This past March brought record cold weather for a large swath of the United States, including the West Coast and the Northern Plains.
Here in Washington State, frigid conditions persisted even into April, with sea-level sleet and severe snowfall on some hilltops near Seattle (see snowfall at 1,100 feet). ft in Bellevue on Sunday night). April?
April 2. Bellevue, Washington at 1100 ft. Polite Dr. Peter Benda
Satellites can observe atmospheric temperatures from space. Lower atmospheric temperatures in March from such a satellite (see below) indicate that the coldest temperature anomaly (difference from normal) on the planet occurs in a band from the West Coast to the upper plains.
Parts of eastern Oregon had the coldest March on record, as demonstrated by March temperatures in Burns, Oregon over the past 50 years. I mean there is no year close to March 2023.
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A temperature analysis by NOAA representing a difference from normal of about 10,000 ft (700 hPa pressure) for March is shown below.
Amazing. Temperatures are MUCH below normal in the western part of North America, but above normal in the southeast. This creates a very unusual variation in temperature (temperature gradient) across the country.
The large horizontal temperature variation is associated with strong jet stream winds in the upper troposphere. So it’s not surprising that winds are at jet stream level (~30,000 ft, 250 hPa pressure) was much higher than usual in an area with unusually large horizontal temperature variations (see below).
The reds, oranges and yellows show where winds are much stronger than normal, with the most anomalous winds from California to Colorado.
High temperature gradients and high winds have facilitated strong thunderstorms (and severe weather) in the eastern United States.
This historically cold March weather in the west was a godsend in a way: it slowed the melting of California’s massive ice sheet.
Rapid warming would be very dangerous, leading to severe flooding.
Weather for the next 15 days?
You guessed it, colder than usual in the West (see abnormal temperature forecast below). Blue and green indicate temperatures that are significantly below normal.
My advice: don’t even think about buying tomato plants in April.
