Sacramento could top 90 degrees today. What will heat mean for California water?
A big, early-spring heat wave will toast Northern California, with high temperatures that could soar more than 20 degrees hotter than normal in Sacramento by Friday.
The latest National Weather Service forecasts show the capital city reaching 92 on Thursday and 93 on Friday.
The historical average for this time of year in Sacramento is about 72 degrees. The daily records for April 6-8 are each 91 degrees, according to weather service records, all set in 1989.
The weather service’s Sacramento office in a Tuesday tweet called this week’s forecasts “anomalously warm.”
The hottest April day ever in downtown Sacramento, April 26, 2004, soared to 98 degrees. The record for the first half of April is 95, recorded April 9, 1989, and again April 13, 1990.
Several Northern California locales already smashed heat records last month, with Sacramento warming as hot as 84 degrees within the first few days of spring.
Areas farther north in the valley including Chico, and farther south including Modesto, are forecast to peak at 95 degrees by this Thursday or Friday.
The impending heat wave is expected to break by the weekend, with Sacramento expected to drop to the low 80s by Saturday and mid-70s by Sunday, forecasts show.
As for the Sierra Nevada mountains, weather service forecasts show South Lake Tahoe heating from the upper 50s on Tuesday to the upper 60s by Thursday and Friday, nearly 20 degrees hotter than the average for this time of year, which is about 52 degrees. Truckee could hit 71 degrees before the end of the week.
What does heat wave mean for California water, drought?
This week’s heat wave, as well as the one just two weeks earlier, are concerning given a severe drought in California that has already been exacerbated by extraordinarily low rain and snow totals this calendar year.
The U.S. Drought Monitor in an update Thursday said 40% of the state is in “extreme” drought conditions, including wide swaths of the Central Valley and the north coast region. Another 54% was only a step better in “severe” drought, and the entire state was in at least “moderate” drought conditions, per the monitor.
State water officials last week, after conducting the final manual snow survey of the 2021-22 water year, reported statewide snowpack at 38% of normal, an extreme disappointment given the powerful storms that struck last October and December.
Just three days later, in a Monday data update, state water officials reported snowpack falling five more percentage points to 33% of average.
“The recent rate of Sierra Nevada snowmelt is extraordinary,” Daniel Swain, a UCLA climate scientist, tweeted Monday.
“With upcoming heatwave, it’s starting to seem possible that vast majority of snowpack could be gone by mid-late April.”
California snowpack had been 154% of normal on New Year’s Day, then fell to 93% by Feb. 1 and 64% by March 1.
Sean de Guzman, snow survey manager for the Department of Water Resources, said last Friday that the first three months of 2022 marked the driest start to a year ever for the Sierra Nevada mountains, with records that go back more than a century.
“The small amounts of snowfall that have happened since (December) haven’t been enough to outpace the amount of snow melt,” he said.
All 17 of the state’s reservoirs are below average levels for early April, according to state water officials, and 10 of them are below 70% of average.
De Guzman said one piece of good news is that California “watersheds look to be in better condition this year for that snow to actually melt and run off, and hopefully not soak up into those dry soils as much” as in early 2021.
That’s due in large part to the “bomb cyclone” storm last October and the powerful rain and snowstorms that followed in December, soaking the ground.
But time is very quickly running out for any last-minute miracle storms to give California a boost, even a small one, before months of consistently hot weather dry out the state and melt the remaining snowpack.
This story was originally published April 5, 2022 at 11:29 AM.
