textproduct: San Joaquin Valley

UPDATE

Fire weather section updated.

KEY MESSAGES

1. Strong wind gusts expected through Sunday in the Tehachapi Mountains and Mojave Slopes as low pressure moves through. Wind Advisory in effect through 10PM Saturday.

2. An fire risk concern exists in Kern and Tulare county foothills this weekend.

3. A warming trend is expected this weekend and into next week.

DISCUSSION

An inside slider trough will move in from the northeast tonight through Saturday leading to strong winds across mountainous regions and elevated winds for the rest of the area. These winds are expected to be 20-30 mph with gusts up to 50 mph over the peaks above 8000 feet for the Sierra Nevada and for the highest peaks of the Tehachapi Range. There is a 10-20% chance for wind gusts over 50 mph in the Mojave and 60 mph for the highest peaks Saturday morning.

A Wind Advisory is in effect for the Upper Sierra through 10PM Saturday and the Mojave and Lower Sierra from 10PM tonight to 10PM Saturday.

The northeasterly wind coming from over the Sierras will become a weak Mono wind downsloping into the Valley. This will lead to lowering relative humidities as the air warms and dries on the way down, increasing fire risk particularly for Tulare and Kern County foothills. Moist fuels will keep the fire risk from rising further.

After this cut-off trough moves through our area, a ridge is expected to build in over the southwest, leading to above normal temperatures and little likelihood for rainfall. Current model guidance suggests a 10-30% chance for temperatures above 90 degrees in the valley next weekend.

This pattern is likely to continue through the next two weeks as the Climate Prediction Center maintains above normal temperatures and below normal precipitation for our CWA through Day 14.

AVIATION

VFR conditions expected for the next 24 hours. Surface wind gusts exceeding 40KTS over the Sierra Nevada Crest during the period.

FIRE WEATHER

Fire weather is a concern in Tulare and Kern Counties foothills this weekend, where increasing northeasterly winds and drying air will create potentially volatile conditions. Moist fuels will keep fire risk from rising further.

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 10 PM this evening to 10 PM PST Saturday for CAZ333-334-337>339. Wind Advisory until 10 PM PST Saturday for CAZ323-326-328-330- 331.