January Storm Term Threat Discussions (Day 3 - Day 7)

[psuhoffman]

14 minutes ago, Ji said:

Maybe feb is where north America gets the lions share of the cold air? 2014-15 was a good winter that started on Feb 15

Also...I get losing the gfs blizzard but why was it all or nothing lol. It had to go from 25 to 0 instead of 25 to 4 lol.

I saw that all or nothing dichotomy because either the wave has the necessary amplitude to begin to amplify a surface system and cut off to our west and it would then foster a bombing secondary along the coast that would tuck in tight with the upper low...or it would fail to reach the necessary amplitude and get suppressed by the flow.  In between doesn't really work.  Its a a critical mass thing to spark the chain reaction we needed...there is a very narrow zone for the in between options...its more likely it amplifies or gets squashed because its too weak.  

[psuhoffman]

9 minutes ago, Wentzadelphia said:

Icon has some front end I thought? I could only see surface temps and accum precip so was hard to tell what was going on. It’s a close call for you guys. Gfs and cmc nail New England. Philly does well on front end too. The backside of trough kind of rotates around the trough since the block just stops all movement. The way this year has trended its fine at this point. It’s a marginal setup but there is decent cold ahead, but the gradient is pretty far north. Well see, with how these two events have trended im happy just to be able to track another one. The chances of tomorrow quell the pain of today. 

It has some light snow on the front...but when you say it looked nice I think most aren't really chasing an inch or two followed by rain on a day 7 threat.  But I am not even worrying about those details at that range anyways...but I agree the way the run was described did not align with what the run looked like.   That GFS run the other night was NICE.  That ICON was...ehh at least its got some pity flakes.  

[Heisy]

Just now, psuhoffman said:

It has some light snow on the front...but when you say it looked nice I think most aren't really chasing an inch or two followed by rain on a day 7 threat.  But I am not even worrying about those details at that range anyways...but I agree the way the run was described did not align with what the run looked like.  

Yea my fault, Sv doesn’t offer much on the icon, this is what I got which is annoying to decipher since it overdoes snow for some reason

[psuhoffman]

15 minutes ago, Wentzadelphia said:

Yea my fault, Sv doesn’t offer much on the icon, this is what I got which is annoying to decipher since it overdoes snow for some reason

Yea that looks off.  It’s more like 2-3” which is a hecs by recent standards  

[CAPE]

6 hours ago, Maestrobjwa said:

So this time around...it wasn't the thermally challenged base state that did it, but just another bit of random chaos unable to be seen at a longer range? Oh the roll of the atmospheric dice...lol

It was always going to be a challenge to get the flow to back enough to allow the southern wave to gain much latitude, given the massive NA vortex- yes our beloved "50-50" low, which is actually a deep trough that is positioned too far west. It is sitting there and absorbing all the waves progressing off the coast, including the one that exits later tomorrow. What was to be our 'good storm' is a healthy southern stream wave, but there simply isn't enough spacing between it and the energy from the previous one being ingested into that vortex. Then we have the TPV lobe pressing in. In retrospect what we needed to happen was the southern wave to be slower and/or a phase with that NS energy. Without that, the southern wave can only track straight off the coast and out to sea, where it does induce a  deepening surface low, but way too late, Hopefully we can get some decent wind out if it!

[Ralph Wiggum]

I dont see right now how the day 7 system doesnt undergo the same shred/shear as every other system that has taken the same trajectory all season. Its a wash, rinse, repeat thing. We all know how remainder of this season will play out....threats at days 7-10 that trend to meh most of Feb....Likely some warming days later into Feb, then things get convoluted and turn topsy turvy in March with clusters of well BN temp days and a couple of pasting snow events by mid Month. This is the new norm.

[csnavywx]

Next week looks like a sloppy gyre of disappointment. Some light stuff possible around the slow-moving upper low or perhaps in association with the clipper-type shortwaves that drop in, but don't count on it. Thermals are just anemic for January. Not much quality cold air around to tap into over Canada either.

[frd]

21 minutes ago, csnavywx said:

Next week looks like a sloppy gyre of disappointment. Some light stuff possible around the slow-moving upper low or perhaps in association with the clipper-type shortwaves that drop in, but don't count on it. Thermals are just anemic for January. Not much quality cold air around to tap into over Canada either.

 

Eastern Canada with above normal temps. So far from December 1 st never got a signal form the Canadian 10 day mean that portended an incoming cold air mass,  let alone an arctic air mass with staying power. 

Unless the Pac improves and the EPO delivers last lasting cold into Northern Canada that eventually bleeds SE in time we are cooked. 

Meaning Atlantic Ocean SSTs continue to remain relatively stable due to the lack of  arctic intrusions.  For all the - AO , etc. no deliver of Old Man winter. 

 

    

[chris21]

6 minutes ago, frd said:

 

Eastern Canada with above normal temps. So far from December 1 st never got a signal form the Canadian 10 day mean that portended an incoming cold air mass,  let alone an arctic air mass with staying power. 

Unless the Pac improves and the EPO delivers last lasting cold into Northern Canada that eventually bleeds SE in time we are cooked. 

Meaning Atlantic Ocean SSTs continue to remain relatively stable due to the lack of  arctic intrusions.  For all the - AO , etc. no deliver of Old Man winter. 

 

    

Still pretty meh, but honestly a fair amount better than two weeks ago. If there is a month where that type of cold will work it’s February. Hate to be that guy...  it will snow again...

[CAPE]

1 hour ago, losetoa6 said:

Nice to see the Eps double down on day 7/8 . 

Not impossible, but all kinds of potential issues with this one. We need something simple lol.

[frd]

1 minute ago, CAPE said:

Not impossible, but all kinds of potential issues with this one. We need something simple lol.

This is modeled to slow down and spin and then move out. Will feel like a winter's day next Monday. 

Complex is the new norm around here 

[frd]

 

Mount Holly AFD for next Monday, meh, more of the same. 

 

 

For Sunday...An upper-level trough which may be comprised of a
closed low centered near the western Great Lakes during Sunday
sends leading energy in its base into the Mid-Atlantic region.
This will drive surface low pressure near or just south of
Delmarva Sunday night. There is a surface high centered well
north in Canada with some semblance of a wedge down into our
region, however the overall setup is less certain. Given the
main energy hanging back over the Great Lakes, we may be dealing
with some snow to a wintry mix to a change to rain in some
areas. These details are much less certain this far out in time.

&&

[Heisy]

Looks like some really good MJO news. We’ll have opportunities in February.  We may start playing with a -epo or +pna by first week or so

[CAPE]

1 minute ago, frd said:

 

Mount Holly AFD for next Monday, meh, more of the same. 

 

 

For Sunday...An upper-level trough which may be comprised of a
closed low centered near the western Great Lakes during Sunday
sends leading energy in its base into the Mid-Atlantic region.
This will drive surface low pressure near or just south of
Delmarva Sunday night. There is a surface high centered well
north in Canada with some semblance of a wedge down into our
region, however the overall setup is less certain. Given the
main energy hanging back over the Great Lakes, we may be dealing
with some snow to a wintry mix to a change to rain in some
areas. These details are much less certain this far out in time.

&&

Cold leading in, then cold behind is the general idea on the means. so temps are an obvious problem esp for the lowlands, and the coastal transfer has the typical look of occurring too far north/too late for our area. Maybe the WDI will overwhelm the complexity and high probably of failure lol.

[frd]

1 minute ago, CAPE said:

Cold leading in, then cold behind is the general idea on the means. so temps are an obvious problem esp for the lowlands, and the coastal transfer has the typical look of occurring too far north/too late for our area. Maybe the WDI will overwhelm the complexity and high probably of failure lol.

I would think if I were a betting man that the event on Monday has better thermal odds than this week.  

At least maybe start as snow and even end as snow , but that hardly ever works out.  

Are you forming any ideas about mid to later Feb. ? 

I feel there is some growing evidence that after the cold period ( you posted about earlier ) a cutter visits and then based on evolutions in the Pac we may get another opportunity to get fooled near the 17  th to 28  th of Feb. Thoughts ?  

[CAPE]

6 minutes ago, frd said:

I would think if I were a betting man that the event on Monday has better thermal odds than this week.  

At least maybe start as snow and even end as snow , but that hardly ever works out.  

Are you forming any ideas about mid to later Feb. ? 

I feel there is some growing evidence that after the cold period ( you posted about earlier ) a cutter visits and then based on evolutions in the Pac we may get another opportunity to get fooled near the 17  th to 28  th of Feb. Thoughts ?  

I haven't thought too much about it, but the LR looks I am seeing don't imply a 'close the shades' situation. Historically it finds ways to snow in February, but we know we are in somewhat different times. In general I like seeing a mechanism to inject polar air into the midlatitudes, but we need the Pac to cooperate enough to allow it to propagate east.

[arlwx]

LWX on the start of next week:

High pressure will dominate Saturday with a little moderation in
temps. However, by Sunday, another system is pushing northeastward
towards us, with warm advection precip breaking out in our region by
day`s end. Cold air looks marginal by this point, so while a mix may
start, this again looks like a system which will transition to more
liquid than frozen. The low track towards the lower Great Lakes
certainly will not help keep the cold air around, though some
damming could result in more wintry mix in the favored spots
northwest of I-95.

[dallen7908]

Penultimate update as our window is nigh;

about half of the total for the last run are for this weekend's possible storm, which I had kind of forgot about until yesterday morning when I checked my "trusty" weather app and saw that my snow chances (percent) for next weekend were higher than either today/tomorrow or Thursday. 

EPS members snow/sleet totals (inches) for the last 16 (00 and 12 UT) runs (College Park) through 00 UT Feb 3

90th percentile: 9 15 12 15 12 16 18 12 13 10 10 11 9 10 10 11

80th percentile: 6 10 11 9 10 12 13 9 11 7 6 8 6 8 9 9

70th percentile: 6 6 9 8 7 11 11 8 9 6 3 6 5 6 6 7

60th percentile: 4 5 8 6 6 7 9 7 7 4 2 5 5 5 5 6

50th percentile: 3 4 6 5 4 6 7 6 6 2 1 4 4 4 5 6

40th percentile: 2 3 4 4 4 5 6 5 6 2 0.8 4 3 3 4 5

30th percentile: 2 1 4 3 3 4 5 4 5 0.9 0.6 3 3 2 4 4

20th percentile: 0.7 0.6 3 2 2 3 3 4 3 0.5 0.4 2 2 1 3 3

10th percentile: 0.5 0.3 1 1 1 1 3 3 1 0 0.1 1 2 1 3 3

[psuhoffman]

2 hours ago, Wentzadelphia said:

Looks like some really good MJO news. We’ll have opportunities in February.  We may start playing with a -epo or +pna by first week or so

If the Mjo gets into 8 with a -AO and we still fail lol. We’ve been fighting a somewhat hostile Pac base state. Although I think some are using that as a comfort blanket honestly because the pac forcing has been mostly blah and muted. Definitely not good but not awful. And we’ve overcome a similar pac with a -AO/NAO before. But if we get the pac into a favorable forcing state in Feb and its still not cold enough the excuses start to run out. 
 

BTW when I say forcing I don’t mean the longwave pattern necessarily. I have my suspicious the typical response is being altered somewhat. But that altered response if somewhat permanent is irrelevant. If the forcing takes on a typical nino phase 8 look and we still see a hostile longwave pattern....well at least we can eliminate the “we need the pac to cooperate” posts. 

[psuhoffman]

1 hour ago, CAPE said:

Not impossible, but all kinds of potential issues with this one. We need something simple lol.

Simple isn’t an option. Simple would be a wave running under us with a nice WAA snow shield. That cannot happen because there isn’t enough cold. Look at the thermals I posted last night from the icon as the wave gets into the plains. It has no snow shield to it’s NE again because there is no tight thermal gradient to focus along. You can go 250 miles and only get a 5-10 degree change because it’s 28 degrees all the way up into Canada where it should be 10 degrees.    Because of this we will likely continue to see storms where there is little to no WAA snow shield to the northeast of them.  We need some kind of dynamic system that amplifies in just the right spot and given the blocking that’s going to involve some form of west track transfer hybrid system. And yes that’s the complicated way and we prefer simple but without the overrunning option simple is gone. I guess you could consider tonight simple except the snow shield is sooooo narrow because of the factors above its not really simple and it’s pretty limited in potential and scope. 

[Maestrobjwa]

14 minutes ago, psuhoffman said:

You can go 250 miles and only get a 5-10 degree change because it’s 28 degrees all the way up into Canada where it should be 10 degrees.

So what does the long range show in terms of getting more cold into Canada?

[Heisy]

44 minutes ago, psuhoffman said:

If the Mjo gets into 8 with a -AO and we still fail lol. We’ve been fighting a somewhat hostile Pac base state. Although I think some are using they ask a comfort blanket honestly because the pac forcing has been mostly blah and muted. Definitely not good but not awful. And we’ve overcome a similar pac with a -AO/NAO before. But if we get the pac into a favorable forcing state in Feb and its still not cold enough the excuses start to run out. 
 

BTW when I say forcing I don’t mean the longwave pattern necessarily. I have my suspicious the typical response is being altered somewhat. But that altered response if somewhat permanent is irrelevant. If the forcing takes on a typical nino phase 8 look and we still see a hostile longwave pattern....well at least we can eliminate the “we need the pac to cooperate” posts. 

Yea i just want to shake it up and looks like we’ll get that, probably after a that cutter that’s being progged day 10-12. This current pattern is just not working.

[Ji]

icon blues us sunday

[jaydreb]

1 hour ago, psuhoffman said:

If the Mjo gets into 8 with a -AO and we still fail lol. We’ve been fighting a somewhat hostile Pac base state. Although I think some are using that as a comfort blanket honestly because the pac forcing has been mostly blah and muted. Definitely not good but not awful. And we’ve overcome a similar pac with a -AO/NAO before. But if we get the pac into a favorable forcing state in Feb and its still not cold enough the excuses start to run out. 
 

BTW when I say forcing I don’t mean the longwave pattern necessarily. I have my suspicious the typical response is being altered somewhat. But that altered response if somewhat permanent is irrelevant. If the forcing takes on a typical nino phase 8 look and we still see a hostile longwave pattern....well at least we can eliminate the “we need the pac to cooperate” posts. 

How much of this winter has just been bad luck though?  DC was super close to a good event in December and then another one this Thursday.  A few very minor adjustments and we’re talking about nearing climo by the end of January.  

[jaydreb]

12z GFS not too shabby for early next week.  

[WinterWxLuvr]

7 minutes ago, jaydreb said:

How much of this winter has just been bad luck though?  DC was super close to a good event in December and then another one this Thursday.  A few very minor adjustments and we’re talking about nearing climo by the end of January.  

There really isn’t an event Thursday. But I agree. Plenty of bad luck.

[Cobalt]

7 minutes ago, jaydreb said:

12z GFS not too shabby for early next week.  

12z Para agrees, pretty decent hit for many DC and NW. Even though the GFS camp seems to not want to transfer to the coast until way late, it still has some decent front end snow with that retreating coldish airmass. 

[Ji]

figures--no we cant get a a south shift with the low to induce a transfer to the mid atlantic coast. Of course our 50/50 low has to move out

[Amped]

CMC is way south with sundays storm. Looks like a hit incoming.

[Quasievil]

19 minutes ago, WinterWxLuvr said:

There really isn’t an event Thursday. But I agree. Plenty of bad luck.

Interesting how Thursday has become a nothing burger for EVERYONE.