textproduct: San Joaquin Valley

KEY MESSAGES

1. Extreme Heat Warning continues for the Mojave Desert and Indian Wells Valley through Monday evening. Major HeatRisk expected with afternoon highs 102 to 110 degrees through Monday.

2. High pressure over the region will maintain temperatures near season averages for the remainder of Central California Monday and Tuesday.

3. Warming trend begins Wednesday with Major Heat Risk by Friday for the Mojave Slopes and Desert and by the weekend in the San Joaquin Valley.

4. Dry conditions to prevail through the week.

DISCUSSION

Today's highs reached near or just below the century mark once again in the San Joaquin Valley, while highs were generally 100 to 105 degrees in the eastern Kern County portion of the Mojave Desert. Generally near average to slightly above average temperatures took place. Similar temperatures are in store for Monday and Tuesday, while dry conditions prevail. A few mid- level and high clouds persist over portions of the forecast area; these earlier produced light echoes on radar, but with no reports of precipitation. Otherwise, mainly clear skies prevail along with a persistent ridge of high pressure centered over the Rockies and western Great Plains with southwest flow over the Golden State.

The ridge is forecast to strengthen and retrograde a bit. This will provide a rising trend in temperatures starting Wednesday with even hotter temperatures Friday into next weekend. Many areas could see Major HeatRisk in the Central Valley and once again in the Kern County desert Friday into next weekend. The probability of a maximum temperature of at least 105 degrees is now at 65-75 percent for the San Joaquin Valley, while the chances for 110 degrees in the Mojave Desert are at 80-90 percent. Unfortunately, overnight lows will be very warm in the desert and larger cities of the SJ Valley (mainly in the 70s, except for lower 80s towards the Indian Wells Valley in northeastern Kern County). Dry conditions will remain until next weekend. Lower daytime humidity will also accompany the hotter temperatures with minimum values ranging from 5 to 10 percent in the desert to 10-20 percent in most other locations. Moderate to poor overnight humidity recoveries will also occur, including in the higher terrain and desert.

AVIATION

VFR conditions will prevail for the next 24 hours.

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

Extreme Heat Warning until 9 PM PDT Monday for CAZ337-339.