Tuesday, May 24, 2016

Memorial Day Temperatures Doing A Complete 180!

Back on May 10th, I posted this long range outlook showing that our confidence of warm finish to the month of May was very high. This was my thinking at the time.

The first 23 days of May were cool not only in Cleveland and northern Ohio but across 85% of the US.

The final 8 days will feel summer like across a 15 to 20 state area.

Who says realistic long range outlooks aren't possible?

Friday, May 20, 2016

The Weather Cast

Some days weather casts flow with metronomic ease. Each segment evolves with seemless precision incorporating sprinkles of down-to-earth science, flawless grammar resulting into an easy to understand message. It permeates the air with the richness of a chocolate cake. Other days it's like driving a dump truck through a nitroglycerin factory with no chance of rescue.  I've blown up a bunch of factories.

Monday, May 16, 2016

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

Monday, May 09, 2016

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.

Friday, May 06, 2016

How big is the largest Alberta Fire?

The Fort McMurray fire as of Thursday May 5th is around 85,000 hectares or 210,000 acres! These comparison to big cities around North America are staggering. Images courtesy Macleans.

The Omega Block in the middle of North America kept central Canada dry accelerating an already dry region from this past winter. Well above normal temperatures surged north.

Omega Block (looks like a double)

More heat this weekend. Some relief is on the way late this weekend as the temperatures will fall back into the 50s.

Saturday high temperatures

Rainfall Sunday into early Tuesday

Cooler air Sunday