Onyx, California 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

546
FXUS66 KHNX 161830
AFDHNX

Area Forecast Discussion
National Weather Service Hanford CA
1130 AM PDT Wed Apr 16 2025

.KEY MESSAGES...

1. Temperatures are expected to cool to slightly below normal
on Thursday. Warming begins again by Friday and will be back to
above normal by the weekend.

2. Breezy conditions are expected for the Mojave Slopes on
Thursday.

3. There is a chance for showers and a slight chance for
thunderstorms across the Sierra Nevada today and Thursday.

&&

.DISCUSSION...A closed upper level low pressure system
continues to meander off the Socal coast and has pushed some low
level moisture northward into our CWFA with low clouds
prevailing over the Kern County portions of the San Joaquin
Valley and West Side Hills as well as over the east side of the
San Joaquin Valley and the lower Sierra Foothills. Temperatures
are running 5 to 7 DEG F cooler than yday across much of the San
Joaquin Valley as the result of the marine cooled air which has
spilled over into the valley and areas impacted by low clouds
have cooled by 8 to 11 DEG F since yday at this time. With the
low progged to move slowly toward the coast on Thursday and
inland on Thursday night, there will be increased instability
over the Sierra Nevada which will result in chances of showers
and a slight chance of afternoon and evening thunderstorms today
and better chances on Thursday. QPF progs are indicating
between a tenth and a quarter inch of rainfall for the higher
Sierra Nevada, but due to the convective nature of the
precipitation, it will very from location to location. Snow
levels are progged to range from 8000 to 9000 feet with 1 to 3
inches of new snowfall above 9000 feet by Thursday evening. The
cooling trend is also progged to continue with the probability
for maximum temperatures remaining below 70 DEG F in the San
Joaquin Valley between 25 and 60 percent on Thursday.

Meanwhile, a cold upper trough is progged to drop southward
over the Great Basin region on Thursday night and Friday which
will provide for enough instability for chances of showers
across the Sierra Nevada and Tulare County and across the Kern
County mountains and deserts. It will also bring a period of
increased winds to the Mojave Desert Slopes on Thursday evening.
This trough is then progged to move into the central CONUS this
weekend while and upper ridge nudges inland into CA. This will
result in a warming and drying trend across our area this
weekend with warmer than normal temperatures and dry conditions
prevailing across our area from Saturday through the middle of
next week.

&&

.AVIATION...18Z:

In the San Joaquin Valley and West Side Hills, Local MVFR in
low clouds. Otherwise VFR thru 18Z Thu.

In the Sierra Nevada and adjacent foothills, areas of MVFR in
low clouds and showers with local mountain obscuring IFR thru
18Z Thu. Isolated thunderstorms possible thru 06Z Thu.

In the Tehachapi Mountains, areas of mountain obscuring IFR in
low clouds thru 18Z Thu.

In the Kern County portion of the Mojave Desert, VFR will
prevail thru 18Z Thu.

&&

.AIR QUALITY ISSUES...None.

&&

.CERTAINTY...

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
www.weather.gov/hnx/certainty.html for additional information
and/or to provide feedback.

&&

.HNX WATCHES/WARNINGS/ADVISORIES...None.

&&

$$

public/aviation...DAS
idss...EW

weather.gov/hanford