Thursday, May 30, 2013

Hurricane Season Begins!

Hurricane season officially starts on June 1st. The National Hurricane Center updated their hurricane season forecast. It continues to highlight above average activity. Here is this year's forecast with comparisons to average and last year:

Why the increase?  First, no El Nino this year.  El Nino's lead to stronger steering current with act to shear apart storms as they develop. 1997 was a great example!

This year, the upper level winds will be more favorable for storms. 

Second, since the mid 1990s, the Atlantic Ocean has been in a "warm mode".  This warm mode is part of a cycle called the AMO or Atlantic Multi-decadal Oscillation. This oscillation switches every (20-40 years).

When its positive or warm, the storms make landfall along the US coast more frequently.

The other more short-term variable is the current water temperatures in the Gulf of Mexico and atlantic ocean. Notice how warm these waters are running this early in the season. This favors early season storm development along the Gulf Coast and Florida.

In fact, the GFS is showing some development in the Gulf of Mexico by the middle of next week. Something to watch for sure!

Tuesday, May 28, 2013

Why Can't We Handle Probability in Weather Forecasts?

Our minds don't easily handle probability. Complex systems like the global economy, the financial sector, ecosystems or quantum mechanics are riddled with counter-intuitive randomness. We can visualize the movement of an electron as a point particle flying around a nucleus of an atom. Yet the real picture is filled with uncertainty. The electron's existence is a hazy cloud of probability. Its nature is not just a particle but BOTH a particle AND a wave! Say what? 

Much of our human experience is filled with such truths. We especially hate probabilities in our weather forecasts. Why? For our minds to grasp probabilities, we need to be able to handle multiple possible outcomes at once. Just our luck, weather has many, many outcomes over a large area over a significant period of time. Change the initial weather conditions (humidity, wind flow, frontal position, upper level energy, etc) and you create more uncertainty. Factor in time and the probability becomes significantly higher.

Typically, our brains work much better with a theme that is linear: A story that has a beginning, middle and an end. We want to visualize a line of showers that moves in at a specific time, stays for a select amount of time and then moves out without fanfare. Unfortunately, rain events rarely behave in this manner.

Here is a quick radar loop from May 28, 2013. Notice the disjointed nature of the rain/storm clusters and how they evolve. Some smaller cell develop independently of the main cluster. I guarantee that by the time they made it to Ohio, they looked nothing like what you are seeing here.

The radar loop above is an excellent example of why—much to the chagrin of the general public—probabilities are the only way to tell the weather story. We use 90% chance of rain, 40% chance of rain, etc. Yet if it doesn't rain over their house when the probability is 90% chance of rain, the forecaster is wrong even if the rest of the area was hit with a good downpour. We want to know if it will rain or not; a black and white scenario without caveats. Yet the behavior of some small scale weather events like warm frontal rain/storms can behave semi-independently of the overall large scale pattern. I’ve tried multiple times to convey this idea on the air. The explanation of small scale rain clusters as behaving somewhat “on their own” falls on deaf ears.

It all goes back to basic human nature. A good weather narrative (a feel-good forecast with some folklore) is desired versus something data/science driven. Nebulous weather data and science makes most of us feel uncomfortable even if the on-air meteorologist has the best of intentions. We have created some sophisticated models of the weather that can make some very good “probabilistic” outcomes for weather events and situations. Yet a level of uncertainty still remains and we humans don’t like it!  We try to rationalize the irrational. Our biases quickly dismiss the probabilistic science as irrelevant or at the very worst, an excuse.

Instead, we favor more simplified stories even though that story might gloss over important details. Our minds involuntarily cherry-pick elements of the story so that it fits our biases. Think of a time when someone told you a weather fact or forecast which you didn’t believe. You felt uneasy. Your mind shrugged it aside only to be replaced by a story, forecast or explanation that made you feel better…accuracy be damned.

A great financial blog called The Big Picture written by Barry Ritholtz explains the narrative vs data idea succinctly: (I inserted the weather components)

* Narratives (straight forward simple weather forecasts) are about hitting emotional buttons making the reader feel good by focusing on less qualitative aspects (weather science and probability) of an issue.

* Narratives (weather forecast) are/is about the outcome not the process (explanation of the science and probability)

* The process (weather science) is important in developing solid results

 So remember the psychology. How you react when you hear a weather forecast?  Do you dismiss the science? How do you handle probability?  Do you like hearing an explanation to why the weather does what it does? Do you overly simplify the weather? Are you aware of your biases?

The science of the atmosphere is never as straight forward as we'd like it to be…and never will.

Friday, May 24, 2013

Summer Must Be Over! 80s to 40s in late May

Photo courtesy: Scott Sabol, May 24th as temps hovered in the lower 40s

Before eating dinner, I had to look up the instances where we had high temperatures in the 40s AFTER May 24th (today's date). Here they are...

5/29/1984    48
5/25 & 26/1979   49   49
5/25/1925    46 & 47
5/31/1910   46
5/27/1902    49

The bigger question...what were the high temperatures like in these years DAYS BEFORE we plunged into a late fall chill? Has there EVER been an instance where we went from the mid 80s to the mid 40s in a few days this time of year?

YES! It happened in 1925 and 1902

1984:    63 and 55 before we dropped to 48
1979:    72 and 56 before we dropped to 49 and 49
1925:    85 before we dropped to 46 & 47
1910:    69 and 57 before we dropped to 46
1902:    88, 77, 74, 68, 65 before we dropped to 49

What about the last few days?.....

83, 87, 85, 74 before we dropped into the mid 40s late yesterday....daytime temps today have yet to recover!

This marks the ONLY time we've gone from three days in the 80s to the mid 40s in less than 36 hours this late in the spring!


Thursday, May 23, 2013

High Resolution Image of Post-Tornado Moore, OK

Where would we be without Google Maps, high resolution satellite images and the ability to plot all sorts of important data on these images?

My sister used to live in Moore, Oklahoma, She and her family were present in 2011 during some very significant tornado outbreaks that spring. They have moved on but the name Moore, Oklahoma because of the family connection has stuck in my mind since. Earlier in the week, my memory of Moore was infused with adrenaline after the EF5 tornado struck. My family continued to wonder if this tornado was close to my sister's old house. This is where Google Earth/Maps came in very handy.

Using the Google Crisis Response website, I took a screen capture of the satellite image from May 22nd of her house within the context of the neighborhood and the decimated neighborhood only a few thousand feet to the northwest that took a direct hit. This image really hit home.

To put the tremendous size of this tornado into perspective, the image below shows most of the tornado track/damage. The red box on the right side is drawn in the approximate location of the image above. Notice the debris pattern.

Tuesday, May 21, 2013

Oklahoma Tornado Recap


The Moore, Oklahoma tornado has been upgraded to an EF5 with winds of 200-210 mph as determined by damage assessments. The tornado's track length was 17 miles, on the ground for 50 minutes from 2:45PM to 3:35PM CDT and had a maximum width of 1.3 miles according to the NWS office in Norman, Oklahoma. 

The NWS office in Norman, Oklahoma has a comprehensive slide presentation which illustrates the chronology of events leading to the tornado event HERE

Oklahoma Tornado, May 20, 2013 - Courtesy: Christie Lightfritz

What is it like to emerge from a storm cellar after a tornado passes? Check out this video below...

Vivid video of the tornado on the ground

The evolution of the Oklahoma Tornado....

Another angle...

Tornado Path: Courtesy; KFOR-TV

Before people start criticizing the forecasting of this outbreak, remember this:

There WAS advanced warning of severe weather and the strong possibility of tornadoes. In fact, last week I remember mentioning the possibility for severe weather in the middle of the country late last week MORE THAN 5 DAYS OUT! The National Weather Service in Norman, Oklahoma issued a tornado warning 16 minutes before it touched down; 30 minutes before it hit the population center of Moore, Oklahoma.  That might seem like a lot of time but in a tornado situation, this is an eternity.  This doesn't bring back the people lost but it does show that severe weather forecasting is getting better. Ultimately, this will save more lives in the long term.

Now the wind speeds...

Most wind speed measuring devices don't survive the tornado. Only a few dozen tornadoes have has their winds directly measured. Maybe you've seen the "Doppler on Wheels" on storm chasing tv programs. The greatest wind speed EVER measured was done by "DOW" on May 3, 1999.

Although the proliferation of these doppler radars has increased as storm chasing becomes more frequent (partially driven by consumer demand--reality tv), the wind speed data from tornadoes is still determined by examining damage as noted in the first graphic from the NWS Tuesday afternoon.

Now for some historic tornado data...

Has EF5 tornado frequency increased? Data indicates that it has decreased overall since the 1970s

Only 58 tornadoes of EF5 strength have occurred since 1950. Most occurred in the 1950s, 60s and 70s. Here is the map with the tornadoes numbered in order of occurrence.

Tuesday, May 14, 2013

Is the Weather Keeping Indians Fans Away?

Yesterday on the morning show, we discussed why the Cleveland Indians attendance, even after their winning streak of late, still ranks at the bottom on MLB in attendance per game.

Answers ranged from northern Ohio's depressed economy, the Indians recent history of mediocrity, the cold spring weather to football being the more popular sport in Cleveland and the surrounding area. While all have merit, the connection between lack luster attendance and the changeable northern Ohio weather is the element that I wanted to investigate further. In the graphic above, I circled the cities that reside in cold climates.

First, I separated the attendance figures into two parts. The first part is home attendance in April and May since 1988. This counts the last 6 years at old Cleveland Municipal Stadium and the first 20 years at Jacobs/Progressive Field. The figures are through May 12th of this year. The second part is the home attendance figures for June and July until the All-Star Break for comparison which is at the end of the post.

First, the April/May attendance. The April/May attendance trend has been overwhelmingly down since 2000.

Note the obvious lower numbers through the lean years of the late 1980s and early 1990s before the new ballpark opened. Note the small jump during the last year of Cleveland Stadium in 1993 and the HUGE surge in attendance when Progressive Field opened in 1994 which continued through the playoff years of the late 1990s. A few spikes in the mid 2000s were unsustainable as 90+ loss seasons started piling up.

Is the cold weather along the Lake Erie  shoreline a MAJOR contributor to the drop in early season attendance?  The average HIGH TEMPERATURES for April and May since 1988 show a dip this year. Yet temps have stayed slightly milder over the last 5 years. Also note the colder springs during the boom years in the late 1990s.

When we superimpose the TOP 10 COLDEST April/May periods over the attendance during that period, we see that huge drops in attendance don't necessarily correlate to colder temperatures.

I often write about how people's perception of the weather is very powerful. Our biases become the driving force in our memory formation and recollection. For example, temperatures might drop or rise significantly only a few days during a month. If these huge changes occur during a big event like a wedding or graduation, the extreme cold or warm days will leave a bigger impression in your mind than regular run-of-the-mill day during the week. That bigger impression will weigh heavier in your assessment of how the weather was over a specific period. When people say that attendance is down because of the cold weather, they don't think of averages, they think of extremes! This is why the TEMPERATURE AVERAGE over a 60 days period might not be the best data to use when comparing it to attendance. Its the COLD extremes that guide people's decisions whether or not to go to a game.

In northern Ohio, a cold day in April would be temperatures at or below 50 (an arbitrary cutoff). Are the number of days at or below 50 this year dramatically different than in year's past? Not really. Again, notice the jump in the late 1990s.

Do colder April days set the stage for below normal attendance? The distribution looks similar to the average high temperature graph earlier

A cold day in May would be temperatures at or below 60 (an arbitrary cutoff). Are the number of days at or below 60 this year dramatically different than in year's past? YES! Temperatures are running WELL ABOVE NORMAL.

The first two weeks of May ranked top 10 warmest in 140+ years of record keeping in Cleveland. The distribution of cold temperature extremes in May seems to be random.

 So what can we conclude from all of these graphs of temperature averages, extremes vs attendance?

You can almost always guarantee that more people will come to games after school lets out and summer weather becomes the rule. Green line is summer attendance; red line is spring attendance. Even during the summer, the trend recently is still down.

While the weather can and does have an effect on the decision of whether or not to attend an Indians game, the drop in attendance can't be solely attributed to the colder temperatures. In the late 1990s when the Indians were winning, we experienced some of our coolest springs (April and May) in 25 years yet people came out to support the Tribe.  Its hard considering how great those days in the 90s were but we can't base current attendance expectations on the late 1990s numbers for several reasons: Cleveland had its first new ballpark in 60 years, the team was winning AND going to the World Series and--though not shown here--the economy was booming!  On top of that, the Browns moved to Baltimore and Cleveland was WITHOUT a football team.

Guess what? The springs were colder than this year! The weather NEVER kept people from the ballpark

Over the last 10+ years, the new park aesthetic has worn off. The team has been dismantled and restructured multiple times. The bottom line is fans nowadays still don't know what to expect. The weather overall isn't the driver of poor attendance that people want to believe. Throw in a few cold days (nothing record setting) on top of the doubt that's festered for over a decade in the minds and hearts of Indians fans you create a huge detractor. 

It will take more than a few weeks of wins to bring even the hardiest of fans to the ballpark.

Monday, May 06, 2013

Canadian Shoreline Visible? Not So Fast

Over the weekend, Jay Reynolds, local Cleveland Astronomer sent me a photo of an optical illusion over Lake Erie. Its called REFRACTION!

While it looks as if we can actually see the Canadian side of the lake, in reality, its over 50 miles away! Why can we see it in this photo?

The light from the Canadian shoreline is refracted (or bent). The rapid change in air density and temperature between the warm air aloft (70s) and cool air over the lake (40s) acts to bend the light down. The wind needs to be calm for this to happen so that the different air layers don't mix too much.  The result is we see that light here in Ohio when under normal circumstances, that light would have been "beamed" into the atmosphere away from our field of view.

Close up of Optical Refraction (Canadian Shoreline): Courtesy: Jay Reynolds

While it looks like the Canadian shoreline is close, its actually a mirage and over 50 miles away!

Another atmospheric phenomena I witnessed late last week was a ring around the sun at noon Friday. What causes this?

The perpetual cloud cover we've seen are cirrus clouds. These are made of ice crystals and don't produce any precipitation. Many of the ice crystals are hexagonal. If the ice crystals are oriented at just the right position, the sunlight is refracted (there's that word again!).

The sunlight is deflected twice inside the ice crystal.


As the light interacts with more ice crystals, it will form a ring of light at exactly 22 degrees from the sun or moon. Some of the light is dispersed broken up into its component colors) as it is refracted inside the ice crystal.

Special thanks to the University of Illinois website for the great graphics!

Wednesday, May 01, 2013

US Temperatures: April 2012 vs April 2013

What a difference a year makes! WELL BELOW NORMAL APRIL ACROSS THE US!


What I find interesting is that the center of the "colder than average" area has stayed virtually the same since the beginning of the year.

Here are the April temperatures compared to the average across North America

 Once we include MARCH AND APRIL, the map looks virtually identical

How about FEBRUARY, MARCH and APRIL? Little change in the map

The entire year from JANUARY through APRIL shows how the center of the cold evolved over the last 4  months

The BIG QUESTION will be whether or not the CORE OF THE COLDER THAN NORMAL AIR breaks down, drifts west or east or expands?  More on this later.....