December Medium/Long Range Discussion

[CAPE]

2 minutes ago, WinterWxLuvr said:

Euro sucks. Did you not watch it on the last storm?

I watched the globals pretty closely from the perspective of my yard, and the Euro was showing next to nothing here due to the warm temp profile, while the CMC still had significant snow, and the GFS was somewhere in between depending on the run. I am not into grading model performance, but among the globals none of them were very good 4-5 days out(surprise). The EURO(and the NAM) seemed to do better with depicting the extent of warm air intrusion inside 3 days.

[WxUSAF]

15 minutes ago, CAPE said:

We need something like the mid Feb 2015  event that kicked off our backloaded winter. Not sure how to characterize that one, but it was along a sharp cold front and intense af. That would be fun to have on Xmas eve.

That was the arctic front event that was the first real MoCo-HoCo deathband?  Forecast was flurries or a dusting and ended up with over 4" of powder.  We had family over for my son's birthday party and it was a disaster for them getting home.  

[nj2va]

11 minutes ago, WinterWxLuvr said:

Euro sucks. Did you not watch it on the last storm?

I hear you on this one.  The Euro is taken as gospel and we’ve seen it struggle at times (this last storm as a good example).  All of the models were way too wet out here...HRRR actually did the best with sniffing out lower QPF out of the all of the mesoscale/short term models.

[frd]

2 minutes ago, CAPE said:

I watched the globals pretty closely from the perspective of my yard, and the Euro was showing next to nothing here due to the warm temp profile, while the CMC still had significant snow, and the GFS was somewhere in between depending on the run. I am not into grading model performance, but among the globals none of them were very good 4-5 days out(surprise). The EURO(and the NAM) seemed to do better with depicting the extent of warm air intrusion inside 3 days.

Ah, the old days of the Euro/ ETA combo ..... when they agreed Accu-Weather looked like a genius, versus the American models back in the 1980's and 1990's.  

Hopefully the old NAM was called the ETA, little early still.  

[CAPE]

4 minutes ago, WxUSAF said:

That was the arctic front event that was the first real MoCo-HoCo deathband?  Forecast was flurries or a dusting and ended up with over 4" of powder.  We had family over for my son's birthday party and it was a disaster for them getting home.  

I recall it being pretty well forecast at least a couple days leading up to it. It was convective in nature but fairly widespread. Totals ranged from 1 to maybe as high as 4". I maximized here pretty good with over 3. It all fell in an hour or so, and the end had a mini whiteout as the actual arctic cold came in.

[H2O]

Dec 2000 had a decent frontal snow IIRC

[nj2va]

@frd - curious how that will impact things if it happens as depicted for the rest of winter coupled with DTs recent post about ensemble guidance moderating Nina in the middle/end of the winter.  I’m not a LR guy at all and I haven’t finished my coffee so I’m probably barely sounding intelligent (as usual!).

[WinterWxLuvr]

12 minutes ago, CAPE said:

I watched the globals pretty closely from the perspective of my yard, and the Euro was showing next to nothing here due to the warm temp profile, while the CMC still had significant snow, and the GFS was somewhere in between depending on the run. I am not into grading model performance, but among the globals none of them were very good 4-5 days out(surprise). The EURO(and the NAM) seemed to do better with depicting the extent of warm air intrusion inside 3 days.

I was joking. 

[JakkelWx]

@CAPE That mid-Feb 2015 snow event was a true arctic airmass with temps in the teens with about a half foot of snow accumulations here. 

ETA: A couple days after featured highs in the high teens with lows close to zero IIRC

[WinterWxLuvr]

9 minutes ago, nj2va said:

I hear you on this one.  The Euro is taken as gospel and we’ve seen it struggle at times (this last storm as a good example).  All of the models were way too wet out here...HRRR actually did the best with sniffing out lower QPF out of the all of the mesoscale/short term models.

To be fair, from about 4 days none of them did that great. But also to be fair, the euro had the low almost in Baltimore from about 36 hours out. I guess my thing is that I wouldn’t put too much faith in anything for next week until about Sunday

[CAPE]

1 minute ago, WinterWxLuvr said:

I was joking. 

lol sorry. Hard to know when it comes to 'objectively' assessing model performance.

I will say I think some folks here would be better served to never look at the ridiculous WB snow/ p-type maps and do some actual analysis of the data. I literally never look at them when I am analyzing a model run. Unfortunately I get to see them here ten times over. 

[frd]

1 minute ago, nj2va said:

@frd - curious how that will impact things if it happens as depicted for the rest of winter coupled with DTs recent post about ensemble guidance moderating Nina in the middle/end of the winter.  I’m not a LR guy at all and I haven’t finished my coffee so I’m probably barely sounding intelligent (as usual!).

 

I continue to feel that any weakening of the Nina has a lag effect, based on the readings of several highly respected mets. I value DT's thoughts on the matter, we will have to see how it plays out. 

Having a weaker SPV and an improved NAM state can only help us, in a broad brush view.  As psu stated we really need a - AO to get opportunities of snowfall, and then beyond that a -NAO in the correct area, and maybe rising or oscillating such as a HA event for the big one. A delicate balance as we all know. 

This year there seems to be a disconnect the SPV and the TPV. Also it appears, at least so far that we are in play when it comes to cold air delivery. As CAPE mentioned the one thing is the source region has been an issue. Canada has  gotten colder, but not severely so, at least not yet. In Jan that source region concern becomes less of an issue. Another positive has been AAM. 

Moving forward, a jet extension and the eventual outcome hopefully of a +PNA and even a -EPO will set the stage for a colder and and snowier January. 

January looks to have decent potential to produce for our area. 

Also, look for any PV  displacements and even minor SSWEs. Again, maybe our area seems favored for a PV orientation near Hudson Bay. Feb. to hard to take a jab at. 

 

[osfan24]

34 minutes ago, WinterWxLuvr said:

Euro sucks. Did you not watch it on the last storm?

Thermals were pretty good. Low location was awful.

[CAPE]

7 minutes ago, JakkelWx said:

@CAPE That mid-Feb 2015 snow event was a true arctic airmass with temps in the teens with about a half foot of snow accumulations here. 

ETA: A couple days after featured highs in the high teens with lows close to zero IIRC

I don't recall any snow amounts that high. The event was in and out in under 2 hours. It started with marginal temps, 33-34. Most of the snow here fell at 32 degrees, with massive aggregates. It piled up fast despite the temps. Yes the cold behind the front was impressive.

[Scraff]

21 minutes ago, CAPE said:

lol sorry. Hard to know when it comes to 'objectively' assessing model performance.

I will say I think some folks here would be better served to never look at the ridiculous WB snow/ p-type maps and do some actual analysis of the data. I literally never look at them when I am analyzing a model run. Unfortunately I get to see them here ten times over. 

Always need to keep in mind that in this forum, the WB snow / p-type maps are specifically for feeding the weenies. Gotta make sure everyone eats. 

[CAPE]

4 minutes ago, Scraff said:

Always need to keep in mind that in this forum, the WB snow / p-type maps are are specifically for feeding the weenies. Gotta make sure everyone eats. 

Yeah I get it. I still think people get biased when they see 20" over their yards run after run, when in reality it is actually more like 10 verbatim, and then when they actually get 7..well you know.

[osfan24]

4 minutes ago, CAPE said:

Yeah I get it. I still think people get biased when they see 20" over their yards run after run, when in reality it is actually more like 10 verbatim, and then when they actually get 7..well you know.

Yeah, those maps are great when there is no temperature concern. When there are major temperature concerns, those maps are almost worthless.

[CAPE]

Just now, osfan24 said:

Yeah, those maps are great when there is no temperature concern. When there are major temperature concerns, those maps are almost worthless.

Yup. And it is pretty rare to not have p-type issues in these bigger, high qpf storms.

[poolz1]

Just now, osfan24 said:

Yeah, those maps are great when there is no temperature concern. When there are major temperature concerns, those maps are almost worthless.

Exactly....those snow maps verified just fine in PA and NY.  If you are on the fringe, take with a huge grain of sleet...i mean salt

[Yeoman]

22 minutes ago, osfan24 said:

Thermals were pretty good. Low location was awful.

I'm waiting for the NAM

[HighStakes]

37 minutes ago, CAPE said:

I don't recall any snow amounts that high. The event was in and out in under 2 hours. It started with marginal temps, 33-34. Most of the snow here fell at 32 degrees, with massive aggregates. It piled up fast despite the temps. Yes the cold behind the front was impressive.

He's probably thinking of the event that followed the front a couple days later. Low pressure stayed a bit to the south producing 3-6 over the region. A few spots may have gotten 8. It happened on a Monday night into Tuesday morning. Extremely cold temps.

[Weather Will]

I am ecstatic on how this December is turning out.  Definitely different from last year.  And so far no sign of a late December torch that I recall was the consensus in early December.  A cold Christmas is always nice.  If we can pull off a couple of inches it would be fantastic!

[JakkelWx]

Yes.. the one around the 18th.

[WinterWxLuvr]

Sunday is still interesting 

[CAPE]

Mount Holly: nothing to see here, but stay tuned, just in case!

The next surface low will be crossing east, with the center of the low likely remaining near the US/Canadian border. This is likely to result in a cold front approaching our region late next week. Another low may develop along the cold front, but even so, it appears that most of the precipitation with this event will come ahead of the front, solidly in the warm sector. Thus, it appears if we see any precipitation associated with this system, it will be mostly rain on Thursday. However, stay tuned to the latest forecast as at least one model shows QPF behind the strong cold front, which would be changing to snow.

[snowmagnet]

4 hours ago, yoda said:

Clouded the future is... but 06z GFS... strong in the Force it is

Love it! Thanks Master Yoda!

[poolz1]

06z gefs with a better look for a wave forming on the Arctic front....Any snow on x-mas is a win but a nice wave developing down south creates some upside potential.

[psuhoffman]

4 hours ago, CAPE said:

With a persistent vortex in/near the WPO domain, and a strong Asian-Pacific jet, it wont be easy to get super cold air in our source region. We probably need the AO to be significantly negative to mitigate that somewhat, and allow TPV lobes to break off and come south.

That vortex is keeping the central PAC ridge suppressed though. You’re right it’s preventing an epo ridge and cross polar flow but in runs that break that down the pac ridge pops and we end to with a trough in the west ridge east. I think I’ll take my chances with the WPO vortex and hope as Canada gets colder we can make die with N American domestic cold sources. 

[Ralph Wiggum]

1 hour ago, JakkelWx said:

Yeah but does the JMA also have it?

Yes

[Scarlet Pimpernel]

4 hours ago, yoda said:

Clouded the future is... but 06z GFS... strong in the Force  Farce it is

 

FYP!! 

But seriously, that would be quite nice if it happens!  At this point, I'll be glad to even have a nice, crisp Christmas rather than being in the 50s or raining or whatever, for a change.  At least a little fresh wintry feel even if there's not much snow.