textproduct: San Joaquin Valley

KEY MESSAGES

1. The heat trend continues with temperatures about 10-15 degrees above average for the next several days.

2. Moderate to Major Heat Risk in the Central Valley through Wednesday. Heat Advisory has been extended further to 11 PM Wednesday.

3. Dry and calm conditions will persist for the week ahead.

DISCUSSION

Early October is typically when we say goodbye to 90s and triple digits. Unfortunately, summer is not ready to go. Temperatures yesterday were about 10-15 degrees above average, with Bakersfield tying the all-time record high minimum temperature of 72 degrees. Today, even more records are going to be challenged as high pressure is set to build even stronger over Central California. Most of the San Joaquin Valley will be at Major Risk of heat illness this Sunday, with heat this extreme affecting anyone without access to proper cooling and hydration. The hottest parts of the valley will still be at Major Risk until Wednesday, though most of the valley and elsewhere will be at Moderate Risk after Sunday.

Looking at the latest National Blend of Models run from this morning, almost the entire San Joaquin Valley has a 50% or greater chance of a high temperature above 100 degrees. Higher chances are expected on the western and southern edge of the valley. Here, there is a 90% and even higher chance of exceeding 100 degrees, including the Bakersfield area and the Interstate 5 corridor between Highway 166 to the south and 198 to the north. In these areas, there is also a 10-15% chance of exceeding 105 degrees. Hot, hot, hot!

Later into this week, high pressure ridging over California is set to gradually break down. As this happens, chances for exceeding 100 degrees back off by about 20% on Monday and Tuesday. However, multiple models are in agreement that a notable temperature drop is not set to occur until Thursday, then (hopefully) return back to about average by Friday. Starting next weekend, there is growing (but still low) confidence a eastward moving trough from the Pacific will bring the next regional chances for rain and High Sierra snow.

AVIATION

VFR conditions will prevail 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

Heat Advisory until 11 PM PDT Wednesday for CAZ300>322.