Possible Snow Threats and Upcoming Cold Spell

[Dsnowx53]

That is a classic KU potential. The shortwave is going neutral at the Mississippi Valley and amplifying.

[IsentropicLift]

Okay, I agreed that it was a nice setup. I just thought it was pre-mature to predict a KU.

[Allsnow]

Okay, I agreed that it was a nice setup. I just thought it was pre-mature to predict a KU.

I did not predict anything. I stated that run screams ku at 240 hr. It's agreed on by a good amount of respected mets/posters on this board. I'm sorry you mis-read my post

[friedmators]

SUNY MM5 has a lot of frozen precip on it for route 78 and north.

[allgame830]

What is your location?

My location is Hawthorne ny... North of I-287

[ag3]

MM5 is the coldest model right now. Hour 21 of the 12z run has it cold enough for KLGA. At that hour, the best precip is over that area:

 

[ag3]

80%+ chance of frozen for northern Queens, NYC and North shore of LI at hour 21:
 

[IsentropicLift]

18Z NAM keeps the 850 freezing line right around I-80 until about 15z. Then it moves north into Upstate NY. 0.50-0.75" falls before that. Total precip now exceeds 0.75" from about I-95 SE.

[IsentropicLift]

Per the NAM bufkit if taken verbatim at KMMU, 1.1" of snow followed by 0.20" of ice.  Keeps surface temps below 32 for a couple hours longer than 12z.

 

130116/0500Z  11  04006KT  34.2F  SNPL    0:1| 0.0|| 0.00|| 0.00|| 0.026    0:1|  0.0|| 0.00|| 0.00|| 0.03    6| 87|  6
130116/0600Z  12  06007KT  32.8F  RAIN    0:1| 0.0|| 0.00|| 0.00|| 0.071    0:1|  0.0|| 0.00|| 0.00|| 0.10    0|  0|100
----------------------------------------------+----++-----+-------------++--------------++-------------++-----------+---+---
130116/0700Z  13  05007KT  32.3F  RAIN    0:1| 0.0|| 0.00|| 0.00|| 0.071    0:1|  0.0|| 0.00|| 0.00|| 0.17    0|  0|100
130116/0800Z  14  05007KT  31.7F  SNPL    1:1| 0.1|| 0.10|| 0.00|| 0.061    1:1|  0.1|| 0.10|| 0.00|| 0.23   18| 82|  0
130116/0900Z  15  04009KT  31.0F  SNPL    5:1| 0.4|| 0.04|| 0.00|| 0.068    3:1|  0.5|| 0.14|| 0.00|| 0.30   68| 32|  0
130116/1000Z  16  05007KT  30.8F  SNPL    4:1| 0.4|| 0.10|| 0.00|| 0.100    4:1|  0.9|| 0.25|| 0.00|| 0.40   48| 52|  0
130116/1100Z  17  06007KT  30.6F  FZRA    0:1| 0.0|| 0.00|| 0.05|| 0.046    4:1|  0.9|| 0.25|| 0.05|| 0.44    0|  0|100
130116/1200Z  18  03005KT  31.0F  SNPL    5:1| 0.2|| 0.04|| 0.00|| 0.046    4:1|  1.1|| 0.29|| 0.05|| 0.49   54| 46|  0
----------------------------------------------+----++-----+-------------++--------------++-------------++-----------+---+---
130116/1300Z  19  05006KT  31.0F  FZRA    0:1| 0.0|| 0.00|| 0.04|| 0.037    4:1|  1.1|| 0.29|| 0.09|| 0.53    0|  0|100
130116/1400Z  20  04006KT  31.2F  FZRA    0:1| 0.0|| 0.00|| 0.00|| 0.003    4:1|  1.1|| 0.29|| 0.09|| 0.53    0|  0|100
130116/1500Z  21  05006KT  31.4F  FZRA    0:1| 0.0|| 0.00|| 0.07|| 0.070    4:1|  1.1|| 0.29|| 0.16|| 0.60    0|  0|100
130116/1600Z  22  08004KT  31.7F  FZRA    0:1| 0.0|| 0.00|| 0.03|| 0.033    4:1|  1.1|| 0.29|| 0.20|| 0.63    0|  0|100
130116/1700Z  23  35005KT  32.1F  FZRA    0:1| 0.0|| 0.00|| 0.00|| 0.009    4:1|  1.1|| 0.29|| 0.20|| 0.64    0|  0|100
130116/1800Z  24  33005KT  32.8F  RAIN    0:1| 0.0|| 0.00|| 0.00|| 0.005    4:1|  1.1|| 0.29|| 0.20|| 0.65    0|  0|100
----------------------------------------------+----++-----+-------------++--------------++-------------++-----------+---+---
130116/1900Z  25  32004KT  33.2F  RAIN    0:1| 0.0|| 0.00|| 0.00|| 0.006    4:1|  1.1|| 0.29|| 0.20|| 0.65    0|  0|100
 

[IsentropicLift]

Euro vs GFS

The NAM also has mostly rain for the city and freezing rain for the I-287 folks.

[Ericjcrash]

Euro vs GFS

Everything vs, Euro. maybe throw the MM5 in the Euros court but even that differs,

[MJO812]

Looks like the clipper is redevloping on the coast at 156

[Allsnow]

Looks like the clipper is redevloping on the coast at 156

Yes. Light snow in the area early Monday morning. Temps look to be in upper 20's

[Allsnow]

Gfs says miller b snowstorm monday

[Kaner587]

the 18z GFS shows our best case scenario(pretty much) for the clipper/miller B threat. Looks like a low thickness event where we would actually be able to get some solid ratios. My fingers are crossed.

[Allsnow]

Man would love to lock that in. Temps fall through 20's during the storm

[ace0927]

HM has a post in the Phl thread about the ku setup on 12z euro

 

 

HM has a post in the Phl thread about the ku setup on 12z euro

and its not such a positive one..

 

"I posted this over in the NE subforum and wanted it here too WRT the ECMWF run:

 

Is it time to sound the KU alarms for Jan 25-27?

 

The window here would open if the ECMWF is correct in lifting the entire polar vortex into the North Atlantic. The GFS is more robust in bringing down the blocking (down as in strat-->tropo and AO-->NAO) and holding the vortex in place instead of shifting out. Now the Jan 20-25 period will be a time, stratospherically, when anomalies will be squeezed through the N Atlantic-UK pipeline in an area of high PV. Is it possible the whole damn Arctic Source/tropo PV goes for the ride too?

 

My early thoughts are that it ...gulp...won't move out quite that fast and the blocking will continue to trend stronger toward the 25th. While we can definitely see snow events during this period, I'm not sold yet on the ECMWF KU setup....but eventually the threat will become real."

 

and there is a follow up one that says he is more confident on the snowy pattern being in early feb...

[SnowGoose69]

The eventual location of the re-developing low if it happens will probably be between the GFS and Euro, the Euro is probably too far north and the GFS probably too far south due to cold bias.  These events historically give nothing to DC, Philly can do so-so and usually from NYC north does well.

[Allsnow]

-510 line is over city during hight of storm. Man would be a sundog dream storm

[CooL]

the 18z GFS shows our best case scenario(pretty much) for the clipper/miller B threat. Looks like a low thickness event where we would actually be able to get some solid ratios. My fingers are crossed.

 

Disagree. That vort really digs. If it closes off the storm can tuck into the coast and we get a lot more snow. Only takes a few minor changes

[Allsnow]

and its not such a positive one..

"I posted this over in the NE subforum and wanted it here too WRT the ECMWF run:

Is it time to sound the KU alarms for Jan 25-27?

The window here would open if the ECMWF is correct in lifting the entire polar vortex into the North Atlantic. The GFS is more robust in bringing down the blocking (down as in strat-->tropo and AO-->NAO) and holding the vortex in place instead of shifting out. Now the Jan 20-25 period will be a time, stratospherically, when anomalies will be squeezed through the N Atlantic-UK pipeline in an area of high PV. Is it possible the whole damn Arctic Source/tropo PV goes for the ride too?

My early thoughts are that it ...gulp...won't move out quite that fast and the blocking will continue to trend stronger toward the 25th. While we can definitely see snow events during this period, I'm not sold yet on the ECMWF KU setup....but eventually the threat will become real."

and there is a follow up one that says he is more confident on the snowy pattern being in early feb...

How is that not positive? He stated might be rushing the ku pattern, snow could still fall during this time frame. A lot more encouraging then what has gone on so far. We don't often see ku patterns to often

[SnowGoose69]

Disagree. That vort really digs. If it closes off the storm can tuck into the coast and we get a lot more snow. Only takes a few minor changes

 

The Miller Bs are dangerous as far as room for error, you sometimes want a positive NAO and just the insanely huge ridge out west which we have here, if you have the -NAO the pattern can slow down too much and the redevelopment occurs too far west...see 12/14/89 for that scenario.  I usually like taking my chances with just a big western ridge and not too blocked up a pattern with Miller Bs.

[Kaner587]

Disagree. That vort really digs. If it closes off the storm can tuck into the coast and we get a lot more snow. Only takes a few minor changes

thats true...but im making an assumption we don't see those "minor changes," but I do acknowledge the possibility obviously. And just as much as it could trend snowier it could easily end up more like the euro, although in this type of pattern I think the result is closer to the GGEM/GFS

[CooL]

The Miller Bs are dangerous as far as room for error, you sometimes want a positive NAO and just the insanely huge ridge out west which we have here, if you have the -NAO the pattern can slow down too much and the redevelopment occurs too far west...see 12/14/89 for that scenario.  I usually like taking my chances with just a big western ridge and not too blocked up a pattern with Miller Bs.

 

Yeah but i don't think this thing can cut west if there's decent confluence in se canada. It can hug the jersey coast and we'd still get snow

[CooL]

thats true...but im making an assumption we don't see those "minor changes," but I do acknowledge the possibility obviously. And just as much as it could trend snowier it could easily end up more like the euro, although in this type of pattern I think the result is closer to the GGEM/GFS

 

Yup. Agreed. 

[Allsnow]

Gfs gives us another snowstorm at the end of next week.

[SnoSki14]

The gfs looks very nice, with high ratios we could easily see even a MECS in this setup. It's like winter officially arrives late Sunday with the arctic front, it looks cold with a ton of snow possibilities and even KU's perhaps going forward. 

 

Could we be looking at a historic winter transformation from Dec to mid January and from mid January through February?

[CooL]

The shortwave that dives in on the backside is a beast

 

[Kaner587]

The gfs looks very nice, with high ratios we could easily see even a MECS in this setup. It's like winter officially arrives late Sunday with the arctic front, it looks cold with a ton of snow possibilities and even KU's perhaps going forward.

Could we be looking at a historic winter transformation from Dec to mid January and from mid January through February?

-qbo favors this midwinter transition. I think we do quite well from her on out

[SnoSki14]

-qbo favors this midwinter transition. I think we do quite well from her on out

 

And starting Monday, this winter will likely leave last winter in the dust.