textproduct: San Joaquin Valley

KEY MESSAGES

1. Lake Wind Advisory continues for West Side Coastal Mountains north of 198 and San Luis Reservoir through 11 PM PDT Tuesday, July 7th. Beware of unsettled waters.

2. Chance of thunderstorms across the Sierra Crest Monday evening and Tuesday afternoon.

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

4. Hot, dry, and windy conditions will create significant fire risk, particularly in eastern Kern and Tulare Counties.

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 Tuesday, July 7th. West winds of 10 to 15 mph with gusts up to 25 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 Tuesday, 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 be in the mid 100s and increase toward 110-113 over the same period.

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.

Concurrent with the warming trend will be a decrease in minimum relative humidities, with the days of greatest concern being Wednesday and Thursday. On Wednesday, minimum relative humidities will be 17-21% in the Valley and 6-10% in the desert. On Thursday, minimum relative humidities will be 14-18% across the Valley and 4-8% in the desert.

Daily maximum wind gusts will hover around 15-20 mph, occasionally higher, in the Valley during the week. However, gusts may reach 40-50 mph in eastern Kern and Tulare Counties.

The combination of hot, dry, and windy conditions will create significant fire concerns, particularly in eastern Kern and Tulare Counties on Wednesday and Thursday.

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.

FIRE WEATHER

The Hot-Dry-Windy Index will be above the 95th percentile in eastern Kern and Tulare Counties this week, where a distinct combination of above-average temperatures, below-average moisture, and strong winds will create dangerous conditions. A surge of monsoonal moisture this weekend may create lightning conditions as well. Fire products may be necessary as the week progresses.

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 Tuesday for CAZ300.