Kelvin-Helmholtz Wave Clouds November 18, 2013

Photo by: Kathleen Dimmel, Navasota

These cloud-waves rarely occur because you need almost perfect atmospheric conditions.  Much like ocean waves, the air on the tops of these clouds is moving faster than the bottom of the clouds.  The clouds near the surface are cooler than above and the wind speeds are light, like fog.  Over the low clouds is a warmer and faster-moving layer of air creating the crest, like we see in the ocean.

Rita Casserly sent in this picture.

 

This is probably the best example from Birmingham, Alabama.

Advertisement

How Well Do You Know Us? January 23, 2012

To view past weather quiz answers click here:

Past Weather Quiz Answers

Track Santa This Christmas December 23, 2011

NORAD, the North American Aerospace Defense Command, has been tracking Santa since 1958.  You can watch Local2 Christmas Eve and we’ll update you as to where Santa is or you can Track Santa right here on NORAD’s website any time Saturday.  It’s a funny story how NORAD started their Santa Tracker.  In 1955 the department store Sears, in Colorado Springs, ran an ad for kids to call Santa at ME2-6681.  The problem, this wasn’t the phone number to Santa Claus at Sears, it was the number to the Colorado Springs Continental Air Defense Command (CONAD).  The people answering the phone didn’t know what to do when hundreds of calls came in asking for Santa.  The Colonel told staffers to give the current location of Santa and the rest as they say is history.  (On a side note: NORAD replaced CONAD in 1958.)  Here is the newspaper ad.     

 

To view past weather quiz answers click here:

Past Weather Quiz Answers

Hole Punch Clouds December 21, 2011

 

Earlier this year I went to a weather conference and one of the talks was on hole punch clouds.  The latest research shows they are not created by engine combustion at all.  The first requirement is the clouds have to be vertically thin.  Researchers then discovered that the clouds usually form beneath C-130 planes (shown below).  Beneath the wings of these planes temperatures were around 14 degrees warmer than the rest of the plane and surrounding environment.  This temperature difference created a dry punch of air falling from the sky evaporating the clouds beneath.            

On a side note, a big thanks to Stephen Kornblitt who took this picture and sent it to Frank Billingsley.  A lot of people said it looked photo shopped but our engineers at the station said it was authentic.  Most hole punch clouds are circular.  This one is unique because it looks like an outline of a plane or the state of Texas. 

To view past weather quiz answers click here:

Past Weather Quiz Answers

Tornadoes in Texas November 22, 2011

 

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

To view past weather quiz answers click here:

Past Weather Quiz Answers

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.   

To view past weather quiz answers click here:

Past Weather Quiz Answers

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.

To view past weather quiz answers click here:

Past Weather Quiz Answers

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. 

To view past weather quiz answers click here:

Past Weather Quiz Answers

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. 

To view past weather quiz answers from archive #5 click here:

Past Weather Quiz Answers

John a Hurricane & Typhoon September 21, 2011

 

Besides setting these records, Hurricane John (that formed in the Eastern Pacific Ocean) was one of only a handful of hurricanes that crossed the international dateline and moved into the Western Pacific Ocean.  Western Pacific cyclones are named typhoons, so once John moved that far west it was re-named Typhoon John.  Despite the long journey, John never made landfall and only caused minor damage to Hawaii.   

 

To view past weather quiz answer click here:

Past Weather Quiz Answers

Measuring Humidity with Hair September 20, 2011

 

Before modern meteorological measurements, humidity was measured using hair. In 1783 Swiss scientist H.B. Saussure invented the hair hygrometer. It’s similar to the image above. As the relative humidity increases, hair becomes longer, and as the humidity drops it becomes shorter. On very humid days, your hair actually becomes longer and this extra length causes the frizziness that gives us bad hair days. This instrument uses strands of human or horse hair with the oils removed attached to levers that magnify a small change in hair length. Red hair works best. An ink pen and rotating cylinder, known as a hygrograph, can provide a record of how relative humidity varies throughout the day. The disadvantages of the hair hygrometer and hygrograph are that they are not as accurate as other kinds of hygrometers such as the sling psychrometer. Also, a hair hygrometer needs frequent adjustment and calibration. Hair hygrometers also tends to have large errors at very high and very low relative humidities. You can get your “haircast” forecast at: www.justweather.com

To view past weather quiz answer click here:

 

Past Weather Quiz Answers

Dust Bowl Fires September 9, 2011

This question was brought to you by the students at the Continuum Academy & Learning Center in Livingston.  They visited me at the station and presented their research on Texas droughts in the last 100 years.  They explained how the Dust Bowl of the 1930s would not happen today because we learned from our mistakes of taking  land for granted.  They also shared how there were almost no fires during the dust bowl because of the blowing sand.  Sand puts out fires.  With the abuse of the land there also wasn’t a lot of vegetation or grass to burn.      

To view past weather quiz answers click here:

Past Weather Quiz Answers

A Sun Pillar August 29, 2011

 

 When the atmosphere is cold, ice sometimes forms flat six-sided crystals as it falls from high-level clouds. Air resistance then causes these crystals to lie nearly flat much of the time as they flutter to the ground. If viewed toward a rising or setting Sun, these flat crystals will reflect sunlight and create an unusual column of light — a sun pillar as seen above.

To view other sun pillars click here:

Sun Pillars

To view past weather quiz answers click here:

Past Weather Quiz Answers

The Shawshank Redemption Tree August 2, 2011

 

Last Friday afternoon a thunderstorm moved through Mansfield, Ohio, at 2:30 p.m. producing straight-line winds.  It severely damaged the tree made famous by the film “The Shawshank Redemption.”  The tree is on private property but that never stopped people from visiting it and even proposing under its vast branches.  Half of those branches are now gone.  The owner of the property has not said if the tree will be removed due to the damage.     

To view past weather quiz answers click here:

Past Weather Quiz Answers

What The Cone Represents July 29, 2011

According to a national study, most people believe that the cone represents where the winds from a tropical storm or hurricane will impact.  It actually represents the probable track of the center of a tropical cyclone based on the errors of the past five years.  The National Hurricane Center plots where it thinks the storm will be in 12, 24, 36 hours etc. and places those dots on a map.

This image is of Tropical Storm Don on Friday morning.  The dots are the forecast from the NHC, but the cone represents the how far the center of the storm can be away from the forecast point.

Notice the circles in this image.  The size of each circle is set so that two-thirds of the five-year historical forecast centers fall within the circle.  The red dots out of the track are the past position of Hurricane Danielle in 2010.  The cone is created by connecting the circles.  In the cone, you can see how the 12- and 24-hour forecasts were just a touch off.  The center of Danielle was faster and to the right of the circles, but still in the cone.  But the forecast was off big time four and five days out.  The center of the storm wasn’t anywhere near the cone because the storm went a lot faster than expected.  What I always tell people is the forecast cone is good three days out, but four or five days a lot can change.  Danielle is a good example of the 1/3 of the time being outside the forecast cone.

Hottest Temperature Ever Recorded July 22, 2011

To view past weather quiz answers click here:

Past Weather Quiz Answers

California Hurricanes July 11, 2011

Only one tropical storm has ever hit the California coast. It hit near Long Beach in September 1939 with 50-mph winds. The rest of the tropical systems that near California die before making land because the water temperatures off the coast are too cold to support tropical growth. Tropical systems need the ocean to be at least 80 degrees, otherwise the storm will weaken. Southern California has received some good rain from dying tropical storms, but only one has made a direct hit.

This is an image from the National Hurricane Center.  Notice how active storms are in the Gulf, Florida, and the Carolina’s.  Most storms that form in the Eastern Pacific Ocean move west and if they do curve north they quickly weaken in the colder waters.   

To view past weather quiz answers click here:

Past Weather Quiz Answers

A Hot Problem for Galveston July 1, 2011

 

This is a quote from the National Weather Service, “We’ve been informed that concrete was put in at the ASOS site in Galveston a few days ago, which may be affecting the records that have been set there since June 26th. For now the records will count until we determine otherwise.”  The problem with concrete with it absorbs heat and probably is adding a few degrees to the recording station.  The NWS has strict rules that official recording sites must have grass surrounding the station. 

This is the follow up I received from Patrick Blood at the NWS: 

“As of this past month, the KGLS ASOS site has been moved and new sensors installed.  The site, while still on airport grounds, is now more representative of the local soil/radiative properties that before…and it should not be as influenced by local asphalt.”

To view past weather quiz answers click here:

Past Weather Quiz Answers

Weather Quiz Archive #4 May 23, 2011

 

 It seems silly, but the British Navy refused to install lightning rods – even though they protected ships from lightning strikes – because they were invented by rebel Benjamin Franklin.

To view past weather quiz answers click here:

Past Weather Quiz Answers

Straight Line Wind Damage May 13, 2011

      100 year old oak tree brought down Thursday.

The severe weather we saw on Thursday came from straight-line or microburst winds.  These winds are a result of air being rapidly accelerated down from the mid and upper parts of the thunderstorm to the ground.  The downflow can occur due to several factors: by air being pulled down by rain or hail, by the increases in air density as the air is cooled by rain and by the cooling produced with melting ice crystals.  These three factors, if strong enough, can create massively intense and sudden downward movements of air.  Most microbursts last only five to 15 minutes.   

An interesting note: These winds used to cause quiet a few plane crashes in the 60s and 70s.  For a pilot getting caught in a downburst wind, the plane would experience a sudden headwind followed by a strong tailwind a few moments later.  An inexperienced pilot would accelerate trying to slow the plane down, but the tailwind would come right after that causing the plane to lose the air flow across the wings (the critical principle to maintain flight.)  Consequently, the sudden loss of air moving across the wings would literally cause the aircraft to drop out of the air.   The best way for a pilot to stay in the air is to increase speed as soon as the abrupt drop in airspeed is noticed.  This will allow the aircraft to remain in the air when traveling through the tailwind portion of the microburst.  Forecasting of downburst winds is a lot better today than it was in the 70s.  Planes can completely avoid these type of storms.   

To view past weather quiz answers click here:

Past Weather Quiz Answers

Why So Many Tornado Deaths? May 11, 2011

 

This is a theory presented by Accuweather meteorologist Mike Smith.  It took a while to wrap my mind around this idea, but it makes sense and should be a lesson to us in southeast Texas as hurricane season approaches.  First, Smith says it isn’t about the strength of the tornadoes.  Remember St. Louis, the week prior, had an EF-4 tornado going through a heavily populated area and an airport and no one died.  The tornado warnings with the St. Louis tornado and the outbreak April 27 were excellent.  In fact, on average, tornado warnings went out 24 minutes before the tornadoes hit.  What Smith presents is power failures stopped many people from getting these important tornado warnings.  Prior to the tornado outbreak, power went out for much of state because of morning storms west of Alabama.  The image below shows 260,000 people didn’t have power the entire day.  Without TV or radio, some people didn’t know what was coming their way.  This highlights the importance of having a NOAA weather radio or a battery-operated TV/radio.  A lot of us went through this same type of scenario with Hurricane Ike.  We lost power and it took days/weeks for us to get it back.  Have we learned our lesson?  I sure hope so.

To view past weather quiz answers click here:

Past Weather Quiz Answers

Crimes Against the Environment May 10, 2011

 

The website has a list of the top environment offenders with pictures, charges and last known location.  Their misconduct ranges from illegal dumping of oil to selling ozone-depleting R-12 freon to selling cars that do not meet EPA standards.  The website warns visitors to “not attempt to apprehend any of these individuals,” instead asking that any information be provided to local authorities or through the site itself. 

 

Click image to view the EPA’s most wanted site.

 

To view past weather quiz answers click here:

Past Weather Quiz Answers

Ice Cream For A Year! May 6, 2011

This week Blue Bell Ice Cream offered ice cream for a year to the best mom in southeast Texas.  Owen, Lauren, Halie and I picked the winner from hundreds of letters written about moms that were sent to hotshots@click2houston.com  Audrey Ingle, 13, sent in this gem about her mom Lori:

Congratulations, Lori, and thank you, Blue Bell!  Happy Mother’s Day!

Latest on the Killer Tornado Outbreak May 5, 2011

The average lead time is 18 minutes.

• Warnings were in effect for more than 90 percent of the tornadoes.
• To date, NOAA estimates the outbreak spawned 305 tornadoes, making this the largest tornado outbreak in history – surpassing the April 3-4, 1974, outbreak with 148 tornadoes. So far, the National Weather Service has surveyed damage from 178 tornadoes and determined that two topped the scale at EF-5, four were EF-4, and 21 were EF-3. Dozens more have been categorized as EF-2 or lower.
• NOAA estimates there were more than 600 tornadoes during the month of April 2011, shattering previous records. The previous April tornado record was 267, set in 1974. The previous record number of tornadoes during any month was 542, set in May 2003. So far there have been an estimated 881 tornadoes in 2011. The annual tornado record is 1,817, set in 2004. May is historically the most active month for tornadoes.
• With an estimated 327 deaths, this is the 3rd deadliest tornado outbreak on record, behind 1925 with 747 and 1932 with 332. So far, 2011 is the 13th deadliest year for tornadoes on record with 369. The deadliest year on record is 1925 with 794.

Courtesy: NOAA To view past weather quiz answers, click here:

Past Weather Quiz Answers

How Wildfires Get Their Names May 3, 2011

 

In general, naming rights go to the group that makes the “initial attack” on a fire, whether it’s a squadron of local firefighters or a team from the U.S. Forest Service. (In contrast, every tropical storm in the Atlantic gets its name from a single organization.) The commander on the scene often uses a nearby geographical feature to describe the fire, but he’s not bound by any official rules. He first suggests a name to the interagency fire dispatcher, who passes it along in fire reports, dispatches, and so on.

 

 

These are the active fires Tuesday May 3rd.  The big Texas fire is called the “Rock House Fire” after a landmark near Fort Davis. 

 

To view past weather quiz answers click here:

Past Weather Quiz Answers

Ozone – Good & Bad March 25, 2011

        

 

A good way to remember this is ozone is GOOD up high, BAD nearby. 

 

 

Ground level ozone can irritate the lungs, especially for those with suffer from emphysema and asthma.  Upper level ozone is good because it blocks out harmful UV rays.  

 

 

We are now in ozone season, and days with warm temperatures, sunny skies and light winds will trigger the formation of ozone on the ground. 

  

To view past weather quiz answers click here:

Past Weather Quiz Answers

Why We Have Seasons March 21, 2011

 

The Earth’s seasons are not caused by the differences in the distance from the Sun throughout the year (these differences are extremely small). The seasons are the result of the tilt of the Earth’s axis.

The Earth’s axis is tilted from perpendicular to the plane of the ecliptic by 23.45°. This tilting is what gives us the four seasons of the year – spring, summer, autumn (fall) and winter. Since the axis is tilted, different parts of the globe are oriented towards the Sun at different times of the year.

Summer is warmer than winter (in each hemisphere) because the Sun’s rays hit the Earth at a more direct angle during summer than during winter and also because the days are much longer than the nights during the summer. During the winter, the Sun’s rays hit the Earth at an extreme angle, and the days are very short. These effects are due to the tilt of the Earth’s axis.

To view past weather quiz answers click here:

Past Weather Quiz Answers

An Extremely Dry February March 1, 2011

 

We received .69″ of rain for the month in Houston, putting us in 8th place. 

Top 10 Driest
0.03	1916
0.17	1954
0.38	1976
0.45	1937
0.55	1974
0.63	1925
0.68	1947
0.69	2011
0.77	1962
0.80	1999

To view past weather quiz answers click here: 

Past Weather Quiz Answers

What Most People Think a 20% of Rain is January 18, 2011

 

Two answers and they are both wrong. It’s fascinating for me to see that most people in the United States view a weather forecast as deterministic, or if there is a rain percentage on the map, it definitely will rain. In other words, people interpreted 20% as it will rain 20% of the time or that 20% of the viewing area will get wet. The people conducting this study speculated that the general human tendency is to avoid complications of incorporating uncertainty in the decision process by ignoring it or turning it into certainty. Another example showed that people living in floodplains appeal to perceived cyclical patterns to predict the size of the next flood, rather than regarding it as uncertain.

The correct answer is if there is a 20% chance of rain today it may rain. In my experience, I’ve found that people in Southeast Texas view the chance as so small that it simply won’t rain. Most of the e-mails I receive from people upset about the forecast are on days with a 20% chance of rain and it does rain. The quote is usually, “You said it wouldn’t rain.”

Social science studies like this are important because it shows the correct message isn’t getting to the viewer. We as forecasters have to do a better job communicating the forecast. But the biggest problem is the forecast itself. The reason we use probabilities is because the future is uncertain. An 80% chance of rain means I feel strongly there will at least be a minimum amount of rain. As Frank Billingsley likes to say, “You only know what you know.”

To view past weather quiz answers click here:

Past Weather Quiz Answers

Record High and Low Temperatures December 17, 2010

  

Courtesy: Earth Gauge

From January 2000 to October 24, 2010, 310,531 record high temperatures were set across the contiguous United States. During the same period, 152,087 record low temperatures were set, giving a record highs to record lows ratio of more than 2:1.

There are close to 5,000 quality-controlled weather stations across the United States and every day at least some of these locations will set record high or record low temperatures. During periods of warming – even periods of pronounced warming – daily record low temperatures will continue to be set. Daily record high temperatures are also set during periods of cooling. Yet, it is not the existence of record highs or record lows that indicate whether a warming or cooling trend is occurring. Instead, it is the proportion or ratio of record highs to record lows that indicates whether the climate is getting warmer or cooler. During the warmest decade on record, the 2000s, lots of daily record lows were set. Between January 1, 2000 and October 24, 2010, 152,087 record lows were set. All other things being equal – meaning that there is no increase or decrease in average surface temperature – the ratio of record highs to record lows should be around 1:1. But, from January 2000 to October 24, 2010, 310,531 record high temperatures were set, giving a high to low ratio of more than 2:1. The disparity between record highs and record lows reflects the above normal temperatures experienced over the last decade.

• For a chart illustrating trends in decadal ratios of daily record highs to daily record lows, visit www.earthgauge.net/2010/climate-fact-record-highs-to-record-lows-ratio.  The chart has been provided courtesy of The Weather Channel and is based on data provided by NOAA’s National Climatic Data Center.

To view past weather quiz answers click here:

Past Weather Quiz Answers