textproduct: San Joaquin Valley

KEY MESSAGES

1. Changing weather patterns bringing cooler weather and the next regional chances for rain.

2. Potential for thunderstorms over the Sierra Nevada crest continues for this afternoon and evening, with 20-30% probability on Wednesday and Thursday.

3. Potential for wildfires with cured fuels still remains a threat this week.

DISCUSSION

Heat Dome continues to shift east as temperature began a cool- down as we go through the week. While triple digit heat was still felt this Tuesday, max temperatures will struggle to reach 100 degrees (outside the Mojave Desert) by mid-week and the latter half of the period. Probability of Exceedance (PoE) of reaching 100 degree drops to below 10 percent out-side of Kern County with the entire San Joaquin Valley falling below 10 percent by Thursday. By Friday, PoE of reaching 95 degrees will struggle to rise above 15 percent. Afterward, PoE of reaching 100 degrees remains very low as confidence in keeping max temperatures in the 90s through early next week will be high.

Ensemble precip-water analysis is still showing an increasing trend in values surging into the area over the next few days. At the moment, moisture is expected to surge across a good portion of Central California with orographic lift supporting the best afternoon convection across the Sierra Nevada. While the lower end of the Probability of Precipitation Percentiles spread for the period for Wednesday and Thursday is zero (0.00), the upper end shows a chance (10 percent) of receiving a wetting rain (0.10-0.30). Therefore, while the probabilities of seeing heavy precipitation over the valley is low, the support over the Sierra will allow probabilities to lean more toward the 90th percentile range. Yet, these percentage will also coincide with the probability of thunderstorms on both days. Ensembles show the moisture shifting east by Friday as probability of precipitation diminishes.

AVIATION

VFR conditions will prevail for the next 24 hours with light northwest winds during the day and variable winds overnight. Thunderstorms will have a 5-15% percent chance from 21Z Wednesday until 03Z Thursday across the San Joaquin Valley Central California.

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

None.