New boss at Houston NWS

Congratulations to Gene Hafele, the new Meteorologist-in-Charge at the Houston-Galveston National Weather Service office! Gene replaces Bill Read who left to direct the National Hurricane Center.

Gene has been the Warning Coordination Meteorologist since 1993. He also worked for about ten years in NASA's Spaceflight Meteorology Group, providing weather guidance for nine shuttle missions.

The media works very closely with the National Weather Service during severe and tropical weather events. Gene will provide stability in the local office and maintain our great working relationship.

Contrails crossing over Houston

On almost any sunny day, you can look up and see contrails crossing the sky.  These "condensation trails" are produced by jets flying across the country. When hot, humid air in the jet exhaust mixes with the cooler air temperatures aloft, the moisture condenses and creates an artificial "cloud."

The length of a contrail and the amount of time it takes to dissipate depends on the weather conditions aloft. If the atmosphere at flight level is humid, the contrail will last for hours; if it's dry, the contrail will dissipate more quickly. Also, since the temperature, humidity and wind vary greatly throughout the atmosphere, contrails can be dashed, jagged, wavy, short, long, fat and skinny. And depending on the direction planes are flying when they pass over Houston, the contrails can sometimes create interesting patterns in the sky, like the "X" you see in the TowerCam snapshot above.

Over the years these patterns have captured the attention of some folks who believe the white streaks are not contrails, but rather chemtrails. Conspiracy theorists believe our government is spraying chemicals, viruses and cancer into the air. Once such believer called the ABC13 weather center last week when the "X" pattern seen above showed up over Houston.

Giving the caller the benefit of the doubt, I immediately checked the flight paths over Houston. The image to the right is from FlightAware and was captured at the same time as the TowerCam snapshot above. The map shows the position of every passenger plane in the air. If you look carefully, you'll see several paths crossing each other in an "X" pattern. (Contrails can be much longer than the lines shown on the map which only indicate position reports received from the planes.)

There could be a real concern about contrails, however it has nothing to do with our government trying to kill us. The man-made cirrus clouds could block sunlight during the day and hold in the heat at night. As air traffic increases in the future, more studies will need to be done to determine if contrails cause a general cooling or warming of the atmosphere.

As always, you can post your comments below.

Stormy Weekend

Updated Sunday morning: The front is moving slower than originally forecast, but it's still coming. Scattered thundershowers are developing ahead of the front which will push through the area this afternoon.

The threat for severe weather is diminishing. Due to the weak flow ahead of the front, damaging winds are less likely, but there could still be a little hail in some of the stronger storms. I'm still expecting very heavy rainfall because the storms will be moving slowly.

Lower pressure in the Gulf has turned the winds in from the north, dropping the dew points at the surface. However, there's still enough moisture aloft for heavy rain in storms that develop ahead and along the cool front. Showers will also linger in the cooler air this evening.

The previous discussion follows:

We had three great weekends in a row-- with sunshine and mild temperatures! This weekend, on the other hand, will be stormy. Our lucky streak of great weather is over.

A cool front is pushing across Texas. Scattered showers will develop ahead of the front on Saturday while a squall line will blow into town early Sunday when the front pushes through.

Our exclusive FutureTrack computer model shows active storms on Saturday. Some of the rain will be heavy because upper level winds are light. An inch of rain wouldn't be unusual from any single storm that develops. And if a storm sits in one location long enough, we could see more than three inches of rain with isolated flooding problems.

I'm also concerned that a few of the storms could produce large hail and damaging winds.

The front will meander around the area on Saturday, even shifting north again before it finally plows through early Sunday. There could be a few showers ahead of the front very early Sunday. But at this time, it looks like the worst of the weather will develop after 6 AM Sunday. The front will hit Houston about 10 AM. The rain should end in Houston shortly after Noon, and by 2 PM in Galveston.

Very strong winds will blow in behind the cool front. Temps will probably be in the upper 60s most of the day Sunday, with a brief high in the low 70s. But with 20-30 mph northwest winds, it will feel much cooler.

Lights out Houston!

Have you ever looked at our beautiful skyline at night and wondered whether somebody is really working late in all those offices? Truth is, some of the lights around town are on all night even when nobody's there.

This Friday, commercial property owners, managers and tenants are being asked to shut off the lights when they leave for the day.  According to organizers of Lights Out Houston, "by eliminating just 50% of the lights routinely left on overnight and on the weekends, we can save 8.4M KW-Hours annually. That equals to almost $1 million annually."

Astronomers have been trying to get us to shut off the lights for years. We can't see the stars over Houston because of light pollution. From space, it's easy to pick out large cities because of all the lights, many which are aimlessly pointed toward the sky where the light (and energy) is wasted.

No one is asking you to shut off lights that keep your home and neighborhood secure. But look around your office and your house. If you don't need the lights on, shut them off. Didn't your Dad always tell you that?

Isolated shower produces heavy rain

Here's why we put a 20% chance of rain in the forecast.

Sure, chances are you'll stay dry. But there's enough moisture in the atmosphere that if a shower does show up on Live MegaDoppler13, the rain could be heavy.

That happened on Tuesday. An isolated thundershower developed in northern Harris County and just sat there for over an hour. Winds in the mid-levels of the atmosphere were weak so the storm didn't move much. The image to the left shows the radar rainfall estimate. The dark green shading represents more than 3 1/2" of rain!

The chance of rain will be going up this weekend. A stronger storm will be pushing across the state on Saturday and Sunday. Again, some of the rainfall will be heavy. I'm also concerned some of the storms could produce isolated wind damage.

Today is Earth Day. Try Something New!

I did something scary this weekend: I rode my bike to the store.

I just needed a few things and in honor of Earth Day, I decided to try and bike it. So I put on a backpack and my helmet and set off to maneuver through the traffic. That's the scary part-- traffic.

It's not a long trip; I only live about four city blocks from the store. And honestly, all the drivers I encountered left me plenty of room as I peddled along, going a fraction of their speed.

However, I made up time in the parking lot. I could move much more quickly than the big lumbering SUVs most people were driving. I was cautious while passing through the rows of parked cars, knowing most drivers backing out would be looking for cars, not bikes.

I was in/out of the store and back home in no time. An added bonus: I used my backpack to carry the things I bought, saving a grocery bag.

It worked so well I tried it again Sunday night. I needed a cable for my computer. So once again, I hopped on my bike and peddled off to the store.

I could get used to this! The second trip was easier than the first. And I'm sure if I do this more often, I will get accustomed to cars zipping around me. And if more people start biking, the folks driving cars will get accustomed to sharing the road with bicyclists.

What are YOU doing for Earth Day?

Subtropical jet stream right over Houston

We'll feel a lot of heat and humidity in Houston this week. But despite all the moisture in the air, there won't be much rain.

The map to the left shows the wind speed at about 30,000 feet above the ground. The main branch of the jet stream is well north of Houston right now. However, the weaker subtropical jet is directly overhead. The little bump, or ridge right over Texas, represents higher pressure which should keep us mostly dry. Small disturbances moving with the upper level winds could still produce some isolated showers through Thursday, but the chance that you'll get wet is less than 20%.

By Friday a shift in the jet stream will bring a stronger storm to the middle part of the country. That could produce a few more showers around Houston as well.

Chaos Theory Effects Weather Forecast

The man who developed the concept of the "Butterfly Effect" died last week.

Edward Lorenz, 90, discovered that even the smallest discrepancy in data can produce vastly different results when using computer models. This, he explained in a paper published in 1963, is why weather is unpredictable.

Later in 1972, Lorenz gave a presentation titled, "Predictability: Does the Flap of a Butterfly's Wings in Brazil Set Off a Tornado in Texas?"  The "Butterfly Effect" suggests a small flicker of a butterfly's wings can set off a chain of events that can eventually grow into a major disturbance.

Celebrate Earth Day at the Weather Museum

Earth Day is Tuesday, April 22 and the John C. Freeman Weather Museum will celebrate with a day of family fun.

The date also marks the second anniversary for the Weather Museum, the nation’s first and only museum dedicated to weather. 

The doors will be open from 10 AM to 7 PM and admission is free on that day. The Weather Museum, is located at 5104 Caroline Street in the Museum District.

Houston E-Cycles for Earth Day

The second ABC13 E-Cycle Drive was another huge success...thanks to YOU!

I don't have specific numbers.  But from the looks of it, you donated as much, if not more, electronic waste as last year. Folks dropped off their old computers, laptops, monitors, printers, cell phones, fax machines and computer mice. We also have a huge pile of power cords now.

Everything you donated will be taken apart and reused. As a whole your old computer and e-waste probably isn't worth anything. But the individual components have value and can be reused. Even the smallest capacitors and resistors can be reused.

Special thanks also to all the volunteers who helped unload the e-waste from cars as they drove through the ABC13 parking lot. Crews will be working into the night to separate the waste, pile it on palettes and prepare it for shipping to the recycling center.

I hope the spirit of the day stays with you. During a special program that aired from 9-10 AM Friday morning, Casey Curry and I gave you lots of ideas on how to "stay green" every day. 

Earth Day is Tuesday, April 22. Let's celebrate!