Scientific Forecaster Discussion

NWS Discussion
			
				

Area forecast discussion 
National Weather Service San Joaquin Valley - Hanford California 
320 am PDT Sat may 25 2013 


Synopsis... 
a storm system over the Pacific northwest will bring a cool onshore 
flow to the central California interior through the Holiday weekend. 
Temperatures will be near normal through Sunday. Memorial Day will 
bring increasing clouds and cooler afternoon temperatures with the 
possibility of light precipitation mainly over the High Sierra toward 
evening. 


&& 


Discussion... 
satellite loops show the upper-level low over the Pacific northwest 
this morning with a trough moving over the northern half of 
California. A westerly jet moving around the base of the trough has 
produced local gusts over 40 miles per hour near Cache creek...but these have 
been confined to that area and do not plan any wind headlines at 
this time. 


At 09z /0200 PDT/ this morning...temperatures in the central and 
southern San Joaquin Valley were running mostly a few degrees above 
persistence. With the trough nearly stationary...little change is 
forecast in 500-mb heights from 00z Saturday /1700 PDT Friday/ to 
00z Sunday. The onshore flow likely will offset the slightly longer 
daylight period and high temperatures today should be similar to 
Friday. Sunday should be similar to today...except that as the 
trough deepens there will be better support for an increase in 
desert winds. 


The forecast problem for this morning is the possibility of 
precipitation for Memorial Day and Tuesday. There is disagreement 
between the 00z GFS and the 00z European model (ecmwf)...with the GFS having a dry 
solution and the European model (ecmwf) being the wetter model. Both models bring the 
trough axis through the Hanford warning/forecast area Monday night 
and the main difference between the two models is that the European model (ecmwf) has 
more middle-level moisture. 


The forecast is a blend between the two models with heavier weight 
toward the European model (ecmwf). Precipitation will begin Monday afternoon near 
Yosemite National Park...with the snow level around 8500-9000 feet. 
Rain and high-elevation snow will spread south overnight...with 
chance probability of precipitation as far south as Kings and the northern half of Tulare 
County...and slight chance probability of precipitation south through the Tehachapi 
Mountains and the western Kern County desert. Precipitation will 
diminish from the south Tuesday into Tuesday evening...lingering 
over the southern Sierra Nevada through Tuesday night. 


At this time...total snow accumulations for Yosemite National Park 
are forecast to be 1-2 inches above 9000 feet. 


Temperatures are forecast to remain a few degrees below normal 
through the weekend...then fall back into the 70s Monday as the 
trough deepens over the central California interior. Temperatures 
will warm back into the lower 80s Wednesday...and will be near 
normal by the end of the week. 


&& 


Aviation... 
VFR conditions will prevail across the central California interior. 


&& 


Air quality issues... 
none. 


&& 


Certainty... 


The level of certainty for days 1 and 2 is high. 
The level of certainty for days 3 through 7 is low. 


This information is provided as part of a trial project conducted 
by the National Weather Service San Joaquin Valley - Hanford. 
Certainty levels include low...medium...and high. Please visit 
www.Weather.Gov/hnx/certainty.Php /all lower case/ for additional 
information and/or to provide feedback. 


&& 


Climate... 
records 
site date hi_max:year lo_max:year hi_min:year lo_min:year 


Kfat 05-25 102:1890 59:1906 68:1890 42:1980 
kfat 05-26 103:1974 66:1946 68:1951 40:1953 
kfat 05-27 104:1974 55:1971 69:1896 46:1998 


Kbfl 05-25 106:1982 58:2008 77:1982 39:1893 
kbfl 05-26 107:1951 68:1998 72:1979 40:1918 
kbfl 05-27 106:1974 66:1971 75:1974 42:1917 


&& 


Hnx watches/warnings/advisories... 
none. 


&& 


$$ 


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


Weather.Gov/Hanford