161 
fxus66 khnx 141445 
afdhnx 


Area forecast discussion...updated for aviation 
National Weather Service San Joaquin Valley - Hanford California 
740 am PDT sun Mar 14 2010 


Synopsis... 
a ridge of high pressure is moving into the area. Warmer 
temperatures and dry conditions will prevail today through much of 
next week. 


&& 


Discussion... 
at 08z /midnight PST/...the fast-moving storm was over northern 
Arizona. Satellite loops show stratocumulus pooled over the south 
end of the San Joaquin Valley and into the adjacent valley-facing 
passes and canyons...otherwise skies are clear. Except for the cloud- 
covered south end...dewpoints around the central and southern San 
Joaquin Valley at 08z were in the upper 20s to middle 30s. This is a 
dry airmass...with dewpoints down as much as 22 degrees from 08z 
Saturday. Wind speeds were between 3-10 miles per hour...and the main concern 
this morning is whether there will be enough mixing to keep minimum 
temperatures above freezing. 


An upper-level ridge will begin building into northern California 
this morning...with the ridge axis over the Hanford warning/forecast 
area by 18z Monday. 500-mb heights over the region are forecast to 
climb to 5820 meters by 06z Tuesday as the ridge amplifies ahead of 
a trough moving into the Pacific northwest. 


The trough will move onshore Tuesday...pushing the ridge southeast 
into The Four-Corners area. The trough is forecast to dig into the 
Great Basin by 12z Thursday...and may bring enough dynamics for a 
slight chance of snow showers along the southern Sierra Nevada 
crest Wednesday night and Thursday. 


The next upper-level ridge approaches the California coast Thursday 
afternoon and moves over the state Friday. The ridge flattens Friday 
night as the next trough moves into the Pacific northwest... 
rebounding a bit Saturday. 


With the exception of the slight chance probability of precipitation along the Sierra crest 
Wednesday night and Thursday...the forecast is dry through the 
extended forecast period. However...both the GFS and European model (ecmwf) do hint 
at changes for the first part of next week. 


Concerning temperatures...the models increase 1000-500-mb 
thicknesses over the Hanford warning/forecast area to around 5600 
meters Tuesday...and again Friday. 850-mb temperatures over the 
central California interior warm to 12-14 c by 00z Wednesday...and 
are forecast to be around 1 c warmer on Friday. Tuesday should be 
the warmest day of the week...though...as temperatures will build on 
the warming today and Monday...while Friday/S warming immediately 
follows Thursday/S trough. Highs Tuesday are forecast to be in the 
middle to upper 70s...around 7-10 degrees above normal...then remain 
above normal through the rest of the week. 


Note...Spring begins at 1732z /1032 PDT/ on March 20th. 


&& 


Aviation... 
VFR conditions can be expected throughout the central California 
interior through at least 12z Monday. 


&& 


Air quality issues... 
none. 


&& 


Hnx watches/warnings/advisories... 
none. 


&& 


$$ 


Public...Sanger 
AVN/fw...durfee 
synopsis...pj 


Weather.Gov/Hanford