April in the U.S. came out colder than normal (despite what NOAA say), which has extended the nation’s stark cooling trend observed over the past five years. And now, into the second week of May, the Arctic is still refusing to abate as it delivers record low temperatures and record mid-spring snow to many states.
A fresh round of unseasonable polar chills is plunging southward as I type.
Here’s your Monday evening, America:
GFS 2m Temp Anomalies for May 10 [tropicaltidbits.com].
These forecast temperature anomalies are staggering.
States such as Texas, Oklahoma, Colorado and Kansas are set to suffer departures some 20C below the seasonal norm, perhaps even more in exposed spots — but the entire CONUS (excluding Florida and eastern Cali) will be hit.
The cold is expected to prove persist, too, lingering through midweek from the Rockies and Plains to the South and East.
Many states should brace for rare May freezes, with unprecedented snowfall to boot:
GFS Total Snowfall (inches) May 10 – May 12 [tropicaltidbits.com].
And already, states such as Pennsylvania are reporting inches of mid-spring snow.
Flakes settled along the I-80 in central PA on Sunday, May 9: “impressive yet pretty ridiculous at the same time,” said one local driver.
“Nothing like snow for Mother’s Day,” said John Hickey on Twitter:
Across vast portions of North America, rare May snowfall is settling.
Confirmed reports of are coming in from states and provinces such as Ohio, Montana, Alberta, Ontario, and even New York.
Below was the scene in Northeast Ohio Sunday afternoon:
The MSM is blaming this rare phenomenon on blocking in Greenland, which, although true, isn’t the full story.
CBS News writes:
“You may have noticed that cool temperatures have been slow to lessen their grip this spring. That’s because there is an atmospheric condition that meteorologists call a blocking pattern near Greenland. This is when a ridge of high pressure — you can think of it as a mountain of warm air in the atmosphere — gets stuck over the Polar regions of eastern Canada and the North Atlantic. The result is cold pockets of air that would normally be way up north get pushed out and displaced south across the northern U.S. This stubborn pattern has been around since the beginning of April. In fact, we can trace this pattern all the way back into winter when Texas and the Central U.S. suffered with historic cold. In climate, these blocky patterns are sometimes tough to break down, especially when they are as robust as what we saw this past winter.”
This is a perfectly accurate summary, but CBS stops short of informing its readers of the cause.
Research shows “blocking persistence” increases when solar activity is low, and that this blocking can lead to weather patterns becoming locked in-place at high and intermediate latitudes for prolonged periods of time.
During a Solar Minimum –such as the one we’re still struggling to escape from now (of SC24)– the jet stream’s usual Zonal Flow (a west–east direction) reverts to more of a Meridional Flow (a north-south direction).
This pattern exaggerated further during a Grand Solar Minimum, and explains why regions become unseasonably hot or cold and others unusually dry or rainy for extended periods of time.
In one recent paper, Mikhaël Schwander, et al discuss the setup as it pertains to Europe:
“The zonal flow characteristic of westerly types is reduced under low solar activity as the continental flow for easterly and northerly types is enhanced. This is also confirmed by the higher blocking frequency over Scandinavia under low solar activity.”
The paper goes further:
“The 247-year-long analysis of the 11-year solar cycle impact on late winter European weather patterns suggests a reduction in the occurrence of westerly flow types linked to a reduced mean zonal flow under low solar activity. Based on this observational evidence, we estimate the probability to have cold conditions in winter over Europe to be higher under low solar activity than under high activity.”
The setup is the same for the U.S., you simply replace “Scandinavia” with “Greenland.”
Furthermore, this low solar activity / colder conditions theory is a robust one (unlike CO2 / warmth).
The Northeast was struck by a very similar snowy setup back in 1977 — that year fell during the very weak Solar Minimum of cycle 20.
On the evening of Sunday, May 8, 1977, a mass of unseasonably cold, Canadian air wrapped itself around a developing storm and produced a cold rain which ultimately changed over to heavy, wet snow — the heaviest to have ever fallen in May.
You can pinpoint the Solar Minimum of cycle 20 in the ‘Sunspot Number’ chart below.
Note that cycle 20 was indeed weak, but also that is hasn’t a patch on the cycle we’re exiting now (24) which more closely resembles those of the Centennial Minimum (SC12, SC13, & SC14)
Looking ahead, most solar forecasts see SC25 being just as weak as SC24, with SC26 (due to commence around 2031) potentially rivaling the cycles of the Dalton Minimum (SC5, SC6, & SC7), and even the Maunder Minimum before it (1645-1715) where the Sun was devoid of sunspots for years an even decades at a time.
And finally, winter storm watches were issued in Hawaii late last week.
According to the National Weather Service: “A Winter Storm Watch means there is potential for significant snow or ice accumulations that may impact the summits. Anyone planning travel to the summits should consider postponing their trip until improved weather returns.”
To repeat, that’s a winter storm watch, in Hawaii, in May:
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