Jan 11-12 Model/Forecasting Discussion

[mitchnick]

if the NAM is right with its depiction at 500mb at 84 hours, or even close to it, we're in trouble

those "tentacles" of energy coming off of the Canadian vortex are what seem to be kiling us

if the vortex could consolidate, we'd be in better shape

now, I am speaking verbatim with respect to this run of the NAM, but the NAM doesn't seem to be the only model doing this

maybe all we get is a sheared out pos snowfall, I don't know

but I do know its way to early for anyone to be running for the life boats (said the Captain of the Titanic!)

[PhineasC]

NAM looks juiced at the end of its run.

[WxUSAF]

Looks like a solid storm for ATL

Yeah, Birmingham and Atlanta are looking at a good accumulation possibly, just so long as the column can stay cold enough at all heights.

78 and 84hr NAM doesn't look quite as good as the 12z's 84hr did, but it still looks decent. PV is lifting out, but the southern s/w is faster and the northern s/w looks more sheared.

[mitchnick]

dang, +3C 850's in Alaska at 84 hrs

http://www.nco.ncep....am_850_084l.gif

[donsutherland1]

If you forecast 10 events and 1 come in. How has you map helped anyone. The false alarm ratio is just too large if you are actually statistically verifying your forecasts and then are comparing them to some type of standard (for example a model forecast) or if you're forecasting probabilities MOS.

I strongly agree and could not have said it any better, Wes. But human psychology being what it is, people will often remember the grand slam or long touchdown pass more than they'll remember the far more numerous strikeouts or incomplete passes. Performance assessment requires an objective comparison of right and wrong. Public perceptions/media ratings, though, can easily be skewed by the occasional big "win" that captures attention and is far more memorable than the a consistently strong performance garners less attention because extremes are not involved.

[BaltimoreWxGuy]

LWX is not very impressed with Tuesdays storm chances...

We're already receiving calls about the potential for the Tuesday storm. Low pressure

looks to develop along the Texas CST sun...tracking along the Gulf CST Monday

and then reappearing off the SC CST Monday night. At this time there is

nothing to indicate that this would track up the CST. The upper level

flow is such that it would be carried out to sea. I'm not a big fan

of analogues - every situation is different...but this pattern does

bear some similarities to the minor storm of Dec 16...where the bulk

of the snow stayed to the S of the County Warning Area. Highest totals in the County Warning Area

that day were 3-4" in Nelson...District of Columbia received 1... 1-2". So depending

on how things develop an advisory may be needed next Monday. Stay tuned.

[mitchnick]

Yeah, Birmingham and Atlanta are looking at a good accumulation possibly, just so long as the column can stay cold enough at all heights.

78 and 84hr NAM doesn't look quite as good as the 12z's 84hr did, but it still looks decent. PV is lifting out, but the southern s/w is faster and the northern s/w looks more sheared.

I think the problem is the northern stream enrgy is pushing the southern stream along; that's a real problem for anything substantial around here

like I said earlier, give me the juicy, double barreled Lows and I'll deal with the changeover/mix problems for a few hours

[mitchnick]

LWX is not very impressed with Tuesdays storm chances...

We're already receiving calls about the potential for the Tuesday storm. Low pressure

looks to develop along the Texas CST sun...tracking along the Gulf CST Monday

and then reappearing off the SC CST Monday night. At this time there is

nothing to indicate that this would track up the CST. The upper level

flow is such that it would be carried out to sea. I'm not a big fan

of analogues - every situation is different...but this pattern does

bear some similarities to the minor storm of Dec 16...where the bulk

of the snow stayed to the S of the County Warning Area. Highest totals in the County Warning Area

that day were 3-4" in Nelson...District of Columbia received 1... 1-2". So depending

on how things develop an advisory may be needed next Monday. Stay tuned.

well, their opinion is as good as everyone else's opinion at this point so I wouldn't be too concerned

they're looking at the same models we are and unfortunately made the same snow forecast mistakes as just about everyone else the day before Christmas as well as through most of the day on 12/26

[PhineasC]

LWX is not very impressed with Tuesdays storm chances...

We're already receiving calls about the potential for the Tuesday storm. Low pressure

looks to develop along the Texas CST sun...tracking along the Gulf CST Monday

and then reappearing off the SC CST Monday night. At this time there is

nothing to indicate that this would track up the CST. The upper level

flow is such that it would be carried out to sea. I'm not a big fan

of analogues - every situation is different...but this pattern does

bear some similarities to the minor storm of Dec 16...where the bulk

of the snow stayed to the S of the County Warning Area. Highest totals in the County Warning Area

that day were 3-4" in Nelson...District of Columbia received 1... 1-2". So depending

on how things develop an advisory may be needed next Monday. Stay tuned.

Good news.

[mattie g]

LWX is not very impressed with Tuesdays storm chances...

We're already receiving calls about the potential for the Tuesday storm. Low pressure

looks to develop along the Texas CST sun...tracking along the Gulf CST Monday

and then reappearing off the SC CST Monday night. At this time there is

nothing to indicate that this would track up the CST. The upper level

flow is such that it would be carried out to sea. I'm not a big fan

of analogues - every situation is different...but this pattern does

bear some similarities to the minor storm of Dec 16...where the bulk

of the snow stayed to the S of the County Warning Area. Highest totals in the County Warning Area

that day were 3-4" in Nelson...District of Columbia received 1... 1-2". So depending

on how things develop an advisory may be needed next Monday. Stay tuned.

That was surprisingly easy to read, especially without the caps.

1-2"? It would double my snowfall for the season. Sad as that may be, we take what we can and deal with it.

[Yeoman]

Yeah, Birmingham and Atlanta are looking at a good accumulation possibly, just so long as the column can stay cold enough at all heights.

78 and 84hr NAM doesn't look quite as good as the 12z's 84hr did, but it still looks decent. PV is lifting out, but the southern s/w is faster and the northern s/w looks more sheared.

Snow in the deep south never portends anything decent this far north.. unless it's a March '93 situation

[needbiggerboat]

Snow in the deep south never portends anything decent this far north.. unless it's a March '93 situation

occasionally this leads to anomalous warmth in the north, a la the infamous deal brokered by mother nature between heat miser and snow miser....

[JB Fins]

occasionally this leads to anomalous warmth in the north, a la the infamous deal brokered by mother nature between heat miser and snow miser....

Owen Wilson to play Snow Miser and Rush Limbaugh to play Heat Miser in the Broadway version. Ah, love the old Rankin Bass specials.

[Ender]

west of the op.. not terrible actually.. nc coast to near the benchmark

west of 0z ens as well

That sounds like the ECE mean. Have you seen the spaghetti plot as well? It looks like there are quite a few members that have a low just SSE of HAT at 120hr. They're very tightly clustered there. The OP is quite a bit south of that clustering at the same time. Six hours later there appear to be many members (as in too many overlapping circles to count them all) that are somewhere along 74W from just north of HAT to about the latitude of Chincoteague. Six more hours and there appear to be two camps/clusters of members forming. One set is from right over ACY, or just barely east of there, to about 39N/73W. I'd say the majority of this cluster are right around that 39N/73W spot. Meanwhile the second cluster of solutions is doing the OP's elongation thing along an ENE axis that starts at 35N/73W. I'd say that it's a significant minority of the members that look similar to the OP. The next six hours shows a ton of spread, but the OP is very clearly on the southern edge of the ensemble spaghetti.

Still, for us, only a tiny fraction of the solutions would be good. I'd think we'd be in the game if that first camp above were to verify and if it were 80mi further west. Of course that'd mean that it didn't really verify, but whatever...

[PhineasC]

That sounds like the ECE mean. Have you seen the spaghetti plot as well? It looks like there are quite a few members that have a low just SSE of HAT at 120hr. They're very tightly clustered there. The OP is quite a bit south of that clustering at the same time. Six hours later there appear to be many members (as in too many overlapping circles to count them all) that are somewhere along 74W from just north of HAT to about the latitude of Chincoteague. Six more hours and there appear to be two camps/clusters of members forming. One set is from right over ACY, or just barely east of there, to about 39N/73W. I'd say the majority of this cluster are right around that 39N/73W spot. Meanwhile the second cluster of solutions is doing the OP's elongation thing along an ENE axis that starts at 35N/73W. I'd say that it's a significant minority of the members that look similar to the OP. The next six hours shows a ton of spread, but the OP is very clearly on the southern edge of the ensemble spaghetti.

Still, for us, only a tiny fraction of the solutions would be good. I'd think we'd be in the game if that first camp above were to verify and if it were 80mi further west. Of course that'd mean that it didn't really verify, but whatever...

This is the most positive post I have ever seen from you.

[Ender]

This is the most positive post I have ever seen from you.

It felt weird writing it. Kind'a like trying to swim across the pool with your jeans and sweatshirt on. Sure you can do it, but you'll probably get exhausted and you might even drown.

[mattie g]

That sounds like the ECE mean. Have you seen the spaghetti plot as well? It looks like there are quite a few members that have a low just SSE of HAT at 120hr. They're very tightly clustered there. The OP is quite a bit south of that clustering at the same time. Six hours later there appear to be many members (as in too many overlapping circles to count them all) that are somewhere along 74W from just north of HAT to about the latitude of Chincoteague. Six more hours and there appear to be two camps/clusters of members forming. One set is from right over ACY, or just barely east of there, to about 39N/73W. I'd say the majority of this cluster are right around that 39N/73W spot. Meanwhile the second cluster of solutions is doing the OP's elongation thing along an ENE axis that starts at 35N/73W. I'd say that it's a significant minority of the members that look similar to the OP. The next six hours shows a ton of spread, but the OP is very clearly on the southern edge of the ensemble spaghetti.

Still, for us, only a tiny fraction of the solutions would be good. I'd think we'd be in the game if that first camp above were to verify and if it were 80mi further west. Of course that'd mean that it didn't really verify, but whatever...

So basically what you're saying is that there are no good solutions - either the op or in the ensembles.

Throw 'em out.

[PhineasC]

It felt weird writing it. Kind'a like trying to swim across the pool with your jeans and sweatshirt on. Sure you can do it, but you'll probably get exhausted and you might even drown.

Nice analogy. In all seriousness, it sounds like the operational Euro might slide west a little more tonight.

[needbiggerboat]

That sounds like the ECE mean. Have you seen the spaghetti plot as well? It looks like there are quite a few members that have a low just SSE of HAT at 120hr. They're very tightly clustered there. The OP is quite a bit south of that clustering at the same time. Six hours later there appear to be many members (as in too many overlapping circles to count them all) that are somewhere along 74W from just north of HAT to about the latitude of Chincoteague. Six more hours and there appear to be two camps/clusters of members forming. One set is from right over ACY, or just barely east of there, to about 39N/73W. I'd say the majority of this cluster are right around that 39N/73W spot. Meanwhile the second cluster of solutions is doing the OP's elongation thing along an ENE axis that starts at 35N/73W. I'd say that it's a significant minority of the members that look similar to the OP. The next six hours shows a ton of spread, but the OP is very clearly on the southern edge of the ensemble spaghetti.

Still, for us, only a tiny fraction of the solutions would be good. I'd think we'd be in the game if that first camp above were to verify and if it were 80mi further west. Of course that'd mean that it didn't really verify, but whatever...

ncep 12z ensemble also has a preponderance of not so good tracks

[usedtobe]

ncep 12z ensemble also has a preponderance of not so good tracks

Where's you find the tracks? I need to bookmark the site.

[PhineasC]

GFS looks set up to miss.

[needbiggerboat]

Where's you find the tracks? I need to bookmark the site.

NCEP/EMC

[WinterWxLuvr]

GFS looks set up to miss.

Almost looks like its going to crank up a second storm? We sure are lacking any consistent solutions. I guess that's good if it's showing something we don't want.

[psuhoffman]

That sounds like the ECE mean. Have you seen the spaghetti plot as well? It looks like there are quite a few members that have a low just SSE of HAT at 120hr. They're very tightly clustered there. The OP is quite a bit south of that clustering at the same time. Six hours later there appear to be many members (as in too many overlapping circles to count them all) that are somewhere along 74W from just north of HAT to about the latitude of Chincoteague. Six more hours and there appear to be two camps/clusters of members forming. One set is from right over ACY, or just barely east of there, to about 39N/73W. I'd say the majority of this cluster are right around that 39N/73W spot. Meanwhile the second cluster of solutions is doing the OP's elongation thing along an ENE axis that starts at 35N/73W. I'd say that it's a significant minority of the members that look similar to the OP. The next six hours shows a ton of spread, but the OP is very clearly on the southern edge of the ensemble spaghetti.

Still, for us, only a tiny fraction of the solutions would be good. I'd think we'd be in the game if that first camp above were to verify and if it were 80mi further west. Of course that'd mean that it didn't really verify, but whatever...

Not sure I understand this part. The op run of the euro even gets some precip up into DC. I am not sure how then a cluster of solutions that is west of the op would not be a good solution for DC. The op run was not a miss by hundreds of miles. Furthermore, unlike the last event this is not likely to have as tight a gradient. The track of the h5 features is actually pretty good and much further west then the SLP track. The track you mentioned for the west cluser of the ece seems similar to the slp track of the 18z DGEX and that gets significant precip very far west, all the way into the ohio valley, due to the track of the upper level energy. Im not sure in this type of system evolution that we need the slp to track as close to the area as we would normally to get a good snowfall. Now if we want a HECS then yea we would need it to hug the coast more but if 3-6" would make us happy that western cluser of the ece might do the job.

[Ender]

Not sure I understand this part. The op run of the euro even gets some precip up into DC. I am not sure how then a cluster of solutions that is west of the op would not be a good solution for DC. The op run was not a miss by hundreds of miles. Furthermore, unlike the last event this is not likely to have as tight a gradient. The track of the h5 features is actually pretty good and much further west then the SLP track. The track you mentioned for the west cluser of the ece seems similar to the slp track of the 18z DGEX and that gets significant precip very far west, all the way into the ohio valley, due to the track of the upper level energy. Im not sure in this type of system evolution that we need the slp to track as close to the area as we would normally to get a good snowfall. Now if we want a HECS then yea we would need it to hug the coast more but if 3-6" would make us happy that western cluser of the ece might do the job.

You're already confident of the H5 feature's track "saving the day" as a worst case scenario that could result should the OP run prove to be the "most correct" solution? That's brave.

[real]

This is quickly turning into a depressing situation, after this period has been talked about since nearly XMAS as one of our better opportunities. If nothing here, I am becoming resigned to the fact there very well may not be a 6 plus inch snow this season in D.C.

[psuhoffman]

GFS looks set up to miss.

That first wave is not the storm, that is going to wash out with the PV there

Its the energy from out west that needs to evolve better and the GFS is washing it out on the 12z and 18z runs versus allowing it to amplify on the 0 and 6z. Still the track of the upper level energy is good just need things to adjust some.

[TowsonWeather]

This is quickly turning into a depressing situation, after this period has been talked about since nearly XMAS as one of our better opportunities. If nothing here, I am becoming resigned to the fact there very well may not be a 6 plus inch snow this season in D.C.

Yeah. Still a ways to go of course, but this just feels like another kick in the teeth. This winter is killing me.

[psuhoffman]

You're already confident of the H5 feature's track "saving the day" as a worst case scenario that could result should the OP run prove to be the "most correct" solution? That's brave.

sorry I guess what I meant came out wrong...

I mean if the western cluster of the ensemble is correct... with the track of the H5 energy being what it is I am confident that precip would make it into DC. If the op run is correct not so much.

[PhineasC]

Wes makes me cry.