December 24-25 Snowstorm

[A-L-E-K]

You will not get a mix.

Bookmarked for possible future bump trolling/praise. You like making firm calls 100+ hrs out, I like that.

[tornadotony]

Yowzers, that 18z GFS...holy crap. Too bad we're still several days out...

[dilly84]

Meh, we've seen huge jumps both ways 100+ hrs out and if a quality met is worried about it cutting far enough north to bring mixing to Chicagoland, so am I.

Not worried. Neither are the NWS mets at ILN, PIT, or CLE

[cyclone77]

I think the excitement level is pretty high due to the fact this is on xmas eve. Not only that, but overall the models have been unusually consistent with this thing so far. We're now getting close to the 100hr mark as well, which is only a little over 4 days away.

[The_Global_Warmer]

Bookmarked for possible future bump trolling/praise. You like making firm calls 100+ hrs out, I like that.

You can save it...if that H5 low amplifies enough to give you a mix I would be stunned...part of it being stronger will also be deeper coming out of the rockies and possibly further south.

I get an amplified solution, the H7 and H8 lows will have to be closed off moving into Iowa for it, I can't see that. This is coming out of the Rockies pretty far south. and if may come out stronger and dive south before a bowling ball cuts north.

So yeah places like me might get hosed on the front end..I can't see a SLP ending up taking a track for that much warm air to get up there....or the UL's.

[jhamps10]

if there's one thing that worries me is how ILX is so aggressive on this one... totally unlike them. heck they have 70% likely snow on Friday... NOT like them at all...

speaking of ILX, here's the afternoon AFD from them:

LONG TERM...THURSDAY THROUGH SUNDAYOVERALL PATTERN BECOMES MORE AMPLIFIED EARLY IN THE PERIOD AS AWEATHER SYSTEM DEVELOPS IN THE PLAINS AND MOVES INTO THE TN/KYREGION. CONFIDENCE HAS INCREASED AS GFS AND ECMWF ARE IN VERY GOODAGREEMENT ON THE TIMING AND TRACK OF THE SYSTEM. BELIEVE PCPN WILLBEGIN IN FORM OF WAA SNOW THURSDAY AFTERNOON IN THE WEST HALF OFTHE CWA...THEN SPREAD ACROSS THE WHOLE CWA FOR THURSDAY NIGHT. ASTHE LOW PRSS AREA TRACKS SOUTH OF THE STATE ACROSS ARK AND INTOTN/KY SNOW WILL CONTINUE ACROSS THE AREA THROUGH FRIDAY. GULF WILLBE WIDE OPEN SO THERE WILL BE PLENTY OF MOISTURE TO CONVERT INTOSNOWFALL. CURRENT INDICATIONS SUGGEST THAT THIS WILL BE A MAJORWINTER STORM WITH SIGNIFICANT ACCUMULATIONS OF SNOWFALL. MODELSALSO BRING IN SOME WARM AIR OVER-TOP OF THE COLD SFC TEMPSTHURSDAY NIGHT...JUST AHEAD OF THE LOW PRSS AREA. THIS COULD BESOME FREEZING RAIN IN THE AREA. HOWEVER...MODELS CURRENTLY AREKEEPING THIS WARMER AIR TO THE SOUTH OF THE CWA...SO THINKSOUTHERN IL WOULD BE THE PRIME AREA FOR FREEZING RAIN AND SLEET.THIS SYSTEM WILL BE CLOSELY WATCHED OVER NEXT COUPLE OF DAYS ASTHIS WILL HIT RIGHT BEFORE THE CHRISTMAS WEEKEND AND THERE WILL BELOTS OF TRAVELERS.

[Thundersnow12]

I think the excitement level is pretty high due to the fact this is on xmas eve. Not only that, but overall the models have been unusually consistent with this thing so far. We're now getting close to the 100hr mark as well, which is only a little over 4 days away.

we will get a look at what the NAM is showing with the 12z run tomorrow.

[csnavywx]

I like what Csnavy and yourself are saying, but doesn't the fact that NAO and AO are in the tank argue against a deeply amplified solution? Or can this "Sutcliffe-Pettersen self-development " process override the unfavorable teleconnections?

NAO/AO is rapidly rising from now until after Christmas. Only borderline weak/moderate negative when this storm comes through, but going beyond the indices, there isn't much of a block left when this thing emerges over the Plains, just a remnant circulation with weak flow over much of E Can/E. US. Real story is the rapidly amplifying pattern upstream, which will translate downstream, and I expect this wave will play a big part in that. Other piece of the puzzle seems to be a PV anomaly heading SSW towards Quebec, and whether or not that system comes in quick enough to suppress the storm track further east.

Getting dry slotted this far north may seem radical at this point, but if this thing does manage to amplify and go neutral tilt west of the MS River, then it's a real possibility. At the moment, I'm liking my buffer.

[baroclinic_instability]

I like what Csnavy and yourself are saying, but doesn't the fact that NAO and AO are in the tank argue against a deeply amplified solution? Or can this "Sutcliffe-Pettersen self-development " process override the unfavorable teleconnections?

Teleconnections are more of a long-term favorable type of weather forecasting. Within the medium range teleconnections pretty much go out the window and dynamic forecasting comes into play. We have had a number of rapid-feedback systems this winter already that have gone against favorable teleconnection patterns. Either way, looks potentially like a fun storm.

[toronto blizzard]

NAO/AO is rapidly rising from now until after Christmas. Only borderline weak/moderate negative when this storm comes through, but going beyond the indices, there isn't much of a block left when this thing emerges over the Plains, just a remnant circulation with weak flow over much of E Can/E. US. Real story is the rapidly amplifying pattern upstream, which will translate downstream, and I expect this wave will play a big part in that. Other piece of the puzzle seems to be a PV anomaly heading SSW towards Quebec, and whether or not that system comes in quick enough to suppress the storm track further east.

Getting dry slotted this far north may seem radical at this point, but if this thing does manage to amplify and go neutral tilt west of the MS River, then it's a real possibility. At the moment, I'm liking my buffer.

Are you saying this storm has the potential to come further north?

[csnavywx]

I meant I think he is dead on with the NW track and slowing due to upstream amplification....not the dry slot.

You're probably right. I'm probably just gun shy after getting burned by so many dry slots. But who knows!? These types of systems are wild-cards.

[Indystorm]

I'd have 20"+ if every 18z GFS solution 100hrs+ out verified this year. Just saying.

Realistically, yes, but wouldn't it be loverly? The good thing scientifically is we are solidly in a Nina and a stormier pattern.

[csnavywx]

Are you saying this storm has the potential to come further north?

Further north than the 18Z GFS? Yes, provided we get that type of cyclogenesis underway.

[csnavywx]

Teleconnections are more of a long-term favorable type of weather forecasting. Within the medium range teleconnections pretty much go out the window and dynamic forecasting comes into play. We have had a number of rapid-feedback systems this winter already that have gone against favorable teleconnection patterns. Either way, looks potentially like a fun storm.

This.

[snowstormcanuck]

NAO/AO is rapidly rising from now until after Christmas. Only borderline weak/moderate negative when this storm comes through, but going beyond the indices, there isn't much of a block left when this thing emerges over the Plains, just a remnant circulation with weak flow over much of E Can/E. US. Real story is the rapidly amplifying pattern upstream, which will translate downstream, and I expect this wave will play a big part in that. Other piece of the puzzle seems to be a PV anomaly heading SSW towards Quebec, and whether or not that system comes in quick enough to suppress the storm track further east.

Getting dry slotted this far north may seem radical at this point, but if this thing does manage to amplify and go neutral tilt west of the MS River, then it's a real possibility. At the moment, I'm liking my buffer.

Teleconnections are more of a long-term favorable type of weather forecasting. Within the medium range teleconnections pretty much go out the window and dynamic forecasting comes into play. We have had a number of rapid-feedback systems this winter already that have gone against favorable teleconnection patterns. Either way, looks potentially like a fun storm.

As always, appreciate the input from the pro mets. We'll just wait and see how this one plays out.

And I agree Csnavywx that the piece of energy dropping through Quebec beyond 96 hours is a wildcard. It could provide enough confluence to shunt the ejecting storm in the Plains more to the east than north. Although I suppose if the timing's right, it could also potentially phase with Plains storm, setting up quite the monster.

[JoMo]

Here comes the dryslot on P004

[patrick7032]

Further north than the 18Z GFS? Yes, provided we get that type of cyclogenesis underway.

I think that will happen too....I like my NW of KPAH to KCMH track.

[okie333]

I like what Csnavy and yourself are saying, but doesn't the fact that NAO and AO are in the tank argue against a deeply amplified solution? Or can this "Sutcliffe-Pettersen self-development " process override the unfavorable teleconnections?

Actually the --AO (by that time the -NAO will be near neutral, but the --AO will still be alive and kicking) would cause a more amplified solution since -AO tends to cause lower pressure in the mid-latitudes (since pressure = amount of air above you, just makes sense that high pressure up north creates low pressure down south... air is not magically created or destroyed). It would also cause a south and somewhat west trend though (probably best described as a roughly S 20deg W trend).

[Indystorm]

and then watch the 0z come back to say OK alek you can double the productivity.... How a lot of folks get so excited or upset from an 18z run shocks me, now if it was a 0Z or a 12Z that's a different story... but the 18z, come on that's like saying the Rams offensive coordinator can actually call up a play of more than 20 yards...

I tend to agree, but I have been surprised and educated by Baroclinicity defending the 06 and 18z runs with sound scientific reasoning in an earlier post in some thread.

[A-L-E-K]

Realistically, yes, but wouldn't it be loverly? The good thing scientifically is we are solidly in a Nina and a stormier pattern.

Amen to that

[Hoosier]

Actually the --AO (by that time the -NAO will be near neutral, but the --AO will still be alive and kicking) would cause a more amplified solution since -AO tends to cause lower pressure in the mid-latitudes (since pressure = amount of air above you, just makes sense that high pressure up north creates low pressure down south... air is not magically created or destroyed). It would also cause a south and somewhat west trend though (probably best described as a roughly S 20deg W trend).

Anyone else not following this post?

[dilly84]

I think that will happen too....I like my NW of KPAH to KCMH track.

So you're going way north then. 300 miles anyways. And I assume you're saying the low tracks NE and not w -e?

Guess at this point I disagree. Haven't seen anything to suggest this much of a north track

[cyclone77]

Here comes the dryslot on P004

That would be par for the course for northern Illinois.

[csnavywx]

Anyone else not following this post?

http://nsidc.org/arcticmet/patterns/arctic_oscillation.html

I think this is what he's getting at.

[patrick7032]

So you're going way north then. 300 miles anyways. And I assume you're saying the low tracks NE and not straight across?

Yeah somewhat....I'm thinking the low will track roughly on a 060 heading....when I saw NW of KPAH I mean from between KSTL and Cape Girardeau to the KCMH area give or take 50 miles....but this is just an early guess and will likely change.

[buckeye]

oh god here we go again.... haven't you guys learned your lesson yet? Remember what happened last time everyone started rattling the cage of the nw gods? 90% of the people here ended up waiting out a prolonged rain event and hanging their hopes on a quick changeover

this thing either stays roughly where it's at, within 50 miles or so...OR...it goes TURBO NW. That's the way it's been this year....suppressed or minnesota.

[buckeye]

Yeah somewhat....I'm thinking the low will track roughly on a 060 heading....when I saw NW of KPAH I mean from between KSTL and Cape Girardeau to the KCMH area give or take 50 miles....but this is just an early guess and will likely change.

man that would be a perfect track for you

[ArmyGreens]

oh god here we go again.... haven't you guys learned your lesson yet? Remember what happened last time everyone started rattling the cage of the nw gods? 90% of the people here ended up waiting out a prolonged rain event and hanging their hopes on a quick changeover

this thing either stays roughly where it's at, within 50 miles or so...OR...it goes TURBO NW. That's the way it's been this year....suppressed or minnesota.

Actually, what it is going to do is shoot a low from central Iowa to NW Ohio which in turn will form a secondary along the Ohio River...

[JayPSU]

Yeah somewhat....I'm thinking the low will track roughly on a 060 heading....when I saw NW of KPAH I mean from between KSTL and Cape Girardeau to the KCMH area give or take 50 miles....but this is just an early guess and will likely change.

So essentially the ideal track for your area which no model is close to. Ok. Could happen I guess.

[patrick7032]

oh god here we go again.... haven't you guys learned your lesson yet? Remember what happened last time everyone started rattling the cage of the nw gods? 90% of the people here ended up waiting out a prolonged rain event and hanging their hopes on a quick changeover

this thing either stays roughly where it's at, within 50 miles or so...OR...it goes TURBO NW. That's the way it's been this year....suppressed or minnesota.

Yeah I remember when I rattled the cage....I ended up being right when I said it would track from north of Peoria to north central or northern Ohio....and that was 102 hours out...the verified track was from the KRFD area to the KFWA to KTOL area....so I was REAL close....and it has not gone turbo NW nor stayed the same....not sure why you think those tenancies have occurred.