Scientific Forecaster Discussion

NWS Discussion
			
				

Area forecast discussion 
National Weather Service San Joaquin Valley - Hanford California 
320 am PDT Wednesday Jun 19 2013 


Synopsis... 
a storm system moving over the Pacific northwest will bring in 
cooler temperatures along with breezy to gusty conditions through 
tonight. A warming trend will begin on Thursday with temperatures 
climbing to above normal for the weekend. Dry weather will prevail 
through the period. 


&& 


Discussion... 
satellite loops show the upper-level trough moving into the Hanford 
warning/forecast area this morning. Although this trough is dry for 
central California...it is bringing gusty winds to parts of the Kern 
County mountains and deserts...and breezy conditions to the San 
Joaquin Valley. As of 0915z /0215 PDT/ this morning...winds continue 
to gust to 45 miles per hour or higher over the piutes and the Indian Wells 
Valley including Ridgecrest...and isolated gusts over 60 miles per hour near 
the crest of the piutes at Bird Springs pass. The NAM-12 shows strong 
subsidence over the piutes pulling a low-level jet down toward the 
crest...and winds funneling through the high-elevation passes and 
canyons likely are the cause of the high winds at Bird Springs pass 
as these winds are not being seen elsewhere in the Kern County 
mountains. 


The models forecast the surface-pressure gradients to tighten this 
afternoon as a short-wave drops into the trough...with gusts 
decreasing a bit around sunrise before increasing back above 
advisory criteria this afternoon. Have therefore extended the Wind 
Advisory for the Kern County mountains and deserts through 12z /0500 
PDT/ Thursday morning. 


Temperatures in the central and southern San Joaquin Valley as of 
09z /0200 PDT/ this morning were as much as 8 degrees cooler than 24 
hours earlier as colder air fills the San Joaquin Valley. With a 
cool airmass in place...high temperatures this afternoon will be only 
in the lower to middle 80s...some 10 to 15 degrees below normal. 


The upper-level trough axis is forecast to swing through central 
California this morning...with the aforementioned short-wave keeping 
troughiness over the region through tonight. 500-mb heights will 
begin to rise Thursday...with the 500-mb 5820-meter height line over 
the Tehachapi Mountains by 00z Friday /1700 PDT Thursday/. 


Temperatures are forecast to warm to near normal Friday...and to a 
few degrees above normal for the weekend into the first part of 
next week. An upper-level short-wave rotating around a low in the 
Gulf of Alaska will move through the central California interior 
Sunday. This short-wave will bring minor fluctuations in temperature 
and an increase in middle and high clouds to mainly the northern part 
of the Hanford warning/forecast area but no precipitation. 


An upper-level ridge is forecast to build westward from the Desert 
Southwest into California by the middle of next week for a warming 
trend for the end of the month. 


It will be dry through the seven-day forecast period...including 
June 21st and extending the record of it never having rained in 
Fresno on a June 21st since rainfall records began in 1878. This 
is the only day for Fresno never to have seen any rain in the 
history of weather observations. 


Note...Summer begins on June 20th at 2204 PDT. 


&& 


Aviation... 
VFR conditions can be expected throughout the central California 
interior. Wind gusts around 45 knots possible near the Kern County 
mountain passes and around 30 knots along the west side of the San 
Joaquin Valley through 12z Thursday. 


&& 


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 medium. 


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 06-19 106:1962 72:1897 75:1918 51:1893 
kfat 06-20 110:1920 78:1897 75:1918 50:1908 
kfat 06-21 110:2008 77:1944 75:2008 51:1912 


Kbfl 06-19 107:1947 75:1923 75:1988 43:1913 
kbfl 06-20 113:1920 82:1944 79:1981 47:1913 
kbfl 06-21 110:2008 75:1944 77:1981 46:1907 


&& 


Hnx watches/warnings/advisories... 
Wind Advisory until 5 am PDT Thursday for the Kern County 
mountains and deserts /caz095-098-099/. 


&& 


$$ 


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


Weather.Gov/Hanford