textproduct: San Joaquin Valley

UPDATE

Updated Aviation Section.

KEY MESSAGES

1. Strong wind gusts continue through Sunday along the Sierra Nevada crest, as well as the Tehachapi Mountains and Mojave Slopes due to a passing upper-level low pressure system. Wind Advisory remains in effect through 10 PM Saturday.

2. Elevated fire risk concerns exist in the mountains and adjacent foothills in Kern and Tulare Counties this weekend due to gusty winds and low humidity.

3. A warming trend is expected through next week.

DISCUSSION

The inside-slider trough will continue its trek over the Great Basin and move southward through this weekend. This feature will provide a northeasterly flow over the Sierra Nevada and the Kern County mountains and desert. Downsloping winds will result due to this pattern, and humidity lowers over the Sierra Nevada and adjacent foothills, as well as the Kern County mountains. Minimum humidity will fall to near 20 percent coupled with strong winds, mainly tonight into Saturday evening. In addition, some mountain locations will not see much overnight humidity recovery. Thus, the risk is elevated for large fires. A Wind Advisory will remain in effect for the Sierra Nevada crest as well as the Kern County mountains/desert through Saturday evening. Widespread gusts to 50 mph will occur, and the typical prone areas, including the Mojave Desert slopes and exposed ridges/peaks, will see stronger gusts as much as 65 mph. The latest probabilities for gusts of 50 mph is at 40-50 percent over the Sierra Nevada crest, and the chances for gusts at least 65 mph are 50-60 percent, including over the Mojave Desert slopes. Greater chances (80-90 percent) for gusts at least 50 mph exist over the Mojave Desert slopes.

Winds relax by Sunday, but the ridges and peaks remain breezy, as well as the prone areas of eastern Kern County. Humidity will gradually moderate Sunday into next week, although a noticeable warming trend takes place with well above average temperatures by the latter part of next week. Highs reach the mid 80s by the end of next week in the Kern County desert, while valley highs reach into the 70's. The warmest spots in the San Joaquin Valley have a good chance (60-70 percent) to reach 80 degrees on Thursday and next Friday. As for the desert, there is a slight (20-30 percent) chance for highs to reach or top 90 degrees by next Friday.

Latest CPC outlooks continue to show the odds tilted towards below average precipitation and above average temperatures for both the 6-10 day and 8-14 day periods (until March 20th).

AVIATION

VFR conditions expected for the next 24 hours. Surface wind gusts 35-40 KTS over the Sierra Nevada Crest and Kern County mountains/desert through 06Z Sunday.

FIRE WEATHER

Fire weather is a concern in Tulare and Kern Counties in the mountains and foothills this weekend, where increasing northeasterly winds and drying air will cause elevated concerns. However, 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 until 10 PM PST Saturday for CAZ333-334-337>339.

Wind Advisory until 10 PM PST Saturday for CAZ323-326-328-330- 331.