Scientific Forecaster Discussion
Area forecast discussion
National Weather Service San Joaquin Valley - Hanford California
309 am PDT Thursday Aug 21 2014
Synopsis...daytime high temperatures will remain near normal for
the middle to end of August...generally in the low to middle 90s.
Temperatures will slowly rise during the second half of next week
as high pressure builds over the area. Otherwise...thunderstorms
will be possible along the Sierra crest this afternoon.
Discussion...an upper low off the Southern California coast will
shift quickly east today into early Friday morning. Southeast flow
associated with this low will bring a steady stream of middle level
moisture to the Sierra crest. This moisture in combination with
most unstable middle level cape values in excess of 300 j/kg will be
sufficient for at least a slight chance of thunderstorms along the
Sierra crest this afternoon into early this evening. If
thunderstorms do form...they will likely form along the highest
elevations in Tulare and Fresno counties. Forecaster confidence
Otherwise...moderate onshore flow and a marine layer depth of 2200
feet (according to The Fort Ord profiler) will result in another
day of slight below normal temperatures for the region.
Temperatures this afternoon are forecast to rise into the middle 90s
for the valley locations as well as the desert locations.
The upper low will quickly move northeast into Arizona...resulting
in a persistent northwest upper flow into the beginning of next
week. This will keep the area free of Sierra thunderstorms as the
steering flow becomes westerly. In addition...daytime high
temperatures will remain in the low to middle 90s...a few degrees
By Tuesday of next week...a ridge of high pressure will begin to
build north from Southern California...resulting in a warming
trend during the second half of next week. Middle level moisture will
begin to move northwest toward Arizona on Tuesday and possibly
into far southeastern California by Thursday. However...all
chances of thunderstorms will remain well to the south of the
area. We would not be surprised if another round of monsoonal
moisture impacts the Sierra Nevada next weekend...but it is so far
in the future that forecaster confidence remains very low. Just
something interesting to keep in mind.
Aviation...isolated thunderstorms are possible over the mountains
and desert after 20z today. Otherwise...VFR conditions will
prevail across the central California interior during the next 24
Air quality issues...
The level of certainty for days 1 and 2 is medium.
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 08-21 108:1919 80:1968 76:1913 51:1959
kfat 08-22 108:1897 81:1960 75:1995 50:1899
kfat 08-23 112:1891 79:1959 78:1913 51:1960
Kbfl 08-21 110:1919 80:1968 77:1982 51:1918
kbfl 08-22 109:1919 82:1983 78:2009 44:1903
kbfl 08-23 110:1913 83:1960 80:1982 49:1915