468 
fxus66 khnx 052151 
afdhnx 


Area forecast discussion 
National Weather Service San Joaquin Valley - Hanford California 
251 PM PDT Sat Jul 5 2008 


Discussion...water vapor satellite imagery shows zonal flow over 
central California with the last bit of shortwave trough energy shifting 
inland over the pacnw. Clear skies have allowed temperatures to 
rebound from yesterday/S cooldown and are on track to top out 
close to climatology. Upper ridging will begin building over the epac 
on Sunday and then merge with the Desert Southwest ridge on Monday. 
This ridge pattern will remain in place for much of next week 
leading to hot and dry conditions across the central and southern 
San Joaquin Valley...the adjacent foothills...and the Kern desert. 
Temperatures will steadily climb through Wednesday then change 
little on Thursday. Triple digit heat will first become widespread 
over the valley by Monday then increase further Tuesday and 
Wednesday to as much as 10-15 degrees above climatology. Valley highs 
Tuesday through Thursday will generally range from 105-110 degrees 
and up to 115 degrees in the Kern desert. But given the dry 
airmass...heat index values are expected to be a little below the 
ambient air temperature. Therefore heat advisory conditions are 
not likely at this time. But a Special Weather Statement has been 
issued highlighting the concerns of this upcoming heat wave. The 
models are trying to bring an upper trough into California on 
Friday to bring some relief from the heat. Often times the models 
are too quick to break down such a strong ridge and feel this may 
be the case again. While some weakening is probable at the end of 
the week leading to a cooling trend...will keep temperatures a little 
above guidance. 


One other concern is for the potential for monsoonal moisture to 
affect the district later next week. The medium range models do 
show an increase in 700 mb relative humidity from the southeast...possibly enough 
by Thursday to lead to some convection. So have increased cloud 
cover Thursday and Friday primarily over the Kern Mountains and 
desert and up the Sierra crest. But only introduced token probability of precipitation at 
this time as confidence is low. 




&& 


Aviation...conditions will remain VFR through 00z Monday over most 
of the region with local MVFR conditions over the mountains due to 
smoke from wildfires. 




&& 


Air quality issues... 
none 


&& 


Hnx watches/warnings/advisories... 
none. 
&& 


$$ 


Public...dch 
AVN/fw...ds 


Weather.Gov/Hanford