Scientific Forecaster Discussion
Area forecast discussion
National Weather Service San Joaquin Valley - Hanford California
348 am PST sun Dec 21 2014
a ridge of high pressure over the eastern Pacific will gradually
build into central California during the next few days. Spotty light
precipitation is still possible through tonight in the Kern County
mountains. Meanwhile...much of the San Joaquin Valley will be
plagued with low clouds through Tuesday along with patchy dense fog
and drizzle each night and morning.
Discussion...central California will be on the eastern side of a rather
strong upper level ridge of high pressure over the eastern Pacific
during the next few days. A northerly flow aloft will continue to
bring cirrus over the County Warning Area through at least Monday. Upslope regions
of the Tehachapi Mountains may still get light rain or drizzle
through tonight as low clouds remain banked up in the northerly
flow. In the San Joaquin Valley and lower foothills...low level
moisture will remain abundant through Tuesday morning underneath
the ridge where stratus will prevail along with patchy dense night
and morning fog and possible drizzle. Sprinkles cannot be ruled
out in the sj valley during the afternoon and evening hours through
Monday as well. In fact...the models forecast the lowest boundary
layers of the atmosphere (below 2500 feet) to remain close to
saturation through Monday night. There is a concern that as the
upper level ridge builds over the County Warning Area early this week...it will
strengthen the inversion...tighten the lid so to speak and
prevent low stratus from lifting out of the sj valley. This will
make maximum temperature forecasts very problematic Monday and Tuesday.
Elsewhere...the ridge will bring mostly clear skies and
relatively mild afternoon temperatures Monday through Wednesday.
A short wave trough is slated to track through California as an inside
slider xmas evening. Although it is moisture deficient...this trough
could generate some light precipitation over the southern Sierra Nevada
and in the sj valley and adjacent foothills north of Fresno County
late Wednesday night as Santa is delivering his gifts. A few
showers could linger over the mountains through xmas day morning
..especially around Yosemite np. Otherwise...this system will
effectively flatten the ridge and weaken the inversion over the
County Warning Area during the xmas Holiday and mix some of the low crud out of
the sj valley. The northwesterly flow aloft...however...will shove
low clouds into the western slopes of the Sierra and the north
facing slopes of the Kern County mountains where they will remain
through xmas day.
The models are coming into somewhat better agreement in the 5 to
7 day period and forecast an upper level ridge to build back over
central California Friday and remain in control through next weekend. Dry
weather will prevail during this period with above normal afternoon
temperatures but it will also set the stage for a return of night and
morning fog in the sj valley.
LIFR conditions will impact all terminals through at least 18z.
Medium confidence. Conditions will improve to MVFR between 18z and
19z and continue into the evening hours. Patchy dense fog will once
again be possible late tonight into Monday morning.
Air quality issues...
!!!! bulletin error !!!!
please make a note in the station log
The level of certainty for days 1 and 2 is medium.
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 12-21 71:1955 34:1998 54:1964 23:1897
kfat 12-22 70:1964 35:1998 57:1955 19:1990
kfat 12-23 68:1964 37:1928 60:1964 18:1990
Kbfl 12-21 78:1919 36:1998 59:1977 23:1905
kbfl 12-22 76:2005 34:1998 56:1977 20:1990
kbfl 12-23 73:1964 36:1928 63:1955 14:1905