December Mid/Long Range Discussion

[NorthArlington101]

  On 12/6/2023 at 6:29 PM, WxUSAF said:

Euro ends the weekend rain storm as accumulating snow for N/W crew again.

Pretty solid 2-4” for I-81 corridor… favored spots closer by get a little something.

I’m so desperate to see some snow that it might almost be worth a trip out that way if it came to fruition

[Ji]

  On 12/6/2023 at 6:29 PM, WxUSAF said:

Euro ends the weekend rain storm as accumulating snow for N/W crew again.

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cant wait...last time i saw that was Christmas 2003 lol?

[osfan24]

  On 12/6/2023 at 6:29 PM, WxUSAF said:

Euro ends the weekend rain storm as accumulating snow for N/W crew again.

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That literally never happens, though. The winds switch and dry things out before the cold air can get there.

[TSSN+]

  On 12/6/2023 at 6:35 PM, osfan24 said:

That literally never happens, though. The winds switch and dry things out before the cold air can get there.

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This one would be different pre euro cause there’s a secondary low that keeps the precip going 

[WxUSAF]

  On 12/6/2023 at 6:35 PM, osfan24 said:

That literally never happens, though. The winds switch and dry things out before the cold air can get there.

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It definitely does happen? A lot of our storms start as rain. The early January 2022 event was deluge rain for 3-4 hours (temps were in the 50s and 60s day before?) and then switched to snow. 
 

It takes a certain set of conditions, but it can happen.

[TSSN+]

  On 12/6/2023 at 6:38 PM, WxUSAF said:

It definitely does happen? A lot of our storms start as rain. The early January 2022 event was deluge rain for 3-4 hours (temps were in the 50s and 60s day before?) and then switched to snow. 
 

It takes a certain set of conditions, but it can happen.

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Ya it’s more than just a cold front passage per euro. Secondary low forms and that’s what provides the snow. 

[brooklynwx99]

GEFS showing the transition well as the AK trough retrogrades and the PNA rises. SE trough starting to develop

[stormy]

GEFS definitely looking better on the 20th than a couple days ago. A reversal of the h5 pattern has possibilities.

[osfan24]

  On 12/6/2023 at 6:38 PM, WxUSAF said:

It definitely does happen? A lot of our storms start as rain. The early January 2022 event was deluge rain for 3-4 hours (temps were in the 50s and 60s day before?) and then switched to snow. 
 

It takes a certain set of conditions, but it can happen.

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I don't remember that one. I'm looking at the Euro now and it just looks like a low develops right along the front and passes west/north of us.

[WxUSAF]

  On 12/6/2023 at 6:51 PM, osfan24 said:

I don't remember that one. I'm looking at the Euro now and it just looks like a low develops right along the front and passes west/north of us.

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Was like 6” at my house and I believe had some 10-12” reports S and E of DC. Had a strong gradient with the N and W folks getting actually fringed for once. 

[NorthArlington101]

  On 12/6/2023 at 6:37 PM, TSSN+ said:

This one would be different pre euro cause there’s a secondary low that keeps the precip going 

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take a 2 run comparison of the GEFS for what it's worth but a lot more pop a trailing low this go-around.

[NorthArlington101]

  On 12/6/2023 at 6:53 PM, WxUSAF said:

Was like 6” at my house and I believe had some 10-12” reports S and E of DC. Had a strong gradient with the N and W folks getting actually fringed for once. 

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This was the storm where Tim Kaine and others were stuck on I-95 for ~2 days. Think there was almost a foot and a half down in SE MD/Fredericksburg area.

[Round Hill WX]

  On 12/6/2023 at 6:53 PM, WxUSAF said:

Was like 6” at my house and I believe had some 10-12” reports S and E of DC. Had a strong gradient with the N and W folks getting actually fringed for once. 

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It was a mess on 95 for that one.

Virginia's I-95 reopens after winter storm strands drivers | CNN

[clueless]

At least the models are keeping it interesting this month.  

[osfan24]

  On 12/6/2023 at 6:53 PM, WxUSAF said:

Was like 6” at my house and I believe had some 10-12” reports S and E of DC. Had a strong gradient with the N and W folks getting actually fringed for once. 

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That explains why I don't remember it then, lol.

[Ji]

  On 12/6/2023 at 6:38 PM, WxUSAF said:

It definitely does happen? A lot of our storms start as rain. The early January 2022 event was deluge rain for 3-4 hours (temps were in the 50s and 60s day before?) and then switched to snow. 
 

It takes a certain set of conditions, but it can happen.

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i dont think that january 2022 event was similar to what the european is showing now was it? I think h he meant rain changing to snow from a super cold front passage that the euro is showing. Jan 2011 also started as rain so yea its very possible to start as rain and go to snow. But the euro is showing 60 at 7pm going to 39 by midnight

[stormy]

  On 12/6/2023 at 6:53 PM, WxUSAF said:

Was like 6” at my house and I believe had some 10-12” reports S and E of DC. Had a strong gradient with the N and W folks getting actually fringed for once. 

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I received 8 inches and had 3' drifts.

[NorthArlington101]

EURO OP and Control are outliers (more snow) compared to the ens but very slight ticks up from 00z -> 6z -> 12z for the area in general for Sunday/Monday. Better in favored spots, obviously

[Wxdavis5784]

  On 12/6/2023 at 6:56 PM, NorthArlington101 said:

This was the storm where Tim Kaine and others were stuck on I-95 for ~2 days. Think there was almost a foot and a half down in SE MD/Fredericksburg area.

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My in-laws down in King George, VA got over a foot and lost power for days from that storm. 

[psuhoffman]

  On 12/6/2023 at 6:40 PM, brooklynwx99 said:

GEFS showing the transition well as the AK trough retrogrades and the PNA rises. SE trough starting to develop

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Yes, the pattern the seasonal and monthly models have forecasted for a while is now starting to show at the very end of the ensemble guidance.  The last step after that would be for wave breaking to help the western Atl ridge to migrate to the NAO domain once the TPV has vacated and then we are in business.  

[WxUSAF]

  On 12/6/2023 at 7:01 PM, Ji said:

i dont think that january 2022 event was similar to what the european is showing now was it? I think h he meant rain changing to snow from a super cold front passage that the euro is showing. Jan 2011 also started as rain so yea its very possible to start as rain and go to snow. But the euro is showing 60 at 7pm going to 39 by midnight

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No, they’re not really. But the one thing that is common to our rain—>snow scenarios is a more Sw-NE oriented front vs very S-N orientation. Euro is getting that tilt more and hence the changeover.

[psuhoffman]

  On 12/6/2023 at 7:01 PM, Ji said:

i dont think that january 2022 event was similar to what the european is showing now was it? I think h he meant rain changing to snow from a super cold front passage that the euro is showing. Jan 2011 also started as rain so yea its very possible to start as rain and go to snow. But the euro is showing 60 at 7pm going to 39 by midnight

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It's not super common but there have been numerous anafront snow events over the years.  They probably actually produce accumulating snow like once every few years.  They aren't typically events we remember though since they are never going to be some 6" plus event...we are talking 1-3" type things...sometimes up here and in the mountains they can be 3-5" type deals...but that have a pretty low ceiling in terms of potential.  It requires there to be a wave along the front that stalls the progress allowing the cold to catch up to the precip.  

[psuhoffman]

I think there was a post frontal snow event in January 2019.  There was also one that put down a few inches up here sometime in like 2017 or 2018.  It's been a while...probably mostly because its simply been a while without us getting much snow at all from ANY type of storm...so 

[PrinceFrederickWx]

  On 12/6/2023 at 6:56 PM, NorthArlington101 said:

This was the storm where Tim Kaine and others were stuck on I-95 for ~2 days. Think there was almost a foot and a half down in SE MD/Fredericksburg area.

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That's correct, I had 9.3" IMBY, just north of me in Huntingtown was the bull's eye at 15". Much of Southern MD did better with that storm than HECS 2016.

[Maestrobjwa]

  On 12/6/2023 at 6:58 PM, osfan24 said:

That explains why I don't remember it then, lol.

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Same, lol And I'm not even that far north. The city kinda got skunked even though BWI recorded 6 inches (I don't think we got more than 2-2.5)

[nj2va]

The January 2022 event was a fun one - got about 11" in Alexandria and it was 65 the day before.  Snowed heavy for like 6 hours before tapering off - lost a few trees around us with the weight of the snow.  I still had my Christmas lights/decorations up which put the icing on the cake for the beauty of it.  

[psuhoffman]

  On 12/6/2023 at 6:53 PM, WxUSAF said:

Was like 6” at my house and I believe had some 10-12” reports S and E of DC. Had a strong gradient with the N and W folks getting actually fringed for once. 

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I actually do get fringed regularly up here...but in a more typical season it just doesn't matter because there are several more storms where up here gets significantly more and by the end of the season no one remembers that one time DC beat me.  It's just rare to get a season where there is like only one big storm and that happens to fringe up here.  

[Eskimo Joe]

  On 12/6/2023 at 6:35 PM, osfan24 said:

That literally never happens, though. The winds switch and dry things out before the cold air can get there.

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Euro amplifies a wave of low pressure along the front that tugs the cold air in before things can dry out. GFS does the same thing, but to a lesser extent so it's mainly a car topper N&W. Still would be more snow for many than the last 2 years.

[SnowenOutThere]

[wawarriors4]

  On 12/6/2023 at 6:53 PM, WxUSAF said:

Was like 6” at my house and I believe had some 10-12” reports S and E of DC. Had a strong gradient with the N and W folks getting actually fringed for once. 

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We had 14.5" just NW of Fredericksburg, VA. It was paste, power was out, 95 was shut down for like 50 miles. And that 14.5" fell in like 6 hours after we got over an inch of rain.......