Mid-November 2016 Winter Storm Weather Forecast Model Loop - Cold Air Sweeping Through Virtually Entire United StatesRead Now
Over the next few days, much of the United States will be seeing a pretty powerful, early winter storm migrate all the way from the Great Plains to the Atlantic. This storm has already impacted much of the western US, and brought heavy snows and frigid temperatures throughout the inter-mountain west. Now that it's out into the Great Plains and well on it's way to the East Coast (and Gulf Coast), I thought I'd share a cool little loop from the North American Mesoscale Model (NAM) from it's 12-UTC run this morning.
Winter Storm Warnings...even Blizzard Warnings...remain in effect for the upper Great Plains & Midwest...with subfreezing temperatures, strong winds, and heavy snows anticipated.
See video loop and description below:
Equivalent Potential Temperature, also known as Theta-E, is an outstanding weather parameter for outlining cold, dry air masses and warm, moist air masses. When cold fronts pass through, they overtake the warm, moist air ahead of them and replace it with cold, dry air.
Essentially, Theta-E depicts the potential temperature if the moisture were completely eliminated. Warm, moist air has the potential to reach a higher temperature, if the moisture is removed, than cold, dry air. Therefore, it sticks out real well on weather forecast graphics, and points to where the two air masses meet - where the fronts are.
- Meteorologist Dan Schreiber
Courtesy College of DuPage.