Case Study: January 31, 2008

A line of thunderstorms moved across southeast Texas early in the morning ahead of a strong cold front. A Tornado Watch was issued for the area at 5:50 AM. No tornadoes were reported. There were a few reports of large hail in Montgomery and Hardin counties. A tree was also knocked down by strong winds near Alvin.

In the weathercasts that aired the day before these storms, ABC13 meteorologists used exclusive FutureTrack computer model data to illustrate when and where the stronger storms would develop. Below is a comparison of the forecast maps shown during the 10 PM news the night before, and the actual satellite/radar images of the storms.

Image One: Rainfall coverage and intensity was forecast fairly well by FutureTrack. The storms in east Texas are not quite as strong as forecast and the line of activity developing ahead of the cold front is about 50 miles farther west than forecast.

(There is a notable difference in the resolution between the FutureTrack model and the observed radar data. FutureTrack uses a 12km grid. This means there are 12 kilometers between data points which accounts for the large contours. Radar data is high resolution so the individual cells are more discreet.)

Image Two: This comparison shows the forecast and actual location of the storms at 7:00 AM. Again, FutureTrack showed a wider area of precipitation than actually developed and the storms were more intense than forecast.

Image Three: The position of the storms is almost identical to what was forecast by FutureTrack. The clearing line behind the storms is perfectly timed along the entire line of activity. The storms are a bit more intense than forecast (more reds in the actual radar data), but that could be attributed to a difference in the resolution between the two data types.

Image Four: Again the position and the coverage of the storms was well forecast by FutureTrack.

Conclusions:  The thunderstorms along this cold front did not develop until the boundary reached central Texas, just northwest of Brenham and College Station. This is different and more difficult for computer modeling to simulate than those storms systems that form well west of the area and simply move across the state. The initial storms developed farther west than forecast, but once the squall line developed the timing verified perfectly. The intensity was under-forecast by FutureTrack throughout the whole event. This is something that will need to be monitored.

The FutureTrack computer model is exclusive to ABC13.  It is the only forecast model focused on southeast Texas. Since the computer is housed locally at ABC13, we have the ability to adjust the model parameters based on past performance. Honest analysis, such as this, is intended to help us improve the forecast you rely on.

Rush hour thunder on Thursday

Strong thunderstorms are likely early Thursday morning, and there's a possibility some of the storms could be severe. The main threat will be large hail and damaging winds. Strong rotation within the lower atmosphere caused by gusty winds could also allow a few tornadoes to form.

The first showers will develop in the warm, humid air after midnight. Additional storms will develop ahead of the cold front throughout the morning rush hour. The sky will quickly clear after the cold front passes between 9 AM and Noon.

Track the storms online and on your cellphone with our million-watt MegaDoppler 13, the most powerful radar in southeast Texas.

Venus and Jupiter in the morning sky

The planets Venus and Jupiter will both be visible in the sky over Houston at the end of this week. Look southeast, just above the horizon early Friday morning.

You'll see both planets right next to each other. It shouldn't be hard to find; Venus and Jupiter are two of the brightest planets in the solar system.

Visibility will be good. There won't be any clouds to block your view. While showers are forecast for Thursday, the sky will clear out behind a cold front.

Houston man to lead Hurricane Center

Congratulations to Bill Read, the Meteorologist-in-Charge at the Houston-Galveston National Weather Service Office. Bill has been selected to lead the National Hurricane Center.

The announcement was made today by National Oceanic and Atmospheric Administration. Bill has "spent 30 years of his career as a weather professional with NOAA dedicated to protecting lives from severe weather, much of it hurricanes and tropical storms," said one NOAA official.

Bill has been in charge of the local NWS office since 1992. He was appointed to be the Deputy Director of NHC after embattled Bill Proenza stepped down last summer.

In addition to being a nice guy, he plays well with others. We've always enjoyed a great working relationship with the Bill and his staff of meteorologists at the National Weather Service. He has also earned the respect of local emergency managers and public officials. Now the rest of the country will benefit from his casual, comfortable leadership.

Global Cooling!??

Scientists in Russia are predicting a drop in global temperatures over the next several years. Their research suggests global warming has peaked. "By the mid-21st century the planet will face another Little Ice Age," said Khabibullo Abdusamatov, head of a space research lab in St. Petersburg, Russia.

This reminds me of medical research that warns "Chocolate is bad for you" one week and then proclaims "Chocolate is good for you" the next. After awhile you stop believing the research.

Strong Cold Front Tonight

Temperatures are dropping about 30° behind a strong cold front now moving across Texas. While some of us in southeast Texas got to see a peek of sunshine today, this front will bring back cloudy, wet weather for Wednesday.

None of the forecast models have a good grasp on the strength of the cold air coming in. All the models forecast temps behind the front at least five degrees too warm. Since the model data isn't accurately depicting the weather that is actually developing, today's forecast requires greater skill. 

We write our own forecast at ABC13 so you'll probably see different numbers during our weathercasts compared to other radio and TV stations. Our forecast calls for much colder weather Wednesday, Thursday and Friday...much colder than what we previously forecast. A little sun might break through the clouds on Thursday, but we're still keeping the chance of rain pretty high through the weekend.

Wet all week

The weather pattern I blogged about last week has developed. There's rain in the forecast every day this week and into next weekend.

Most of the rain on MegaDoppler 13 will be light to moderate, although a few heavier showers are possible. We are not expecting any widespread flooding problems at this time. This rain is more of a nuisance...more of a bummer, really.

The first chance for a sunny day will be next week.

Moon and Mars: Together Tonight

The clear sky over Houston tonight will give us a good view of the meeting between the Moon and Mars.

Look east after sunset. The red planet will be less than 2 degrees away from the Moon (about the width of two fingers viewed at arm's length.)

But wear a coat! Temps will drop quickly tonight.

More rain next week!

The weather pattern for next week does not look good. A flat, west-to-east zonal flow will develop in the upper atmosphere by Monday. Usually when this happens, we get stuck with wet weather that lasts for several days.

The jet stream will be positioned right over Texas and blowing horizontally across the map. Moisture will keep us cloudy while ripples moving along the jet stream will bring us rain.

Dry air will not have a chance to drop into Texas until the upper wind flow changes. And that might not happen until next weekend!

Sharp clearing on satellite

We saw something interesting on the visible satellite on Thursday. As the sky cleared, the clouds had a very distinct edge. Normally, clouds are a little fuzzy. Not today. Look at the area between Conroe and Liberty. The edge of the cloud bank was almost a straight line!

The sharp clearing brought sunshine back to most areas until more clouds rolled in from the southwest. The new clouds were your typical, fuzzy type of clouds.