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Record heat to bake California as April snowpack nears 70-year low

Much of California will see highs in the 80s and 90s on Thursday

High temperature differences from normal Thursday forecast by the National Weather Service across the West. (WeatherBell)

It’s only early April but spring’s first substantial bout of hot weather is set to scorch large parts of California on Thursday. The pulse of heat should be fairly short-lived, lasting only a couple of days, but scores of records could fall between Thursday and Friday.

The abnormally high temperatures are the result of a dome of high pressure sprawled over the western United States. Long-term warming from human-caused climate change also increases the frequency and intensity of such events.

The heat comes as April snowpack in the Sierra Nevada has dropped to one of its lowest levels in 70 years due to a record lack of precipitation in January, February and March. The high temperatures will further melt what little snow remains.

California snowpack vastly depleted after record dry start to year

The National Weather Service is predicting temperatures 10 to 25 degrees above normal over most of California on Thursday and Friday. The biggest differences from normal are forecast for the central and northern portions of the state.

This equates to widespread high temperatures in the 80s and 90s, even along the coast on Thursday. Some of the hottest weather is projected for the Central Valley both Thursday and Friday, with record-setting highs from 90 to 95 degrees. Sacramento, Redding and Stockton could all approach or surpass records.

“[T]he much advertised and talked about mini-heat wave is still on track,” the Weather Service office serving the Bay Area writes. Its forecast discussion says the warm-up is considered “extreme” compared to what is typical for this time of year.

Temperatures may fall short of records in the Bay Area, but the high in San Francisco on Thursday is forecast to be in the mid-80s, about 20 degrees above normal. Temperatures are expected to pull back on Friday as winds come in from the Pacific, with a high closer to 70.

In Southern California, temperatures are also likely to be considerably above normal both Thursday and Friday. The forecast high in Los Angeles are in the low 90s compared to an average in the low 70s. On Friday, some record highs are possible. Heat advisories are in effect for much of southwest California until then.

“Drink plenty of fluids, stay in an air-conditioned room, stay out of the sun, and check up on relatives and neighbors,” the advisory states. “Young children and pets should never be left unattended in vehicles under any circumstances.”

Heat to further deplete snowpack amid drought

Temperatures in the Sierra Nevada are predicted to rise into the 60s and even the 70s and 80s in the lower elevations, further melting a depleted snowpack.

“Needless to say, it will feel like near-summer late this week,” the Weather Service in Reno, Nev., writes.

On Friday, the California Department of Water Resources conducted its monthly snow survey at Phillips Station in the Sierra Nevada. It measured only 2.5 inches of snow, 4 percent of the average for the date at that location. January, February and March were the driest period on record for the Sierra.

The latest federal drought monitor shows the entirety of California facing drought conditions. The long-range outlook is for the drought to persist or worsen.

Western drought to worsen this year, NOAA says

Cooler times ahead along with some precipitation

The hot weather pattern through Friday will not be sustained. A cool front is expected to drop south across California over the weekend.

Computer model simulations “give high confidence in a pattern change by Sunday with a significant drop in temperatures,” the Weather Service office in Sacramento writes.

The cool pattern should endure for much of next week across the western United States, and some beneficial rain and mountain snow are expected, mainly in the northern and central part of California. However, a warm, dry pattern may return by the second half of the month.

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