December Medium/ Long Range

[SnowenOutThere]

16 minutes ago, NorthArlington101 said:

also has a squall/snow shower come through later in the evening, leaving us with honestly a moderately interesting snow map. Thread??? 

Good test subject on if we can make a sacrificial thread and then revive it with a second one this year

[winter_warlock]

I'll take this kinda storm!! Lol

[psuhoffman]

34 minutes ago, MDScienceTeacher said:

Which years are your analogs?

Top 5 were 2008-9, 2016-17, 2000-01, 1950-51, 1954-55

[WEATHER53]

Looking at radar with snow showers squalls and lake effect all over the place is a long absent sight to see!!!

[WEATHER53]

6 minutes ago, psuhoffman said:

Top 5 were 2008-9, 2016-17, 2000-01, 1950-51, 1954-55

50-51 and 54-55 are on the mark but these older ones do give me some pause in our new day 

[frd]

1 hour ago, Eskimo Joe said:

Our source air looks primed.

 

 

Having a decent source region is something we have lacked for a long time. 

Also, SE Canada is going to have a large increase in snow cover over the next couple weeks.  

 

 

 

 

 

[yoda]

12z GFS is nice for the 10th to the 12th time period 

[winter_warlock]

Some nostalgia  for u all .....

 

New York City after a snowstorm in 1888.

[87storms]

46 minutes ago, yoda said:

12z GFS is nice for the 10th to the 12th time period 

And it's only 11 days out, too.

[87storms]

...though seeing digital snow early in the season is an improvement over the last couple of years.

[Terpeast]

All ens show a trough digging into the OH valley, which is a decent signal for a storm that might bring us snow in the dec 10-12 timeframe (12z gfs op shows this playing out) 

0z EPS shows that too, look at the height lines even if the 500mb anomaly colors show neutral.

[WxUSAF]

These guys say pattern continues in mid December fwiw. Some cold analogs in that group. 

 

[Eskimo Joe]

27 minutes ago, WxUSAF said:

These guys say pattern continues in mid December fwiw. Some cold analogs in that group. 

Keep the Alaska/Inside Passage Ridge and we're going to score.

[stormy]

This cold pattern likely to last thru mid month then warm up thru Christmas IMO.

No reload evident after mid month on EPS or GEFS at this time.           

[yoda]

Wednesday into Thursday maybe?  Afternoon discussion from LWX 

LONG TERM /MONDAY THROUGH FRIDAY/...
The extended forecast will be defined by a large upper trough
centered over eastern Canada with axis extending into the southern
US. A series of potent shortwaves are expected to pivot around the
trough. The finer details of these features have been variable run-
to-run, but as of now one shortwave is expected Monday into Tuesday
and then a stronger shortwave Wednesday into Thursday.

The deep trough over the eastern CONUS will put the region squarely
in a frigid cold air mass, with high temperatures topping out in the
low 40s for most of the area through Wednesday, 20s to 30s in the
mountains. Wind chills could knock an additional 10-20 degrees off
that. With forcing and cold temperatures present, the main
uncertainty lies then with available moisture. The deep cold air
mass is also expected to be starved of moisture, with less than
1.00in PWATs throughout the extended. The most likely scenario for
next week is a burst of upslope mountain snow with each shortwave.

However, probabilities of snow east of the mountains have trended
higher for the Wednesday/Thursday wave. Recent runs have
strengthened this second disturbance, and moisture has trended
higher as well, with ensembles showing a range of 0.30-0.50 PWATs.
Snow probs for measurable snow east of the mountains, including the
I-95 corridor/DC metro, are now around 40-50% for 12z Wed to 12z
Thu.

If this materializes, not much accumulation is expected given
the lack of moisture, but even so the main concern will be timing.
Given the extended period of bitter cold, surface temperatures could
be near or just below freezing. Currently the better timing for
precip is Wednesday afternoon when temperatures are warmer, but a
slower system could mean wintry precip coinciding with colder temps
and Wednesday`s morning commute. Even light accumulation in these
conditions could present significant traveling hazards. As such, we
will continue to monitor closely for this potential.

For beyond Wednesday, a strong upper low is progged to swing into
southeast Canada/the Northeast near the end of the week. While
expected to dunk the NE CONUS into another bitter cold air mass, the
air mass is also likely to be very dry. Some upslope snow could
continue Thursday into Friday, but the better forcing also appears
to stay to our north.

[psuhoffman]

2 hours ago, WxUSAF said:

These guys say pattern continues in mid December fwiw. Some cold analogs in that group. 

 

Some of my analogs are in there too.  Problem is while they are cold most of them were not snowy years. 

[Maestrobjwa]

1 hour ago, psuhoffman said:

Some of my analogs are in there too.  Problem is while they are cold most of them were not snowy years. 

Sounds like something we're just gonna have to keep in mind and not subconsciously project what we're about to see the next two weeks onto the rest of the winter.

[Weather Will]

I see why no one talked about the 12Z EURO suite...dry and cold....

[Stormchaserchuck1]

Nice 1046mb High pressure in SE Canada on Dec 7th on the 18z GFS, for that storm threat. I'm actually surprised that surface temps aren't colder with such a strong High pressure to the north.. probably because the NAO is positive. 

[frd]

8 minutes ago, Weather Will said:

I see why no one talked about the 12Z EURO suite...dry and cold....

Fits @psuhoffman analog set for this coming winter.  Expect the cold, but most were not snowy years.  

[frd]

6 minutes ago, Stormchaserchuck1 said:

Nice 1046mb High pressure in SE Canada on Dec 7th on the 18z GFS, for that storm threat. I'm actually surprised that surface temps aren't colder with such a strong High pressure to the north.. probably because the NAO is positive. 

Not the first time strong highs up North did not funnel in colder air to our region. 

However, maybe that will change with future model runs, as snow cover is increasing up North while the NAO is not going crazy positive. 

[Terpeast]

14 minutes ago, Weather Will said:

I see why no one talked about the 12Z EURO suite...dry and cold....

Are you talking about the Op or ensembles?

[SnowenOutThere]

GFS just dished up the funniest possible outcome for the 12th window

[Stormchaserchuck1]

14 minutes ago, frd said:

Not the first time strong highs up North did not funnel in colder air to our region. 

However, maybe that will change with future model runs, as snow cover is increasing up North while the NAO is not going crazy positive. 

It could work though, as the Pacific is still favorable at that time and a -NAO dries everything out.. That h5 pattern actually favors sleet/fz rain storm

 

In future model runs, if the NAO trends more positive, it could happen with a wetter storm, and a more -NAO could be a little drier. I like those low's undercutting a ridge in Alaska 

[CAPE]

32 minutes ago, Stormchaserchuck1 said:

Nice 1046mb High pressure in SE Canada on Dec 7th on the 18z GFS, for that storm threat. I'm actually surprised that surface temps aren't colder with such a strong High pressure to the north.. probably because the NAO is positive. 

lol what?

That high is north of Minnesota.

There is a 1034 HP in SE Canada and its snowing on us with temps in the mid 20s.

[87storms]

Nice 1046mb High pressure in SE Canada on Dec 7th on the 18z GFS, for that storm threat. I'm actually surprised that surface temps aren't colder with such a strong High pressure to the north.. probably because the NAO is positive. 

I think those high pressures along with radiational cooling can become more impactful and lead to colder air building up north as the season goes on if the pattern stays on the chilly side. I used to wonder how pressures relate to surface temps and it’s not straightforward.

[Eskimo Joe]

7 hours ago, psuhoffman said:

Top 5 were 2008-9, 2016-17, 2000-01, 1950-51, 1954-55

[Stormchaserchuck1]

16 minutes ago, CAPE said:

lol what?

That high is north of Minnesota.

There is a 1034 HP in SE Canada and its snowing on us with temps in the mid 20s.

With those high pressures it would normally be snowing down to the mountains in northern Georgia.  Will be interesting to see if >1030s mb Highs down to the CONUS hold, as we haven't seen that pattern for a long time.. 

[WxUSAF]

GEFS has some nice hits next weekend 

[Ralph Wiggum]

1 minute ago, WxUSAF said:

GEFS has some nice hits next weekend 

It's nearing go time. Won't be long now.