textproduct: San Joaquin Valley

UPDATE

Updated Aviation Section.

KEY MESSAGES

1. Lake Wind Advisory continues through Thursday for West Side Coastal Mountains north of 198 and San Luis Reservoir.

2. Dry and breezy conditions create elevated fire risk this week, especially in the Mojave Desert.

3. Near-normal temperatures expected across the area.

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

DISCUSSION

The troughing pattern that has primarily dominated the forecast through the beginning of this week is slowly starting to weaken across the area. The result will be a gradually warming trend for central California over the next few days and into the weekend. Afternoon highs will maintain a few degrees below season averages Thursday due to continued west-northwest influence, but will return to averages beginning Friday. In the San Joaquin Valley, there is less than a 10 percent probability for maximum temperatures to exceed 95 degrees Thursday, but these probabilities rise to 40 to 50 percent on Friday, then 80 to 90 percent on Saturday. An period of insignificant synoptic scale pattern will develop moving into next week, keeping temperatures near season averages at least through next Wednesday.

In the meantime, the westerly flow will continue to bring stronger wind gusts to the San Luis Reservoir as the winds navigate through the complex terrain. West winds 15 to 30 mph with gusts up to 45 mph remain expected for this area and there is a 70 to 80 percent probability for maximum wind gusts to exceed 30 mph each day through Monday. Gusty conditions will also continue in the Mojave Desert in the lee of the Tehachapi Range, however there is only a 40 to 50 percent probability for gusts to exceed 30 mph at Mojave each day.

The continued flow over the region and warming trend will keep relative humidities low, with minimums in the Central Valley anticipated at or below 20 percent. Desert RH values are expected between 10 and 15 percent, with Sierra values between 15 and 25 percent. Grass fire potential remains elevated in areas where stronger wind gusts pair with the lower humidities.

AVIATION

VFR conditions expected across the area for the next 24 hours.

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

Lake Wind Advisory until 11 PM PDT Thursday for CAZ300.