Thursday, February 9, 2012

February 14-18 Possible Snowstorm (Issued 2/9/12)

I am in awe at the consistency of the storm strength that the ECMWF has been trending with, so let's get down to it.

12z ECMWF Hour 216
For the past at least 6 model runs, the ECMWF has been consistently showing a strong storm system impacting the Great Lakes and Midwest. In case you did not know, the ECMWF is a very reliable model in these times of model instability (which have moderated recently, for some models). Seeing this trend of a strong storm in the Ohio Valley only increases my confidence in this actually occurring.
Not seeing much of a change from yesterday's 12z runs, as the ECMWF portrays two storm systems phasing into one massive storm system in the Plains that moves north.

12z ECMWF ENS Hour 192
 Today's 12z ECMWF Ensembles show there is still room for change, with the ensembles showing the storm being a more progressive one than the ECMWF model itself is showing. It also does not phase the two systems, which essentially takes power out of every aspect of the storm- warm air advection north, cold air following the storm, precipitation, etc. I do feel that the presence of the storm on the ensembles is a reassuring one, however, and believe that there is a good amount of confidence right now of having this system happen.

12z ECMWF ENS Hour 216 500mb Height Anomalies
I found this image of 500mb height anomalies at the time of the storm. What I am seeing is a big ridge in the Pacific that could very much be a key player here. The reason it is disrupted is due to a low pressure system moving along, but I am paying attention to the main ridge and imagining it without the low pressure disruption in the Pacific Ridge, as the low pressure system really doesn't make a difference- it's the big ridge that counts.
Analyzing the ridge leads me to see that the ridge favors possibly going into the Western US. This would lead into a +PNA-like storm track, which would happen if we didn't have a monster ridge just south of Greenland. What this ridge will do is essentially lift the jet stream north and slice through the Northeast. This slice would bring the jet stream from North Texas through Tennessee and dashing north into Pennsylvania/Ohio. This is indeed the solution that the operational ECMWF is showing.

Model Tips & Caveats
•This is still long range, so the models are subject to major changes.
•The ECMWF has been trending very long, adding a lot of support to forecasting.
•The GFS has been flip-flopping, so I do not want to use it.

Looking through the latest PNA and NAO forecasts from the ESRL/PSD and NCEP agencies on the left and right sides respectively, I'm not seeing anything major. The PNA is forecasted by the NCEP (basically the GFS) to be positive, which could lead to a little ridge over the west US. At the same time, the ESRL/PSD is showing the PNA to be negative. Due to the inconsistency, I do prefer to not comment on it right now.
The NAO forecasts are having slightly better agreements at this point, showing a strong negative NAO around mid month going back neutral around the storm. Seeing as the storm will be arriving when a strong -NAO is just leaving, I would think that some effects of the -NAO would still be lingering. This is agreed by some characteristics of the ECMWF ENS/ECMWF OP models and ensembles. (ECMWF ENS are the ECMWF Ensembles, while the ECMWF OP is the ECMWF model itself.) While both ECMWF ENS/ECMWF OP do not show a -NAO in their calculations, look back to that strong ridge just south of Greenland in the 500mb height anomalies image I showed earlier. A +NAO is characteristic of a trough of low pressure south of Greenland. The height anomalies show a ridge south of Greenland. I believe that this inadvertently shows a -NAO still lingering but not shown in the model forecasts. This would still keep parts of the Northeast in the game.

I am opting to not show the PSD ESRL Ensembles as I cannot confirm that the storm is in the right timeframe or if it even exists in those ensembles.

My Preliminary Thoughts
I'm liking the way the ECMWF has been handling this. While the ECMWF ENS may still be a tad shaky, I am really liking the way the ECMWF has been trending the storm, while keeping the same general placement and strength of this storm through the past several runs. Trending is always a good sign, especially on such a reliable model like the ECMWF. If I had to put a VERY PRELIMINARY guess % chance on if this storm will occur, I would put it at 35% due to model uncertainty in other models and the long range-ness of it, but increased by the ECMWF's trending.

Side Notes:
Tom Skilling, reputed meteorologist in Chicago, IL and a personal favorite meteorologist of mine, has been talking up this storm for the past couple days. He is not one to hype storms at all, so him talking about it this far out is grabbing my attention.

If you have any questions you may ask them below. They will most likely be answered tomorrow morning.


eddie said...

does detroit look to be in the snow (big SNOW)

Anonymous said...

Thanks for the update, Andrew! Because I don't really know how to read weather maps, aside from what a weather presenter might show, what is this forecast currently showing for Ohio, in terms of temperature and p-type? No specifics are necessary, just some direction on what the map is showing. Thanks again!

Anonymous said...

Hey andrew, have been checking your Blog more often these days...thanks for all the info...

Do you think Southern MN will be impacted at all with this storm?

Kyle said...

Fox 59 in Indianapolis mentioned this storm last night also, which is unlike them to talk about a storm this far out.

Anonymous said...

will Charlotte NC see snow from that

Owen12789 said...

Like some of the others I am still not sure how to read these maps real well, and I noticed that another post had Indianapolis in it, so with that being said do you think that this storm is going to give Springfield, IL any snow? Your thoughts would be appreciated.

DLCS said...

NOAA in moline says that this storm may stay south of northern Illinois and that we will be dry, do you see this too?

Eddie said...

My news wxyz in Detroit says 41 and rain

mike paulocsak said...

Hello Andrew.Do you think the low will move northeast through Ohio.The way it looks as of now it will.I know you have to be northwest of the track to get the heaviest snow.150 miles northwest to be approximate.This track would basically leave me snowless.

mike paulocsak said...

Hello Eddie.Same here.

Anonymous said...

More important storm in the 21-26 timeframe!!!!!!!!!!

mike paulocsak said...

I miss the winters in the 1990's.These were AWESOME winters full of snow.

Joshua Steiner said...

Hey Andrew, do you think that Northwest Ohio and Northeast Indiana could be in the threat zone for a major snowstorm, or at least a significant winter storm (of any kind?)

Anonymous said...

what is this storm going to do in northern VT? 0" on the ground sure makes for a tough snowmobile season.

Anonymous said...

Hey Andrew, I was just wondering what the deal is for the area of low pressure that is going to drop some snow for the NE in the next few days (Fri Night-Sat). How much snow for Bethel, CT and is it going to strengthen once it moves out over the atlantic, maybe dropping some more snow for New England?

Thanks, Always,

- Reid

Andrew said...

Eddie: Yet to be determined.

Anonymous #1: Ohio is looking dicey.

Anonymous #2: Time will tell. In over words, it's too early to tell.

Kyle: Intriguing. Thanks!

Anonymous #3: Likely not.

Owen: It's looking dicey right now.

DLCS: I do not know, as we use the ECMWF which does not provide free precipitation forecasts at this moment that we could use for this.

Eddie: Things could still change.

Mike: It appears to be going that way, but things can and likely will change.

Anonymous #4: That is too long range.

Joshua: I am seeing that potential, but it is looking a little unsure right now.

Anonymous #5: You might be able to net a couple inches.

Reid: It looks like a good 3-6 inches in West NY/West Pennsylvania with 1-4 inches across the rest of the Northeast.

Anonymous said...

Yep i called it magically the models just lose the storm. Hmmmm. Never happening this year. People may as well give up on winter just not happening. No such thing as big winter storm this year.

Anonymous said...

Hey anonymous.All we can do is hope next year is more filled with winter storms.

Andrew said...

Anonymous #1: It still shows the storm, but now shows it going into the Northeast.

mike paulocsak said...

Hello Andrew.Is it going to track south of Ohio?A side note,i noticed it's starting to warm up in certain parts of Europe.It's been down right deadly cold over there.

mike paulocsak said...

Hey Andrew.I don't know if your familiar with WGN-TV out of Chicago,but the have an article on this storm today.I read an insert of it on the web.Thae Canadian model takes it south of Ohio,the NWS GFES OPERATIONAL takes it along the Ohio River,and the European slices right through Ohio.It mentions that these are just trends.Quite interesting!!!!!!

mike paulocsak said...

Sorry Andrew i spelled a few words wrong,typing too fast bad habit.