Houston Weather Blog

Gulf moisture might bring a few showers

Tim Heller — Sat, 11 Jul 2009 09:13:00 -0500

High pressure has been sitting over Houston since early June, pushing our temperatures well above normal. Now that same weather feature could help bring us a few showers.

The air under high pressure sinks and warms; the higher the pressure in the upper atmosphere, the higher the temperatures near the ground. A few weeks ago, the high was centered right over Houston. That's when we topped out over 100° for seven days in a row. Now the high is located in north Texas and central Oklahoma and that's where the hottest temps are being reported. The high was 117° in Alva, Oklahoma on Friday.

We're on the southeast side of the high pressure circulation now. The easterly winds in the mid and upper atmosphere will draw moisture from the Gulf of Mexico. With the intense surface heating (which causes warm, moist air to rise) and the sea-breeze, a few late afternoon/early evening showers could develop on Saturday and Sunday.

However, the high pressure is very strong and will be working against any clouds that try to build during the heat of the day so coverage will be limited. Very few of us will get wet. But those who do, should enjoy a good soaking.

New weather satellite reaches orbit

Tim Heller — Fri, 10 Jul 2009 15:55:32 -0500

The latest Geostationary Operational Environmental Satellite to be launched into space has reached its orbit and unfurled the solar panels.

Built by Boeing, GOES-14 cost $499 million and will orbit 22,300 miles above the Earth. It will be positioned to monitor weather conditions in the Atlantic Ocean and eastern United States.

Eventually the satellite pictures you see during the weathercasts on ABC13 will be taken by GOES-14. But not for awhile. It will take NASA about five months to check all the on-board systems and prepare the weather satellite for daily use. Then operational control will be transferred to NOAA, the National Oceanic and Atmospheric Administration.

Once it's ready, NOAA plans to store GOES-14 in orbit. There are currently two older weather satellites in use. Another weather satellite, GOES-13, is also being stored in orbit and is ready to monitor the weather in the Pacific and western United States.

A little known fact about satellites

It's actually cheaper to store the instruments in orbit. It costs over $3 million a year, plus man-power, to store a satellite on the ground. Sitting in space, the satellite uses a little fuel and battery power to maintain its position, but NASA designs the satellite so it can be stored for two years.

The normal life span of a weather satellite is ten years. But like everything NASA builds, they usually last much longer.

Image courtesy NASA/Honeywell Tech Solutions, C. Meaney

El Nino has fully developed in the Pacific

Tim Heller — Thu, 09 Jul 2009 16:06:13 -0500

Water temperatures off the west coast of South America have warmed about 1°C above normal. That's enough to declare the official onset of El Nino. This alters the weather patterns around the world.

Of importance to us, is the affect El Nino has on hurricanes. West-to-east blowing winds in the upper atmosphere tend to increase when the water temps rise in the Pacific. The faster winds tear apart developing tropical systems.

Furthermore, NOAA's Climate Prediction Center expects El Nino to continue to build into the coming winter. That usually means wetter weather for us...eventually.

The graph to the right shows the output from various long-range computer models. While the amount of warming varies among the models, they all forecast some additional warming of the water near the equator in the Pacific Ocean.

El Nino conditions develop every two to five years and usually last about 12 months. The last El Nino was in 2006.

Radar X-Ray detects small, but powerful storms

Tim Heller — Wed, 08 Jul 2009 19:09:45 -0500

ABC13's exclusive Radar X-Ray identified several thunderstorms that were topping out over 50,0000' Wednesday afternoon.

Radar X-Ray slices through thunderstorms to see what's inside the clouds. The image above shows a cluster of storms east of Lake Livingston, as seen during 13 Eyewitness News at 6.

The first line on the graph indicates a height 20,000' above the ground. Each additional line represents another 10,000'. The storm on the left side is about 35,000' tall, while the stronger storm on the right is about 55,000' high! Thunderstorms this tall often produce large hail and gusty, damaging winds along with extremely heavy rainfall. You can also see how the upper level winds have displaced the top of the thunderstorm to the east of the rain core.

Here's a screen capture of the thunderstorm that was rumbling along the West Loop about 8:30 PM Wednesday. The main rain core was only 35,000' high. But looking out the window, you could see clouds bubbling up over other clouds, which Radar X-Ray also shows here. Another cluster of storms over eastern Liberty County is visible on the right side of the image.

This radar analysis tool allows us to show you when thunderstorms are getting stronger or weaker and gives you advance warning of a possible severe storm. And you'll see it only ABC13.

Hotter, drier, cooler, wetter....it's all relative

Tim Heller — Wed, 08 Jul 2009 09:13:00 -0500

A few weeks ago, we were moaning when the temperatures first reached the mid 90s. Then we hit 100° for seven straight days and suddenly 95° seemed cool. And it was, relative to the 104° record high temps.

Weather is always relative to recent observations.

Most of the time people ignore a 20% chance of rain when they see it in the extended forecast. Many wrongly assume it will stay dry since there’s an 80% chance it won’t rain. But after weeks and weeks of drought, suddenly we get very excited when there’s a 20% chance of rain in the forecast.

Even some of the features you see drawn on the map every night are relative to other weather. A cool front indicates the edge of air that is cooler relative to the air in front of it. The temperatures might 2° cooler or 20° cooler, but the front looks the same. High pressure is really higher pressure surrounded by relatively lower pressure.

Occasionally I'll get an email from someone who will argue with my description of the weather. I might call it "cool" during the weathercast while someone might prefer "mild." Is 95° very warm or hot? It depends on your perspective, which is relative to the weather in recent days.

95° or 105°. It's all hot to me.

Heavy rain soaks part of the Houston area...finally!

Tim Heller — Tue, 07 Jul 2009 17:56:26 -0500

Your Eyewitness Storm Spotters reported heavy rain from the morning showers. Vernon Reed in Kingwood called in with 4.25" of rain. A healthy 3.24" fell at Terri Williams' house in Pasadena. Unfortunately, the rain was not evenly distributed across the area; only a trace of rain fell in many neighborhoods.

Officially, 1.48" fell at Bush IAH, the heaviest rain in 69 days!

The opportunities for rain are drying up almost as quickly as the ground soaked up the rain that fell Tuesday morning. We have a slight 20% chance of rain in the forecast for Wednesday. A few showers could develop in the residual moisture, but without a stationary front to focus the storm development, there won't be as much rain showing up on MegaDoppler 13 radar.

I see more moisture blowing into the Houston area this weekend which could bring us more scattered showers on Saturday and Sunday.

Send us your rainfall reports on Twitter. Follow "abc13weather" for daily weather reports and storm updates.

Twitter is a free social-networking website that allows us to communicate with you in real-time. We'll be using Twitter during hurricane season to bring you tropical weather updates as well. Sign up today!

Quiet start to 2009 hurricane season

Tim Heller — Mon, 06 Jul 2009 11:06:00 -0500

The first month of hurricane season passed with just one little tropical depression developing off the east coast. There were no named storms in June, which is not at all unusual.

Based on historic data from the National Hurricane Center the first named storm of the season usually develops around July 10. The first hurricane develops about August 14. The most active time of the season is from mid-August through mid-October.

During the month of July, tropical cyclones tend to develop in the Gulf of Mexico and along the east Coast. Decaying frontal systems that stall in these areas can spawn tropical systems. That leaves little time for coastal residents to respond, another reason to have your hurricane plan in place before a storm develops.

Even though our air temperatures have topped out over 100° ten times over the past few weeks, the water temperatures in the Gulf of Mexico are just slightly warmer than normal. As I pointed out here on the Houston Weather Blog two months ago, there's not a lot of deep, warm water in the Gulf. That's still true today.

Meanwhile, water temperatures in the Pacific Ocean are about 1°C above normal...but that's a good thing! This phenomena, called El Nino, tends to increase upper air west-to-east wind speeds which can hamper tropical development in the Atlantic basin.

There's still five months left in the hurricane season. While it might be starting off quiet, I expect things to start to pick up later this summer. Still, all current indications continue to suggest this year won't be active as previous years. Here's a link to all the hurricane season outlooks issued for this year.

New this year: we're tracking hurricanes on Twitter. Follow "abc13weather" for real-time updates on tropical activity and your daily forecast.

When storms develop you'll find the position and forecast track here.

"Normal" temperatures and rain in the forecast

Tim Heller — Sun, 05 Jul 2009 15:13:00 -0500

Another break from the heat is coming this week. This time, instead of temps dropping from 104° to 97° like last week, we'll actually drop back down to normal; the average normal high temperature this time of year is 93°. We haven't been that "cool" since the first week of June. Since then, we've had 27 consecutive days with high temps 95° or warmer and ten +100° days.

The hot high pressure in the upper atmosphere is finally breaking down and allowing a cool front to approach from the north. The Dallas area got a few showers on Sunday. We get our chance on Monday. Our exclusive FutureTrack shows scattered showers developing in the Houston area by late afternoon. With the front stalling out over southeast Texas there's rain in the forecast for Tuesday and Wednesday as well.

There's enough moisture in the air that some downpours are likely. I still expect the rain to be scattered, however, not widespread. So you might hear the thunder, but get no rain or not as much as your neighbors just down the street.

International Space Station visible this week

Tim Heller — Sun, 05 Jul 2009 09:45:00 -0500

The International Space Station will pass over Houston several times this coming week. Here's when and where you need to look this week:

Monday, July 6

9:38 PM Appearing from the southwest
9:41 PM Look toward the southeast
9:44 PM Disappearing into the northeast

Tuesday, July 7

5:40 AM Appearing from the northwest
5:43 AM Look toward the northeast
5:46 AM Disappearing into the southeast

Wednesday, July 8

8:52 PM Appearing from the southwest
8:55 PM Look toward the southeast
8:57 PM Disappearing into the northeast

Thursday, July 9

4:54 AM Appearing from the northwest
4:57 AM Look toward the northeast
5:00 AM Disappearing into the southeast

The International Space Station is about 350 feet long and 45 feet tall. The solar arrays, which are 240 feet wide, reflect light from the sun as it moves across the evening or pre-dawn sky. It moves too fast to watch it through a telescope. But you should have no problem seeing it.... provided the weather cooperates.

Hot as a firecracker this weekend!

Tim Heller — Fri, 03 Jul 2009 09:13:00 -0500

Temperatures will top 100° this weekend, with the Heat Index a little closer to 105°. Temperatures will stay in the 90s through the evening hours but it should drop into the mid 80s by the time fireworks are set off Saturday night.

Earlier this week the jet stream shifted and allowed a weak cool front to sag into Texas. That helped produce a few showers here and elsewhere across the state. This also allowed temps to drop off with highs "only" in the upper 90s for a couple of days. But that hot, high pressure is starting to build again. This will shut off the rain for the weekend and send our temps above the century mark.

However, another adjustment in the upper air pattern should allow another weak front to come near us early next week, producing a few more showers.

Drought conditions worsen

Tim Heller — Thu, 02 Jul 2009 21:55:11 -0500

All of Harris County is in a moderate drought again, that's according to NOAA and the USDA. Counties west of Houston are in an worst shape. The red colors on the map to the right indicate extreme and exceptionally dry conditions.

Altogether, the drought covers 38% of the state now. That's not as bad as it was in early April when almost 80% of the state was in a drought and over half of the state was dealing with a severe drought.

The heavy rain at the end of April washed away the drought worries in Houston. But little rain has fallen since and little rain is in the forecast. Unless the jet stream pattern suddenly changes, expect conditions to worsen over the next few weeks.

June 2009: The second warmest on record in Houston

Tim Heller — Tue, 30 Jun 2009 21:26:13 -0500

It's official-- June was hot!

With an average temperature of 85.6°, June 2009 was the second warmest* on record at Bush Intercontinental Airport. It was warmer than June 1980 when the average temp was 85.1° and June 1998 when the average temp was 85.5°. By the way, the "average temperature" is a combination of the highs AND the lows. The average high temperature was 96.7°.

* I previously wrote that 2009 was the warmest on record. But I got an email from the National Weather Service. Apparently there was a mistake in their records. Data from 1905-1907 was missing from the climate database. Once those records were added, it was revealed that 1906 was actually the hottest June on record with average temperature of 85.9°.

We topped 104° twice, June 24 and 26, which was the hottest temperature ever recorded in Houston during the month of June. Altogether, we had seven consecutive triple digit days, another new record.

Rainfall totaled .27" at Bush IAH, which was -5.08" below normal. June 2009 was the 4th driest on record.

Galveston was not as warm, although it was still much warmer than normal. The average temperature at Scholes Airport was 84.3° which ties with June 2005 for the 5th warmest on record. The hottest day on the island was also June 24, but the temperature was ten degrees cooler in Galveston than it was in Houston.

Only .32" of rain fell in Galveston last month. That's -3.72" below normal. June 2009 was the ninth driest on record.

Historically, when the summer starts off warm it usually stays warm. That doesn't mean we won't have some cool-ish days. But you should expect temperatures to average warmer than normal in July and August as well.

Heat relief coming Tuesday

Tim Heller — Mon, 29 Jun 2009 14:59:06 -0500

Today's record high temperature also tied a record for the most consecutive days with high temps 100° or higher. We've had seven straight days of triple digit temps. That's one more than we had in 1980, considered the hottest summer in Houston. And we still have two more months of summer ahead of us!

But after today, we're not expecting any more triple digit temps this week. And we're cautiously optimistic rain will return as well.

Two weeks ago, Dave Ward asked me on-air how long the heat wave would last. I answered then that the high pressure in the upper atmosphere would start to break down Saturday, June 27 and within a few days temps should begin to fall along with some rain.

Now that the high is breaking down and moving westward, the upper air flow is allowing a weak cool front to push south across Texas. Pockets of heavy rain fell around Dallas early Monday. I expect some scattered showers around here tonight and Tuesday as the front sags south. The real cool air will stay north of us, but we should get a bit of a break on the heat. We're forecasting highs in the mid 90s for the rest of the week! That's still a little warmer than normal, but cooler than it has been.

So far this month, only .27" of rain has fallen at IAH, making this the fourth driest June on record. But with rain in the forecast, that record probably won't stand.

There is some uncertainty in the forecast models about how much moisture will be around this weekend. We put in a slight 20% chance of rain for Friday and Saturday. There is a possibility we might need to put more rain the forecast for the weekend.

If you follow "abc13weather" on Twitter then you knew about the changes to the forecast before everyone else. Twitter is a free, social networking service. In addition to posting daily weather updates, we will be using Twitter this year to tracking tropical weather systems. Sign up today!

Record heat keeps tropical weather away

Tim Heller — Sun, 28 Jun 2009 13:08:52 -0500

Updated Monday morning: The tropical wave has dissipated. There are still a few residual showers but development is unlikely at this point.

Some more good news: an influx of moisture toward the end of the week could produce a few more showers around here. Data is still coming in from the morning forecast model runs. Check back for an update this afternoon.

Previous discussion follows:

Temperatures will hit record highs again today, for the fifth time in six days. Saturday's high was "only" 101° which was one degree below the record high. What concerns me is the records we're breaking were all set in 1980, the hottest summer on record.

The bubble of hot air is good for one thing: it keeps hurricanes away. The tropical wave in the northwest Caribbean is moving into the southern Gulf of Mexico now. Northerly wind shear has kept the storm from becoming organized, but there's still a slight possibility it could strengthen this week if/when the shear weakens.

There's no consistency among the various forecast models. On Friday, most of the guidance showed the weak wave tracking northeast toward Florida once it cleared the Yucatan Channel. Late Saturday, the models shifted 90° and showed the storm tracking toward northern Mexico or south Texas. Today, the models are split between both possible scenarios.

I still think the upper high over Texas will keep this storm away from us. Is that a good thing? While you never wish for a hurricane, we do need the rain.

One thing is fairly constant: while most of the models show the wave developing into a tropical storm, none of them predict a hurricane. Then again, intensity forecasts are not reliable.

New this year, I'll be posting tropical weather updates on Twitter, a free service. Follow "abc13weather" on Twitter.

Tropical wave develops in the Caribbean

Tim Heller — Fri, 26 Jun 2009 16:25:32 -0500

Updated Saturday Evening: The tropical wave over the western Caribbean is still very weak and disorganized. But there is still a chance of this developing once it moves into the Gulf of Mexico on Sunday.

The late computer model runs Saturday night showed a change in the forecast track, which is not unusual. The forecast now moves the system northwest, not toward Florida but into the southern Gulf of Mexico. The intensity forecast, which is always difficult, shows it developing into a tropical storm...but not a hurricane. At least not now.

Even if this thing does track farther north, it probably won't make it to Houston/Galveston. The upper high pressure responsible for our heatwave is still very strong. The clockwise windflow around the high would cause the storm to move westward into Mexico or far south Texas.

Check back for another update Sunday afternoon.

New this season: Track the tropics with "abc13weather" on Twitter.

Previous Discussion follows:

We're watching a big flare-up of clouds over the central Caribbean. The tropical wave quickly intensified Friday afternoon.

The National Hurricane Center put the hurricane hunters on stand-by for a possible flight into the storm on Saturday if it continues to show signs of organization.

The GFDL computer model develops the disturbance into a tropical storm within 24 hours, tracks it through the Yucatan Channel and then dissipates the storm as it moves northeast toward Florida. The HWRF also develops the storm very quickly but holds it together as it tracks toward southern Florida early next week.

The big player in the forecast is a trough of low pressure that is forecast to move across the country over the weekend. We think this trough could help generate a few showers around hereon Monday and Tuesday. If the trough doesn't pick up the storm in the Caribbean, it could make it into the Gulf of Mexico. And depending on where the storm tracks it could quickly strenthen into a hurricane as it moves northward.

The heat goes on

Tim Heller — Thu, 25 Jun 2009 15:35:04 -0500

The Heat Advisory has been extended. We're still forecasting a high temperature of 100° on Friday with a heat index near 105°.

The National Weather Service issues a Heat Advisory when the heat index reaches 108° for two hours over two days. But once the Advisory is issued, the maximum heat index must drop below 105°. That won't happen on Friday.

The upper air high pressure will shift westward this weekend and early next week. This will give us a bit of a break on Saturday and Sunday; temperatures should only top out in the upper 90s this weekend. More importantly, this slight change in the jet stream pattern could allow a weak cool front to push into Texas bringing us some scattered showers on Monday and perhaps Tuesday.

Honestly, we're not very confident on the timing and strength of the front so we might need to adjust the forecast over the next few days.

Unfortunately, the upper high looks like it will strengthen again by the middle of next week sending our temperatures back toward 100°.

Heat Advisory issued for the Houston area

Tim Heller — Wed, 24 Jun 2009 15:54:39 -0500

The high temperature in Houston hit 104° Wednesday afternoon. That's a new record high for the day and it's also the hottest temperature ever recorded in the month of June.

The Heat Index topped 108° at 3 PM Wednesday afternoon. With temperatures expected to hit 103° again Thursday and with the Heat Index expected to be +108° again, the National Weather Service has issued a Heat Advisory for all of southeast Texas.

Our record heat is becoming dangerous. You are encouraged to limit the time you spend outdoors during the afternoon hours when the heat, humidity and sunshine are most intense. Keep in mind the temperature, and thus the heat index, are measured in the shade. Direct sunshine makes it feel another 10-15° hotter.

We expect temperatures to hit 100° again on Friday. But the high pressure in the upper atmosphere begins to weaken this weekend. By early next week, temperatures should drop back into the mid 90s and we've added a slight chance of rain to the forecast beginning Monday.

Until heavy rain returns, Burn Bans are in effect for several local counties.

Watering tips

Tim Heller — Wed, 24 Jun 2009 10:45:00 -0500

I was walking around my yard yesterday morning (before it got terribly hot) and I noticed that there were big cracks in the dirt. Next to the house and my driveway, the ground is so dry it's pulling away from the concrete.

A landscaper I know suggested I change my lawn watering schedule. Instead of running the sprinkler for 10-15 minutes, he suggested I cut the time in half and water twice. This uses the same amount of water, but it allows the moisture to soak into the ground a little deeper and cuts down on run-off.

He also said that with this extreme heat, we need to water more often if we want a lush, green yard. And that, of course, means our water bill will be much higher next month. At some point, we might have to be satisfied to have a yellowish-green yard, which is still better than a brown yard.

Some local communities like Conroe, the Woodlands and Pearland have restrictions which limit when and how often you can water. Other cities could follow if we don't get rain soon.

Everything you wanted to know about 100° heat in Houston, but were too afraid to ask

Tim Heller — Tue, 23 Jun 2009 15:05:01 -0500

The numbers guy in our weather center is meteorologist Travis Herzog. He loves digging through climate data and coming up with little known facts.

Here's what he's uncovered about 100° temperatures in Houston:

Hottest ever: 109° on September 4, 2000

Hottest ever in June: 104° on June 24 and 26, 2009 (Previous record: 103° on June 18, 1918 and June 30, 1980)

Most 100° days in a single year: 32 days in 1980

Earliest date to hit 100°: June 10, 1902

Years temperature has hit 100° during the month of June:

1902 10 times
1906 4 times
1907 1 time
1911 2 times
1918 1 time
1930 2 times
1934 2 times
1978 1 time
1980 8 times
1990 1 time
1998 2 times
2006 1 time
2009 4 times (as of June 26)

First 100° day every year this decade:

Year Date Temp
2009 6/23 101*
2008 7/14 100
2007 8/12 102
2006 6/13 100
2005 7/1 100
2004 8/3 100
2003 8/7 104
2002 8/3 100
2001 8/5 101
2000 7/12 100

*The temperature at Bush Intercontinenal hit 101° Tuesday afternoon, a new record high for the day and the first triple digit day for the year 2009.

Getting even hotter this week!

Tim Heller — Mon, 22 Jun 2009 15:47:30 -0500

Record high temperatures are likely this week. The first triple digit day of the season will be on Wednesday, but we're also forecasting highs 100° or warmer for Thursday and Friday.

Higher pressure in the upper atmosphere has shifted the jet stream to the northern part of the country. The air sinks under the high pressure which leaves us sunny and causes the atmosphere to warm. We started off with temps near 90° at the beginning of June. We first hit the mid 90s on Tuesday, June 9. Now we're headed toward 100° on Wednesday.

There's really nothing unusual about this pattern; it happens every summer. In fact, it was pretty warm here last June. While we didn't hit 100°, the temperatures throughout June 2008 averaged 3.2° above normal. So far, this June is 3.0° warmer than normal.

Here's a list of the record highs for this week and the ABC13 forecast:

Tuesday, June 23

Record High: 99 in 1990
Forecast High: 99

Wednesday, June 24

Record High: 99 in 1980
Forecast High: 101

Thursday, June 25

Record High: 100 in 1980
Forecast High: 101

Friday, June 26

Record High: 102 in 1980
Forecast High: 100

Saturday, June 27

Record High: 102 in 1980
Forecast High: 99

The big question is: when will this heatwave break? We still think the upper high should break down a little this weekend, which should allow temps to begin to fall and perhaps allow precipitation to slide into the Houston area.

NHC Director responds to my blog post

Tim Heller — Sat, 20 Jun 2009 08:13:00 -0500

A few weeks ago I wrote about changes the National Hurricane Center is making to the Saffir-Simpson Scale. Starting this year, the Scale will no longer include references to storm surge.

You shared your comments here on the Houston Weather Blog and, as promised, I emailed them to Bill Read, Director of the National Hurricane Center (shown to the right.) Bill and I swapped emails back and forth several times this past week and he gave me permission to share his comments with you.

First of all, Bill appreciates a “good healthy dialog" which benefits all of us. He wrote, "The tables as shown in your blog and carried on NOAA/NHC web sites and preparedness pamphlets have been a bad addition since day one. You know my ideal world view would be to not have a scale."

Rather than getting rid of the scale or changing it, I suggested NHC should separate the wind and surge levels, but ultimately rank the storm based on whichever poses the greatest threat. During Hurricane Ike, for example, NHC was expecting a 15-20' surge. Using my method, statements would have read, "Hurricane Ike is a dangerous category four hurricane based on storm surge."

Bill explained that very few people know the surge values assigned to the different categories. However, I responded, most people do know a category 3 storm is a major hurricane, 4 is bigger, and 5 is the worst.

Let me be clear: NHC will not be withholding storm surge information from the public. (Based on a few comments to my original blog post, I'm afraid some people misunderstood.) Instead of a storm surge category rank which I propose, NHC meteorologists will be providing specific water levels for locations along the coast, like that shown to the left. Storm surge probabilities will also be issued for coastal communities. The information is complicated and requires people living in surge zones to spend a lot of time deciphering their personal risk which is why, in addition to that mountain of information, we should also offer a simple category that (1) ranks the intensity of the storm and (2) emphasizes the greatest threat.

"Social Science studies consistently say people need specific information (how strong the winds, how much rain, how deep flooding) to elicit the best response." Bill explained.

I'm all for giving people as much information as possible, that's why I show things on-air like the forecast computer models. But in reality, the public is making decisions based on the category ranking. Many folks in Bolivar waited because Ike was "only a category 2 hurricane."

In conclusion Bill wrote, "The message scientists have given me loud and clear is that (a) Saffir Simpson scale, which was developed solely on the basis of maximum wind, cannot be used as an index for surge, and (b) the range of possibilities based on maximum wind, size of wind field, and bathymetry preclude any meaningful universally applicable range of values. A scale will only work if the information is correct and universally applicable.”

Even though NHC says the revised "Saffir-Simpson Hurricane Wind Scale" is an experiment, the changes are most likely permanent. The category of a hurricane has always and will always be based only on the wind speed. It gives no indication of how bad the storm surge will be at landfall.

Storm chasers catch Nebraska tornado

Tim Heller — Fri, 19 Jun 2009 10:45:00 -0500

Over 80 tornadoes have been reported across the country since Sunday. Some areas have been hit more than once.

Storm chasers captured this video of a twister outside of Aurora, Nebraska on Wednesday. The large wedge tornado was about a half-mile wide and stayed on the ground for about 18 minutes. Despite the damage, there were no injuries.

The Storm Prediction Center expects another outbreak of severe weather across the midwest and northeast on Friday and Saturday.

The storms are developing around the edge of the hot high pressure that's keeping our temperatures in the upper 90s.

Venus now a "morning star."

Tim Heller — Thu, 18 Jun 2009 09:45:00 -0500

Early birds will see the planet Venus shining brightly in the eastern sky about an hour before sunrise early Friday morning. And if you look carefully, you might even see Mars and Mercury.

This skymap from StarDate shows Venus and Mars aligned with a sliver of the waning moon early June 19. To the lower left, you might see Mercury if you look through binoculars.

Sunrise is around 6:20 AM. So the best view will be from 5:15-5:45 AM. After that the sky will start to brighten making it impossible to see the faint planets.

Burn bans in effect across southeast Texas

Tim Heller — Wed, 17 Jun 2009 15:32:43 -0500

Several local counties have banned outdoor burning because of the dry conditions. Burn bans are in effect until further notice for the following local counties:

With no widespread, soaking showers in the forecast, I expect the burn bans to expand into several more counties. In past years, even fireworks have been banned due to dry conditions. Watch for updates as we get closer to the 4th of July.

Updated June 26, 2009

Watch "Hurricane Ike: His Story" online

Tim Heller — Tue, 16 Jun 2009 16:03:25 -0500