January Pattern Discussion

[PDIII]

Today I don't have the stormvista euro ens analogs but today's CPC superens mean still is advertising the potential for a really cold shot towards the latter half of the 1st week of January.  the composite of the 10 dates gives us one day with an 8C negative departure...for those math challenged that's a 14.4F departure.  A couple of the analogs were quite a bit colder than that. 

 

Four of the 10 dates yielded snowstorms within 3 days of the centered mean.  Three 2 inch events and one 7.  I still like the 30-40 percent chance of DCA getting their first inch between jan 2-jan 8. 

I read your article and as usual I think it is great.  You have a talent for explaining complex meteorological concepts to lay people like my self.  Now as for interpretation, I think you can go a little higher than 30-40%.  If the climo says 30% and the long range pattern is favorable, I would think that the chances are better than 30-40%.  If it plays out and we see the coldest air of the season... we just need to get one disturbance to track to our south.. or maybe even clipper or something.  Wouldn't take much.  I would say 50-50.   

[Bob Chill]

yeah...I think at day 10 it is good to just stick with ensemble means for the overall pattern..esp with the GFS which when you get outside of 192 hours tends to fluctuate way too much with major features...GEFS and EPS are very close with the pattern at day 10....Strong vortex east of Hudson Bay, +PNA, heights too low in the target NAO region...

 

That was the thing I didn't like about the last 2 gefs runs and also looking at the individual members. Plenty of spread of course but it was pretty obvious which members lacked the blocking necessary. We lost a little ground on the means as well. I think Wes' thoughts are spot on irt snow chances at this lead. 

 

I would chuckle if the vort the euro has mid next week produces. It's not a clipper. It comes out of the rockies and rides underneath the big hp in the center of the country. It would be a weak and sheared system but still would be kind of amusing if it dropped some snow on us. 

[WinterWxLuvr]

I'd take the same pattern we had on Dec 7, all winter long.

[aldie 22]

I'd take the same pattern we had on Dec 7, all winter long.

Agree...this is fast becoming an every man for himself winter

[WinterWxLuvr]

Agree...this is fast becoming an every man for himself winter

2 degrees colder and it would have been great for all of us.

I'm wary of the infamous "twelve day winter" as in its always 12 days away.

[usedtobe]

I read your article and as usual I think it is great.  You have a talent for explaining complex meteorological concepts to lay people like my self.  Now as for interpretation, I think you can go a little higher than 30-40%.  If the climo says 30% and the long range pattern is favorable, I would think that the chances are better than 30-40%.  If it plays out and we see the coldest air of the season... we just need to get one disturbance to track to our south.. or maybe even clipper or something.  Wouldn't take much.  I would say 50-50.   

I'd say 50% if we had the Atlantic blocking in the right place.  We don't.  Also, the analogs the last 3 days have hovered between 3 and 4 events which puts the probability in the 30 to 40% range.  Our near Winterluvr, it probably is 50%, not at DCA. 

[snow.]

Agree...this is fast becoming an every man for himself winter

 

 

It usually is...Though despite the nature of our banter in between storms, I thought those of us who didnt do as well in the 12/8-13 period were EXTREMELY resilient and well "behaved" during those 2 events, especially the bust in the 2nd one.  I think most of us were truly psyched for the people who did well, and there was certainly no resentment.  Most of us were over the bust by the end of the day.  We have suffered and we have learned.  Which is why the display from people inside and outside this region that did well, that we were resentful and complaining was preposterous, ignorant and frankly juvenile.  We are going to see more storms with gradients.  Hopefully some of the same people who embarrassed themselves on 12/10 with unsupportable accusations, don't do so again.

 

back to the pattern.  GFS running now.

[clskinsfan]

 I know its way out there. But anyone else thinking about storms being suppressed with the modeled pattern. It really would not take much of a shift of the PV a little further south and we are talking about fish storms for our area. 

[Ian]

 I know its way out there. But anyone else thinking about storms being suppressed with the modeled pattern. It really would not take much of a shift of the PV a little further south and we are talking about fish storms for our area. 

Anecdotal evidence points to us liking suppressed patterns in January these days but I have only barely looked at the models at range so don't take that for much.

[Bob Chill]

 I know its way out there. But anyone else thinking about storms being suppressed with the modeled pattern. It really would not take much of a shift of the PV a little further south and we are talking about fish storms for our area. 

 

If we had a big -nao then definitely a problem. I'm not seeing a suppressed pattern except for possible timing on an individual storm. If anything I'm much more worried about nw track than anything else. 

[snow.]

Anecdotal evidence points to us liking suppressed patterns in January these days but I have only barely looked at the models at range so don't take that for much.

 

usually, thought not always, the big suppressive patterns that do well for Carolinas have a strong southern stream and really high heights all through Canada down into New England.  I think in the upcoming pattern at least, storms have a better chance of cutting to the west than sliding under us...though those weak silly lows do often get shunted out to sea, but usually dont do much for anyone

[Ian]

usually, thought not always, the big suppressive patterns that do well for Carolinas have a strong southern stream and really high heights all through Canada down into New England.  I think in the upcoming pattern at least, storms have a better chance of cutting to the west than sliding under us...though those weak silly lows do often get shunted out to sea, but usually dont do much for anyone

Yeah, what I've seen didn't make me too concerned for it.. though I certainly wouldn't be shocked if we get cold with no snow except on the edges of the pattern.. but again I've barely looked so I'm just talking out my arse.

[snow.]

Yeah, what I've seen didn't make me too concerned for it.. though I certainly wouldn't be shocked if we get cold with no snow except on the edges of the pattern.. but again I've barely looked so I'm just talking out my arse.

 

I always like when there is big representation in the upper levels because then we can still get 2" with a bad track....or in the alternative, Orange, va can get 6-10" and we can get a cartopper

[clskinsfan]

Thanks for the info

 

If we had a big -nao then definitely a problem. I'm not seeing a suppressed pattern except for possible timing on an individual storm. If anything I'm much more worried about nw track than anything else. 

 

usually, thought not always, the big suppressive patterns that do well for Carolinas have a strong southern stream and really high heights all through Canada down into New England.  I think in the upcoming pattern at least, storms have a better chance of cutting to the west than sliding under us...though those weak silly lows do often get shunted out to sea, but usually dont do much for anyone

 

I guess my thoughts are that the PV can get displaced far enough south to be the block. Thus shunting storms OTS. But to Ians point displaced PV patterns have worked out pretty well for us in the past (09/10)

[Bob Chill]

GFS looks ok @ 192 in the upper levels. Vort positive tilt digging just south of west tx. It would be a juicy system down the line verbatim. I hate post truncation so whatever it shows is suspect. Looks ok to me leading in. 

[snow.]

GFS looks ok @ 192 in the upper levels. Vort positive tilt digging just south of west tx. It would be a juicy system down the line verbatim. I hate post truncation so whatever it shows is suspect. Looks ok to me leading in. 

 

 

day 9 still has the snow to rain event..the track is too far inland for us, but subtle changes would make it more frozen...too many moving pieces to feel safe...not having a -NAO makes it so much harder

[snow.]

Thanks for the info

 

 

 

I guess my thoughts are that the PV can get displaced far enough south to be the block. Thus shunting storms OTS. But to Ians point displaced PV patterns have worked out pretty well for us in the past (09/10)

 

yes..but we really want the vortex to be further east...not near Hudson bay..

[mitchnick]

day 9 still has the snow to rain event..the track is too far inland for us, but subtle changes would make it more frozen...too many moving pieces to feel safe...not having a -NAO makes it so much harder

looks like there's another one not too far on its heels

[snow.]

looks like there's another one not too far on its heels

 

 

and the pattern is way better too...

[snow.]

Thanks for the info

 

 

 

I guess my thoughts are that the PV can get displaced far enough south to be the block. Thus shunting storms OTS. But to Ians point displaced PV patterns have worked out pretty well for us in the past (09/10)

 

Here is PD1 and PD2....Neither had west based blocking (They did have east based -NAO), but both had an insane 50-50 low with sick confluence to the west of it.... (they had other good factors of course - split flow, high heights to the west of Hudson Bay)...but you see where we want the vortex...it can even be west of 50-50, but not as far west as where it is progged in the upcoming pattern

 

When I was 1st learning about patterns in 2003..DT would always honk about a good PV over Hudson Bay, but I have realized over time, it is never really good for us to have a PV to our NW...

 

[stormtracker]

These post truncation storms are the worst.

[usedtobe]

Here is PD1 and PD2....Neither had west based blocking (They did have east based -NAO), but both had an insane 50-50 low with sick confluence to the west of it.... (they had other good factors of course - split flow, high heights to the west of Hudson Bay)...but you see where we want the vortex...it can even be west of 50-50, but not as far west as where it is progged in the upcoming pattern

 

When I was 1st learning about patterns in 2003..DT would always honk about a good PV over Hudson Bay, but I have realized over time, it is never really good for us to have a PV to our NW...

 

sick5050.gif

 

 

No when we get a good PV over hudson bay it almsot always results in either having a low dive to the great lakes to mess up the pattern or a track inland enough to screw you.  That's why even though this is probably the best pattern for us this winter, for dc it still is not one assured of giving us our inch.  I don't expect a pure snow event unless we can keep the wave really flat. 

[Heisy]

Just got a look at the GFS, I know it truncates, but the pattern at 192 hours is, imo, the best chance we've had all year at MECS. Way out there though. 

[Bob Chill]

No when we get a good PV over hudson bay it almsot always results in either having a low dive to the great lakes to mess up the pattern or a track inland enough to screw you.  That's why even though this is probably the best pattern for us this winter, for dc it still is not one assured of giving us our inch.  I don't expect a pure snow event unless we can keep the wave really flat. 

 

I totally agree here Wes. I've seen enough individual ens members the last couple days to make me go crosseyed. Virtually every single wound up storm went west or miller b'd. Neither solution is a good one. 

 

I suppose timing of the vort across the sw means quite a bit here. Speed it up just 12-18 hours verbatim @ the ul's and confluence to the N keeps it weaker, flatter, and snowier. There are plenty of members showing that solution as well. This is what I'm going to focus on. If it goes big then anyone hoping for all snow will likely get their feelings hurt. 

[PhineasC]

Just got a look at the GFS, I know it truncates, but the pattern at 192 hours is, imo, the best chance we've had all year at MECS. Way out there though. 

If the regular crew starts looking at day 10 you'll need to be looking at the CFS to maintain your niche as the "sick pattern in 2 weeks guy"

[Heisy]

If the regular crew starts looking at day 10 you'll need to be looking at the CFS to maintain your niche as the "sick pattern in 2 weeks guy"

 

I'll use a Ji phrase, the pattern that leads up the pattern is only 5 days out, and that pattern of the pattern to that pattern is only 3 days out. 

[Bob Chill]

If the regular crew starts looking at day 10 you'll need to be looking at the CFS to maintain your niche as the "sick pattern in 2 weeks guy"

 

I won't go a single hour past 228. 9.5 day leads are money. 

[WinterWxLuvr]

I totally agree here Wes. I've seen enough individual ens members the last couple days to make me go crosseyed. Virtually every single wound up storm went west or miller b'd. Neither solution is a good one.

I suppose timing of the vort across the sw means quite a bit here. Speed it up just 12-18 hours verbatim @ the ul's and confluence to the N keeps it weaker, flatter, and snowier. There are plenty of members showing that solution as well. This is what I'm going to focus on. If it goes big then anyone hoping for all snow will likely get their feelings hurt.

So it's better to stop hoping for all snow. Learned that a long time ago.

I'd rather have big, even if it means it goes to slop at the end. I won't call an inch an event. Oh sure, I'd take it but I'm not getting excited for it.

[Bob Chill]

GEFS members are all over the place with timing, track, ptype and even existence. 

[usedtobe]

Matt, Bob,  here's one of the big anomalous snowstorms.  We had a negative AO but and east based on.  Low heights up north of Hudson Bay, the ridge in the west is farther west than optimal but with a strong southern stream and positive tilting trough embedded in it, we managed to get 10 inches on the 6th of February.

 

 

 

I looked at the 1961 case which is one of today's analogs and it had a a nice southern stream shortwave that passed well to our south.  Over the east, it's nt a very good analog for the pattern.