Scientific Forecaster Discussion
Area forecast discussion
National Weather Service San Joaquin Valley - Hanford California
129 PM PDT sun Jul 5 2015
scattered afternoon and evening thunderstorms will continue over the
high country of the southern Sierra Nevada through Monday...then
only a slight chance each afternoon through Wednesday. A weather
disturbance will cross the area on Thursday bringing a chance of
thunderstorms to the Sierra and a cooling trend late next week.
Discussion...marine air has been flow through the passes along
the west side of the San Joaquin Valley since last night
and early this morning...wind gusts have reached around 40 miles per hour
through Pacheco Pass as of around 7-8 am PDT today and continue
around 35 miles per hour early this afternoon. Latest feet Ord profiler data
shows the marine layer around 2500 feet deep. Expect the marine air
to gradually cool the sj valley over the next few days...temperatures
are expected to reach the lower to middle 90s by the middle of the
week. Meanwhile...isolated thunderstorms have begun to develop
over the southern Sierra Nevada...mainly along the crest over
Sequoia nf...np and Kings Canyon np. A south-southwest flow aloft
continues over the region...so expect storms to move from this
direction through this afternoon and evening.
Satellite loops show an upper-level low remaining over the east
Pacific around latitude 36n / Lon 129w or several hundred miles off the
central California coast. The deeper monsoonal moisture is well to the east
although central California remains under the influence of the lingering
moisture that has been around for the last several days. As
the low pressure center moves closer to the coast...expect a more
southwesterly flow to develop...the region is expected to be
generally dry except for the southern Sierra Nevada. Also...expect
synoptic cooling over the mountains and desert. Overall temperatures will
trend down around a couple degrees lower each day during the
early to middle parts of this week. Remnant moisture and minor
disturbances will continue to rotate around the upper-level
low...so convective activity cannot be ruled out in these areas
during Monday-Wednesday and have kept slight chance to lower-end
chance category probability of precipitation.
By Thursday...models forecast the upper-level low to move inland
over central California. Exact placement of this low remains
uncertain...so have medium confidence in the extended period.
Temperatures will likely remain a few degree below average during
the latter part of the work week. For now...increased cloud cover
a bit for Thursday afternoon over the sj valley. However...will continue
to monitor the potential for showers and possible thunderstorms
over much of our County Warning Area including the sj valley. At this time...have
kept chance probability of precipitation over the southern Sierra and southward to the
Tehachapi Mountains the chance for showers and thunderstorms is expected
to linger at least over the Sierra into Friday as the upper-level
low moves towards the Great Basin.
By next weekend...expect high pressure to nudge westward from the
desert SW...temperatures will likely warm back up...or towards similar
values to those that have been occurring recently. Southwesterly
flow aloft is prognosticated to return during this period...which generally
keeps our region dry.
MVFR ceiling possible in scattered showers and thunderstorms over
the southern Sierra Nevada and Tehachapi range through 06z Monday.
These conditions will be possible again after 19z Monday.
Elsewhere...VFR conditions will prevail 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 07-05 112:1991 77:1909 77:1991 52:1948
kfat 07-06 111:2007 83:1903 78:2007 50:1955
kfat 07-07 111:1905 84:1891 76:2014 53:1903
Kbfl 07-05 114:1931 80:1961 81:1970 53:1948
kbfl 07-06 116:1913 85:1955 81:2011 52:1915
kbfl 07-07 114:1905 85:1983 81:1968 46:1903