"Normal" temperatures and rain in the forecast

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

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!

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

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

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

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

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

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

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

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

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

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!

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

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

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."

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

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

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Another hot week ahead

As I mentioned on-air last week, it looks like the extremely hot weather will be around all this week too. 

High pressure in the upper atmosphere is parked right over south Texas. This has pushed the jet stream well to our north and left us high and dry.  Afternoon temperatures will continue to average 5-8 degrees warmer than normal all week. That's within 3-5 degrees of the record highs.

And despite all the humidity in the lower atmosphere, there's no chance of rain this week.

There is something good about this particular type of weather pattern. Should any little tropical wave try and drift into the Gulf of Mexico, it won't be tracking toward us. The same hot, high pressure also protects us from tropical weather systems. 

You want it cooler and perhaps a little wetter? Be careful what you wish for.

Drought conditions return to southeast Texas

Only a trace of rain has fallen at Bush Intercontinenal Airport this month. And June is usually the wettest month of the year for us.

We started the year with drought conditions, then excessive rainfall in April brought us back to normal.  Only a third of an inch or rain fell at the airport in May. The last widespread heavy rain fell on April 27 and 28 and that was almost six weeks ago!

The latest survey of soil moisture across the state shows drought conditions are starting to creep back into the area. The map to the left shows dry conditions now cover Fort Bend, Brazoria and most of Galveston county again. Matagorda, Wharton and southern Colorado County didn't get the heavy rain in April and it's still dry in these areas.

We still don't have any soaking showers in the forecast for the next several days. And the long range FutureTrack computer guidance suggests the hot, dry weather will hold for at least another two weeks.

Your old battery powered TV won't work after June 12

When all TV stations switch to a full-digital broadcast this Friday, you will only be able to watch ABC13 on a digital TV.  That battery powered TV you use to watch storm coverage when the power goes out will no longer work, unless it is a digital TV.

Just in time for the digital TV switch (and Father's Day), the price has come down on rechargeable digital TV's.  I found one on sale at Target for $99, plus free shipping!  Radio Shack and Best Buy are selling models for $149. 

I noticed these three models use rechargeable internal batteries. You can't use standard batteries. Our engineers here at ABC13 tell me that's because the LCD screen requires more power than standard batteries can supply. 

However, most come with adapters that allow you to recharge the TV using a standard wall outlet or the outlet in your car.

Hurricane Workshop Tonight

Here's another chance to get some important information about the upcoming hurricane season. The Southeast Harris County Hurricane Workshop is scheduled for tonight at the Pasadena Convention Center.

Doors open at 5:30 PM. Presentations start at 6:30 PM until 9:00 PM.  I'll be making the keynote address, looking back at Hurricane Ike and ahead to the upcoming season.  There will also be a presentation about some new warning components from the National Weather Service.

Vendors will also be on hand passing out information.  And of course, it's all free!

Air France Flight 447 weather conditions

High resolution satellite data shows the pilots of Air France 447 flew through some very intense thunderstorms which probably caused the plane to crash on June 1.

Meteorologist Tim Vasquez obtained the flight plan for AFR447 and used several different weather sources to map out the conditions along the flight. Read his report here.

Based on the position of the last transmission from the pilots before the distress messages were received, Tim's expert analysis indicates the plane was southwest of a cluster of severe thunderstorms and flying northeast. The cloud tops were 56,000-60,000 feet high, an indication of extreme instability with turbulent updrafts and downdrafts. These types of storms would most certainly produce a lot of lightning as well.

We still don't know for sure what brought down the plane. But the meteorological conditions Tim presents in his thorough analysis proves weather was most likely a factor.

"Tiny Tim" tropical storms

Have more hurricanes been developing in the last few years or are we just getting better at finding them?

The most active hurricane season on record was 2005 during which 28 tropical storms developed.  This broke the old record of 21 storms in 1933. But is that a fair comparison? 

Satellites, which we didn't have in 1933, now allow us to identify storms we might otherwise miss.  Eight of the storms that developed in 2005 were found by satellites over the open water of the Atlantic Ocean and never made landfall.   And a few were "Tiny Tim" storms.

I swear I'm not making up that term. Tiny Tims are small, meaningless, short-lived tropical systems.

We had one off the east coast a couple of weeks ago.  It's not that these are new types of storms, but we probably didn't know many of them existed before 1963, before weather satellites started monitoring the ocean.  Steve McIntyre wrote on his blog back in 2007, Tiny Tims are "so minimal that the NHC end-of-season reports do not report a single ship or single shore report of storm-force winds."  Yet they get named because they look like tropical storms on satellite data.

Hurricane records are used in climate research and help set insurance rates. But not every little clump of clouds in the Atlantic will develop into a full-strength hurricane. The problem is we still don't know which ones will strengthen and which storms will fizzle out.

It's a "dry heat" for Houston

Any time the humidity drops around here, it's a nice change in the weather.

The cool front that cleared the coast early Thursday morning blew in lots of dry air. Dew points were a sultry 70° around sunrise. But by early evening, the dew points had dropped into the low 60s.

This dry air cools and heats very efficiently. So although Friday morning will be nice and comfortable, it will get hot. We'll be in the low 80s by midday, and near 90° by mid-afternoon. 

However, it will be a little more comfortable than it has been thanks to the lower humidity.

I expect the ugly muggies to come back this weekend. It will be warm and sticky again by Sunday.