Scientific Forecaster Discussion
Area forecast discussion
National Weather Service San Joaquin Valley - Hanford California
326 PM PST sun Dec 28 2014
Update...air quality issues updated.
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...and snow over the Kern County
mountains and desert.
Discussion...upper level northwest flow will continue over the
region through early Tuesday morning...with near normal daytime
high temperatures and dry weather. Patchy frost will be possible
each morning through many of the valley and foothill locations.
Forecast confidence continues to increase with a significant
winter storm for the Kern County desert and mountains. An upper
low will slide south into Nevada and far eastern California early
Tuesday morning. This low will move southwest into central
California by Tuesday evening and into Southern California by
Precipitation will begin over the Sierra Nevada as early as
Tuesday morning and impact Kern County by Tuesday evening. Very
cold air will accompany this storm...with snow levels between 3000
and 4000 feet with the onset of precipitation along the Sierra
Nevada from Fresno County northward. As the chance of
precipitation increases in Kern County...snow levels are forecast
to plummet to 2000 feet late Tuesday night into Wednesday morning.
The higher resolution models are indicating between a few
hundredths of an inch to around a third of an inch of
precipitation for the Kern County desert and mountains. This will
translate into 1 to 2 inches for the desert floor with 2 to 6
inches possible over the Kern County mountains.
Forecast confidence is high with this event for a few reasons.
First...the relative measure of predictability from ncep's ensemble
mean forecast calls for high predictability and has increased
significantly from this time yesterday. Additionally...the napes
probability of measurable precipitation has increased and honed
in on a region generally from Kern County southward into far
Southern California. Additionally...the probability of a tenth of
an inch has even increased significantly for this same
area...adding to forecast confidence of a high impact winter
Given that this winter event will happen over new years evening day
and impact all major Kern County roadways in the mountains and
desert...a Winter Storm Watch has been issued from Tuesday
afternoon into Wednesday afternoon and will likely be upgraded to
a Winter Storm Warning on Monday. Please continue to monitor the
forecast closely for additional information leading up to this
In addition...very light snow accumulation will be possible for
the same time frame along the Sierra Nevada and surrounding
foothills down to 2000 feet and a possible mix of rain and snow
down to 1500 feet.
Lastly in reference to this cold air...valley temperatures are
forecast to drop to the coldest readings so far this season. As of
now...Wednesday and Thursday mornings look to be the
coldest...with valley temperatures falling into the middle to upper
20s. Forecast confidence is only medium at this time and will
continue to grow as we near the event and have access to the high
res model data.
The upper low is forecast to shift slowly east Wednesday night
into the first part of the weekend...allowing weak high pressure
to build over the area. This will result in dry weather and a
subtle warming trend. Daytime high temperatures in the valley be
in the upper 40s Wednesday and Thursday and warm into the low 50s
by Friday and middle 50s by the weekend.
in the San Joaquin Valley...local MVFR in mist after 06z
otherwise...VFR conditions can be expected throughout the central California
interior during the next 24 hours.
Air quality issues...
on Monday December 29 2014... fireplace/wood stove burning status
is: no burning unless registered in Fresno... Kern... Kings...
Madera...Merced and Tulare counties.
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 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 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
Winter Storm Watch from Tuesday afternoon through Wednesday