Monday, December 4, 2017

Tracking Snow with BIG Weather Changes Ahead

It happens with the flip of a switch every year in the Mid-South. It's not uncommon to go from very warm and stormy to blustery and cold (snowy) all in a matter of a week. That time has arrived for the Local 6 area this week and the big change will happen late Monday Night and Tuesday. 
Warm and windy conditions ahead of a BIG cold front will lead to showers and storms tonight and early Tuesday. While wintery precipitation is not widely expected the stark change will come in temperatures behind the front. This shift in weather dynamics will not be short term. The overall weather pattern will favor a trough (dip) in the jetstream to allow cold, Canadian air to spill southward for several days and favor a few small chances for snow in the next seven days. (Snow lovers clap here!) 
As we switch to this northwest flow regime, the cold air in place and energy swinging down through gives us our first chance at flurries and light snow Thursday night. A slightly bigger piece of energy swings through Friday night and Saturday morning. This will likely be our first chance of lightly accumulating snow especially over Southern Illinois, the Pennyrile of Western Kentucky and the Lakes area. You can see the projected snow areas below. We are still 5 days out from the forecast so this is likely going to change a bit over the next couple of days and it's why I don't put specific snow totals attached to it. Those will be added Wednesday. It is good practice to only show forecast snow totals for specific cities at 48-60 hours out. You'll see that here all season long and it cuts down on error and confusion. 
GFS model output for Saturday morning. Click to enlarge.

Friday, October 20, 2017

Using Folklore to Predict Winter 2017-2018

The beauty of fall can also bring indicators of how the surrounding environment is preparing for the winter ahead. There are two popular folklore that people tend to look for this time of the year. The first being the woolly bear (Isabella tiger moth caterpillars). Their striking appearance usually catches your eye by late summer, thus spreading fears of an overly warm or particularly snowy winter. The fascination is fun but usually doesn't prove scientific unless you happen to find "the one" that lines up with the actual outcome of winter. They vary from region to region and are part of the bristled species of caterpillars which can lead to mis-identification. The image above shows how you can be sure you are spotting a true woolly bear and not an impostor. 
To have some fun with the folklore of the little guy, here are a few tips: 
  1. Woolly bears have 13 segments made of black and orange and are known to represent the 13 weeks of winter.
  2. The front segment represents the start of winter, the middle segments represent the middle weeks of winter, and so forth.
  3. The position and length of the orange bands signify when and how long a warm period (weeks) will occur during the winter. 

Another popular folklore that think of when using nature to predict an upcoming winter is the persimmon seed. When a persimmon seed if cut in half, it reveals a kernel in the distinct shape of a spoon, knife, or fork. Each of those shapes are believed to represent a type of average winter condition we can expect ahead. Here is a guide to identifying the shapes and their meanings:

  1. Knife: Very cold and icy. Winds will "cut" right through you.
  2. Fork: Warm and dry. Powdery, light snow is possible.
  3. Spoon: Cold and snowy. Snow to "shovel" can be expected.

Pictured below is a set of persimmon seeds I cut open this fall that I collected from multiple fruits from a tree at Noble Park. Despite the outlook of a slightly milder winter per NOAA, the seeds I dissected gave the "spoon" and "knife" appearance in most cases. One seed produced a fork-like shape. 
I'd love to see what you are collecting in your part of the Local 6 area so we can compare notes and see if folklore can verify this upcoming winter!