Author Topic: "Triple play" affecting our weather this January.  (Read 168 times)

elagache

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"Triple play" affecting our weather this January.
« on: January 07, 2021, 11:35:28 pm »
Dear WeatherCat observers of the changing weather,

The conclusion of this morning's forecast discussion of the Monterey office of the National Weather Service was rather ominous:

It seems to be common place now where we receive only meager rainfall for Dec/January and finds ourselves counting on Feb/March to make up for rainfall deficits. Of course last February we saw no rain in the City. We cant predict that far out but the latest thinking for late January is the impacts of the sudden stratospheric warming (SSW) event will send cold air over the eastern US which portends a ridge along the West Coast. The models still suggest the PNA will trend negative after about January 20th but skill in that time scale and the overall long range patterns has once again been poor so far this winter. The impacts of the SSW on the mid-latitudes will be interesting to monitor as the La Nina continues to strengthen as well.

This led me into trying to find out more about the unusual weather pattern we find ourselves in.  The Weather Underground blog had this piece called:  Weaker Polar Vortex Just One Ingredient to an Interesting Pattern for Winter Storms Into February.

https://www.wunderground.com/article/storms/winter/news/2021-01-05-polar-vortex-weakening-winter-pattern-january-2021

It suggests unusually cool weather for the eastern parts of the United States and Europe.  What concerns me is the "negative phase of the Eastern Pacific Oscillation (EPO)."  This is the principle reason for the below normal precipitation in the western parts of the United States.  For 2 months in a row, this oscillation was expected to reverse and bring ample precipitation - both times the predication didn't come to pass.  As pointed out in the discussion, last year, northern California had essentially no rainfall at all in February.  It is difficult not to get concerned with these sorts of blocking patterns remaining so persistent thus far in this so-called "rainy season."

Oh well, . . . . . Edouard

Blicj11

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Re: "Triple play" affecting our weather this January.
« Reply #1 on: January 07, 2021, 11:59:54 pm »
Thanks for sharing this. Those of us living in the western United States are are concerned about the extent of this drought. Or, at least anyone with any sense (which does not apply to quite a few of our denizens) is concerned. 2020 was our driest year by far, in a long string of drier than the 30-year average years.
Blick