This is December Right? Yes.

First of all, that’s 4 years down. Many more to go. No doubt the blog will morph and adapt along the way, but I enjoy sharing the weather I and everyone else encounters. Thanks for the support, interest, and kind words along the way! Lets keep this short, because we may have a surprise late this weekend/early next week.

Short and sweet, Monday may bring a decent amount of snow that we have missed for a whole year. I say this with better confidence as two major weather models have come into better agreement with a solution. The GFS has been showing a possible storm in the Great Lakes for the better part of 3 days, and the European ECMWF model has strengthened from it’s previous run.

Why does agreement matter? Each model is created with equations all about our atmosphere and earthly relationships. However, they are different and each have their own bias towards one type of weather or another. This is good for different scenarios and what-ifs. Comparing models and using forecaster sense is what nails down forecasts. If some models are coming into line with each other, it is reasonable to believe the weather may occur. So lets have a peek.

GFS continues to have the strongest storm. It has trended south, as the original path a few runs ago had a swath of snow north of Michigan. More recent trends have a swath of synoptic snow (the best type in my opinion, based off the development of a low pressure system) across SW, central, and northern Michigan.

The system looks to develop off a surging trough out of the northwest. This trough will dig very deep into the deep Southwest with an interesting ‘double dip’ looking vorticity layout (will need to look into that more!).  The trough continues to dig and eventually a low forms over the Texas Panhandle. While it may not be an authentic Panhandle Hook, moisture from the Gulf of Mexico will be tapped, and further fuel the system during a process called cyclogenesis, the strengthening/development of a Mid-Latitude Cyclone.

Where the storm center tracks will have a large effect on position of rain/snow and any precipitation at all. This also will change timing of the system. As of Wednesday night, the storm looks to track from north Texas into the Great Lakes region with a center over Northwest Ohio at 996mb, a fairly nice pressure for a system.

Capture

 

The storm does not enter the occluded phase until it is up into the far Northeast. This is where it looks to be the strongest, but potential snowfall looks very decent for our area. Analyzing this same run on the GFS, a line from Grand Rapids, to Mount Pleasant, to Bad Axe could end up with a 8+ inch event. This happens to also be riding the rain/snow line.

That is a very scary place to be. As well as near the dry slot. I’ll use a filled popcorn container as an analogy. You want as much popcorn as you can get for a long movie. So you, or the person behind the counter, try to fill it to the rim, and beyond. But if you put too much popcorn on top, it will all fall over and make a mess. This is similar in that the rain/snow line has strong moisture transport and cloud depth for very heavy precipitation. However  if you go too near this supply, latent heat from condensation and the general surging of warm air from the south will toss you overboard into liquid precip opposed to frozen precip.

That last paragraph is ultimately what sums up heavy snow to no snow for every event. These effects are often based on the small side of meteorology, and it is hard for models to predict. It is often proven taking a look at post storm snow accumulations. Perhaps that swath of heavy snow is smaller, or placed south/north of the forecasted position.

If this all turns out to be hype, I apologize. At least I got to dump a little weather ‘behind the scenes’ for you and want to do more of this (jet streaks perhaps?). A key rule of thumb is to wait for the storm to enter the landmass before making any huge calls. In this case, we still have a day or so before that happens.

Happy snow wishing!

Advertisements

About gweatherc
Live in Michigan and enjoy observing the weather. Want to pursue it as a career! Currently taking classes at Central Michigan University.

One Response to This is December Right? Yes.

  1. Peyrefitte Jr, Ashton G says:

    Greg,

    Very nice blog—first time I’ve ever heard the expression “Panhandle Hook.” I talked about the Petterssen Equation in Current Weather as the grand achievement of Synoptic Meteorology; it can beat a 12-hour forecast of the models, being evaluated directly from the charts.

    A.P.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

%d bloggers like this: