Archive for November, 2011

Squirrel Watch Caption Contest
November 26, 2011

Congratulations to Kenny Waldrum, his comment, “Move out of the way!  I’m trying to see Dominique Sachse!” won our squirrel watch caption contest. 

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Tornadoes in Texas
November 22, 2011

 

Our state accounts for 10% of our nations tornadoes from 2000 to 2010. 

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Giant Weather Man
November 21, 2011

You’ve got to be prepared for anything in this business, like not fitting the TV screen when you walk in front of the weather wall.  Click image to view this morning’s extra-large forecast.

Storm Shots! Tuesday’s Tornadoes
November 9, 2011

      Click image to view a slideshow of other damage from Tuesday’s storms. 

The National Weather Service has completed their surveys of Tuesday’s damage.  The Kingwood tornado has been classified as an EF1 (86-110 mph winds).  Here is what it found.

“A National Weather Service storm survey has determined that Tuesday’s storm produced an EF-1 tornado in Kingwood located in far northeastern Harris County. The approximate track length of this tornado was one mile and its maximum path width was estimated to be 150 yards. The time of the tornado was approximately 1:37 pm.

“This system produced widespread damage: numerous trees snapped or uprooted … four garage doors blown in … and window and roof damage to numerous homes. Most of the damage occurred along Hidden Lakes Drive. The starting point of the track looks to be near the intersection of Willow Terrace Drive and Hidden Lakes Drive.

“A second storm survey was done just north of Texas City at the ISP plant where minor damage occurred around 6 pm. It was estimated an EF-0 tornado did minor damage in the plant with the main damage being 10 empty trailers that were flipped over by the weak tornado. The length of the path was 1/2 mile long and 25 yards wide.”

This picture was taken by Cierra Grace in Crosby, not a tornado but straight line wind damage.

You are always welcome to send your storms shots to:

hotshots@click2houston.com

The Weather Models & The Weather Channel
November 9, 2011

Eric Bickel is a high school friend and is now leads the Graduate Program in Operations Research at the University of Texas.  One of the projects he did was compare the National Weather Service, The Weather Channel and a private forecasting company forecasts to each other.  The research can be found here:

http://journals.ametsoc.org/doi/abs/10.1175/2011MWR3525.1

One of his findings that I found interesting was that the Weather Channel’s performance decreases markedly after six days.  After interviewing some of the meteorologists, Bickel learned that human forecasters rarely intervene in forecasts beyond six days.  So basically the forecasts come straight from the computer models.  This is a good example how human forecasters add considerable skill to what the numerical, statistical and climatological models provide.   

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You Won’t See a 50% Chance of Rain
November 8, 2011

 

Eric Bickel is a high school friend and is now leads the Graduate Program in Operations Research at the University of Texas.  The joke is we were probably the most unlikely pair from high school to get into science-related jobs.  One of the projects he did was compare the National Weather Service, The Weather Channel and a private forecasting company forecasts to each other.  The findings are interesting and can be found here:

http://journals.ametsoc.org/doi/abs/10.1175/2011MWR3525.1

The key to a good forecast is having sharpness and resolution.  Resolution, for example, is if you say there is a 40% chance of rain it will rain 40% of the time, or four out of every ten days you put 40%.  Sharpness is if you say it’s going to rain it will rain, or if you say it won’t rain, it doesn’t.  Sharpness is giving some certainty to the forecast.  In a normal year, without a drought, if I put a 30% chance of rain every day, by the end of the year my forecast will have good resolution because it will have rained on average once every three days.  However, I’ll have poor sharpness because I’m never really saying if it is going to rain or not.

One of the things that stuck out to me from Eric’s work was the Weather Channel avoids putting a 20% and 50% chance of precipitation.  The 50% omission is intentional.  The Weather Channel believes that users will interpret a 50% chance of rain as a lack of knowledge (after all there are only two possible outcomes), when, in fact, a forecast of 50% is more than twice the climatological average and thus a strong statement regarding the chance of precipitation.  Bickel shows in his paper how this policy degrades the quality of their forecasts.

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Cloud Streets
November 7, 2011

 

Howard Stout took this picture at his home in Santa Fe. 

Here is another view of cloud streets from space. 

When the low-level air begins to rise, clouds can form.  Some days there is a layer of stable air above, and that limits the vertical extent of the convection.  If the wind is fairly uniform the clouds can form “streets”.  You’ll get parallel lines of clouds alternating with the clear skies.  These gaps are caused by the rising/sinking air produced by the rotating horizontal cylinders in the atmosphere. 

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Weather Quiz Archive #5
November 3, 2011

The original idea in the late 1800s was to have cannons fire automatically to warn people of an oncoming tornado.  It was never put into practice.  Today sirens go off when the National Weather Service issues a tornado warning.  You will always get tornado warnings or any weather warnings when it is issued right here on Local 2. 

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