textproduct: San Joaquin Valley

KEY MESSAGES

1. Heat Advisory in effect for the majority of the area from 11 AM Thursday until 11 PM Saturday.

2. A warming trend begins Wednesday.

3. Widespread Moderate Heat Risk, including triple-digit heat, in the lower elevations Thursday until next weekend. Pockets of Major and Extreme Heat Risk as well.

4. Hot and dry conditions will create increased fire risk in eastern Kern and Tulare Counties this weekend.

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

DISCUSSION

A Heat Advisory is in effect for the majority of the area from 11 AM Thursday until 11 PM Saturday.

The majority of the area is under a moderate heat risk, with some areas under a major heat risk, including Fresno on Friday. Take appropriate precautions now by reducing outdoor activity, having cooling and hydration available, and having a plan for vulnerable people and animals.

A large ridge off the West Coast will continue to build and slowly migrate eastward over the next few days, bringing with it steadily increasing temperatures. There is a 40-70% chance of exceeding 95 degrees across most of the Valley today. Thursday has a 50-80% chance of Valley areas reaching 100 degrees, and Friday has a 60-90% chance of Valley areas reaching 100 degrees. Similar temperatures will continue into the weekend. Low minimum relative humidities (8-18 percent) will create increased fire risk beginning Friday and continuing through the weekend for eastern Kern and Tulare Counties. Increasing overnight lows will create a cumulative effect in regards to heat risk, as Valley lows are expected to increase from the mid 60s to around 70 by the weekend, except in urban areas, like Fresno and Bakersfield, the thermal belt, and the Kern County desert, where they will be a few degrees warmer.

The heat continues into next week, with a 30-40% chance of temperatures reaching 100 degrees in the Valley on Monday. Current medium-range guidance suggests the ridge weakening in the middle of next week, which will help to cool temperatures a bit.

Despite the heat, water is still running cold and poses a risk to swimmers, both human and animal. Practice safety around lakes, rivers, and streams.

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 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

Heat Advisory from 11 AM Thursday to 11 PM PDT Saturday for CAZ300>321-332.