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Area Forecast Discussion (AFD)

Issued by San Joaquin Valley, CA (HNX)

                            
000
FXUS66 KHNX 160924
AFDHNX

Area Forecast Discussion
National Weather Service Hanford CA
224 AM PDT Mon Sep 16 2019


.SYNOPSIS...
Significant cooling trend today as trough of low pressure ushers
in cooler air. There is a chance of afternoon thunderstorms in 
the Sierra Nevada today near Yosemite NP; some snow showers may 
occur along the higher elevations of the Sierra Nevada as well. 
Another trough arriving Wednesday night/Thursday will keep 
Central California in the high 70s/low 80s before another warming 
trend this weekend.


&&

.DISCUSSION...
Incoming trough of low pressure will lead to much cooler weather
across the San Joaquin Valley this afternoon with afternoon highs
expected to be 12-15 degrees cooler compared to yesterday. As the
trough moves inland, a few light rain showers may occur in 
northern Merced and Mariposa county this afternoon. Also this 
afternoon, some instability associated with cooler air aloft may 
help trigger a rumble or thunder or two in the Sierra Nevada near 
Yosemite National Park. Along with a slight chance of 
thunderstorms, a few light snow showers may occur this 
afternoon/evening with snow levels around 8500-9500 feet. A surge 
of stronger winds across the forecast area with the incoming 
trough are forecast to occur this afternoon and evening. A few 
wind gusts around 20-25 mph are possible this afternoon/evening in
the SJ Valley, which could cause some blowing dust in the western
portion of the valley. Stronger gusts of 45-55 mph are possible 
in Kern County just below the mountain passes. Therefore, a Wind 
Advisory will be in effect this afternoon starting at 2 PM through
11 PM tonight for the Lake Isabella/Tehachapi area, Indian Wells 
Valley, and the Mojave Desert.

Tuesday will be a couple of degrees cooler throughout the 
forecast area, with afternoon highs progged to be in the 80-82 
degree range with zonal flow aloft ahead of the next disturbance.
Dry weather expected Tuesday through midday Wednesday, then 
slight chance showers near Yosemite NP in the Sierra Nevada as the
upper trough begins to impact the region. Models are showing a 
chance of precipitation occuring throughout the day on Thursday 
across the Sierra Nevada, and a few of these showers may produce 
flurries above 8500 feet. Strong winds through the Sierra Nevada 
may occur with the passage of this trough, and some gusty winds 
may also occur in the SJ Valley/Kern passes Wednesday night into 
Thursday. After the trough exits the district, models begin to 
diverge on the upper air pattern somewhat, but general thinking is
that a warming trend will occur starting Friday into this 
weekend.



&&


.AVIATION...
Surface winds will increase after 18Z today 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. Mountain obscuration 20z today through 06z 
Tuesday in showers through the Sierra Nevada. Otherwise, VFR 
conditions can be expected throughout the Central California 
interior during the next 24 hours. 

&&

.AIR QUALITY ISSUES...
None.



&&

.CERTAINTY...

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.

&&

.HNX WATCHES/WARNINGS/ADVISORIES...
Wind Advisory from 2 PM this afternoon to 11 PM PDT this evening 
for CAZ195-196-198-199.

&&

$$

public...Bollenbacher
aviation....Bollenbacher

weather.gov/hanford