Scientific Forecaster Discussion
fxus66 khnx 152230
Area forecast discussion
National Weather Service Hanford California
330 PM PDT Sat Jun 15 2019
Synopsis...little change in temperatures can be expected over
the district through the weekend. Isolated afternoon thunderstorms
are possible over the higher elevations of the Sierra each day
through Monday. Otherwise dry weather will prevail through the
period. A warm up is expected beginning on Tuesday into Thursday,
with temperatures in the valley and desert once again getting
above the century mark.
current analysis at 2 PM pdt: water vapor imagery picking up a
weak upper level disturbance quickly moving through the Bay area.
This disturbance has helped break down the weak ridge that had
built into the central California interior over the last 24 hours.
Since the atmosphere is very dry, 12z Oak soundings' mid-level
humidity was 9 percent, the most this weak feature has done is
lead to a slight increase in upper level cloud cover in the
northern County Warning Area. Today temperatures are quite pleasant and are about
where they should be for mid-June. For tonight, low temperatures
in the southern Sierra foothills, Bakersfield area, and Kern
County desert will be 3-6 degree f above average. But, northward
toward western Merced County low temperatures will be slightly
below average, as models show another push of cooler marine air.
On Sunday, solid model agreement on bringing another weak
shortwave trough through the central California interior. Due to
the quick movement, the overall impact on afternoon temperatures
will be negligible as high temperatures will warm back up to
seasonal averages if not slightly above average. The greater risk
will be thunderstorms into the southern Sierra tomorrow afternoon
and evening. The GFS/nam12 along with the high-res models still
all develop a weak low level circulation along the eastern slopes
of the Sierra, helping enhance convection.
On Monday, another weak upper level low drops southward into
Southern California. Impacts on afternoon temperatures will once
again be negligible as overall synoptic cooling remains weak and
this feature moves quickly out of the area. There will be another
threat of afternoon thunderstorms in the Sierra as easterly flow
on the backside of the weak low level circulation will once again
help enhance afternoon convection.
Starting on Tuesday into Thursday, models have a large high
pressure cell developing over the eastern Pacific. This will lead
to an increase in afternoon temperatures, once again surpassing
the century mark in the valley and desert.
Aviation...isolated thunderstorms are possible near the Sierra
crest between 20z Sunday through 03z Monday. Otherwise, VFR
conditions will prevail over 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.
Certainty levels include low...medium...and high. Please visit
www.Weather.Gov/hnx/certainty.Html for additional information
an/or to provide feedback.