Tuesday, August 27, 2013

Forget the Old Farmers' Almanac. Stick with the Meteorologist!

It never ceases to amaze me how people latch onto weather forecasts that attempt to nail down the exact temperature and condition for individual days months out!  There is a market for "predictions" like this.  Here we are a week before Labor Day and the Old farmers' Almanac is touting their prediction for a winter storm during the Superbowl in LATE JANUARY OF NEXT YEAR!  

Let’s call it like it is. The Old Farmers' Almanac is trying to sell books. And yes, I buy one each year because it is chalked full of great articles which I reference on occasion. 
Secondly, bad weather is big business.  When the weather gets rough (severe storms, blizzards, high winds, floods, hurricanes, etc) public interest goes through the roof! TV ratings skyrocket. !  Social Network traffic increases exponentially.  I'm not just talking about northern Ohio where I live and work as a television meteorologist but everywhere. The Old Farmers' Almanac is capitalizing on this by highlighting there Superbowl Winter Storm Forecast.  Can you say “Cha-ching”.

(Note: My station WJW FOX 8 does not over hype the weather. We are very conscious of this. We only break into programming during tornado warnings or extreme, large scale snowstorms.)

Weather affects everyone and everything; all aspects of our lives. Everything!  So it stands to reason that we might get revved up about the possibility of knowing the unknowable.  A weather forecast for the Superbowl?  I can hear it now, “Forget  those TV weather people, I’ll go with the Almanac. They are more accurate anyway!”  In truth, there accuracy is much lower than their claim. 

A few years ago, Dr. Jeff Master, Meteorologist over at the Weather Underground wrote this article on the Almanac’s accuracy. 

Here is the main paragraph: 

"...for the winter of 2004-2005 (Figure 1 is below), the November 2004 version of the Old Farmer's Almanac made a simple prediction of "cold" or "mild" for sixteen separate regions of the U.S. The original forecast map they presented only labels the U.S. in fourteen places, and I've overlaid these predictions on a temperature anomaly map showing what actually happened during the winter of 2004-2005. If we assume that "mild" refers to an above average temperature forecast and "cold" refers to a below average temperature forecast, then the Almanac got four regions correct, eight wrong, with two too close to call. Admittedly, I've "eyeballed" this, and it is a subjective verification. Still, I don't see any way that this forecast could approach even 50% (chance) accuracy. Their precipitation forecast fared better, with seven correct regions, five incorrect, and two too close to call. I also looked at the Farmer's Almanac forecasts for the winter of 2006-2007. They did much worse that winter, with only three of sixteen temperature forecasts verifying, and five out of twelve precipitation forecasts verifying (four were too close to call). For these two winters, the Old Farmer's Almanac made a successful forecast just 37% of the time."

Actual day to day weather forecasts are developed with analyzing current conditions, radar, satellite and other parameters to make a forecast for a short period of time in the future. 12 Hours, 24 hours, 36 hours, 48 hours. We utilize computer model projections as guidance. Yes, these projections are getting better as more data is utilized and plugged into faster and faster computers with more sophisticated equations.

Seasonal long range outlooks (winter weather forecast, etc) are created by looking at the ocean sea surface temperature patterns (El Nino, etc), pressure patterns over the Arctic and North Atlantic among some others. Some scientists use solar output and other variables. The elements just mentioned are matched up with other years of occurrence.  A best possible fit is created. Sometimes this works out well.  Sometimes it doesn’t.  Again, this is a trend outlook not a specific forecast for a specific day. Individual storms cannot be forecasted this far out. But by looking at parameters that existed in the past during other storm events, we can say that the chance of say a hurricane making landfall is greater this year than in years past.  

For the lay person, all of these forecasts and trend outlooks are lumped into one group. Yet each are derived using entirely different information.  Its human nature to generalize and simplify complicated subjects like the science of weather prediction.  I've written about this in other posts.   I also write how the Recency Effect (in this case, a weather forecast that doesn't pan out) shapes our view. Sophisticated computer model simulations resulting from complex equations which describe the motions and other atmospheric behavior makes people uneasy and conflicted.  Most of us don’t want to learn about Vilhelm Bjerknes, a Norwegian physicist who has been called the father of modern meteorology.  We could care less about Lewis Richardson who developed the early equations in the battlefield during World War I with no modern day calculator. No one wants to hear that the super computer simulations used in predicting Hurricane Sandy and other monster storms are responsible for saving thousands of lives. To most, this is just an excuse for some other forecast error. 

So as a result, we formulate a concrete, black and white, overly scaled down version of the weather.  Whether its a long range winter outlook, a climate average for a wedding day or the thunderstorm chances for later this afternoon or a hurricane forecast track. Its all the same animal to most! We subconsciously eliminate the nebulous science, weird looking equations, fancy computer stuff in favor of a narrative that tells a better story.  In short, The Old Farmers’ Almanac fits with how our brains are wired.  Its simple. Its folksy with just enough science to make it credible.  Why do we continue believing the Old Farmers’ Almanac?  The simple answer is it makes us feel good!

Don’t get me wrong, I’m not knocking the Almanac.  I love the articles. I love the astronomical charts.  I know my analysis will not sway people from believing the Almanac’s prognostications.  I am a fool to believe that I can counteract human nature.  But meteorology is science and its getting better and better!  If I had to choose between the computer model projections, live radar and satellite data and 20 years of experience to make a storm forecast versus the Almanac, I’m not choosing the latter… But I’ll still keep the Almanac handy....you know, for the articles.

Friday, August 23, 2013

Philosophy Friday: Everything NOW!

My definition of Presentism is this: 

The idea that we want results now--we live in the now--sometimes seeing results before the present has played itself out. Society has evolved into a reality where we want//need results now. In many instances, before the present has drifted into the past. So much information coming at us that we fail to process it all--we have no point of reference anymore. 

 A great quote from Douglas Rushkoff's book "Present Shock" which talks about "Presentism".

"When there is no linear time, how is a person supposed to figure out what is going on. there's no story, no narrative to explain why things are the way they are. Previously distinct causes and effects collapse into one another. No time between doing something and seeing the result. Instead the results begin accumulating and influencing us before we've even completed an action. There is so much information coming in at once from so many different sources, there is simply no way to trace the plot over time."

A little philosophy on this Friday---Thoughts?

Tuesday, August 20, 2013

Kids Are Back At School...A Look Back At Summer

There's a lot of talk about how cool this summer has been so far in northern Ohio. Many people have commented about how they haven't had a "pool-less" summer like this in a long time. I do my best not to respond with weather records showing the contrary. Numbers can get quiet boring.

The truth is, as I wrote last week, we've had plenty of summers similar to this one in Cleveland. Because of the Recency Effect, we tend to forget those years unless we experienced some big event (wedding, great vacation, etc) during that time that helps solidify the memory.

Here is how this summer has stacked up versus the summers of the past:

The average high temperatures since June 1st since the 1870s for Cleveland seem to follow discernible patterns.  Look at the trend over the last 140 years:  Much cooler average high temperatures from 1870 through the 1920s, a sharp spike in the 1930s through the mid 1950s. Since the late 1950s, the high temperatures have averaged 80.3 over the 3 month period (JUNE, JULY and AUGUST).  Note that the year-to-year variation has increased (graph becomes more jagged) since the early 1980s.

So what about this summer?   The AVERAGE HIGH TEMPERATURE WAS 79.0
 1.3 degrees BELOW AVERAGE since 1956

Using 1956 as the cut-off eliminates the 1800s (temperature station changed several times), the spike in the dust bowl days and the scorcher summer of the early 1950s, this summer ranks as the 14th coolest! In other words, Over the same period, 13 summers have had COOLER HIGH TEMPERATURES.

The most recent summers were 2009, 2004 and 2000
What about overnight lows? The trend since 1956 has shown an increase. This summer, the nights have been running warmer than average but cooler than the last 3 summers.

How about rainfall?

This summer ranks 6th WETTEST since 1956 well above the average of 9.03".  The summers that were COOLER than 2013 (circled in green) match up well to summers with above average rainfall.

In summary, this summer was cooler than past summers but not unprecedented. Rainfall was indeed well above average but not as wet as the summer of 2011.

Tuesday, August 13, 2013

Will Below Normal Temps Continue into September?


My projection for August given the "cooler than normal" July and comparing it to the July summers similar to 2013 yielded this:

So far through the 10th, this is what has ACTUALLY HAPPENED...not a bad match. Red dot is over Ohio.

The years that featured summers with "cooler" high temperatures than this summer through August 10th are:  2009, 2004, 2003, 2000, 1997, 1996, 1992, 1990, 1985, 1972, 1969, 1965, 1960, 1958, 1940, 1938, 1937, 1936, 1935.

I charted the summer average daytime high temperatures since 1933 (81 summers). The summers that were "cooler" than this summer are circled in blue  (20 of the last 31 years). The red line is the average over the 81 summers.This summer is indicated with the red arrow on the right.

How about September?

The most recent "cooler" summers since 2000 don't necessarily mean that September will always be cool.  In fact, September of 2009 was near normal while 2004 (a summer markedly cooler than 2013) was above normal.

Since daytime highs above 80 are considered "above normal" in September (daytime highs start to drop significantly), I plotted the number of days at or above 80 in each September from each year (listed earlier). What does this show?

 Overall, we average about a weeks worth of days above 80 in Septembers that follow cool summers similar or cooler than 2013

Here is what the temperatures looked like for each day in September of 2009. I circled the 80 degree days AND the 60 degree days. Notice how they become more numerous later in the month.

I believe that this September will look something like 2009. A handful of 80 degree days, a handful of 60 degree days toward the end with the rest feeling similar to this week!

Friday, August 09, 2013

Tornado Confirmed in Orrville, Ohio

The National Weather Service confirmed that the damage from severe storms Wednesday afternoon in Orrville, Ohio WAS from a tornado. Estimated maximum wind speed: 95 mph; Maximum path width: 50 yards; path length: 1 mile.

There is a misconception that tornado wind speeds are estimated from doppler radar or some other direct measurement. Wind speeds are "reverse engineered" by surveying damage. The estimated wind speed is the--and this is key--AN ESTIMATED THREE-SECOND GUST AT THE POINT OF DAMAGE.

The type of structure/tree is assigned one of the 28 Indicators that describe the type of structure. DEGREES OF DAMAGE (scale of 1 to 9) are assigned to each indicator. After the assessment for all indicators is complete, the estimated three second wind speed is determined. A more detailed EF Powerpoint is provided by the National Weather Service.

Thursday, August 08, 2013

Tornado in Orrville...More Storms Today?

A viewer sent this photo of the funnel cloud (more than likely a tornado) in Orrville yesterday afternoon around 3PM. More on this from the NWS later today.


Will we see redevelopment later today? Yes. However, the conditions are not favorable for severe weather. The front is on our doorstep as of 8AM Thursday.
The front will stall focusing the storms across the southern portions of northern Ohio later today.

Wednesday, August 07, 2013

Severe Storms Possible Later Today

We're already seeing development in southern Michigan. In fact, this cluster started to develop in Wisconsin at 1AM where it moved west over Lake Michigan, weakened a bit and is not fanning out to the west. CLICK HERE FOR THE NEWEST RADAR LOOP

The dew points are climbing; precipitable water levels will be much higher...
Convective Energy is highest in western Ohio later today and this evening
 Severe thunderstorm watch possible later today in this area
The HRRR model still shows spotty storms developing ahead of the Michigan cluster by midday.....
Here is the HRRR projection for this afternoon and early evening showing more widespread storm coverage.

Thursday, August 01, 2013

July is in the books: TEMPERATURE NUMBERS

My last two posts reinforced how common "cooler" Julys like this month are when we look back as recent as the early 2000s. I also mentioned how the RECENCY EFFECT plays a huge role in our skewed perceptions of July temperatures. The last few years of record heat helped us forget about the other "cool" months of July in our recent weather history.

The final NWS numbers are in. I broke down the July temperatures into two categories: AVERAGE MAX TEMPERATURE and OVERALL AVERAGE TEMPERATURE (MAX and MIN). Where does 2013 fit over the last 30 years? VERY NEAR AVERAGE on both measures. (The prior years--2010,11--are circled in red for reference)
How about the final number of days this July below 80 degrees? Believe it or not, the 11 days below 80 degrees was only slightly above the average average since 1980.


Just for fun, here is the 90 degree scorecard comparing this summer to the last 4 summers.