Thursday, June 30, 2011

First Tropical System of 2011

Tropical Storm Arlene is still hanging around in the western Gulf of Mexico drifting into central Mexico.

Forecast continues to drive this west over the next several days

The National Hurricane Center concurs


Since the water temperatures are above normal, we can expect more tropical storms in the weeks ahead


The Atlantic is very quiet due to dust from Africa spreading west

Movement on any tropical waves will be westward.  Unless a storm develops in the Gulf, the Caribbean storms should stay away from the US

We are still looking at an above normal year of tropical storms.  If you are vacationing along the east coast or Florida, your chances of being affected by a tropical storm/Hurricane this year is increasing.

Wednesday, June 29, 2011

Fastball speeds increasing in recent years

Tuesday, June 21, 2011

Is Forecasting the Weather Art or Science?

In this technological world that we live in where the resources for weather related information are readily available for ANYONE in seconds, it still surprises me how many of us still hang onto the belief that simply because we have "super-fast computers", weather forecasting should be a science that is an already mastered discipline. In the minds of most, because of advancements in technology, forecasting should be an old science relic that should have been perfected by now. 

I am a firm believer that weather foreacsting is made up of two parts:  Science and Art.  The science encompasses objective observation and analysis. The art deals with formulating your forecast so it best fits everyones "perception" of what is happening--  a poor-man's exercise in psycho-analysis.  More on that in a moment.

First the science:

Contrary to what many believe, forecasting accuracy is MUCH BETTER than it was 10 or 15 years ago.  This is in part to several factors:  The first is the development and implementation of satellite data. The second is faster computers. The third is more advanced weather simulations (called computer models)
Satellites monitor each and every square inch of the planet. Soil moisture, ground temperature, atmospheric temperatures, infrared radiation, wind profiles, pollution, dust, pressure, ice coverage...you name it.  All of this data is compiled and shuttled onto websites each second of each day.  The first decade of the 2000s will be remembered as the time when volumes of satellite data became available on the internet to most everyone. Want to analyze ocean surface temperatures? You can do it.  Want the dataset for ozone over antarctica?  Its right there!  Our understanding of the oceans and atmosphere is so much greater with this library of satellite data so readily available.

Computers are much faster and getting smaller each year.  A personal computer from 2006 is grossly outdated. In 2015, the best and faster computer in 2011 will be a turtle in comparison.  Faster computers means faster and more detailed computer simulations of thunderstorms, hurricanes, ocean currents and other patterns. Combine the faster computers with more detailed data and you get a much better simulation on what the specific weather will be for a certain area. 

That said, simulations have and will ALWAYS have limitations.  First, simulations by their very nature are not exact answers.  They are approximations. The complex math that describes the atmosphere is one big approximation.  Factor these inexact simulations created by humans with super-fast computers, also made by humans and you get two things: MUCH better forecasts that still have some degree of error.

Now the art (psychology):





Weather accuracy is highly subjective.  If you mention on the air that "90% of the area will get thunderstorms today" and 90% of the area gets rain and storms, your accuracy is pretty darn good.  Yet for the 10% who didn't get any rain, you are the worst forecaster in history!  

Your "weather reality" is what is over your head at any given time.  Much of the public as a whole views the weather around them with a biased lense. Substitute this "weather reality" with politics, the economy, religion, crime, your friends, it doesn't matter. We are all biased to some extent.  That's what makes us human.  Its our built in selective perception of the weather and events around us that gives us perspective.  The art of forecasting is formulating your words based on how people will "perceive" what is going to happen. 

20 years ago, the only sources of weather were:  television, radio, newspapar and word of mouth.  Now, add real-time internet and smartphone updates, 24 hour cable.  Its and endless bombardment of weather both beautiful and destructive.  We are all conditioned partly with this overflow of information to gauge the weather events as something new.  How many times have we heard, "I've never seen anything like this before!", after a weather event?  The most recent weather is overemphasized because its fresh in our minds. This shapes our viewpoint on weather a few days to a few weeks in the future.

Most outside of the field of weather find it very difficult to grasp the fact that the weather is one big approximation. Weather should be exact; we all want a forecast that fits a nice and neat one-size-fits-all package.  I'd like to say that I make a forecast whether short or long term with a cold, rational eye rather than my biased, emtional side.  But I don't.  I take into account how the general public will react to my EVERY word knowing that most selectively perceive the weather to fit their "sphere of reality".  I learned that quickly years ago.  For all of the simulations, super-computers, highly detailed satellite data, it doesn't matter how exact your forecast is or what scientific reasoning you used in coming to your conclusion, people will ignore the facts and the data that disagree with their perceptions and will "rationalize" what they want and react accordingly. More often than not, the reactions are negative.  Worse still, its accumulative.  The more we selectively perceive the weather to fit our negative connotation, the more negative our reaction and the more rigid our bias becomes.  Its a vicious circle that feeds on itself. 

This is called the Disconfirmation Bias. Its the tendency to accept supportive evidence of a belief uncritically, but to discount evidence that challenges that belief.

Here is an example:  Go back to last winter.  The first big snowstorm forecast calls for "4-8 inches" for the following day.  In your backyard, you get 3 inches yet 80% of the area received 6 inches.  You say "what happened to the 4-8 inches?"  Second snowstorm, the forecast calls for "6 to 10 inches".  You get 6 inches.  The majority of the area received 9 inches.  You say "what happened to the "6 to 10 inches?".  By the third snowstorm, you are already frustrated by the "lack of accuracy" so you are primed to think negatively. The forecast calls for 5 to 10 inches.  You get 5 inches and you say "what happened to the other 5 inches?" 

The forecast was accurate given the range in the snowfall prediction.  Since you were pre-conditioned to believe the forecast would be way off because of your established bias, no amount of evidence in the world will break you of that bias!

Weather is an old science. Weather foreacsting is a field that continues to grow.  But the heart of a forecast lies in molding the science to fit the psychology.  Human nature is tough and stubborn.  I'll try to be better sculpter.

Tuesday, June 14, 2011

Are Long Stretches of 70 Degree Highs in June Unusual?

Its the middle of June and Spring is here...after a week of heat and humidity...after three days in the 90s...now a decent stretch of temps in the 70s when the highs should be rising.  A flip-flop to what typically happens this time of year.  Is this drop into the 70s all that unusual?

This first graph shows the years with 5 straight days with temps in the 70s.  The longer the stretch, the longer the "blue line"


8 of the last 13 years we had at least one stretch of 5 straight days with temps in the 70s after June 12th.

The red bars are the consecutive days above 80 degrees that followed each 70 degree stretch.




Notice in 2008 and 2004, we had a second stretch of 70 degree days. How about in 2003?  A stretch that lasted 10 days!

The year 2000 and 2007 were the only years where 70 degree stretches were under 3 days.

The bottom line is that it is perfectly normal to have long stretches of temps in the 70s in mid to late June.  Coming off of a La Nina spring (now neutral) with global temps still cooler than this time last year coupled with soil moisture in the middle of the country well-above normal, the chances of having long stretches of 85 to 90 degree heat here in northeastern Ohio heading into July and August seem very small.

Wednesday, June 08, 2011

Still sticking to my "7 days above 90" prediction

Many people have come up to me and said, "So. What happened to that forecast of '7 days at 90 or better this summer' you predicted"?

My answer, "The summer is still young."  And yes, I'm still sticking to my initial prediction. Cooler air is coming...

So far as of June 8th, we've had 3 days at 90 or better.  Alot of this heat is due to two main factors:  Decreased soil moisture which reduces the amount of evaporation (which is a cooling process) and high pressure aloft which steers warmth north.

Look at the flow last month (May)

Now compared it to the last two weeks. Ridging aloft with steering winds out of the south
Now the soil moisture in May...red indicates high soil moisture
Now for June through the 5th:  Notice the reds are replaced with yellow shades indicating drying across the eastern 1/2 of the US.
The combination of all of the extended forecasts in this next animation shows no significant "southerly flow" like the second map on the page. It illustrates a west to east flow with periods slight warmth with NO BIG HOT PERIODS at least through the 22nd of June.  This also means more quick-moving fronts with better chances of rain/storms.  If it doesn't animate, click on THIS LINK


Even NEW extended models which take into account the interaction between the ocean cycles and general atmospheric conditions around the earth show a "cooler than normal" pattern for July and August. Normal high in July is 82.  So this would predict  a better chance at upper 70s versus upper 80s.


Wednesday, June 01, 2011

A dry June and the start of hurricane season

Just when out weather is starting to dry out after more than 14 inches or rain since April 1st, the start of hurricane season is now taking center stage with the talk of an above year for tropical storms and hurricanes. 


Why the increase this year?

Let look at the total amount of available moisture in the atmosphere in the tropics courtesy of Dr. Jeff Masters at the wunderground.com.


Now take a look at the water temperatures in the same spots compared to the averages and last year. Notice the warm pockets in the Caribbean, Gulf of Mexico and along the eastern US coast. Last year, most of the warmth was located in the central Atlantic.  This year, its all over the place. Click on each image to make it larger.

Last year in late May


Late this May


The latest satellite image shows clusters of storms in these spots as of May 31st.  So look for the first tropical storms to develop in these spots in June and July.


The major hurricanes that make landfall in the US originate in the locations that are the warmest this year. We will need to watch these areas VERY carefully in the months ahead.

La Nina, the temporary cooling trend in the Pacific Ocean is weakening to neutral conditions this summer and early fall.  This allows the winds aloft to weaken allowing tropical storms to develop further without being sheared apart. 

These factors are why the National Hurricane Center is calling for an active hurricane season. Here is their link with the details

One other thing to remember in the next several years:

We are in a period of higher hurricane activity mostly due to the Atlantic Ocean entering a "warm mode" in the mid 1990s.  These warm modes typically last 25-35 years.  We can trace these warm/cold modes back into the 1800s.  These warm modes are directly related to higher hurricane activity.  We can expect a greater than normal number of hurricanes that make landfall in the US in these "warm modes".  This also increases the likelihood of a hurricane making landfall in New England. This is a REAL threat; one that's been a reality in the past and one--according to many forecasters-- will likely occur in the next 5 to 10 years.

If you vacation along the east coast in late August or early September, stay updated on the tropics. The right side of the following graph might be our reality in the future.