Scientific Forecaster Discussion
Area forecast discussion
National Weather Service San Joaquin Valley - Hanford California
250 am PST sun Dec 28 2014
continued mostly clear skies as weak high pressure dominates. Some
patchy late night through early morning fog possible today as well
as some areas of frost. Colder by midweek with a slight chance of
showers Tuesday into Wednesday.
satellite loops show high clouds beginning to move into interior
central California this morning. These clouds are associated with an
upper-level short-wave dropping through the Pacific northwest into
the Great Basin as an inside slider. This short-wave will keep a
highly-amplified east-Pacific Ridge offshore with a northwesterly
flow continuing over California.
Dewpoints were near persistence at most San Joaquin Valley locations
this morning...and at 10z /0200 PST/ temperatures were in the middle
30s. In the Kern County desert and Indian Wells Valley...temperatures
were down a degree or two from Saturday morning...mostly in the middle
to upper 20s.
The models forecast modest warming over central California at 850 mb
the next couple of days...then 850-mb temperatures are forecast to
plunge 7-10 c Tuesday as the next system arrives. This will bring a
cold airmass for the end of the year...and New Year/S evening could see
light snow in the southern Sierra Nevada foothills as snow levels
fall below 3000 feet.
The models are in good agreement with an upper-level low dropping
down the leading edge of the ridge Monday...deepening the short-
wave into a trough that digs southwest across central California. As
the trough deepens over the region...the embedded low is forecast to
be over Yosemite Tuesday afternoon and continuing to drop southwest
to over the Kings/Monterey County line by Wednesday morning. The
circulation around the low will support upslope precipitation over
the southern Sierra Nevada and Tehachapi Mountains Tuesday...and
over the entire weather forecast office Hanford County warning/forecast area Tuesday
The quantitative precipitation forecast for this system is low...only a few hundredths of an inch on
the San Joaquin Valley floor and between a tenth and a quarter inch
for the mountains. Snow accumulations are forecast to be an inch or
two...but with the very low snow levels accumulating snow is likely
on the major roads between the San Joaquin Valley and the
Southland...Interstate 5 over the Grapevine and Highway 58 through
the Tehachapi Pass. This could have a significant impact on Holiday
travel for the New Year/S day Holiday period.
The cold airmass is forecast to linger over interior central
California for the latter part of the week. The majority of models
keep central and South Valley lows in the lower 30s...although the
operational GFS mex guidance calls for lows Thursday and Friday
several degrees below freezing.
850-mb temperatures are forecast to recover next weekend...back to
values close to this weekend. This would bring valley temperatures
back to near normal after a cold start to 2015.
in the San Joaquin Valley...areas of MVFR visibilities and local IFR
visibilities in mist through 18z today and again after 06z Monday.
Otherwise...VFR conditions can be expected throughout the central
California interior during the next 24 hours.
Air quality issues...
on Sunday December 28 2014... fireplace/wood stove burning status
is: no burning unless registered in Fresno... Kern... Kings and
Further information is available at valleyair.Org
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.
site date hi_max:year lo_max:year hi_min:year lo_min:year
Kfat 12-28 66:1945 35:1908 54:1977 24:1962
kfat 12-29 69:1949 36:1908 54:1977 24:1990
kfat 12-30 67:1904 36:1902 54:2001 24:1969
Kbfl 12-28 73:1977 40:1908 58:1977 24:1930
kbfl 12-29 73:1956 40:1929 57:1977 22:1929
kbfl 12-30 74:1904 44:1986 53:1981 15:1905