Friday, November 19, 2010

Cold Air and Snow for Thanksgiving Weekend?

We all knew it was coming.  Temperatures have been way too warm for way too long.  This happens in November every year it seems.  We are teased into thinking that winter won't happen or that it'll be delayed for some extraordinary amount of time, maybe until January.  In reality, it never works out that way.

At this time last year, temps were somewhat warm.  This map below is a birds-eye view over the North Pole looking at the surface temperatures.  Northeastern Ohio is on the far left as we look south (to the right). Notice as the temperatures were warmer here in Cleveland, the cold air was building over the north pole.

By Thanksgiving and into the first week of December, pieces of this arctic air began to break off and seep south into Asia and Canada.

By the middle of December, arctic air was pushing into the northern half of the US.

This upcoming week--like a trip to the dentist--will be the wake up call we all knew was coming.  Just like last year, cold air is building over the north pole and Siberia.  All it will take is a strong cold front to extract that cold air sliding into the eastern US and northeastern Ohio.  Here is how I think it will shake down.

Late this weekend into Monday, temperatures will start to climb quiet a bit.  Notice the cold air starting to push south at the top of the following map. (Maps courtesy:

A strong cold will push east late Tuesday into Wednesday producing some rain and gusty winds.

Today (Friday), cold air is slidding over Hudson Bay and is visible with the lake clouds its created on this visible satellite loop (Click image for the animation).

By Thanksgiving, temps will start to fall somewhat...cold enough for some wet snow late.

By Friday and Saturday, the air gets cold enough for Lake Effect snow with a series of Alberta Clippers thrown in for good measure.

The bottom line:  Late next week and into the first half of the Thanksgiving Weekend, many spots around Northeastern Ohio will have a good amount of snow on the ground.  Expect flight delays and slick road Friday and Saturday.

Wednesday, November 17, 2010

How Often Do We See Little Snow in November & December?

The first two weeks of November were about as atypical a November as it gets here in Cleveland. Nine consecutive days with more than 90% sunshine with average temperatures in the upper 50s and lower 60s.  A stretch like this makes the first shot of winter weather that's coming that much harder to take.

Instead of thinking about heavy snow, how about focusing on small amounts of snow for this time of year.  Is it that unusual to have a November and December without much snow?

The chart below shows that 59 of the 111 Novembers since 1901 have had less than 5 inches of snow in northeastern Ohio. While December has only 20 of 111 Decembers since 1901 with less than 5 inches of snow.

So don't think of this November without abundant snow as something unique. If under 5 inches of snow falls in December then make a special note of it because it doesn't happen that often.

Charting Software