Scientific Forecaster Discussion
Area forecast discussion
National Weather Service San Joaquin Valley - Hanford California
205 PM PDT Friday Oct 31 2014
a winterlike storm will bring rain and High Sierra snow to the
district tonight. The weekend will be unseasonably cool with
residual showers and higher elevation snow showers Saturday into
Saturday night. Dry weather is expected Sunday through Tuesday with
patchy late night and morning fog in the San Joaquin Valley. A
warming trend will begin Monday and continue through Thursday as
high pressure builds into California.
Discussion...unless mother nature has any tricks up her sleeve...
central californians are in for a real treat tonight. For the
first time since late April...the valley...foothills and higher
elevations of the County Warning Area will receive a thorough soaking during the
next 24 hours. The storm that will bring the wet weather is still
centered several hundred miles off the northern California coast this
afternoon. A cold front well ahead of this storm shows up as a
pretty healthy band of rain on radar that currently extends from
Montana Shasta southwestward to the sfo Bay area. Although the front
makes steady southward progress this evening...its precipitation
will probably arrive by sunset in Merced County but not until
about 10 PM in Kern County where trick or treaters stand a better
chance of not getting rained on early this evening. However...
southerly winds on the warm side of this front will be locally
gusty and might kick up dust in some valley locations...especially
on the west side...prior to its arrival. Strong dynamics
associated with this cold front will support briefly heavy
precipitation and possibly even thunder and lightning during its
The arrival of colder air later tonight will bring snow levels
down to about 6k feet in the southern Sierra. Above this elevation
snowfall accumulations will range from as much as 6 inches in
the mountains of Tulare County to around a foot over the highest
elevations of the Sierra north of Kings Canyon by late Saturday
morning. The upper level storm will be moving inland by then and
will continue to generate instability showers into Saturday evening
especially over the higher terrain. Otherwise...temperatures Saturday
afternoon will be a good 8 to 15 degrees cooler than this afternoon
under a good deal of cloudiness. Shower activity will diminish in
most areas by late Saturday evening as the upper level storm exits
into the Great Basin. However...clouds will bank up in the northwest flow
behind it through Sunday morning along the west facing slopes of
the Sierra and the Tehachapi Mountains where a little drizzle is
Sunday will remain much cooler than normal despite a return of
sunshine. A strong northerly jet on the backside of the upper
level trough will support a gusty breeze on the west side of
the sj valley Sunday afternoon. Otherwise...dry weather will rule.
A day to day warming trend will begin Monday and continue through
at least Wednesday as an epac ridge of high pressure builds into
California. As is normally the case after the first wetting rain
of the season in the sj valley...the formation of patchy late night
fog could cause some delays for morning commuters early next week.
The ecm busts down the upper level ridge later next week while
the GFS holds it strongly over central and Southern California.
Temperatures on days 6 and 7 will remain much warmer than normal if the
GFS is right or trend slightly cooler if the ecm wins out. We are
currently leaning toward the model ensembles which forecast upper
level ridging to persist over central and Southern California through the
end of next week. Whatever the case...none of the models hint of
any return to wet weather in the extended forecast period. So
enjoy the Sweet treat mother nature provides US during the next 24
hours. While it will be a drop in the bucket compared to our
extremely large precipitation deficit...it certainly is better than
nothing. After all...in the wake of this storm a view of the snow
capped Sierra will be a welcome sight!
areas of MVFR with local IFR conditions can be expected with and
behind a southward moving cold front this evening. Widespread IFR
conditions will develop southward over the southern Sierra between
03z Saturday and 06z Saturday with mountain obscurations likely in
precipitation through 00z Sunday. MVFR ceilings and visibilities can
be expected in the Sierra foothills and along the west and north
facing slopes of the Tehachapi Mountains after 03z Saturday.
Additionally...isolated thunderstorms are possible until 12z
Saturday. Wind gusts of 35 knots or greater will continue along the
Sierra crest until 09z Saturday. VFR conditions will prevail
elsewhere across the central California interior through 00z Sunday.
Air quality issues...
The level of certainty for days 1 and 2 is high.
The level of certainty for days 3 through 7 is high.
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 10-31 90:1949 57:1974 61:2008 32:1972
kfat 11-01 88:1966 58:1935 61:2008 33:1971
kfat 11-02 88:1949 53:1957 56:2012 34:1946
Kbfl 10-31 92:1949 55:1923 65:2008 33:1935
kbfl 11-01 90:1966 58:2003 64:2008 30:1907
kbfl 11-02 89:1949 60:1947 58:1992 31:1935
Winter Weather Advisory from 8 PM this evening to 11 am PDT
Saturday above 7000 feet for the caz097.
Winter Storm Warning from 5 PM this afternoon to 11 am PDT
Saturday above 6000 feet for the caz096.