Scientific Forecaster Discussion
fxus66 khnx 152131
Area forecast discussion
National Weather Service Hanford California
231 PM PDT sun Sep 15 2019
temperatures on Monday will be much cooler with a chance of
showers north of Fresno County and mainly over the Sierra. Over
the south part of the region, windy conditions will develop on
Monday with areas of blow dusts across the desert. Temperatures
will then remain below normal for the remainder of the week.
change in the weather is on the way as an upper level disturbance
Ushers in cool air, winds and possible precipitation. In the
meanwhile, high clouds will continue to stream over central
California ahead of the next disturbance. With the disturbance
still too far and centered off the Pacific northwest coast,
temperatures will reach into the 90s, once again. Even with
minimal influence, the current weather pattern has temperatures
already starting the cooling trend. Yet, big change will begin
overnight as more of the disturbances influence is felt across
central California. Current model timing has the axis of the
disturbance near the Pacific northwest/northern California coast
Monday morning and pushing ashore during the day. Again, the
initial influence from this disturbance will be felt in the form
cool air and increasing winds. Precipitation will follow as
possible rain and very high elevation snow may fall during the mid
to late day period. In addition, enough instability may exist for
a slight chance of thunderstorms near Yosemite np.
While short range model analysis favors northern California with
the best unsettled conditions, enough dynamics could extend into
central California for change in the weather. The potential for
winds and temperature changes is higher than that of possible
precipitation. Yet, orographic lift may add the needed ingredient
to give the foothills and mountains north of Fresno County a
decent change of rain and high elevation snow. Therefore, will
expect precipitation over the northern portion of the district
after daybreak and closer to mid-day. In addition, enough
instability exist over the Yosemite np area where better dynamics
exist to warrant a mention of thunderstorms slight chance
during frontal passage. In addition to the possible precipitation,
the frontal passage maybe strong enough to help tighten the
surface pressure gradient from ksfo to klas. Alogn with a possible
15 degree drop in temperatures, model surface pressure analysis
has the gradient reaching 10 mb by Monday afternoon. While not
tight enough for a high confident wind event across the Kern
County mountains and deserts, the threshold is reached to warrant
a low-grade Wind Advisory for Monday.
Tuesday will see the back-end of the disturbance and in the zonal
flow ahead of the next disturbance. The zonal flow pattern will
keep the region at near to slightly below normal, temperature-
wise. Models than attempt drop yet another disturbance into the
region later in the week with more cooling, winds and chance of
mountain precipitation. Yet, the difference between the
disturbance will be the path taken by each. The second (later in
the week) disturbance will remain further north and move in more
like an inside slider. Therefore, the mountains will be favored in
the realm of winds and precipitation. Therefore, will confide
precaution to the higher elevations for the second storm.
Afterward, back to a ridge pattern leading into next weekend.
While its become more difficult to reach the triple digit mark on
that its the latter half of September, 90s are a definite
possibility. Even with the changes now taking place across the
region, Summer is not over as warm temperatures continue.
surface winds will increase after 18z on Monday with gusts
reaching above 40 knots across the Kern County mountains and
deserts. At the same time, wind gusts across the Sierra Nevada
crest could reach near 65 knots. Otherwise, VFR conditions can be
expected throughout 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.
Wind Advisory from 2 PM to 11 PM PDT Monday for caz195-196-198-