Thread by @althecat

#WeirdWeather

In the North of the North Pacific up near Alaska there is a very large area of clear Ocean that that can be seen through the clouds which looks a little like a giant rotating eye.

Here we see it in context along side North America, and the entire rotating high-pressure area appears to be roughly the size of North America. Its presence appears to be contributing to the big freeze in Canada and all the snow in the US.

The image above shows the #EyeOfThePacific on December 26-27.

And here we see it on December 27-28. At the bottom of the animations you can see the onshore atmospheric river flows which are bringing massive rains to California, and moisture to the midwest and north east.

The next four tweets contain animations of this behemoth blocking high over the last 4 days - each 12 hours long. This one begins at 1am CET (midnight on Christmas Eve GMT/Midday NZT) and shows the early development of the core on Christmas Day.

By 13:00 CEST on Christmas Day the size of the clear ocean eye is 770k km2,

And by 13:00 CEST on Boxing Day it has grown 1 million km2 to 1.75 million km2.

On the third day of Christmas the clear ocean part has moved north as whispy looking clouds move in to cover the Southern half of the circulation. The clear ocean area looks a lot bigger because it is further north but is actually just 17,000 km2 bigger at 1.82 million km2.

On the fourth day of Christmas the rotation is at its most spectacular, turning into something that looks like a rotating leaf/whale, albeit one which is now 2.2million km2 in size. A little bit bigger than Mexico.

This special animation of this phase runs for 24 hours from 2pm CEST yesterday to 2pm today - and shows the rotating pupil of the #EyeOfThePacific at its most magnificent IMO.

#AwesomeBiosphere

And this final 12 hour animation takes us up to now. The clear area of the eye is beginning to fill but it remains close to its peak at 1.9million km2.

This images shows the overlaid measurements used in this thread.

This five day MLSP forecast suggests the #EyeOfThePacific will remain open for at least one more day, possibly two, and I will update this thread with its final evolution.

(continuing story)

P.S. The GFS model suggests a similar pattern may return in mid January.