate 40. 
&& 


Climate...a record high minimum temperature was set at Las Vegas 
for the 4th of July. The low temperature only dropped to 88 
degrees...which broke the old record of 87 set in 2001. 


Near record to record high temperatures are possible in parts of the 
area on Tuesday and again on Wednesday. The record highs on these 
days are rather low compared to most others in the books for this 
time of year. Las Vegas may also have a good chance to tie the 
record high minimum temperature for Wednesday the 9th of 86 set in 
1996. 


Location record high for 7/8 record high for 7/9 
--------------------------------------------------------------------- 
Las Vegas 113/1989 113/1949 
Bishop 104/2002 107/2002 
Barstow-Daggett 113/1976 113/2002 
Needles 117/1985 119/1961 
&& 


Fire weather...hot and dry conditions will persist through the 
beginning of next week...however...there is an outside chance that 
some moisture may work its way into Mohave County during the middle 
part of next week to possibly allow for isolated thunderstorms to 
develop in the afternoon and evening hours with the main threat from 
any activity being dry lightning. 
&& 


Vef watches/warnings/advisories... 
Nevada...none. 
Arizona...none. 
California...none. 
&& 


$$ 


Morgan/Jacques 


Http://weather.Gov/lasvegas