Scientific Forecaster Discussion
fxus66 khnx 251106
Area forecast discussion
National Weather Service San Joaquin Valley - Hanford California
406 am PDT Tue Jul 25 2017
monsoon moisture nearby will bring a chance of thunderstorms to
the mountains and Kern desert through Tuesday, with just a few
lingering storms possible over the Sierra crest Wednesday.
Temperatures will be around seasonal averages through Wednesday,
then warming back up for the remainder of the week.
some mid level clouds towards Kern and Tulare counties. Otherwise
clear conditions with temperatures running a bit cooler over most
the district. Satellite images indicate a closed upper low
spinning along the north California coast. Southeast of the low, a south flow
aloft bringing dry airmass into central California. However a boundary of
moisture remains over the district with monsoon moisture towards
Kern and Tulare counties. Models prog some weak instability
towards the tehachapis and Sierra this afternoon. Thus surface
wind convergence may help trigger showers and isolated
thunderstorms over our mountain and desert zones this afternoon.
The ncal trough allowing for a deeper marine near 2500 feet at
Fort Ord while providing an onshore southerly flow aloft.
This cool onshore flow should bring cooler temperatures today.
The cool conditions should continue into midweek as models prog
the upper low remaining stationary over the north California coast through
tonight, then moving slowly east through ncal late Wednesday.
While moisture will be decreasing, the monsoon moisture axis will
remain along and east of Sierra. And isolated storms may develop
in the afternoon over the High Sierra country.
The upper low pushes into the Great Basin Wednesday night, leaving
a weak westerly flow aloft resulting in dry and stable conditions
The ridge will then expand farther west through the end of the
week providing dry and warming conditions across our area. Thus,
temperatures will rise a few degrees above normal by the end of
Models diverge for the first part of next week, with the operational
GFS showing a return of moisture to our area around the western
periphery of the ridge. While the ec model progs are less
progressive and drier. For now we are showing just a slight chance
for convection along the Sierra crest starting Sunday.
areas of MVFR visibilities in smoke from area wildfires. Isolated to
scattered thunderstorms developing this afternoon after 19z Tuesday
over the Sierra Nevada and Kern County mountains and desert.
Otherwise, VFR conditions will prevail across the central California
interior during the next 24 hours.
Air quality issues...
please see sfoaqahnx for an air quality alert
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.Php for additional information
an/or to provide feedback.