textproduct: San Joaquin Valley

KEY MESSAGES

1. Winter Storm Warning in effect for the Sierra Nevada above 7,000 ft until 5 PM Wednesday.

2. Wind Advisory for the Kern County desert this afternoon into Wednesday morning and the Mojave Desert slopes from this afternoon until Wednesday evening.

3. An approaching cut-off low brings periods of heavy rainfall and mountain snow through this evening, with favorable conditions for convective weather this afternoon and evening.

DISCUSSION

Currently, a band of precipitation is gradually moving inland, based on latest radar and satellite data. Deeper convection is offshore and moving inland over Northern California. Additional showers and thunderstorms will develop by this afternoon in our forecast area. As much as a 50 percent chance of thunderstorms exists for our region for today. Northern portions, including Fresno County northward, are now under a marginal risk for severe thunderstorms, per the Storm Prediction Center. Otherwise, additional snow will fall in the higher elevations of the Sierra Nevada until Wednesday with current snow levels around 7,000 feet lowering to 4,500 feet by late tonight. Strong, gusty winds will also develop over the higher elevations and into the Kern County desert by this afternoon. Active weather continues through Wednesday afternoon with additional chances for afternoon/evening thunderstorms, as well as gusty winds and precipitation.

We get a break from active weather late this week with near to above average temperatures for Thursday into Friday, but another low pressure system brings a slight chance for precipitation this weekend, mainly over the Sierra Nevada and adjacent foothills. Precipitation chances will also occur into early next week in these particular areas. Overall, we're not looking at significant warming through next week, or similar to what took place last weekend into yesterday.

AVIATION

MVFR with Local IFR over the Higher Terrain of the Sierra Nevada. Otherwise, VFR conditions expected across the area for the next 24 hours, with Valley and Foothill MVFR conditions in and around thunderstorms through 06Z Wednesday.

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 8 PM PDT Wednesday for CAZ338. Winter Storm Warning until 5 PM PDT Wednesday for CAZ323- 326>328-330. Wind Advisory from 2 PM this afternoon to 7 AM PDT Wednesday for CAZ337-339.