textproduct: San Joaquin Valley

KEY MESSAGES

1. Minor Heat Risk across the lower elevations of central California through Tuesday with a warming trend starting Wednesday.

2. Strong winds expected for the Mojave Desert Slopes this afternoon until early Tuesday morning.

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

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

DISCUSSION

High temperatures lower by at least a few degrees today, compared to yesterday's. Chances for a high of 90 degrees today are at 10-20 percent across the Central Valley. However, widespread 90's will still take place in the Kern County desert today, as a high probability (85-95 percent) for a high of at least 90 degrees remains. Gusty winds will also occur each afternoon and evening until Monday along the Mojave Desert slopes. The best probability for a gust over 45 mph (near 90 percent) will be on Monday afternoon and evening, but it is still above 50 percent for this afternoon and evening in many locations. Chances for gusts of at least 55 mph in this area are about 50-60 percent on Monday. Thus, we issued a Wind Advisory for the Mojave Desert slopes from this afternoon until late Monday night/early Tuesday morning. Low minimum humidity (about 10-15 percent) will still be an issue in some areas today, despite lower temperatures. Meanwhile, steady temperatures will occur until Tuesday, with highs near seasonal averages. Temperatures warm markedly as we reach Wednesday and will become quite hot shortly afterward.

By later this week, it will start to feel more like summer, as the ridge builds along the West Coast and shifts inland. Expect largely a moderate Heat Risk, with some pockets of major Heat Risk throughout the lower elevations, including the Central Valley, lower Sierra foothills, West Side Hills and adjacent lower coastal ranges, and the Kern County desert. Widespread triple digit heat begins Thursday, and many locations will reach the hottest temperatures of the year so far. The probability of a reading at least 100 degrees is at 60-70 percent for the San Joaquin Valley and 85-95 percent for the Kern County desert from Thursday until Saturday. There is also a good chance (65-75 percent) for the Indian Wells Valley to exceed 105 degrees. Hotter maximum temperatures will coincide with even lower minimum humidity percentages, or single digits in the desert and 10-15 percent for the valley.

AVIATION

VFR conditions expected across the central California interior for the next 24 hours. Surface Wind gusts to 40kts over the Mojave Desert slopes in eastern Kern County from 21Z Sunday to 12Z Monday.

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 this afternoon to 5 AM PDT Tuesday for CAZ338.