Weather

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fxus65 kvef 071022 cca 
afdvef 


Area forecast discussion...corrected 
National Weather Service Las Vegas Nevada 
320 am PST sun Sep 7 2008 


Synopsis...high pressure will give way to a south to southeast flow 
later today which will persist into the middle of the week. Moisture 
will gradually increase resulting in a slight chance of afternoon 
and evening thunderstorms across mainly northwest Arizona Monday 
through Wednesday. 
&& 


Short term...high pressure which has been over the area for the 
past several days will weaken today giving way to a south to 
southeast flow. This flow will persist through Tuesday with moisture 
gradually increasing. Expect thunderstorms to remain just south and 
east of the forecast area today although we will have to keep an eye 
on the convection which was occurring overnight in central Arizona. 
As moisture and instability works further north and west 
thunderstorm chances will spread into mainly eastern Mohave County 
Monday then across all of Mohave County Tuesday and also across 
eastern San Bernardino and portions of Lincoln County. Expect 
another day of well above normal temperatures today followed by some 
cooling Monday and Tuesday due to the dissipation of the high and 
the increased moisture. Generally light terrain driven winds today 
will give way to somewhat stronger southerly winds in most areas 
Monday and Tuesday. 


Long term...medium range models continue to be in good agreement 
Wednesday with a baggy trough off the southern cal coast which 
provides at least a small chance of precipitation to portions of the southeast 
County Warning Area. The 00z models have followed a trend established by the 12z 
European model (ecmwf) and the 18z GFS diving energy out of Canada Wednesday and 
forming a closed 500 mb low north of the area. This feature is handled 
somewhat differently by the models but they agree that it serves to 
eventually scour moisture out of the region leaving the weekend dry. 
This drier model forecast was in disagreement with the inherited 
pop/wx/sky grids and have thus lowered those values to reflect the 
latest trends. The inherited temperature forecast still looks on 
track with temperatures running slightly above normal and above the mex/men 
guidance numbers. 
&& 


Aviation...for McCarran...other than light overnight southwest 
winds due to diurnal influences...a turn of winds to the southwest 
this afternoon is not clear. The updated 12z taf will likely feature 
an upslope easterly component to the wind for much of the afternoon 
today and Monday. Otherwise...no significant weather is expected at 
the Airport terminal through Monday. Skies are expected to remain 
mostly clear today with some increasing middle level clouds on Monday. 


For the rest of southern Nevada...northwest Arizona...and southeast 
California...no significant weather is expected today with skies 
remaining mostly clear. Winds will generally be from the south to 
southwest at around 10 knots with a few gusts near 20 knots during 
the late afternoon. Increasing moisture will bring increasing clouds 
and a chance of thunderstorms to Mohave County Monday. 
&& 


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


$$ 


Harrison/Salmen 


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