textproduct: San Joaquin Valley

UPDATE

Updated Aviation Section.

KEY MESSAGES

1. Lake Wind Advisory continues for West Side Coastal Mountains north of 198 and San Luis Reservoir through 11 PM PDT Monday, July 6th. Beware of unsettled waters.

2. Chance of thunderstorms across the Sierra Crest Monday afternoon.

3. Slow but steady warmup next week, with Heat Risk reaching elevated to major levels by weekend.

4. Dry and breezy conditions create elevated fire risk into next week, especially in the Mojave Desert.

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

DISCUSSION

Lake Wind Advisory continues for West Side Coastal Mountains north of 198 and San Luis Reservoir through 11 PM PDT Monday, July 6th. West winds of 10 to 15 mph with gusts up to 30 mph will create rough waves dangerous to small craft and difficult driving conditions, particularly for high-profile vehicles.

Models are in good agreement that a ridge will start to build over the southwest this week. This will be a slow but steady process, and as such, expect temperatures to climb across the week. On Monday, Valley high temperatures will be in the mid to upper 90s and increase to the upper 90s to mid 100s by the coming weekend. Desert highs will start the week near 100 and increase toward 110 over the same period.

Concurrent with the warming trend will be a decrease in minimum relative humidities, with Valley min RH around 25% to start the week, decreasing to 13-17% by Friday. The desert will start the week with min RH values of 14-16%, decreasing to 4-8% later in the week. Daily maximum wind gusts are not expected to exceed 12 mph in the Valley during the week. However, gusts along the Mojave Desert Slopes may reach 30-35 mph each day and 20-25 mph in the desert. There is a 10-20% of lightning along the Sierra Crest Monday. Fire risk will increase during the week, peaking on Wednesday, when the combination of dry air, hot temperatures, and strong winds will create significant fire risk in eastern Kern County.

The increasing temperatures will cause an increase in heat risk, with most of the area under moderate Heat Risk by Friday, with a few pockets of major Heat Risk.

As the heat continues, be sure to take appropriate precautions and check in on and make arrangements for vulnerable people and animals. Brachycephalic (short-nose) breeds will have particular difficulties with the heat and should be kept indoors.

If driving or boating in an area with a Wind Advisory, take appropriate precautions.

Water temperatures are still in the upper 60s and low 70s and much colder near water flowing from higher elevations. Exercise cold water safety at all times.

AVIATION

VFR conditions expected across the area for the next 24 hours. Gusty winds, brief heavy rain, and lightning in and near Mountain thunderstorms from 20Z Monday through 03Z Tuesday.

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 Monday for CAZ300.