Flooding in California, May 1 to 30, 2023

Area Forecast Discussion
National Weather Service Hanford CA
141 PM PDT Sun Apr 30 2023

.SYNOPSIS...
Wind gusts of 20 to 30 mph will affect the San Joaquin Valley
tonight. Further cooling will lower high temperatures to around
10 to 15 degrees below normal Monday through Friday. There is a
low to medium chance of showers Monday through Friday with the
higher chances over the mountains. There is also a slight chance
of thunderstorms Tuesday through Thursday.

&&

.DISCUSSION...
Upper ridge has shifted east as an upper trough over the northeast
Pacific digs south over the west coast. Cooler air is advecting in
as is evident in 24 hour temperature trends running down 5 to 10
degrees. Despite the cooling, highs this afternoon are forecast to
still be around 5 to 10 degrees above climatological averages for
the end of April. A push of cool marine air will occur across the
San Joaquin Valley this evening resulting in northwest wind gusts
around 20 to 30 mph.

The trough will deepen over California on Monday bringing in a much
cooler air mass. Temperatures will lower as much as 20 degrees from
today to Monday with highs around 10 degrees below average. Strong
wind gusts will develop in the Kern County desert Monday afternoon
and continue into the late night. A Wind Advisory has been issued
from Noon Monday until 5 AM Tuesday for southwest wind gusts up to
55 mph. There is also a slight chance of showers over the mountains
on Monday. There is good model agreement with the parent upper low
moving over the SF Bay area on Tuesday then drifting south around
Point Conception on Wednesday before moving inland over central CA
on Thursday and finally exiting northeast as an open wave on Friday.
Temperatures lower a little more with highs around 10 to 15 degrees
below normal Tuesday through Thursday. Highs are forecast to mainly
be in the upper 60s across the SJ Valley with NBM probabilities for
a high of at least 70 degrees at less than 50 percent. The chances
for precipitation increase to low to medium Tuesday through Thursday
with the higher chances over the mountains. The proximity of the low
will provide a slight chance of thunderstorms as well. Storm total
rainfall amounts for the week of a few hundredths to one quarter of
an inch are forecast for the SJ Valley with one to one and a half
inches liquid over the Sierra Nevada. Snow levels will generally be
from 5000 to 6000 feet. Temperatures nudge up into the lower 70s in
the SJV on Friday and mid to upper 70s next weekend, which is still
around 2 to 5 degrees below normal.

&&

.AVIATION...
VFR conditions will prevail across the central California interior
for 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
and/or to provide feedback.

&&

.HNX WATCHES/WARNINGS/ADVISORIES...
Wind Advisory from noon Monday to 5 AM PDT Tuesday for
CAZ337>339.

Flood Watch through Tuesday morning for CAZ323-324.

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Public/Aviation/Fire Weather...DCH
PIO/DSS........................BS

weather.gov/hanford