January: Medium/ Long Range: May the Force be with Us....

[CAPE]

There is still a storm signal for the 4th on the 12z GEFS, but a bit weaker than the last 2 runs.

[brooklynwx99]

7th still looking spicy. lots of confluence, good airmass in place, and a potent vort swinging through 

[Ralph Wiggum]

10 minutes ago, brooklynwx99 said:

7th still looking spicy. lots of confluence, good airmass in place, and a potent vort swinging through 

Mentioned it late last week I think the 4th system is the catalyst for a followup system around this time. Get the Jan 4 system to the 50/50 area, setup some decent confluence, get the ridging in the NAO domain in a favorable spot, and then game on. That's my feel on this whole progression anyway....4th system might be rushing it.

[donsutherland1]

Since 1950, Washington, DC has seen 16 6" (15.2 cm) or greater snowstorms in January. Below are the composite 500 mb height anomalies, clusters, and teleconnection combinations for such storms for reference.

[87storms]

Since 1950, Washington, DC has seen 16 6" (15.2 cm) or greater snowstorms in January. Below are the composite 500 mb height anomalies, clusters, and teleconnection combinations for such storms for reference.

Wow…only 16 in nearly 75 years during the coldest month of the year? Definitely less than I expected. I’d be curious how many some of the suburbs like Germantown to Columbia have had. Undoubtedly, a significant difference once you get 10-15 minutes west of the fall line.

[WVclimo]

33 minutes ago, 87storms said:

Wow…only 16 in nearly 75 years during the coldest month of the year? Definitely less than I expected. I’d be curious how many some of the suburbs like Germantown to Columbia have had. Undoubtedly, a significant difference once you get 10-15 minutes west of the fall line.

Dulles has had 18 January storms of 6”+ since 1964. Eight of those came in 4 winters (2 each in 1966, 1987, 1996 and 2000.)

[Kevin Reilly]

Soo..... what happened to Mostly Sunny high 38 today???  Got the temp right but the sun hasn't made an appearance at any point today.  Sounds like a pretty blown forecast at very short leads.  Must be an inversion layer those are always pains to forecasts. 

[cbmclean]

44 minutes ago, WVclimo said:

Dulles has had 18 January storms of 6”+ since 1964. Eight of those came in 4 winters (2 each in 1966, 1987, 1996 and 2000.)

I thought that 2000 was a one-shot year?

[87storms]

Dulles has had 18 January storms of 6”+ since 1964. Eight of those came in 4 winters (2 each in 1966, 1987, 1996 and 2000.)

Yea I was just thinking I guess that’s not too bad. 4-6” is a healthy event and there’s probably quite a few more of those.

[Eskimo Joe]

2 hours ago, donsutherland1 said:

Since 1950, Washington, DC has seen 16 6" (15.2 cm) or greater snowstorms in January. Below are the composite 500 mb height anomalies, clusters, and teleconnection combinations for such storms for reference.

Don this is amazing. Would you be able to run these for BWI and PHL as well?

[WVclimo]

27 minutes ago, cbmclean said:

I thought that 2000 was a one-shot year?

IAD picked up another 6.3” on 1/30, after the surprise snow the previous week.

[frd]

https://x.com/ryankanerWX/status/1872004512376127920

 

Appears that the EPS with trough axis too far East, even at hour 342, hopefully things change in future runs, if not might just end up with very cold and dry conditions, storms way offshore of the Mid Atlantic and even the NE.  

 

[Terpeast]

18 minutes ago, frd said:

https://x.com/ryankanerWX/status/1872004512376127920

 

Appears that the EPS with trough axis too far East, even at hour 342, hopefully things change in future runs, if not might just end up with very cold and dry conditions, storms way offshore of the Mid Atlantic and even the NE.  

 

That’s the mean trough position, with a ton of smoothing out at this range. 

[donsutherland1]

2 hours ago, 87storms said:

Wow…only 16 in nearly 75 years during the coldest month of the year? Definitely less than I expected. I’d be curious how many some of the suburbs like Germantown to Columbia have had. Undoubtedly, a significant difference once you get 10-15 minutes west of the fall line.

The suburbs do better, as does IAD.

[Stormchaserchuck1]

Medium range/long range models went much colder today. Big +PNA. Models like the Euro/GEM have been doing much better than the GFS. 

[frd]

11 minutes ago, Stormchaserchuck1 said:

Medium range/long range models went much colder today. Big +PNA. Models like the Euro/GEM have been doing much better than the GFS. 

+PNA more associated with SECS , is that correct Chuck ?  

[donsutherland1]

1 hour ago, Eskimo Joe said:

Don this is amazing. Would you be able to run these for BWI and PHL as well?

I will post BWI and PHL in the next day or two. I have company here.

[dailylurker]

1 minute ago, donsutherland1 said:

I will post BWI and PHL in the next day or two. I have company here.

Go in the bathroom like everyone else here. You ever check model runs during Christmas dinner before? You can't be a savage and just break your phone out and start drooling at the dinner table. Boxing day anyone? Lol

[Eskimo Joe]

23 minutes ago, donsutherland1 said:

I will post BWI and PHL in the next day or two. I have company here.

No rush on that at all, was just curious to see the data. Merry Christmas sir!

[snowmagnet]

I'm at Dulles waiting for my flight to France.  I return on the Jan 4th, so I would appreciate an epic storm on the 5th or the 8th. Just throwing that out there.. 

[Daniel Boone]

1 hour ago, frd said:

https://x.com/ryankanerWX/status/1872004512376127920

 

Appears that the EPS with trough axis too far East, even at hour 342, hopefully things change in future runs, if not might just end up with very cold and dry conditions, storms way offshore of the Mid Atlantic and even the NE.  

 

If the blocking is realized and a 50-50 manifests that should place the Trough further West.

[87storms]

The suburbs do better, as does IAD.

Agreed…were the clusters based off only those 18 cases? I took a machine learning class over the summer, hence why I’m interested in this stuff. I noticed there’s a couple of distinct clusters (assuming this was based off k-means, etc) with similar teleconnections. Also wondering if it would be better to adjust the snow total down to 4” to create a larger dataset.

[Terpeast]

27 minutes ago, 87storms said:

Agreed…were the clusters based off only those 18 cases? I took a machine learning class over the summer, hence why I’m interested in this stuff. I noticed there’s a couple of distinct clusters (assuming this was based off k-means, etc) with similar teleconnections. Also wondering if it would be better to adjust the snow total down to 4” to create a larger dataset.

I’m just curious, wasn’t 4” the criteria for a winter storm warning here before they changed it to 5”? Or has it always been 5”? My memory isn’t what it used to be. 

[87storms]

I’m just curious, wasn’t 4” the criteria for a winter storm warning here before they changed it to 5”? Or has it always been 5”? My memory isn’t what it used to be. 

I think it used to be.

[Heisy]

Looks like that wave around the 3rd is the first shot at something, but the trough axis isn’t great and spacing is meh. At least so far. However, that wave then potentially sets up our potential confluence for whatever else rolls off the PAC.

This is fun to look at lol..




.

[frd]

3 minutes ago, Heisy said:

Looks like that wave around the 3rd is the first shot at something, but the trough axis isn’t great and spacing is meh. At least so far. However, that wave then potentially sets up our potential confluence for whatever else rolls off the PAC.

This is fun to look at lol..




.

 

 

Rather intense Davis Straits block depicted there. Pretty cool look. 

 

 

[Stormchaserchuck1]

1 hour ago, frd said:

+PNA more associated with SECS , is that correct Chuck ?  

The biggest snowstorms have a +PNA/Gulf of Alaska low pressure. But it is also an on-average drier pattern, so more variance. 

[Ralph Wiggum]

Jan 4th is a thread the needle but an important system that strengthens NAO blocking, sets up a quasi 50/50, and boosts confluence as waves press east under and over the pna via a split flow. Jan 6-10 is the real period to watch.

[Ralph Wiggum]

Merry Christmas and Happy Hannukah!

That PNA 

[stormy]

18 minutes ago, Terpeast said:

I’m just curious, wasn’t 4” the criteria for a winter storm warning here before they changed it to 5”? Or has it always been 5”? My memory isn’t what it used to be. 

The warning criteria used to be 4" or more.