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

Thursday, April 28, 2016

The BIG Winter Recap - Part II - Northern Ohio (Summer Thoughts)

The last "cold" morning in Ashtabula this winter
The strongest El Nino since 1997-98 and a stable arctic tempered the cold of the last two winters. Temperatures across northern Ohio were well above normal with below normal snowfall similar to the winters of 2011-12, 2001-02, 1997-98 and 1982-83. Two of those three were strong El Nino winters.  Our outlook last fall was for above normal temperatures and slightly below normal snowfall.

Above normal temperatures were more extensive across the US. According to the NCDC, global ocean temperatures were at record levels.  (See PART I of my winter recap for other drivers)

Given the panhandle storm track forecast back in September/October, we were very confident that we would get hit with at least ONE big general snowfall which would boost snow totals into the 50-55 inch range. Overall, the heavy snowfalls stayed south and east of northern Ohio which kept our totals even lower. Those big snows came VERY close to northern Ohio!


How does this winter compare to the last two cold winters? How does this compare to the similar winter of 2011-12?  Here are the final tallies.  The same metrics used in last winter's winter recap were used this year to keep everything consistent.

Everyone thought winter was over until our early April snowfall. The April snowfall was almost 24% of the entire winter total; second highest ever!

 Lake Erie Ice Cover reached a peak of 75% for a few days in mid February.

 That's a bit misleading as the peak ice cover went from 3% to 79% in 3 days! In 11 days, it dropped to ZERO in a week and a half.  GRAPH BELOW

Ice cover was thicker and more widespread for much longer last winter.  For comparison, last year it took 28 days to reach 94% and it stayed above 90% for 47 days. Whereas in the winter of 2011-12 (similar to this winter--see above), ice cover reached 13%, only 6 days above 10%.  

Ice cover during the last big El Nino back in 1997-98 was even LOWER than this year. A whopping 8.4% maximum!

Will the leftover winter El Nino play a role in our summer temperatures and precipitation?  Will El Nino continue to weaken?  If so, how will this effect the summer and upcoming autumn? Will severe weather occur more frequently?  Summer Outlook coming up in a few days!  Check out fox8.com 

Wednesday, April 20, 2016

The BIG Winter 2015-16 Recap - Part 1

The winter is finally in the books. I delayed the publishing of the recap because of the snow earlier this month. Since I have so many images and analysis to show, this year's recap will be in two parts. So here we go...

So what did our Winter Outlook illustrate back in October?

Based on the developing El Nino (warmth more basin wide vs 1998 which ended being one of the strongest El Ninos in recent memory), the position of the warm and cool pools in the northern Pacific and Atlantic, our forecast was for a strong, southern jet stream (storm track) for the December-February time period.  Temperatures would be below average in the deep south with above normal temperatures centered in the midwest, upper Great Plains with slightly above normal temperatures for Ohio and the Ohio Valley.

During the early fall, 1997-98 became a stronger analog as the El Nino strengthened  Many used the El Nino split jet stream history formula (including myself) as a guide to this upcoming winter. Not all El Ninos are alike but we felt that this assumption was solid given past history.

Here are the December 1997 through January 1998 jet stream wind speeds anomalies (compared to average) on the left with the associated precipitation rates on the right side.  I labeled the parent lows and highs for guidance.  I circled the areas of heaviest precipitation ALONG THE WEST COAST AND SOUTHERN STATES/MID ATLANTIC

My December blend (issued back in September) was created using 1997-98 and other years showing the positions of the highs and lows at 500mB (steering current level).  The winter 2015-16 southern jet stream position was positioned further south than above.  I believed the southern jet would be a driver early on...

Our snowfall for northern Ohio took this "panhandle storm track" into consideration by calling for snowfall slightly below normal (65") but higher than the strong El Ninos of 1982-83 (38") and 1997-98 (56").  We figured it would take one or two bigger snows to bring this total to reality.

HOWEVER, the southern jet was nullified by the east coast ridge in December.  It stayed well south until January.  Even then, panhandle snow systems stayed close to the east coast and the mid Atlantic.

300mB Zonal Wind
The Pacific northwest received above normal rainfall in December from storm systems that rode over the northern Pacific high pressure cell north of Hawaii. Gulf moisture fed above normal precipitation in the cornbelt.

By January, the southern jet was established but was deflected south by the west coast ridge (high pressure). Above normal precipitation was confined to northern California, Mexico and the deep south. Notice the BELOW NORMAL precipitation over the Ohio Valley. February precipitation was not much better.  The one exception was the historic snow that hit the Mid-Atlantic in late January (see below).

We forget how close the heavy snow came to northern Ohio in Late January.

Snow Forecast for January 22-24
The storm track kept the snow south through Kentucky, West Virginia, Maryland and parts of New England.

As for the winter temperatures, temperatures were in-line with our forecast for the northern states. In the deep south, they were warmer than forecast.

A far cry from last winter (2014-15)...

...yet very similar to the winter of 2011-12 (MORE ON THIS COMPARISON FOR NORTHERN OHIO IN PART 2)

Much of the Great Lakes had well below normal snowfall. Portions of New England it was the opposite.

Seasonal Snowfall
How did this winter compare more specifically to last winter and 2011-12 (recently the most similar winter) in northern Ohio?  Head to PART II for the details >>>