Conditions Far Different This December vs December 2015

The conditions over the higher latitudes at 10mB (65-70,000 feet) are much warmer recently than last November/December...

Hat tip: Peter Mullinax

 ...which translates to higher heights aloft at 10 mB.

Pressure pattern completely the opposite of the polar conditions in early December last year where heights were much lower. Polar vortex was very stable probably influenced by the El Nino.

 Temperatures last December were well above normal across the eastern 2/3 of the US

In fact, over the last 6 Decembers, only 2013 and 2010 were below normal east and/or north.

So far, temperatures in early December through the 5th were above average.

Based on the high latitude conditions at 10 mb (65 and 70,000 feet) mentioned above and the higher than normal Eurasian snow cover which has driven skyrocketing high pressure across Russia, this first shot of colder air across North America was not a surprise.

Nearly Record Setting High Pressure Across Asia in late November

Graphic courtesy Greg Carbin, SPC

In fact, we mentioned this in our winter weather outlook issued back on October 27th and in subsequent tweets on November 22nd and Dec 2nd emphasizing a significant lake effect snow event a week in advance:

The CPC painted its first below normal temperature outlook across ALL of North America for the first time since December 2013. Hat tip: Brian Brettschneider

We haven't had a December with temperatures at least one degree below normal in Cleveland since 2010.

A few days ago (December 6) I retweeted a post from late November highlighting the shifting jet stream position across the middle of the US allowing more frequent storm systems.

Our 8day forecast issued on December 7th and 8th shows these individual systems with high snow potential for northern Ohio through December 16th and beyond.

Anticipate below normal temperatures, overall, the rest of December 2016. 80% Chance for a white Christmas for northern Ohio!

How Rare is May Snow in Cleveland?

Sunday marked only the 12th time since the late 1800s we have had measurable snow in May.  The latest report of snow at a National Weather Service reporting station in Cleveland was May 27, 1907 when we had a trace. Keep in mind that weather reports were recorded at different location around downtown Cleveland from 1870 through the 1930s.  Readings started at Hopkins Airport southwest of the city in the mid 1920s.  

Snow cover in Middlefield, Ohio

It wasn't until the late 1930s when records became consistent and searchable. Officially, we only had a trace at Hopkins Sunday.  850 mB temps were between -5 and -7 early Sunday morning with surface tempertures in the mid to upper 30s.   The rare instances of May snowfall is list below. 

All May snowfall instances recorded at Hopkins Airport (post 1938) and downtown Cleveland 1870 to the late 1930s

Are These Big Spring Temperature Changes Something New?

Many times throughout this spring people have commented to me how they never remember wild swings in temperature in northern Ohio quite like what we've experienced this year.  Rather than assume a specific conclusion, I went back and found the high temperatures for every day since 1975 from March 1st through April 15th and again for April 16th through May 31st. I highlighted each instanced where the day-to-day high temperature change was greater than 20 degrees either. In other words, if the high temperature one day was say 38 and the high temperature the following day was 60, that counted. If the high temperature fell from 75 to 52, that would also count.  Here is what I found.

The number of occurrences haven't varied a lot over the last 40 years between March 1st and mid April. I thought the numbers would have been higher since the late 1990s.

Historically, large temperature fluctuations after April 15th don't occur as often due to the lack of residual cold air left over from winter. So far this year (2016) we haven't had an occurrence since April 15th.

What I found interesting is that the occurrences of day-to-day high temperature drops of 30 degrees is significantly higher than temperature jumps of 30 degrees especially before April 15th.

As much as perceive these fluctuations to be a new thing here in northern Ohio, it is quiet common in early spring and has been for at least 40 years. This is another classic example of the Recency Effect as work.  That is we overly weight in our minds more recent events with greater significance and quickly dismiss events further back in time. Note that these conclusions are derived ONLY from Cleveland temperature data.

Why is PI so important? 2016 Edition

It's one of my favorite days of the year!  A day when geeks of all ages can show off their PI stuff and skills at recitation.  I have PI memorized to 75 digits. Chicks dig it. My wife digs it...so she says. Your kids might have PI day activities planned at school today (Tuesday). I gave my son my PI shirt to wear. Reluctantly, he's going to do it.

I'm sure back in 1737 when Leonard Euler first used the symbol π, he never envisioned the fascination with π that developed since.  There are t-shirts, π plates (yes, I have two), π mugs...and on and on. Novelty websites have just about every π trinket you can think of!

What is PI " π"?

PI is the number that represents the ration of a circle's circumference to its diameter.

As we entered the computer age, the calculation for more digits became a test for computer system efficiency and accuracy. In 2014, scientist Ed Karrel calculated more than 10 QUADRILLION bits (unfortunately not in base 10 units) decimals of PI.  Here is his blog.

The interesting part is that PI is non-repeating and never ending so its very nature is an approximation. Mathematicians have tried to find patterns within π since ancient times. Archaeologists believe that the ancient Egyptians constructed the Great Pyramid of Giza with knowledge of π.  Greek mathematician Archimedes was the first to calculate a range for π  using polygons.

Throughout it's history, π has become a fascination among mathematicians and more recently computer programmers. Welsh mathematician William Jones was the first to use the symbol π to represent the ratio of a circle's circumference to it's diameter in the early 1700s. In the 1940s, a little over 1000 digits of π were known.

As we entered the computer age, the calculation for more digits became a test of computer system efficiency, power and accuracy. In 2014, scientist Ed Karrel calculated more than 10 QUADRILLION hexadecimal digit of PI.  Using hexadecimals make it faster to calculate. Converting hex to base 10 numbers which we all is very difficult when you have these many digits according to Ed.  Here is his blog.

To put the number of digits in Ed Karrel's calculation into perspective, you only need 39 digits of PI to calculate the circumference of the observable universe (assuming it's a sphere) to the accuracy of a width of the inside of an atom!

To put it another way, if you were to recite EVERY digit, it would take you 317,000,000 years to complete. You'd need to start before the dinosaurs were alive in order to finish today!

All of this great if you are a math or computer geek. But why should the rest of us care?

PI is present in every aspect of our lives. PI is used in most calculation in the development of all the world's infrastructure. All communications, CAT scans, MRI machines, genetic research, propulsion systems (space and military aircraft), quantum physics....the list goes on.

Famous scientific discoveries and the math that describes them incorporate PI:

* The calculation for determining the horsepower of your car has PI in it.

* Einstein's famous equations that describe relativity which is now directly applied in
   satellite calibration has PI in it. Here it is in very simple form:

* The math that determines electric force (electricity) includes PI.

*  How about the speed and volume of blood flow inside the first artificial heart? You bet.
    PI is included in that calculation too.

* Want to figure out the position of two planets nearest to the earth? You need PI.

* Radio communications, cellphones, GPS satellites (see Einstein's equation above) computer hard drive/processor technology were both developed using mathematics that incorporates the number "PI".

* Airlines use PI to calculate flying distance around the earth

* Manufacturing uses PI to figure out how much of a substance will fit into a volume
   of circular or cylindrical space


You might not like math. You might not get PI.  Just remember that PI (3.14159...) is integrated into our everyday life unlike any other number. Without it, your daily life would be totally different.