Scientific Forecaster Discussion
Area forecast discussion
National Weather Service San Joaquin Valley - Hanford California
130 PM PDT Sat Mar 28 2015
a weak Pacific disturbance continues to move through the area
producing slight cooling. However...temperatures will remain
several degrees above normal through the weekend and into next
satellite loops show mainly clear skies over the weather forecast office Hanford
warning/forecast area today as an upper-level trough brings a
cooling trend to the region. At 20z /1300 PDT/ today...temperatures
across the central and southern San Joaquin Valley were in the middle
to upper 70s...down 6-9 degrees from 20z Friday.
Despite the record warmth Friday...neither Bakersfield nor Fresno
set record high minimum temperatures this morning although both
cities came close. Fresno missed its record by one degree and
Bakersfield missed its record by two degrees.
One weather concern for today was the possibility of convection over
the southern Sierra Nevada high country this afternoon as well as
Sunday afternoon. The latest hrrr only has surface-computed convective available potential energy of
240+ joules/kg over the southern Sierra Nevada...although surface-
computed lifted indices are around -3 /over eastern Fresno and
Madera counties/ and 850-mb Theta-E peaks at 332 k /over
northeastern Tulare County/. Despite somewhat favorable convective
parameters...the trough does appear to be moisture starved given the
minimal cloud development so far...and expect that any convection
will be confined to the time of peak heating around 00z Sunday /1700
PDT this afternoon/.
Another upper-level short-wave is forecast to move through central
California Sunday afternoon and evening. 500-mb heights over the
region are forecast to fall below 5790 meters. The NAM-12 is
unstable for Sunday afternoon with surface-computed convective available potential energy of 1300
joules/kg...surface-computed convective available potential energy as low as -5 and 850-mb Theta-E
peaking around 333 k. The water-vapor loop shows more middle- and high-
level moisture associated with the second short-wave...so there will
be a better...albeit still low...chance for mountain convection
Sunday afternoon and evening. In fact...the latest /20z/ rfc quantitative precipitation forecast
guidance does have up to 0.02 inch of rain from Yosemite National
Park to Huntington Lake.
Weak upper-level ridging will return Monday...but will give way to
an upper-level trough moving through the Pacific northwest and the
northern half of California the next day. This will set the stage
for a stronger trough to reach California Thursday...and if the GFS
is correct...yet another trough over the state next Saturday into
The result of these systems is that the central and southern San
Joaquin Valley will see warming back to around 90 Monday...then cool
down to the middle 70s by Wednesday. Do not expect mountain convection
from this trough at this time...but will likely see an increase in
mountain cumulus so have boosted sky cover over the southern Sierra
Have gone with token probability of precipitation for the Thursday and Saturday systems at
this time pending subsequent model runs. This is especially true for
next weekend/S trough where the GFS is considerably more progressive
than the European model (ecmwf).
wind gusts up to 22kt will be likely at terminals kmce/kmer until
06z. Otherwise VFR conditions can be expected throughout the central
California interior during the next 24 hours.
Air quality issues...
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 03-28 85:1986 53:1982 57:1957 33:1972
kfat 03-29 87:1969 47:1982 59:1986 32:1891
kfat 03-30 85:2003 52:1936 58:1978 31:1897
Kbfl 03-28 88:1893 53:1998 58:1957 24:1907
kbfl 03-29 94:2004 55:1998 58:1978 23:1907
kbfl 03-30 88:1923 57:1904 59:1978 30:1907