“California Dreaming” is the name of this quilt. That’s what a lot of us in the NE will be doing today as we get hit with a major winter storm.
I was going to talk about forecasting today, but decided that since we are having a big storm to address that topic instead. I will address forecasting next Monday on Groundhog day!
What is air pressure?
You might remember from my first blog about weather that the Earth is surrounded by a blanket of gases that we call the atmosphere (air). This air has weight just like all things have weight on our planet due to gravity. We are located at the bottom of this blanket of air that is about 200 miles thick. That air pushes down on us and all the things on the surface of the Earth. This pushing is what we think of as air pressure. The amount of this pushing can vary from location to location. Some areas have lower pressure and some areas have higher pressure. That means that there is more air abover some locations than others. The difference, however, is very small. But is it enough to cause storms in some locations and beautiful days in others.
If you live along the Atlantic coast of the USA, you are really very familiar with coastal storms called nor’easters. They are major storms for the east coast. A typical nor’easter has a few components.
- It is a low pressure. All the bad weather on our planet is caused by low pressure. Highs bring clear skies and fair weather. So a storm is a strong area of low pressure.
- Not only is a nor’easter a low pressure, but it is a low pressure that gets stronger. That means that the pressure gets even lower. That results in a stronger storm with stronger winds.
- A nor’easter typically has winds that come from the NE (hence why it is called a nor’easter) and moves up the coast toward the NE creating a mess wherever it moves.
- Because it is right along the coast where there is lots of water, we tend to have lots of clouds and precipitation (rain or snow) with it. The storm feeds off of the ocean creating more clouds and huge amounts of precip. You certainly have heard the forecasted amounts for this storm to know that is probably going to be the case.
Lots of people have been discussing other historic storms this past weekend as we have been preparing for the current storm. There is a long list of notable nor’easters. Maybe you remember some of these!
- Great Blizzard of 1888
- Ash Wednesday Storm of 1962
- Groundhog Day gale of 1976
- Great Blizzard of 1978
- Northeastern United States blizzard of 1978
- Late November 1984 Nor'easter
- 1991 Halloween Nor'easter (the "Perfect Storm," combined Nor'easter/hurricane)
- Storm of the Century (March 1993)
- Christmas 1994 Nor'easter
- North American blizzard of 1996
- North American blizzard of 2003
- Atlantic Canada blizzard of February 2004 ("White Juan")
- North American blizzard of 2005
- North American blizzard of 2006
- Late November 2006 Nor'easter
- February 2007 North America Winter Storm
- April 2007 Nor'easter
- March 24-25, 2014
What does a nor’easter look like from space?
These are huge storms that can be a thousand or more across. They have a distinctive shape from space that resembles a comma and hence is called a comma shaped cloud. I have outlined in red the comma cloud sitting along the east coast in this satellite image. This was the Blizzard of March 2014. Can you spot the comma cloud off of the west coast? How about the one entering the NW?
Sometimes a really strong storm even has an eye like feature like a hurricane does. The storm last March had an eye. You can see that in the image below.
Here is a comma cloud from a March 2013 storm that was gigantic. Make sure you click on the picture.
What is a blizzard?
Not only does a blizzard have tremendous snow amounts and cold temperatures, but it also has strong winds. This means winds of about 30 mph or more. Snow and winds can cause all kinds of problems from white out conditions, power outages, flight delays and cancellations, dangerous driving conditions. A blizzard is the worst kind of winter storm. (or is a great ice cream drink from Dairy Queen!)
So if you are hunkered down for the storm today do some California dreaming on such a winter day!
Thanks for reading and stay safe.