textproduct: San Joaquin Valley

KEY MESSAGES

1. Temperatures continue to warm through Friday.

2. Minor to Elevated Heat Risk across the area throughout the week.

3. Increased fire risk through the weekend, particularly Saturday.

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

DISCUSSION

There is much of the same story today as there was yesterday. Zonal flow and ridging are keeping the area quiet in terms of weather. This is leading to increased temperatures and will continue to do so until we finally have a break in the heat on Saturday. Friday continues to be the hottest day this week, with most cities flirting with the upper 90s to the low 100s. The Probability of Exceedance (PoE) of 100 degrees for the San Joaquin Valley on Friday is holding at 5-40 percent, with the highest percentage being the Bakersfield and Taft areas. Lowest percentages are Fresno and Merced areas.

Saturday will have a break in these high temperatures as an inside slider will pass to our North. Within the valley, the slider will keep our temperatures from approaching the 100s, as Saturday's high has a 90 percent chance of exceeding 88 degrees and a 10 percent chance of exceeding 95 degrees in Fresno, King and Tulare counties. Merced county has a 90 percent chance of exceeding 85 degrees and a 10 percent chance of exceeding 92 degrees. Down in Kern County, there is a 90 percent chance of exceeding 92 degrees and a 10 percent chance of exceeding 98 degrees. However, winds are expected to increase and as such, there will be increased fire risk, particularly in Eastern Kern and Tulare counties. With this quick disturbance, min relative humidity values will be 15 to 20 percent throughout the Valley, adding to the fire risk.

By the middle of next week, there will be a second system that follows the slider, however, the jury is still out on if the trough will dig deeper into the valley than this first system. Regardless, it'll help keep the Central Valley at near to slightly below normal temperatures for this time of year.

While temperatures are warm, it's important to exercise cold water safety at all times. Rivers, streams, lakes are often fed by snow-melt and runoff, making the water much colder than air temperatures.

AVIATION

VFR conditions expected across the central California interior for the next 24 hours.

AIR QUALITY ISSUES

Ozone and PM2.5 levels are expected to be elevated the next few days and will be unhealthy for sensitive groups.

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.