By John C. Toman. Posted July 12, 2012, 10:39 PM.

A couple of bands of light showers traveled westward across Southern California's inland valleys Thursday, generating raindrops but not anything measurable.

Daytime conditions ended up being mostly cloudy, as thick cloud cover from monsoonal moisture streamed across the region.

Trace rainfall was reported in Fallbrook, Temecula, Menifee, and Anza, and probably other locations as well. The first wave hit at 9am out in Anza, followed by broader showers in the 2pm hour and more between 7pm and 9pm.

Temperature took a dive from previous days but were still very warm and even hot in some locations. Lake Elsinore was 98°F, Wildomar 97°F, San Bernardino 95°F and Temecula 94°F. The cloud cover led to muggy conditions in many areas and only slow cooling Thursday night.

More thunderstorm action is anticipated tonight, and again tomorrow afternoon and evening. Thunderstorms are capable of producing brief, heavy downpours and small hail.

By Saturday, thunderstorm activity is expected to retreat to the mountains and deserts, and the monsoonal tap is predicted to end Sunday, as low pressure takes over along the west coast.

A suspected calibration issue with our instrumentation in Murrieta was confirmed Wednesday evening. Replacement parts have been ordered.