textproduct: San Joaquin Valley

KEY MESSAGES

1. The warmest temperatures are expected this afternoon before a cooldown begins this weekend.

2. Minor to Moderate Heat Risk across the area today becoming Minor through the weekend into next week.

3. Increased fire risk through the weekend, particularly Saturday.

4. Strong winds expected for the Mojave Desert Slopes, the Kern River Valley and around the San Luis Reservoir from tonight into overnight tomorrow.

5. Practice safety around lakes, rivers, and streams, as water is still running cold.

DISCUSSION

The last of the ridging is expected to raise temperatures across the Valley into the upper 90's this afternoon and continuing the triple digits out in the Mojave Desert. Those temperatures in the desert along with minimum RHs in the single digits will keep fire risk elevated through today and somewhat into tomorrow.

By then, a trough will move through the northwest CONUS and lower the 500mb heights in California. This will lead to a cooling temperatures throughout the region and will also cause strong winds as it moves through the west coast. As a result, a Wind Advisory has been issued for the Mojave Desert Slopes from tomorrow afternoon into the overnight hours, and Lake Wind Advisories have been issued for both the Kern River Valley and the San Luis Reservoir from tomorrow afternoon into the overnight hours.

A greater cooldown is expected by Tuesday as another wave coming down from the northwest Pacific moves further south into Southern California, which will also cause minimum RHs to be less dry than the previous trough wave this Saturday. RHs in the Valley are likely to rise into the 30's and 40's by Tuesday from the mid teens expected this weekend. The desert will also see an increase for single digits into the mid teens, similar to the Valley RHs expected today. After these troughs move east, ridging will reform over the Southwest, leading to a temperature rebound. Long term forecasts are also suggesting further warming in the week after next as the Climate Prediction Center has the Valley region in a slight risk (20%) for hazardous temperatures from 13th through the 18th.

AVIATION

VFR conditions expected 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 2 PM Saturday to 2 AM PDT Sunday for CAZ338. Lake Wind Advisory from 11 PM this evening to 11 PM PDT Saturday for CAZ300-301. Lake Wind Advisory from 11 AM Saturday to 2 AM PDT Sunday for CAZ332.