textproduct: San Joaquin Valley

KEY MESSAGES

1. Wind Advisory in effect 11 PM Monday to 11 AM Wednesday for Indian Wells Valley, Mojave Desert Slopes, and Mojave Desert.

2. Lake Wind Advisory in effect until 5 PM Wednesday for Kern River Valley, including Lake Isabella.

3. Cut-off low pressure system will lead to increased winds and potential for precipitation in the Sierra Nevada and the foothills, with snow levels around 7000 feet.

4. A slight chance for thunderstorms exists for Wednesday and Thursday along the Sierra Nevada crest.

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

DISCUSSION

A strong cut-off low pressure system is expected to move into the region by this afternoon, bring with it strong winds for the Desert and mountain ridges, and precipitation for the Sierra Nevada and its foothills by tomorrow and Thursday. A late season system like this one is fairly unusual fort his time of year, as we would normally be coming into our dry season and seeing warmer afternoons. This system will keep temperatures around 10 degrees below normal through Thursday, with low to mid 70's expected for the Valley and Desert regions.

The main story with this system will be late season precipitation, mainly expected in the mountains and foothills tomorrow and Thursday with some trace amounts this evening along the foothills. Along with that rainfall, snow levels are expected to be low enough that a trace to a few inches of snow above 7000 feet, particularly on the highest peaks. Current probabilities for at least 4 inches of snowfall over the next three days are 30 to 50 percent above 9000 feet. Along with this precipitation, the chances for thunderstorms along the Sierra Crest are expected to be 15 to 25 percent both tomorrow and Thursday (with Thursday closer to 30% on the leeward side of the range). As mentioned above, this system continues producing strong winds along the mountain ridges and Mojave Desert Slopes as of the most current observations. Stronger gusts are also expected to continue in the Kern River Valley and Lake Isabella into tomorrow afternoon.

This system is expected to move east by Friday after remaining aloft for a few days, with zonal flow taking it's place through the weekend. This will lead to an increase in temperatures back up to seasonal normals by Sunday. Then a ridge is expected to slowly build back in over the Southwest and California, leading to temperatures rising above normal once again, as we would expect for early June.

AVIATION

VFR conditions prevailing across interior central California 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

Wind Advisory until 11 AM PDT Wednesday for CAZ337>339. Lake Wind Advisory until 5 PM PDT Wednesday for CAZ332.