textproduct: San Joaquin Valley

KEY MESSAGES

1. 5-15% chance of thunderstorms across the Sierra Nevada today and through the rest of the week.

2. Above average temperatures across the CWA on Friday and Saturday

3. A closed-low enters our area next week, with the best probability for weather impacts on Tuesday and Wednesday.

DISCUSSION

Calm and peaceful spring weather will prevail across the CWA through this week, with the only exception being chances for thunderstorms across the Sierra Nevada. Upslope forcing combined with a weak moisture influence from a closed-low off the coast of Baja California still provides sufficient conditions for a 5-10% probability for thunderstorms across the Sierra Nevada this afternoon, with higher 10-15% probability Thursday onward.

Near-term guidance shows high confidence for a week high pressure ridge to develop across the CWA starting Thursday, bringing above average temperatures. There is a 50-60% probability for Friday afternoon temperatures to exceed 90 degrees in the western San Joaquin Valley, with these probabilities extending to the majority of the valley on Saturday. Probabilities for these temperatures are 70-80% for Synopticthe valley portions of Kern County.

Starting next week, cluster analysis shows good agreement for a closed-low entering the CWA, with the highest confidence for weather impacts next Tuesday and Wednesday. While the expected scenario favors precipitation for the Sierra Nevadas, a higher- end scenario extends these conditions to the San Joaquin Valley along with more widespread chances for thunderstorms.

By next Wednesday, total rainfall of one half to three fourths an inch is expected across the Sierra Nevadas, with 2-3" snowfall accumulation above 7,000 feet. There is also a 40-50% probability for measureable rainfall (>0.01") across the San Joaquin Valley.

In a worst-case scenario, thunderstorms across the CWA will bring total rainfall above a quarter of an inch to the San Joaquin Valley and >1" for higher elevations in the Sierra Nevadas alongside total snowfall of 6-8" above 7,000 feet. During these worst-case thunderstorms, periods of heavy rain are possible along with hail and high wind gusts.

AVIATION

VFR conditions will prevail for the next 24 hours over 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.