textproduct: San Joaquin Valley

KEY MESSAGES

1. Red Flag Warning in Effect Friday 9 AM to Saturday 11 PM for the following Fire Weather Zones: Indian Wells Valley, Kern County Desert, and Lake Isabella.

2. Wind Advisory in Effect for Sierra Nevada Crest Friday 11 AM to Saturday 5 AM.

3. Dry and windy conditions create significant fire risk this weekend, particularly in Eastern Kern and Southern Tulare Counties.

4. Cool down into the weekend will bring below normal temperatures.

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

DISCUSSION

Starting today, a series of upper level troughs will cross over California. These disturbances will coincide with high winds and low relative humidity, with very low confidence for any wetting rain in our area. As a result, there is high confidence conditions will meet or exceed the criteria for advisory products for most of our mountainous areas. This includes:

Wind Advisories for the Sierra Nevada and eastern Kern County for gusts up to 50 mph from 11AM this afternoon to 5AM Saturday and 5AM Sunday respectively.

Lake Wind Advisory for San Luis Reservoir until 1PM this afternoon. Gusts up to 30 mph expected.

Red Flag Warning for eastern Kern County and the Kern River Valley until 11PM Saturday.

The latest NBM run indicates today and Saturday as the proverbial bullseye for high winds, with weaker (but still unusual) low pressure remaining over California afterwards. Newer guidance will be needed to decide whether the aforementioned products need to be extended for Sunday. These conditions are also sufficient for a 5-10% probability for afternoon thunderstorms across the Sierra Crest today. Any thunderstorms that do form bring the risk of heavy downpours, hail, and cloud-to-ground lightning.

Fortunately, the silver lining here is a return to average and even below average temperatures this weekend and to start next week. Temperatures in the mid- to- upper 80s across the Central Valley and even some of the higher elevations of the Mojave Desert will warm only to low-to-mid 90s by the middle of next work week. The probability of temperatures at or above 100 degrees in the Central Valley is effectively zero until the end of next week.

AVIATION

VFR conditions expected across the area for the next 24 hours. 50-75% probability for surface wind gusts reaching 35kts across the Sierra Nevada Crest, Tehachapi Range and Mojave Desert after 22Z Friday. 5-10% probability for thunderstorms across the Sierra Crest from 20Z Friday to 3Z Saturday.

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

Red Flag Warning until 11 PM PDT Saturday for CAZ298-299-595.

Wind Advisory until 5 AM PDT Sunday for CAZ337-339.

Lake Wind Advisory until 1 PM PDT this afternoon for CAZ300.

Wind Advisory until 5 AM PDT Saturday for CAZ323-326-328-330- 331.