textproduct: San Joaquin Valley

KEY MESSAGES

1. Wind Advisory for Mojave Slopes through Thursday night.

2. Above average temperatures continue through Thursday.

3. Chance for unsettled weather as precipitation, winds, and periodic thunderstorms return this weekend.

4. Winter Storm Warning in effect from 5 PM Friday through 11 PM Sunday for the Sierra Nevada above 7,000 feet.

DISCUSSION

Temperatures are expected to remain above normal for one more day as the ridge begins to break down and move out to the East. These highs are expected to drop below normal by Saturday and into the middle of next week. These temperature drops are being brought to the area by not one, but two troughs that will be moving through Central California.

Trough one will be moving into the area tonight into tomorrow. With it, the Sierra Nevada and the Foothills area has a best case (90 percent probability) of seeing 0 precipitation or more while the worst case (10 percent probability) can have 0.34 inches. There will be enough energy within the area that a thunderstorm or two cannot be ruled out. Some of these thunderstorms could be strong. This is in line with the Storm Prediction Center's general risk for thunderstorms for the northern part of our CWA.

Trough two is looking to be wetter and colder for the entirety of our CWA. Temperature wise, the valley is going to be below normal for this time of year. We're looking at temperatures between 60 degrees (90 percent probability) and 68 degrees (10 percent probability) through Monday. On Wednesday, we'll creep back up with temperatures, but still remain on the below normal side. Snow levels will fall with this system, with them starting at 8,000 feet to the levels dropping down to 4,500 at the end of the event. Light accumulation is possible in Yosemite Valley, but this is low probability of happening (30-40 percent). Elevations above Yosemite Valley can see moderate (5 to 10 inches) snowfall.The highest peaks of the Sierra Nevada can see 7 inches (low end chance) up to 21 inches (high end chance).

The storm is expected to move out to the east and a ridge is likely to build on Tuesday following this storm.

AVIATION

VFR conditions prevailing for the next 24 hours. Gusts above 40 knots expected across the Mojave Slopes in the lee side of the Tehachapi Range through Thursday night.

FIRE WEATHER

Elevated fire risk for Eastern Kern County. Min RH values around 20 percent with gusts up to 45 mph on Thursday before winds increase with higher RH values over the weekend.

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.