WxUSAF

For demonstration purposes, todays 12z GFS has this two wave scenario from hour 324-360. Some front end stuff is also on the table and GFS shows that type of scenario as well after Xmas.

^you’re mixing longwave and shortwave comparisons there. At D10, shortwave positions all get averaged together and washed out. But at D3, they’re well forecast. That’s a pretty good D10 longwave forecast: most of the eastern CONUS is ridging.

Ensembles appear reasonably confident that the Xmas-New Years week will be BN in temps. Not dramatically so, but a few degrees F perhaps. Probably works out to low 40s for highs and upper 20s for lows in aggregate. But the dry trend remains with maybe a little more action right around New Years. Definitely not a big snow pattern, but one that could produce frozen with proper wave timing. That’s sort of been the crux…we want one wave to go through and supply sufficient cold air and then a close trailing wave with some moisture. Both have been hard to come by and the southern plains ridging cuts off Gulf moisture to a large degree.

This is basically's JB twitter feed now trying to respond to the new normal: While also telling people to buy his book

It’shappening.gif

Congrats @WxWatcher007 and get well soon to your dad and you @psuhoffman. Hopefully mild symptoms given three shots!

Another great thread from @griteater upshot:

Feb 1986 was pretty good. 13” at BWI

Wow good thing I was only 4 and there was no internet or I would have been cliff jumping in 85-86.

@North Balti Zen and @dailylurker all like

whoa baby...they're a double bunner.

Weeklies apparently might put your weenie back in the bun and EPS signal for 20-21st isn’t terrible…

GLL needs to GTFO

Agree. I think they’re done pretty much regardless. Even if they fall into a WC spot, they’re getting bounced in the first round.

Jesus Ravens. Even a seemingly disastrous game turns into a heart attack.

I remember how that pattern developed in 17-18. Looked like an amazing overrunning pattern at range and the models were keying in on a storm from D8-10, but then the cold push overwhelmed it and it was suppressed to hell and gone. We got a couple minor events in a cold and dry period.

Great thread this morning from @griteater. His best analogs for this MJO progression at this time of year in a Niña are 95-96, 01-02, and 17-18. Three wide ranging outcomes there showing @psuhoffmans reminder that luck always has a big role to play.

Seeing videos and images out of Mayfield, Ky. Staggering devastation. Got to be some EF4 level damage.

Yikes, kiss of death

Agree with everyone else. Tons of very cold air in Canada. Not like last year at all where the blocking was just blocking in modified Pacific air masses. That’s legit arctic air in Canada. We just need a small slice.

LOT to like on that GEFS run. -AO and -NAO builds from east-based to west-based by post-Xmas. And the -EPO keeps nudging eastward in time pushing the western trough more into the Rockies and high plains. And GEFS has actually been accelerating the changes rather than can-kicking. We were wondering about that given that the MJO phases forecast was not jiving with the H5 look.

12z gfs and GGEM both are close with this idea

Reach out to @dendriteand he can change it

As a longwave pattern no, but with the right shortwave timing and the blocking over the pole, it’s possible.

GEFS and EPS both have several nice features by Xmas week: -EPO, ridge bridge across the pole with -AO, -east NAO. But both have a pig of a -PNA also. We need that EPO ridge to move east a bit to kick that trough at least out into the Plains.