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Jan 12th Winter Storm (1/11 Discussion #1)

US Weather Discussions

Jan 12th Winter Storm (1/11 Discussion #1)

12Z Models continue to raise some questions while answering others. Observations out of the Central Plains are suggesting cold air is filtering in faster with the approaching front, allowing for the change over to frozen precipitation to take place faster. Right now the short range mesoscale models get the front to the OH/IN line by Midnight to 1AM going into Friday. The same models are running the below freezing temps a good 5-6 hours behind this timing, so it is going to have to monitored for an early change over. That’s one item to watch.

Second item is going to be the strength of the surface low moving up from the south. Most models recently were more or less keeping it a relatively weak wave coming through and just treating this as a traditional frontal system coming through. This morning they did start to show a bit stronger system coming up into WV later on Friday. So this could help to bring in some additional moisture and also provide for heavier precip near and to the west of the track of the low.  There has been a slight push back to the NW and if the system trends to be stronger than the previous global models picked up on, the forecasts out there will need to be re-evaluated.

So with all of that, how to the models compare from the morning runs.  I’ll start with a baseline of the 12Z runs and then expand from there since there are new updates.

Global Models

GFS – Image from Tropicaltidbits.com

CMC/GEM – Image from Tropicaltidbits.com

 

12Z Euro drawing. Blue = 2-4″, Pink = 6″+

In general the global models are, well in the some state more or less. GFS has the heaviest snowband closer to I-71, the Canadian has is along southeast of I-71, and the Euro has the heaviest snow in SE OH and WV. So about what we can take from these is that it’ll likely snow, but the amounts might be better left to the mesoscale models that are running more frequently. To be fair, the GFS will have another update around 18Z so we’ll be able to see if it changes any.

The one thing that does stick out on all 3 of these, is a separate area of accumulation to the west of the main area. This is associated with the front itself and the ongoing precip changing over.

Mesoscale Models

So let’s compare the snow accumulations on the short range models. Again, I’m sticking to 12Z only here even though HRRR and HRRRX more frequently and have no updates already.

HRRR – Image from College of DuPage.

The 12Z HRRR is kind of a waste to show, but I did want to make a point that is picks up on post-front snowfall in this image with the accumulations through 7AM Friday.

HRRRX (Experimental)

The HRRRX, an experimental model, does go through 48 hours so it gives us a look of what this more detailed model is thinking. Not sure on the accuracy in these type of setups, but it’ll be interesting to watch. It also shows the two features of the precip behind the front and then the large wave with the storm system.

12k NAM – College of DuPage

12km NAM has the double feature, I guess we can call it, but seems to put more weight into the precip with the front and not so much with the storm system itself. We’ll see if this changes in the 18Z.

3k NAM – College of DuPage

The 3km NAM version is a bit different in presentation than the 12km counterpart, because…reasons. Will say the two images the 12km is showing a 10:1 ratio whereas the 3km is showing the Kuchera method of calculating the snow. Generally the same two areas, but the Central OH zone is a bit more covered when looking at the higher resolution model.

FORECAST

So it now comes down to how will the forecast play out. Still a lot of questions, which is unfortunate for something with in 24 hours, but let’s take a stab at it knowing this could all blow up in the next hour with the 18z model runs.

Here is a general thinking right now and this is going to be impacted a ton by how fast the cold air works in, how much sleet/freezing rain takes place to keep snow totals down, and what happens with the southern low moving up and if it is stronger or trackers more to the west like the model solutions a couple days ago. So we’ll see how things play out.

Quickly wanted to hit on some other hazards with this setup…

Icing / Sleet / Freezing Rain / Not the good stuff on cookies…

There could be a decent icing event just behind the front before a change over to all snow takes place.

Using the 3km NAM here, this is 10AM Friday showing freezing rain from Southern Ontario through the Southeast half of the Toledo metro area down towards East Central Indiana and just east of Indy. It is quite possible to see at least a glaze of ice out of this.

NAM gets a little crazy with amounts, with almost an inch of ice around Toledo (not happening), but it at least shows there could be some freezing rain accumulation.

 

Moderate/Heavy snow and Sleet over much of Ohio by mid-afternoon on Friday. Also notice lake effect bands setup on Lake Michigan and also off Lake Huron.

During this time we could be looking at winds gusting over 30 mph through the area. This is something that has been highlighted on most models the last few days, so even with a little snow it is going to blow around pretty good.

The entire state of Ohio should be clear of the system by 10AM on Saturday…and that will be the very SE portion of the state. Lake Effect will be ongoing off of Lake Michigan so some passing squalls or snow showers for IN, Southern MI and NW OH. Then for NE OH some bands off of Lake Erie. Lake Erie is mostly ice covered right now, so not looking for a major LES event.

Follow twitter @WxStuffUS or on Facebook @WxStuff for intermediate updates through the day. Probably another write up tonight after the 00Z models are in. Also will be writing up the outlook for the Monday clipper system that could bring a few more inches of snow to the Lower Lakes region.

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