Rarely have we seen such dramatic temperature swings as that witnessed during April 2009. Following a high temperature of 99 yesterday, tying the record for the date, we will be on a slide back to below normal readings by week’s end.

This roller coaster weather pattern is not uncommon for spring, which is really a transitional season offering extremes from both winter and summer. But it is noteworthy that less than a week ago, Upper Tyndall Creek in the high Sierra dropped to 11 below zero. Several spots in the south valley had lows of 32 degrees and a Frost Advisory was in place- only last Wednesday. Going from deep winter temperatures to July-class heat in the space of a couple of days actually makes for some exciting weather in Kern County. On Tuesday afternoon a thunderstorm popped up in San Luis Obispo County just west of Taft. It was typical of a hot mid-summer afternoon with instability showers resulting from triple digit heat. You could almost smell sulfur from the Fourth of July fireworks. Only 6 days earlier south valley residents needed to cover their tender vegetation to avoid frost damage. Amazing!

There were dozens and dozens of high temperature records broken from Sunday through Tuesday. Downtown Los Angeles beat Bakersfield to 100 degrees on Monday. We have actually set three records: the 99-degree high on Tuesday, plus two high minimum low temperatures in the 60s Tuesday and Wednesday. If Bakersfield had hit 100 on Tuesday it would have been the earliest 100-degree reading ever. Currently that record is April 23rd. All of this was caused by a strong high pressure system aloft together with easterly downsloping winds at ground level. This mountain of hot air developed in the wake of last week’s deep low, which moved east causing snow in Colorado and tornadoes in the southern Plains. Many people really enjoy the hot weather (a good thing if you’re living here in Bakersfield). But we are about to snap back to a cool weather scenario. The massive ridge is already breaking down and primed to be replaced by a trough of low pressure across the western U.S. After one more hot day today with highs in the 90s and a chance for afternoon mountain thunderstorms, a cold front will pass through the region on Thursday bringing windy weather and substantially cooler temperatures. In fact, if you are worried that your electric bill going sky high- don’t. At least, not yet. By Friday, temperatures will be below normal in the low to mid 70s. This weekend looks very pleasant with 70s for highs and 40s for lows. In the mountains, we’re back to the 50s. And there is a chance some blowing dust could kick up during the shift back to cool weather.

Summer is looming on the horizon and will no doubt be hot and dry. But my forecast for above normal rainfall this autumn is still on track. The La Nina conditions in the equatorial Pacific have neutralized and computer models are suggesting El Nino should return by November. That means a good chance for heavy rains in California. If we can make it through the summer of this third drought year, a pay off will come once the next cool season arrives.