Wednesday, February 8, 2012

February 14-18 Possible Significant Snowstorm (Midwest, Northeast Affected)

Storm Level: Level 4: Major Storm Possible with large accumulations possible


I am tracking the potential for a major snowstorm to strike the Midwest and portions of the Plains going into February 14-18. This discussion will involve the weather models as well as teleconnections.

12z ECMWF Hour 192

12z ECMWF hour 216
Does the Hour 216 image look familiar to you? It should, because it is extremely similar to what we posted yesterday (click here) in yesterday's discussion. Either way, the ECMWF is now trending this storm and bringing it through the Plains and Midwest. It looks like the ECMWF is anticipating the storm to result from a phasing of two systems seen at hour 192. The way the system progresses from Arkansas to Ohio makes me think that a Southeast Ridge may be in place, emphasis on 'may'. While it does appear the ECMWF is showing a ridge over Cuba, I do not want to speculate as I am not seeing any big evidence of a ridge.
The ECMWF is indicating that the NAO may be moving from negative into positive, meaning that we will likely see neutral effects of the NAO. We will discuss teleconnections later.
Verification of today's 0z runs
To give you an idea of how accurate the ECMWF can be, this is a verification chart relating to this morning's 0z model runs. While the GFS, CMC, NOGAPS models have troubles with verification starting at hour 36, the ECMWF model stays rock solid through at least hour 120 (the closer the model is to the bottom of the line indicates its better accuracy). For that reason, I believe all ECMWF runs are very much worth watching for this storm. It is also reasons like this image show why I throw out the NOGAPS model and the GGEM (CMC) model if it's doing bad on these charts.

12z GFS Hour 252
The 12z GFS takes the storm through the south and bombs it out on the Northeast. What I find here is a prominent +PNA pattern in some aspects, like the storm tracks. However, that is not exactly confirmed by the model's calculations and this general image above. The MJO appears to be similar for GFS/ECMWF. So what is the problem? Accuracy.
Using the image I put up above of the verification, it is obvious that the GFS is having problems. It was showing a major snowstorm for the Midwest a few runs ago, and seeing this sudden shift leads me to think that it is entering a time of turbulence typical of models in the long range. In summary, I am not buying the 12z GFS solution, even though it obliterates the coastal Northeast with over 12'' of snow.

PSD Ensemble Hour 264

PSD Ensemble Hour 288
The ESRL PSD 0z Ensembles are showing the system as well and mainly keep the entire northern US in the potential for snow, judging by the rain/snow line (red line on the left images). The right images are of the 500mb level. It looks like the PSD Ensembles are indeed showing a storm in this timeframe, indicated by the dipping yellow lines in the Great Lakes and Midwest. Going back to the point of a possible Southeast Ridge I mentioned after the 12z ECMWF images, the PSD Ensembles are not portraying any major ridging in the Southeast per the median line, marked in yellow. A closer look, however, shows individual PSD Ensemble Members indicating some Southeast Ridging going on, so that will have to be closely watched.

As for teleconnections, we have the PNA forecasts on the top and NAO forecasts on the bottom, with the ESRL/PSD and NCEP forecasting on the left and right sides, respectively.
The NCEP sees the PNA mainly keeping a neutral or slightly negative stance into the storm's timeframe. The ESRL has a major negative PNA in place, which would keep the warm air in place across the US. Because it looks like the PNA index initialized incorrectly for one or both agencies, I will not be making a judgement on it right now.
The NAO, however, appears to have a general neutral consensus for the storm's timeframe, possible just coming off a negative NAO. I have a feeling that this slight -NAO period would still linger some effects into the storm's timeframe, which may be why the ECMWF is nudging the storm towards the coast after the Midwest, but nowhere near as drastic as the GFS displays, which looks to equate to a raging positive PNA, storm track wise, which is not what we will be seeing.

Caveats of this storm:
•Still very much long range.
•All models, including the ECMWF, are still subject to major changes.
•NOTHING is set in stone.

Tips of this storm:
•I recommend the ECMWF for model guidance.
•Watch the NAO/PNA closely in this timeframe.

If you have any questions, you may ask them below.
~Andrew

31 comments:

Anonymous said...

What are your preliminary thoughts on the amount of snow for the Milwaukee - Chicago area for this storm?

Aran said...

Do you think Valparaiso could be hammered by this?

Anonymous said...

Andrew,
Would southern mn be in on this or is this too south and east of us as been the case all winter when it did actually snow.
Thanks Amy

Alice McDonald said...

How many storm levels are there? (I've been here long enough, I probably should know that, but I don't). And thanks, Andrew.

mike paulocsak said...

Hello Andrew.As the way it stands for now,would I receive heavy snow from this or not?

ERN WX said...

Will watch this one.

ERN WX said...

Light snow falling attm.

eddie said...

probably will not happen we have seen this a thousand times this winter

Anonymous said...

I have to agree, this is weak this winter looks good but has no show to it. 3-6 inches is weak stuff.

Anonymous said...

I agree eddie and anonymous.It will be rain if it does occur.

Anonymous said...

Lets all not get our hopes up. THis more then likely will just be a rainy system. 1-3inches of snow. To me it looks whimpy on graphs.

Anonymous said...

Let's all wait until next winter for the BIG STORMS!!!!!!!!!!!!

Anonymous said...

It will rain,then the colder air will filter in after the storm leaves then a tiny bit of snow.

Anonymous said...

I hope the 12z gfs model is right I want a blizzard for the Northeast. But keep up the good work Andrew

Anonymous said...

Hey Andrew, Who does ohio look for this storm system? Your thoughts?

Anonymous said...

will nyc be involed in this

RockerRefuge said...

Great post, but I do have one simple question I'd like answered... what site do you get your verification graphics from?? Seems like a handy model...

ERN WX said...

Andrew, excellent post! I really think folks should watch this one. I am currently receiving some light snow and have a coating of it. I want the 12z ECMWF solution to occur for my area this Saturday!!! At least it looks like a period of snow showers/snowsqualls. We need a 985 mb low 250 miles off the coast! I am still confident Easterners and folks from the Ohio Valley/Midwest get a good snow. The 14-18 storm may be it!?! We need a -NAO! This year has been so rough for forecasters. 2012-2013 looks really good for winter! Low sunspot cycle!!! Thanks for what you do.

Anonymous said...

Andrew, Henry's big daddy is showing up around the 20th!!! Farmer's Almanac is saying the same thing. This could be IT for the East Coast!!! Folks, ceck the 18z GFS!!!

ERN WX said...

Oops, the comment I posted about the 20th storm, I accidentally posted as anonymous. ERN WX

ERN WX said...

I am too excited about this potential. I95 needs a big snow!!! Eastern weather Light snow continues to fall at this time. Snow accumuation, 0.4 inches. Need more!!! We NEED A GOOD SNOW!!! I Am GOING CRAZY DUE TO THE LACK OF SNOW!!! If you have a green lawn in winter, it will be brown in summer. Folks in the Midwest, Ohio valley, Mid atlantic, and northeast have gotten too little snow.

ERN WX said...

NOGAPS tends to get excited about coastal storms.

mike paulocsak said...

Hello Andrew.I could go for a 2003 President's Day Blizzard right now.It will be the 9'th year anniversary in a week!

ERN WX said...

Mike, same here!!! That dumped almost 30 inches at my house!!! WOW!!! I just got 0.5 inch of snow. Sad when that is something to get excited about! Have a good night, Mike.

ERN WX said...

Andrew, have you looked at the possible Saturday storm? The 12z ECMWF wants to give my area something good in snow terms. Henry, would love to see bombogenesis occur off the coast. I guess will wait and see what the Euro says tommorow. Thanks for the fabulous work you do. I see you have a tremendous amount of skill. Also, I got 0.5 inches of snow. I just want to report it to you.

mike paulocsak said...

Hello Andrew.I was checking out the GFS ENSEMBLES for the 24'th of this month,and they show an HUGE amount of snowfall for the Ohio area eastward.I don't know how reliable this is but it's worth watching as time nears this event.

mike paulocsak said...

Hello ERN WX!! You have a good one also.I was checking some GFS ENSEMBLES out and they are very interesting that week you mention the big storm Henry mentioned.It shows heavy snow in Ohio eastward.All we can do is wait and see if it happens.Hopefully we can pull off at least one big storm before spring arrives.Take care!!!!!

Andrew said...

Anonymous #1: Too early to tell.

Aran: Right now, it looks pretty dicey.

Amy: It might be too far south, but the storm track and strength of the storm will determine a lot. Both are undetermined at this point.

Alice: I actually just thought of them and I am testing them out. There are 5 levels. I will publish a post on it shortly.

Mike: As of now, it is very dicey with a lot still left to work out.

Eastern WX: Thank you for the report.

Eddie: No- not with this strength and this much trending on the ECMWF.

Anonymous #2: 3-6 inches is classified as a snow event.

Anonymous #3: I'm not seeing why you are giving into that so early. It all depends on strength, timing, location, and a lot of other things.

Anonymous #4: I'm wary of the GFS as it has been flip-flopping around too much for my liking. I guess we will see.

Anonymous #5: Ohio looks very dicey and will have to be watched.

Anonymous #6: Possibly. Too far out to determine right now.

RockerRefuge: First date selection area on the right hand part of the screen:
http://www.emc.ncep.noaa.gov
/mmb/gplou/emchurr
/glblgen/

Eastern WX: Unfortunately, a -NAO doesn't look to be in the cards for this storm. We will have to see though.

Anonymous said...

I really think we need to focus on a storm during the week of the 20-26.

Andrew said...

Anonymous: That is too long range.

Anonymous said...

what about richmond va weve had nooooo snow will we get any this year?