Johannesburg, California 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

936
FXUS66 KHNX 171552
AFDHNX

Area Forecast Discussion
National Weather Service Hanford CA
852 AM PDT Sat May 17 2025


.KEY MESSAGES...

1. A cooldown occurs this weekend, with gusty winds by Saturday
afternoon over the mountain ridges and peaks, as well as the
Kern County desert. Elsewhere, winds will be noticeably
stronger.

2. A 10-15 percent chance of afternoon and evening
thunderstorms exists in the Sierra Nevada today.

3. Increased winds combined with low humidity on Sunday and
Monday will lead to a risk for large grass fires in the San
Joaquin Valley.

4. Well above normal temperatures and mainly dry conditions are
expected Tuesday and the remainder of next week.

&&

.DISCUSSION...
Satellite loops show mainly mid-level and high clouds due to an
upper-level trough over the WFO Hanford Warning/Forecast area.
Noticeably cooler temperatures and stronger winds will take
place today and Sunday as the trough continues its trek over the
Great Basin. Much of the moisture and dynamics has been passing
to our north, although a slight chance of thunderstorms is
forecast for the Sierra Nevada, though mainly in the higher
elevations. The chances for thunderstorms today are around 10-15
percent. Forecast precipitation amounts are light, or up to a
few hundredths of an inch with a dusting of snow over the
highest elevations. Strong and gusty winds develop later today
in the Kern County desert and over the ridges and peaks along
the Sierra Nevada crest, with the highest impacts likely at the
Mojave Desert slopes (including Mojave). The probability for a
gust of at least 55 mph is 75-95 percent along the Mojave Desert
slopes and nearby areas just below, with the peak strength
during this evening. In addition, the risk, while relatively
low, for large grass fires exists in the Central Valley on
Sunday due to the combination of lower humidity with breezy
conditions redeveloping. Winds on Monday won`t be quite as
strong, but the temperatures will be warmer than on Sunday and
will keep daytime humidity low. So, the possibility for Monday
will remain.

Enjoy the mild, more spring-like temperatures this weekend, as
a longer period of above average temperatures commences early
next week. A ridge of high pressure will build and remain
anchored over much of the Southwestern U.S. from Monday and the
rest of next week. Monday`s highs will be slightly above
average, but the warming will become more noticeable by Tuesday.
Probabilities for highs in the 90`s in the warmest locations
are at a minimum of 70 to 90 percent for Tuesday until at least
the next few days. Triple digit heat becomes a possibility once
again by Thursday, including in both the SJ Valley and Kern
County desert, or at 20-40 percent chance. Other locations
besides Kern County could see their first triple digit day for
this year by then. While probabilities for triple digit readings
are a bit lower for next Friday (about 10-25%, with the best
chances in the desert), summer-like temperatures could persist
for a little while based on the latest 6-10 and 8-14 day
outlooks from the Climate Prediction Center, with a probability
of above 50 to 60 percent of above average temperatures for the
latest 6-10 day outlook and about 35-40 percent chance on the
8-14 day outlook.

&&

.AVIATION...
18Z Update:

MVFR with local IFR in mountain obscurations possible over the
Sierra Nevada, from Yosemite NP to Sequoia NP, due to a slight
chance (around 15 percent) showers/thunderstorms through 06Z
Sunday. Westerly winds increasing from 21Z Saturday through 09Z
Sunday in the Kern County desert and adjacent slopes with gusts
45-55 kts. Otherwise, VFR conditions will prevail for the next
24 hours across the Central California Interior.

&&

.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 high.

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...
High Wind Warning from 2 PM this afternoon to 2 AM PDT Monday
for CAZ338.
Wind Advisory from 2 PM this afternoon to 2 AM PDT Sunday for
CAZ337-339.
&&

$$

BSO/EW

weather.gov/hanford