textproduct: San Joaquin Valley

UPDATE

Updated aviation section.

KEY MESSAGES

1. Wind Advisory for the Mojave Desert Slopes and Lake Wind Advisory for the San Luis Reservoir through 2AM this morning.

2. Strong winds along with very low relative humidities are expected this weekend in the western portion of the San Joaquin Valley, increasing the fire risk for that area.

3. Continued warming is expected early next week, along with further drying for the entire region.

4. Practice safety around area lakes, rivers, and streams as waters are still running cold.

DISCUSSION

Gusty winds are expected to continue through 2AM this morning along the Mojave Desert Slopes and at the San Luis Reservoir before calming once again later into tomorrow morning. But strong winds are expected to return for much of the region by Friday into the weekend, especially for the Mojave Slopes and the Lake Isabella areas. This is due to the downstream affects of a trough moving through the northwestern CONUS, causing increased pressure gradients aloft through the weekend. This air is likely to also be dry as it comes out of the continent, leading to very low RHs for much of the region, not just the Desert. This combined with the strong winds will lead to increased fire risk, especially for the western portion of the San Joaquin Valley. Fuels in this region have also been steadily drying throughout the month.

After this trough moves east, ridging is likely to build in by early next week, leading to another warm up by next Wednesday. And even though the winds are expected to calm during that time, RHs are expected to drop a few more percentage points beginning on Monday and continuing into mid-week, with the Valley likely seeing values of 10-15% and the Mojave seeing values in the single digits. This combined with the hot temperatures will continue to keep the fire risk elevated for much of the Valley and the Desert. During this time, rivers and streams continue to run cold, so continue to practice water safety when using those recreational areas.

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

None.