Area Forecast Discussion
Issued by NWS San Joaquin Valley, CA

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FXUS66 KHNX 212130

Area Forecast Discussion
National Weather Service San Joaquin Valley - Hanford CA
230 PM PDT Thu Sep 21 2017

.SYNOPSIS...Scattered showers will continue over the mountains
through this evening as an upper trough to our east keeps
unsettled conditions over the area. Winds will also be strong and
gusty through and below the mountain passes into this evening.
Temperatures will be cooler than normal across the area through
the upcoming weekend as the trough remains over the Great Basin. A
slow warming trend will take next week as highs pressure slowly
builds inland into the region.


.DISCUSSION...Cold front pushed through central CA earlier today
and brought widespread precipitation to our area overnight and
this morning. Several locations in the Southern Sierra Nevada
picked up between half and inch to an inch of rainfall with a few
locations in and near Yosemite Park picking up over an inch of
rain. The precipitation mainly fell as snow above 11000 feet, but
the snow level lowered to 7000 feet by daybreak in the cooler
post-frontal airmass. In the San Joaquin Valley a few locations
measured close to 0.40 inches, but most locations picked up a
tenth of an inch or less. Although the front has now moved out of
our area, radar composites are indicating scattered instability
showers have developed over the Southern Sierra Nevada this
afternoon. Isolated thunderstorms will also be possible in the
Yosemite Park area as the HRRR is showing CAPE and instability are
sufficient for thunderstorm development today. The main concern
through through this evening will be strong winds over the ridge
tops and below the passes in the Kern County Mountains and Deserts
where gusts up to 75 mph will be possible through this evening. A
High Wind Warning remains in effect for these area through 1100
pm PDT this evening. Breezy conditions are also expected along the
I-5 corridor and below the passes along the west side of the San
Joaquin Valley through this evening as well and a Wind Advisory
remain in effect until 1100 pm PDT for the west side of the San
Joaquin Valley.

WRF indicating a deep upper trough will remain situated over the
Great Basin tonight through Satruday with a cyclonic flow aloft
prevailing over Central CA through Friday Night. This will result
in much below normal temperatures across our area on Friday. Other
than some upslope clouds on the valley facing slopes of the
mountains skies should be mostly clear on Friday. There will be a
slight chance of afternoon and early evening showers over the
Southern Sierra Nevada on Friday as instability remains

An upper ridge will begin to push inland on Saturday and bring
about a slow warming trend across our area over the weekend.
However temperatures will remain below seasonal normals as a cool
northerly flow prevails over Central CA as we remain situated in
between the trough over the Great Basin and the ridge off the CA

The medium range models are in good agreement with the ridge
building inland next week as the the trough finally moves east
toward the central CONUS. Rises in heights and thicknesses will
result in a warming trend with temepratures rising to above normal
levels by next Tuesday and continuing to rise through the
remainder of next week. High temperatures in the San Joaquin
Valley, lower foothills and the Kern county desert will be in the
90s during the second half of next week while the nights will be
relatively cool (mid 50s to mid 60s). RH progs are indicating no
signs of significant moisture impacting our area next week and as
a result a dry forecast will remain in place.


.AVIATION...Scattered showers will produce areas of MVFR and
local terrain obscurations over the southern Sierra Nevada through
03Z Friday, while lingering upslope clouds will persist along
north and west facing slopes of the Kern County Mountains through
12Z Friday. Winds will gust near 35 knots along the west side of
the San Joaquin Valley and near 50 knots over the Kern County
mountains and deserts through 06Z Friday. Areas of MVFR and local
IFR visibilities will be possible in blowing dust from the gusty
winds. VFR conditions are otherwise expected over the Central CA
interior during the next 24 hours.





The level of certainty for days 1 and 2 is medium.
The level of certainty for days 3 through 7 is medium.

Certainty levels include low...medium...and high. Please visit for additional information
an/or to provide feedback.


.HNX Watches/Warnings/Advisories...
High Wind Warning until 11 PM PDT this evening ABOVE 1500 FEET
FOR CAZ095-098-099.

Wind Advisory until 11 PM PDT this evening CAZ089-091.



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