12/22/09-12/25/09 Midwest Winter Storm

[Jeff Snyder]

I think it's fine to forecast as much as you want as long as you understand the generally large uncertainty at these forecast ranges. Given the makeup of the membership of this board, I think that many of us are aware of the limitations of numerical weather prediction at 5-7 days out in terms of specific snowfall amounts and locations. As such, I think we should all just forecast away!

I'm intimately interested in this forecast since my wife and I will be driving on I35 from Oklahoma to Minnesota on 12/24 (Thursday). As such, the specific times of heaviest snowfalls are going to be very important, since it may force us to leave during the very early morning hours of the 24th (e.g. 2-3 am), or it may force us to leave later and hope to miss the heavies snow. Of course, either option may well end up with us having to stay at a hotel on Christmas Eve (EDIT: accidentally wrote "New Years Eve" initially), which isn't really how we'd like to spend our holiday considering out limited time off and the family awaiting us in MN. Now that I think about it, we may be forced to take a "detour" that would take us northward through eastern Nebraska all the way to I90 in sthn SD, which may keep us far enough west to avoid nasty roads. Then again, I'd feel more comfortable on a big interstate like I35 compared to smaller, 2-lane, 2-way US or state highways. Time will tell.

EDIT: From the ECMWF that Mike pointed me to down this thread, I'm not even sure a westerly route will do anything for me given the sfc low forecast position. Fortunately, for me, this is the first forecast so far that has had the sfc low so far northwest. If nothing else, at least pull it farther north to put the bullseye closer southern Minnesota, where I can enjoy the fruits of this storm.

 

[Dustin Wilcox]

The Euro seems to take a track that would favor even more snow than the GFS track, that being said, even the GFS looks pretty fun...

Give us a 1/3 of what the 0Z GFS puts down and I'll be out sleigh ridding on Christmas Eve!

Following trends the next few days will prove fun; everyone will be following this storm super close, people at the office were already anxiously talking about it yesterday!

ADD: LOL 981mb over SW IA.... http://vortex.plymouth.edu/cgi-bin/...lay=no&mo=&le=&va=&in=&pl=ln&ft=h24&cu=latest

 

[Joel Wright]

GEM continues it's consistency in tracking the surface low up to about southeast Iowa. WAA just above the surface looks to really kick in out ahead of the storm. 12z Euro showed that as well. With snow cover in place over much of the Midwest, and a strong high pressure to the north that could spell freezing rain potential.

Just going by the basic trend of the more reliable mid-range models and my "hunch", I'd guess the best chances for freezing rain/ice storm potential will be along and just north of the edge of the current snow cover. That would mean places like northern MO, southern IA, northern IL, southern WI, and into lower MI. Obviously that would place the heaviest snow accumulations further northwest of that. A bit early to make a call like that, but what the heck.

 

[mark plate]

Well my family and I have made the long trip from Tulsa to just west of Green Bay, Wisconsin for the Holidays. I'll be watching this storm with great interest from up here...although with less data than I'm accustomed to seeing. What I can see however suggests that the GFS is likely too fast/far south as compared to other normally more reliable models that I've been able to get a glimpse of. My confidence is into the moderate to high range that a significant storm system will greatly impact the weather here where I am. My biggest concern for here is that too much warm air is going to work its way up here and cause quite a bit of our precipitation to fall as rain...maybe freezing rain for a time if surface temps are cold enough. The official local forecast here calls for all snow, but I'm not sold on that at all yet. Will be interesting to watch things over the next few days.

 

[Mike Hollingshead]

http://vortex.plymouth.edu/gifs/091220062542.gif

May end up needing to be fairly far west in NE Jeff lol. At least maybe they'll all converge Christmas eve ish.

 

[rdale]

I think it's fine to forecast as much as you want as long as you understand the generally large uncertainty at these forecast ranges.

Blasphemy on a Sunday of all days

Ensembles still unsure about transferring energy to the East Coast:

 

[Kevin Crawmer]

The NAM appears like it is going to be a slower solution and take it along a path similar to the GFS a few days ago when it ejects the low into AR/MO and then eastward into the Ohio Valley. This solution yielded heavy snow accumulations in the northern third of MO. It appears like it is the most easterly of the model solutions I have seen and probably shouldn't be taken too seriously. I have read some WFOs aren't buying the NW runs either though...believing instead that it will jump around and ultimately be forced into the Ohio Valley. We will see. I'm not surprised at all to see an outlier, but the GFS/ECMWF have been pretty consistent with what they have been showing for about 36hrs.

Basically, I'm saying I don't have a clue....but hoping for some white stuff in STL.

 

[Jeff Duda]

I've been watching this storm for many days now, and between the last 30 hours of GFS ensemble runs, they've been quite consistent in taking the surface low from NE MO through NE IL (like just NW of St. Louis through just SE of Chicago).

I just took a look at the 00Z ECMWF and man is it different, way different than it had been before. I think that run may be out to lunch, or the first to get it right (you know, like the crazy scientist in those movies who proposes a wild strategy and everyone thinks he's way wrong and doesn't listen to him, then it turns out he was more right than anyone else, even the majority). It has the sfc low sitting between Omaha and KC at 00Z Friday!

ADD: The 12Z GEM shows a storm track farther to the NW than the GFS ensemble, but not as far NW as the ECMWF. Interesting. They're all moving this system farther northwest.

 

[Mike Hollingshead]

http://www.weatheroffice.gc.ca/data...th@america@zoomout_I_4PAN_CLASSIC@012_108.jpg

Canadian liking the 981mb idea too now. Just over in ne MO instead of nw MO.

http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/namer/nam/12/images/nam_500_084m.gif

http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/namer/gfs/12/images/gfs_500_084m.gif

GFS has been trending towards the slower nam through 84hrs. That upstream wave looks a lot more ready to start merging with the lead one on the 84hr NAM than the 84 GFS. Just seems like one should expect more slowing on the GFS and perhaps it is off in the whole phasing aspect.

http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/namer/gfs/12/images/gfs_500_108m.gif

By 108hr they still aren't phased on the GFS while they are on the Canadian and ECMWF. Personally I'd love to stick a fork in the GFS. Figuring something 1/3rd east of ECMWF sfc low towards Canadian's at that 108hr...and phasing like they are.

Disclaimer: Moderate amounts of wishcasting here.

 

[Robert Dewey]

With such a strong high to the NE of us here in MI... I'm starting to wonder if this could be a freezing rain event for us. 12z GEM, even with a much stronger SFC low, indicates this possibility.

 

[Mike Hollingshead]

I've been watching this storm for many days now, and between the last 30 hours of GFS ensemble runs, they've been quite consistent in taking the surface low from NE MO through NE IL (like just NW of St. Louis through just SE of Chicago).

I just took a look at the 00Z ECMWF and man is it different, way different than it had been before. I think that run may be out to lunch, or the first to get it right (you know, like the crazy scientist in those movies who proposes a wild strategy and everyone thinks he's way wrong and doesn't listen to him, then it turns out he was more right than anyone else, even the majority). It has the sfc low sitting between Omaha and KC at 00Z Friday!

ADD: The 12Z GEM shows a storm track farther to the NW than the GFS ensemble, but not as far NW as the ECMWF. Interesting. They're all moving this system farther northwest.

Friday night's run had it pretty far nw.

Saturday morning pretty far nw too.

Looks like Thursday night's run got them closer to phasing. Then Friday morning did late and went mad with strength Chirstmas morning. Then just a slow progression nw and phasing well each run since then. It looks like it has been onto something since Thursday and has liked it. I think that was around the same time the 6z GFS had the deep sfc low in far nw MO where the ecmwf had the deep sfc low on last night's run.

Edit: 12z ecmwf fwiw....still goes north along the MO river. Not as deep but can't see what happens to it during that 24hr gap either.

96hr
120hr

Now to get it to be just a smidge se of that. Thanks to Geukes for the amazing list of models: ECMWF ones: http://models-ecmwf.blogspot.com/ Seems Plymouth is the quickest available on the net.

 

[Chris Heater]

So to make sure im understanding right the models are starting to show a little more consistancy? Still seems the NWSs in my area arent convince of a NW track last i checked

 

[Jeff Duda]

Friday night's run had it pretty far nw.

Saturday morning pretty far nw too.

Looks like Thursday night's run got them closer to phasing. Then Friday morning did late and went mad with strength Chirstmas morning. Then just a slow progression nw and phasing well each run since then. It looks like it has been onto something since Thursday and has liked it. I think that was around the same time the 6z GFS had the deep sfc low in far nw MO where the ecmwf had the deep sfc low on last night's run.

My bad. I meant different from the GFS ensemble really.

 

[rdale]

So to make sure im understanding right the models are starting to show a little more consistancy?

Seems like it's going to be tough to not have a low moving up through western Wisconsin. FIM is firmly on board, but I'd still be hesitant to through out a Michigan path...

GFS showing a very warm and wet day across most of my area, but I'm not ready to buy its solution yet.

http://fim.noaa.gov/FIMscp/displayMapScp4.cgi?keys=fim:&runtime=2009122012&plot_type=mslp_sfc&fcst=126&time_inc=360&num_times=41&model=fim&ptitle=Experimental%20FIM%20Model%20Fields&maxFcstLen=240&domain=236&adtfn=0&wjet=1

 

[Dan Robinson]

In line with what Robert mentioned - concerned about headlines being more from ZR impacts than snow on the eastern/northern quadrants of the system based on 12z runs.