Potential Great Plains Blizzard Sunday-Tuesday?

[Danny Neal]

haha i guess if what is appearing is holding up i will be skiing to my finals on friday on the west side of CHI, whats normally a 45 min drive will be more like 4 to 5 hours!!!!!!! haha mike h if u come around here ill look for you on the side of the road.....just look for the 19 yr old with a backpack skiing to class

 

[rdale]

Pretty sure those snowfall maps use 10-1 ratio which of course is way overboard in this case, I'll automate output from the Cobb GRR algorithm tomorrow...

 

[Joel Wright]

Pretty sure those snowfall maps use 10-1 ratio which of course is way overboard in this case, I'll automate output from the Cobb GRR algorithm tomorrow...

The 10:1 ratio may be questionable near the rain/snow line, but just a bit further west where the cold air will be deep I think that should be a pretty respectable ratio. More of a concern for amounts is the unseasonably warm temps that have been in place for over a week now keeping the soil relatively toasty warm.

My main concern at this point is exactly where the meat of the snowband is going to line up. Personally I'm liking things now, but 24hrs from now it may be a different story...

 

[Brian Stertz]

Somebody in C.Illinois up towards the Chicagoland area will be measuring snow with a yard stick on this one. Wow what a bomb out on Thursday !! Nearly 240 dm height falls by late Thursday into Friday morning with a deep surface low over Terre Haute IN by 12z Friday morning. Will have to monitor severe wx potential as the system gets cranked up on Wednesday and into Thursday.

 

[Robert Dewey]

00Z GFS is slightly further east than the 18Z GFS - just a sign that the models are still guessing. Latest 00Z GEM is pretty flat and very far to the east. Right now, I would put a potential track anywhere from central IA all the way to PA. Pretty broad, but with such variation in the ensembles and discontinuity, I think we'll be waiting until the 36-48 hour period before nailing it down within 50 miles or so.

As for ratios... 10 to 1 looks good for the areas with 850MB T's in the -6C to -8C range, which lines up well with the highest QPF on the NAM. If that NAM run was 12 hours before the event, I'd call for 12-18 inches near the Chicago area with isolated higher amounts, then adjust as needed. But... It's still +90 hours out.

 

[Robert Dewey]

Hmm... I know I said I wouldn't be paying too much attention to off hours models, but there are some pretty big changes. The 06Z GFS doesn't even have a system anymore, and the 06Z NAM is considerably eastward. We will have to see what the 12Z models show - hopefully there's still a system left.

 

[Andrew Sorce]

These large variations are getting a little frustrating, however if the models trend the way they have, I won't see much of anything. Therefore I'm still holding out hope that the models trend this one further east. Current forecasts would put me in a prime location for a quick high wind event, so I'll take what I can get.

 

[rdale]

06Z runs have no snow (GFS) or 1.5" snow mixed with freezing rain (NAM) for Chicago based on Cobb GRR precip type. I'll post links to all the sites I have shortly, feel free to ask for more...

 

[Danny Neal]

skilling seems to think 50/50 chance of snow in chi town, while other models seem to trend 1-2 inches of rain and others upwards of a foot of snow.....this is all confusing, i wish there was a clearer picture i have to help my grandma out shovelling so it would be nice to see a clearer picture so i know whether head on over there :-/ .......... maybe by late tonight or even tomorrow we will get a clearer picture, first round is supposed to be a quick blast of snow weds night into thurs morning while the NWS and others seem to think IF the secondary wave can get its act together that thursday night into friday NRN IL will be getting snow, they dont speculate on how much and neither will i, normally we luck out on these things, if i had a guess we will get rain, mixed with sleet, and then a couple hours of snow, temps riding along the 35-40 degree line i cant imagine anything more than a couple of inches of snow....

 

[Robert Dewey]

Shouldn't we move over to that thread in the forecast room? I'm moving over to there, and will no longer be following this thread.

 

[Danny Neal]

i thought we used the general wx forum.......i guess i was wrong :-D

 

[Robert Dewey]

i thought we used the general wx forum.......i guess i was wrong :-D

No, the mods haven't stepped in to say either way... I'm using the thread in the forecast room for continuity purposes and because the thread title better fits the event. I don't think we're looking at a SP blizzard anymore ;-)

 

[Jeff Snyder]

To help clear up some confusion...

In the past, we've done things both ways -- multi-day winter events have taken place in W&C and Target Area / Chase Forecasts. The moderating team has discussed this amongst itself several times in the past. As the rules are currently written, discussion of upcoming "significant precipitation" events (snow included) can take place in the Chase Forecasts forum. Note that if a severe weather threat develops in association with a system that is also being discussed in terms of snowfall / blizzard / etc, a seperate thread should be started. One of the sticky points of this is that snowfall events tend to span several days, and we've tried to keep FCST posts to a single day. We've waffled on this a couple of times in the past, but that is how the rules currently stand. So again, you CAN open a FCST thread in the Chase Forecast forum to address significant snowfall events. Please try to be specific of the states involved by using 2-letter state abbreviations (WI, MI, etc -- not "Great Lakes"), since it makes it easier to search for the thread at a later time.