textproduct: San Joaquin Valley

KEY MESSAGES

1. Heat Advisory remains in effect for the majority of the area until 11 PM Tuesday.

2. Widespread Moderate Heat Risk, including triple-digit heat, in the lower elevations through Wednesday.

3. Hot and dry conditions will create elevated fire risk in eastern Kern and Tulare Counties for the next few days.

4, Chance for thunderstorms in the Sierra Nevada the next few days, which may include dry lightning.

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

DISCUSSION

A high probability (70-80 percent chance) of triple digit heat remains today and again Tuesday throughout the southern Central Valley, mainly south of Fresno. Lower chances remain for Fresno northward (20-30 percent) today and rise to 40-50 percent Tuesday. Thus, the Heat Advisory will remain in effect until tomorrow evening. A slight (10-15 percent) chance for isolated thunderstorms exists for this afternoon along the Sierra Nevada crest and lowers on Tuesday to less than 10 percent. The threat for grass and brush fires continues in these areas, as well as the Mojave Desert in eastern Kern County due to low daytime relative humidity that coincides with the hottest time of the day. Triple digits will also prevail throughout the desert. Moderate Heat Risk is shown for much of the lower elevations in our forecast area through Wednesday. Overnight lows remain relatively cool, although lows will be in the 70s in the warmest locations, including larger metro areas and in the desert.

A cooling trend begins late in the week, and near seasonal temperatures will be in store Friday and Saturday. A minor warming trend returns to our area Sunday into next Monday. The warmest locations will mainly observe high temperatures in the 90s during Friday into early next week, although triple digits creep back into the desert by next Monday. Overall, a dry pattern, except for isolated afternoon thunderstorms along the Sierra Nevada crest.

AVIATION

VFR conditions expected in the San Joaquin Valley for the next 24 hours. Any thunderstorms that form over the Sierra Crest this afternoon may include strong winds, rain, small hail, lightning, and turbulence.

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 high.

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

Heat Advisory until 11 PM PDT Tuesday for CAZ300>321-332.