Flood in California, June 1 to 18, 2023

Area Forecast Discussion
National Weather Service Hanford CA
1048 AM PDT Wed May 31 2023

.SYNOPSIS...
A warming trend will begin today. This trend will continue until
Sunday, where highs may reach in the high 90's in the valley.
High temperatures will start to cool down on Monday and will
continue through Wednesday, with highs back in the mid to high
80's. The Sierra Nevada will continue to see chances for
thunderstorms in the afternoon everyday for the next week.

&&

.DISCUSSION...
Satellite loops show the upper-level low moving eastward into the
Desert Southwest. Expect near average temperatures today, though
a touch below. High resolution guidance continues to depict a
shortwave trough over Northern California for Thursday, but with
little effect on sensible weather for most of our forecast area.
Slight warming will occur each day until Friday as a longwave
ridge of high pressure builds along the West Coast. This ridge
will build, move inland, and provide more noticeable warming for
the weekend. Highs at the warmest spots are expected mainly in the
80's until Thursday then rise to the mid to upper 90's for the
weekend. Ensemble guidance continues to suggest the warmest
temperatures for Sunday. Also, we cannot rule out triple digits on
Sunday for some locations in the San Joaquin Valley and the Kern
County desert, but the probabilities have decreased a bit per
blended guidance (now at 17 percent for Fresno and 10 percent at
China Lake; lower probabilities elsewhere).

We will forecast a slight chance for thunderstorms in the Sierra
Nevada, including from Yosemite to Tulare County over mainly the
crest, each day until at least the weekend. It is possible some
thunderstorms could drift a little lower at times, though mainly
at around 4,000 to 5,000 feet. Moisture will be sufficient for
mainly light rainfall, although a brief downpour can occur with
the heaviest storms. Otherwise, dangerous lightning, small hail,
and gusty erratic winds will occur with any thunderstorm that
develops.

By early next week, another trough of low pressure will arrive
and bring a renewed threat for showers and thunderstorms in areas
besides the Sierra, or into the lower foothills, as well as the
eastern and southern portions of the San Joaquin Valley. It
appears the best chance for precipitation in these areas will be
on Monday. Otherwise, the Sierra threat of thunderstorms
continues for the foreseeable future. At least this pattern will
serve to prevent a significant warmup for now, as it will remain
until the middle of next week. For now, we will forecast a
downward trend in daytime highs, although will still be
seasonably warm for Monday and Tuesday and lower to slightly
below average for next Wednesday. Probabilities of highs in the
lower 90's in the warmest areas are also markedly lower for the
first half of next week.

On a safety note, the water may seem inviting to many folks as we
once again warm up this weekend. However, it is best to stay out
of the rivers, as they are dangerously cold and fast! Snow will
continue to melt in the higher elevations of the Sierra Nevada
over at least the next few weeks, and this will contribute to the
increased flows along the waterways with localized flooding in
some areas, such as Yosemite Valley.

&&

.AVIATION...
VFR conditions will prevail at all of the terminal aerodrome sites
through at least the next 24 hours. MVFR or lower conditions are
likely in and near any thunderstorm in the mountain areas this
afternoon into this evening.

&&

.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
and/or to provide feedback.

&&

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

Public/Aviation/Fire Wx...BSO
PIO/IDSS..................CM

weather.gov/hanford