textproduct: San Joaquin Valley

KEY MESSAGES

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

2. Widespread Moderate Heat Risk, including triple-digit heat, in the lower elevations Thursday until next weekend.

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

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

DISCUSSION

The triple digit heat will be continuing into the weekend. Today, there is a 80 to 96 percent Probability of Exceedance (PoE) of 100 degrees. It may bring only a small comfort, but the PoE of 104 degrees is only 10 percent for most locations. Small victories...Saturday looks to be a similar story, as the PoE for 100 degrees is again high - 80 to 94 percent. Both today and tomorrow, the Mojave Desert will exceed 100 degrees. By Sunday, the PoE for 100 goes down to 40 to 70 percent, with the highest percent chance being Bakersfield. In the Mojave Desert, their PoE is once again near 100 percent. With these hot temperatures, there is a Moderate HeatRisk for the SJ Valley. It is summer time, so hot temperatures are expected. However, those that might not be acclimated, the groups over 65 years of age, infants and those without access to AC may be at risk, so take precautions where needed. Overnight lows are to be in the 60-70 degree range, with the 70's more likely to be in the metropolitan areas. As such, there is a Heat Advisory in place until 11 PM Saturday night.

By Sunday, there is still widespread moderate heat risk for the Valley as we contend with similar temperatures (yes, the triple digits too) until the middle of next week. There will also be dry conditions as Relative Humidity will be between 8-20 percent. This is creating moderate risk of fire danger including grass fires. However, there is a 10-15 percent chance of an isolated thunderstorm or two in the Sierra Nevada's. By Thursday, there will be a low passing through the Pacific Northwest which will aid in disrupting the ridge in place. As such, temperatures will cool into the mid to low 90s. Still warm, but it could be worse!

As people attempt to cool down from these hot temperatures, please remember that waterways are still running cold. Even the most experienced swimmers can lose dexterity in 10-15 minutes in water that is 50 to 60 degrees.

Aviation

VFR conditions expected in the San Joaquin Valley 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 Saturday for CAZ300>321-332.