November Medium/Long Range Discussion

[Eskimo Joe]

 

 

[Stormchaserchuck1]

If this verifies, we could be looking at our first winter storm threat around or after Thanksgiving. Maybe more 40N-north. 

18z GFS ensemble mean at 384hr also had a pretty strong -EPO developing.

Basically, the NAO is negative for the next 15 days, then the block retrogrades to NE Canada, just when the Pacific changes to more -epo/+pna around Nov 24-25 and after. That actually creates a window for a trough to track across the US, under the -NAO ridge in NE Canada, giving us a chance for a storm to hit colder air after Thanksgiving. The H5 in the map below is good, but we probably need a few days to flush out the old slightly warmer pattern. Still a long way to go, but it's looking good for at least below average temps beyond Day-15, based on current long range models.  That cross polar ridge, with a GOA trough and 50/50 trough (although both are weak) is what you want to see -- especially good ridging over Alaska. It's a winterystorm pattern, although early in the year. 

[WxUSAF]

Great thread from @griteater on the weakening early season Strat vortex and connections to a -NAO in December-ish.  His two closest analogs are December 1981 and early January 1982 and December 2000.  December-January 81/82 was a very cold and snowy period for our area, especially January. December 2000 was quite cold, but fairly dry without much snow.  

 

 

[mitchnick]

18 minutes ago, WxUSAF said:

Great thread from @griteater on the weakening early season Strat vortex and connections to a -NAO in December-ish.  His two closest analogs are December 1981 and early January 1982 and December 2000.  December-January 81/82 was a very cold and snowy period for our area, especially January. December 2000 was quite cold, but fairly dry without much snow.  

 

 

I'm not confident on the MJO getting thru phases 7-8-1-2 as he mentions at the end of his post. Failure to get thu them would be a negative for us.

https://www.stormsurf.com/page2/links/mjo_phase.html

[WxUSAF]

Just now, mitchnick said:

I'm not confident on the MJO getting thru phases 7-8-1-2 as he mentions at the end of his post. Failure to get thu them would be a negative for us.

https://www.stormsurf.com/page2/links/mjo_phase.html

Fair point. The IOD and Nina are going to favor phases 5-6.

[frd]

2 minutes ago, mitchnick said:

I'm not confident on the MJO getting thru phases 7-8-1-2 as he mentions at the end of his post. Failure to get thu them would be a negative for us.

https://www.stormsurf.com/page2/links/mjo_phase.html

Without help from the Pac you can have weeks and weeks of a - NAO and nothing will come from it in terms of snowfall for our area. As we know, depending on the pattern out West and in Canada some -NAO blocks don't work out for us,  and some do not even produce a pattern that leads to a cold enough airmass for snow, it is all dependent on the pattern upstream. 

I do believe the MJO slows, evens stalls for a bit, but we will get to the favorable phases in December and January.   

[Weather Will]

Latest EPS extended MJO.  I read 7 is good in December.

[frd]

Lastest AO update  11/09/25  - an increased negative forecast without a return to going positive.  Looking good ! 

 

[bncho]

The conversational flurries seem to want to go south to Richmond. When have we heard that story before... 

[Eskimo Joe]

 

 

[yoda]

I'll take what the 12z Euro is selling at 204 please Alex

[mitchnick]

1 minute ago, yoda said:

I'll take what the 12z Euro is selling at 204 please Alex

Just looked! Me too!!!

[mitchnick]

It'll be gone by 0z unfortunately. 

[mitchnick]

Kuchie not as kind.

[Maestrobjwa]

3 hours ago, bncho said:

The conversational flurries seem to want to go south to Richmond. When have we heard that story before... 

I'd love to have a new storm track one of the years. The one of the last decade sucks...not even "higher amounts north and west of the city" exists anymore! I find the fact that there is no clear cause rather annoying, lol

[Heisy]

Just looked! Me too!!!

Made that post yesterday basically saying I wish this setup happened about a month later


.

[WEATHER53]

It’s not scientific but it is reality for DC/

-15 departures are hard to come by and it’s a waste at this time in Nov.

if it’s the beginning of a near constant 30-45 day reload pattern then that’s  different but usually not the case 

The main thing we need turned around us the absence of Miller As.

second and in conjunction are clippers cutting under us pulling down reinforcing cold air .

whatever causes those two is what I want to see in projections 

mjo and SSW stuff to me is unproven.  The two circumstances referenced  above are proven

 

[WEATHER53]

6 hours ago, WxUSAF said:

Great thread from @griteater on the weakening early season Strat vortex and connections to a -NAO in December-ish.  His two closest analogs are December 1981 and early January 1982 and December 2000.  December-January 81/82 was a very cold and snowy period for our area, especially January. December 2000 was quite cold, but fairly dry without much snow.  

 

 

1982 is highly underrated.  Those consecutive cold Sundays were bitter  cold and record setters!

[mitchnick]

2 minutes ago, WEATHER53 said:

1982 is highly underrated.  Those consecutive cold Sundays were bitter  cold and record setters!

And sadly the plane and train crashes.

[wxdude64]

8 minutes ago, WEATHER53 said:

1982 is highly underrated.  Those consecutive cold Sundays were bitter  cold and record setters!

Had 8.3 inches of snow on the 12th, then a 2 degree low on the 13th. BUT still ended up a +5.1 for the month of Dec 1982 with the massive warmth (+15 to 20) the first week of the month and the few days after Christmas running +15's. 

[mitchnick]

9 minutes ago, wxdude64 said:

Had 8.3 inches of snow on the 12th, then a 2 degree low on the 13th. BUT still ended up a +5.1 for the month of Dec 1982 with the massive warmth (+15 to 20) the first week of the month and the few days after Christmas running +15's. 

I was assuming he meant 81/82 winter.

[DarkSharkWX]

[wxdude64]

43 minutes ago, mitchnick said:

I was assuming he meant 81/82 winter.

Makes more sense, Dec 1981 was a -4.3 for me here.

[Daniel Boone]

1 hour ago, WEATHER53 said:

1982 is highly underrated.  Those consecutive cold Sundays were bitter  cold and record setters!

Yeah, multiple Arctic Front's.

[Stormchaserchuck1]

With long range models trying to build a -EPO at Day-15, the Euro weeklies continue the theme forward and build the cold the first 2 weeks of December.. It looks like a -NAO over the top. 

Today's Euro weeklies for Dec 1-8

Dec 8-15

[WEATHER53]

2 hours ago, mitchnick said:

I was assuming he meant 81/82 winter.

Yes 

[WVclimo]

3 hours ago, WEATHER53 said:

1982 is highly underrated.  Those consecutive cold Sundays were bitter  cold and record setters!

That was my last winter in western MD, where I had grown up.  It rivaled the more-heralded winters of the late 70’s.

Had seven below-zero nights in January, including back-to-back -13’F’s.  45” winter in the valley around Cumberland, where the average is about 30”