textproduct: San Joaquin Valley

KEY MESSAGES

1. A warming trend is expected today through next week with well above average temperatures by the weekend.

2. Record high maximum temperatures will be challenged next week.

DISCUSSION

An area of high pressure off the coast of Baja California is extending into the southwestern US this morning, resulting in clear conditions and above-average temperatures. Over the rest of this week and into next week, this high is expected to expand eastward and strengthen, resulting in a strong warming trend over central California, especially for the Mojave Desert and in the San Joaquin Valley. By next Monday, there is a 80 to 90 percent probability for maximum temperatures to exceed 85 degrees in the Central Valley, with similar probabilities to exceed 90 degrees on Tuesday. For next Wednesday, NBM ensemble output suggests a 40 to 50 percent probability for maximum temperatures above 95 degrees for the SJV, and 80 to 90 percent for the Mojave Desert. If the forecast holds at these temperatures, the area will be approaching daily record highs and flirting with monthly record highs.

AVIATION

VFR conditions are expected for the next 24 hours.

FIRE WEATHER

Warming air temperatures and steady dew point temperatures will lead to a decrease in minimum relative humidities, especially for the Mojave Desert which will fall between 10 and 20 percent, and for the high Sierra, dropping to 20 to 25 percent. This will coincide with a sharp decrease in 100- and 1000-hr dead fuel moistures and an increase in ERC in these areas, however values remain below critical thresholds.

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.