Sunday, July 31, 2011

Something to watch in the tropics

A strong tropical wave is pushing westward in the Atlantic Ocean, and by the time you read this, it could be a tropical depression or even Tropical Storm Emily.

That system will be the first of the season to grab the attention of the Carolinas and others on the Southeast coast.

Odds are it will curve away from the U.S. coast late this week or early next week, but if the system -- which hurricane specialists expect to become a named storm within a day -- survives its trek across the Caribbean islands this week, it looks as if it will take a swing at the Southeast.

This system is the first of the year to form in the eastern Atlantic and move across the ocean, and odds are there will be a number to follow.

High pressure over the Atlantic Ocean and a trough (weakness between the Atlantic high and another high pressure system over the United States) somewhere off the East Coast will have a big role in determining where this system goes -- should it survive an encounter with Puerto Rico or Hispaniola.

It's for too early to take a guess, but for the first time this year, we have something to watch.

Tropical Storm Don vs. Heat Pump -- No Match! Did you notice what happened Saturday morning, when Tropical Storm Don moved inland in Texas, right into the teeth of the powerful and hot high pressure system which has been baking the Longhorn state for months?

It was no match.

Tropical systems sometimes have the power to break down high pressure ridges, but the system anchored over the Texas-Oklahoma area is a blockbuster.

Forecasters at the National Hurricane Center had expected Don to dump heavy rain as it moved into west Texas, but the tropical storm evaporated.

One National Hurricane Center meteorologist said it was the fastest disintegration of a tropical storm he'd ever seen in a non-mountainous area.

It's gonna take a very strong change in the weather pattern to break down the heat pump over Texas, Oklahoma and the rest of the lower South.

Thursday, July 28, 2011

Just what Texas needs

One of my brothers from Austin was talking with me last week about what it would take to bring an end to the endless string of hot, dry days in Texas.

We agreed a tropical storm would be perfect. It would deliver plenty of rain, but without the dangerous storm surge and hurricane-force winds.

As anyone who has followed weather knows, even a weak tropical storm can produce big trouble. Tropical Storm Allison dumped more than 40 inches of rain near Houston and killed 23 people in 1989. Nobody's wishing for that.

But rain is desperately needed in the Longhorn State, and now Tropical Storm Don appears poised to deliver.

Consensus seems to be that Don will make landfall Friday night near Corpus Christi, but its path is a major issue. Earlier forecasts called for Don to be moving northwest, and since it is a small tropical storm, most of its rain would fall west of the state's major populated areas -- Dallas, Austin, San Antonio, Houston.

The rain shield in tropical storms tends to spread as it makes landfall, but if Don plows into southwest Texas, it would be too far west to help some of the places where precipitation is needed most.

At midday Thursday, however, the computer models started indicating Tropical Storm Don might curve a bit farther north than first thought. That would make a huge difference in where the heavy rain falls.

This is something worth following, because it has implications that amount to millions of dollars in agriculture revenue.

Wednesday, July 27, 2011

Which NFL teams have it worst?

Maybe the NFL's players should have waited a few more weeks before settling their dispute with owners. Then they might have missed the worst of this summer's heat wave.

But as teams return to training camp over the next few days, they will start workouts in some nasty heat.

The Weather Channel published a list Tuesday of the 10 hottest NFL training camps (see, and the Panthers' camp in Spartanburg ranked eighth-worst. Weather Channel meteorologists used averages and factored in both heat and humidity.

This summer's pattern has sent heat into the upper Midwest at times, and that means NFL training camps for teams like the Detroit Lions (Allen Park, Mich.), Green Bay Packers (De Pere, Wis.), and Minnesota Vikings (Mankato, Minn.) might not be a lot of fun some days. Highs of near 100 degrees are expected in some of those places this week.

The added problem this year is the feared lack of conditioning among players. Due to the lockout, NFL players were not able to participate in typical offseason preparations, and it's possible some of them might not be ready to deal with heat, humidity and tough practices.

The NFL has been careful about this issue since Minnesota Vikings player Korey Stringer died in 2001 of heat-related problems.

It's also an issue for fans. If you're headed to Wofford University for Saturday's Panthers' practices, you'll be dealing with 100-degree temperatures and a heat index around 110 degrees. Take plenty of water, and stay in the shade.

This will all seem like a distant dream in December and January, when snow is falling at games in Cleveland (in December, not January -- the Browns have zero chance of making the playoffs); Chicago; Green Bay; Buffalo (December only ... see Cleveland); and New England.

By the way, the Weather Channel's list of the 10 hottest NFL camp sites: 1. Houston Texans (Houston); 2. New Orleans Saints (Metarie, La.); 3. Tampa Bay Bucs (Tampa); 4. Miami Dolphins (Davie, Fla.); 5. Jacksonville Jaguars (Jacksonville); 6. St. Louis Rams (Earth City, Mo.); 7. Tennessee Titans (Nashville); 8. Panthers (Spartanburg); 9. Kansas City Chiefs (St. Louis, Mo.); 10. Atlanta Falcons (Flowery Branch, Ga.).

Tropical Storm Don?: Watch an area of low pressure moving from Mexico's Yucatan Peninsula into the Gulf of Mexico. It shows signs of developing into a tropical system and could be a tropical storm within a day or two.

That system could make landfall anywhere from Mexico to Corpus Christi, Texas. But forecasters seem to think the Mexico-Texas border area is the most likely destination.

Tuesday, July 26, 2011

Another heat wave looms

You know you're in the hottest part of the year when a day with high temperatures in the low 90s is considered a cool-down, but that's how I'm hearing some meteorologists describe today's weather.

This "cool-down" won't last long, as the powerful heat-producing high pressure system that has been baking the Midwest for two months will push back into the Carolinas on Wednesday and control our weather for several days.

It's not clear if we'll be looking at 110-degree heat indices again, as was the case late last week, but conditions probably will be similar.

High temperatures will soar into the middle 90s Wednesday and into the upper 90s Thursday through Saturday. The big question surrounds dewpoint temperatures. They were in the low and middle 70s last week, and that's downright New Orleans-ish. Add those dewpoint readings to 98-degree temperatures, and you get Excessive Heat Warnings.

Today, on the "cool" side of the front, dewpoint temperatures remain in the low 70s, so we can assume Thursday, Friday and Saturday or this week will resemble last week.

A break in the pattern appears in the offing for early next week. Computer models indicate a trough will set up in the eastern United States, and with the upper-level flow coming from the northwest, we can expect a cold front or two to cross the region. That would bring cooling thunderstorms and less heat.

In the meantime, I guess we'll have to enjoy today's low 90s, because it'll seem pleasant by the time we get to late this week.

Sunday, July 24, 2011

This, or January?

The heat wave seems to be broiling every last bit of good nature out of most people, and the National Weather Service's computer models indicate more of the same ahead.

We'll catch a break for a few days -- Monday and Tuesday, to be specific -- when a cold front (well, sort of a cold front) crosses the Charlotte region. Thunderstorm chances will be fairly high Monday, and most areas probably will get some rain.

But the strong high pressure system that seemingly has been anchored over the lower Midwest for many weeks will strengthen again at midweek, and its impact will be felt again in our area. That means high temperatures will be back in the upper 90s by late next week.

I saw a poll Sunday morning on CBS-TV, in which people were asked if they would trade July heat for January's weather. If I saw it correctly, 59 percent said they'd prefer July. Another 39 percent wanted January. I don't know what the other 2 percent asked for -- maybe an end to the NFL lockout.

So I went back six months, exactly a half-year, to Jan. 24 and checked on Charlotte's weather. The high that day was in the mid 40s, and lows were in the lower 20s. That was six to eight degrees below average for late January, just as our recent temperatures have been six to eight degrees above average.

So which do you want -- mid-winter or mid-summer?

Our heating and cooling bills are equally outrageous. In the winter, you can dress in layers. That option is limited in summer. But you won't find 4 inches of snow and ice making the roads treacherous in July.

I always said I prefer the heat, and even the last few days hasn't changed that, although I'm ready to scale back the temperatures a few degrees. I think I understand where the 59 percent in that CBS poll were coming from.

Monday, July 18, 2011

A tropical storm, but no threat

We talked last week about the possibility of a tropical system forming off the South Carolina coast on Sunday and Monday, and the computer models had the right idea.

Tropical Storm Bret is about 100 to 150 miles south of where the computers predicted it might be, but it's roughly in the ballpark.

Meteorologists can't see any way this storm will affect the Carolinas directly, although vacationers on the Outer Banks might see rougher surf and possibly rip currents Wednesday, when Bret is moving to the northeast, several hundred miles offshore.

Bret isn't even forecast to become a hurricane, with most predictions call for it strengthening to a 60-mph tropical storm as it zooms to the northeast, into the open Atlantic Ocean. Eventually, wind shear (a strong counter-clockwise flow around low pressure in the Northeast) will weaken Bret.

Once again, however, we see the same pattern affecting the Carolinas.

High pressure is centered in the Atlantic, and another high is over the Midwest. For several weeks, the Carolinas frequently have been in the middle, between these two highs. Occasionally, the Midwest high pushes eastward a bit and brings higher temperatures (upper 90s). Then it moves back to the west a bit, and the Carolinas get into the flow of low pressure systems moving clockwise around the edge of the high's circulation area.

What happens in another month or two, when tropical storms and hurricanes approach the Southeast coast? Where will the high pressure systems be, and where will the channel between those two highs be set up?

Will the circulation around the Atlantic high serve to steer systems toward the Southeast? Or will tropical storms and hurricanes be recurved back out to sea as they approach the U.S. coast?

If the current pattern persists into August and September -- and weather patterns often persist -- there could be a lot of nail-biting this hurricane season along the coast.

Thursday, July 14, 2011

Enjoy the break ... it won't last

The nice break we're getting over the next few days from typical Carolinas summer heat and humidity will be truly unusual, but it won't last.

OK, I can hear you now, saying it doesn't take a genius to predict that hot weather will return to our area in July. And you're right. It's a no-brainer.

In the meantime, if you're sick of 107-degree heat indices, enjoy it.

High pressure over New England will dominate our area for a couple of days, pushing a cold front to southern South Carolina and Georgia. Incidentally, that situation could provide a hint of what to expect later in the hurricane season, and it isn't good news for the Carolinas. It's a topic I'll write about next week.

Suffice to say the pattern for several weeks has featured a high pressure system over the Atlantic, another high in the Midwest, and a weakness in between. Often, that weakness has been over the Carolinas, and it could be a place where an approaching tropical storm or hurricane could reach the coast.

But that's another topic for another day.

In the meantime, high pressure over the Northeast means cooler weather for a few days. A flow off the Atlantic usually brings clouds, and that could happen Friday and part of Saturday. If we get socked into a low overcast situation Friday, high temperatures might not escape the upper 70s.

By later in the weekend, the Atlantic fetch should be relaxing, which means we'll return to more typical conditions. And the 90s should be back by Monday or Tuesday.

The computer models agree that a huge area of high pressure will dominate the eastern and central United States next week. If the Carolinas are under the control of that high, we'll have some very hot and humid days. If we're on the edge of the circulation, we'll get occasional outbreaks of thunderstorms from weak low-pressure systems moving around the perimeter of the high.

Tropics update: The computer models still show low pressure forming along the stalled front Sunday or Monday. Forecasters say it's too early to determine if that low could take on tropical characteristics.

But you can expect some showery weather early next week from Myrtle Beach southward.

Wednesday, July 13, 2011

Poof! Tropical storm disappears

The computer model giveth, and the computer model taketh away.

Tuesday at this time, we were talking about computer models' predictions that some sort of tropical system would form late this weekend or early next week off the South Carolina coast.

Today, it's difficult to find evidence of such a system on the computer-generated forecasts.

Some of the ingredients definitely will be there.

A cold front that is expected to move across the Charlotte area later tonight or early Thursday is predicted to stall, on an east-west line, from southern South Carolina across southern Georgia and the Gulf coast. The computers agree that some type of low pressure probably will form along the stalled front.

But the more recent forecasts point toward a weaker, more diffuse system.

Such is the danger of engaging in what weather fans call model-hugging -- making wild changes in forecasts every time a new computer model is run.

So let's just leave it at this ... a cold front will stall in an area where stalled fronts sometimes help generate tropical weather systems. And it's July, a time of the year when such systems can form. But the law of averages says the system will be non-tropical -- something that produces a lot of showers and thunderstorms.

We have several more days to change our minds on this.

Tuesday, July 12, 2011

Computers see tropical system for S.C. coast

In the midst of all this talk about heat and high humidity, here's something else to think about.

Two of the more highly regarded computer models are hinting at the development of a tropical system late this weekend or early next week off the Carolinas coast.

It's certainly well before the peak of the tropical weather season, but records show that a storm forms off the Southeast Coast once every two years, on average. So it's not beyond the realm of possibility.

We're not talking about Hurricane Hugo here. The GFS and European models show some sort of tropical low or weak tropical storm forming off the South Carolina coast, then meandering along the coast for a day before sprinting out to sea and intensifying (after it leaves the coast).

The catalyst for this formation would be a cold front that is expected to plow into our region late Wednesday and push into southern South Carolina and Georgia by later Thursday or Friday. The idea, according to the computers, is that low pressure would form along the front and then take on tropical characteristics.

It could mean some big-time rain for the eastern half of South Carolina and probably southeast North Carolina. That's an area still suffering from drought, and heavy rain would do wonders in helping put out some stubborn wildfires.

We'll keep an eye on this over the next few days, because while the system would be too far away from Charlotte for much local impact, it certainly could provide a rainy day (or two) at the beach for local folks down there on vacation.

Dew Points: The real culprit in our current heat wave is the humidity, which can be measured by looking at dew point temperatures.

While the actual air temperature has climbed near 100 degrees in some places Tuesday afternoon, it's the dew point readings that are crazy high. Albemarle's reading at 2 p.m. was 81 degrees. Keep in mind that anything above 65 is humid, and anything above 70 is nasty. An 81-degree dew point temperature is like something you'd find on the Saudi Arabian coast.

Speaking of which ... the supposed world record for highest dew point temperature is 95, set July 8, 2003, in the Saudi city of Dhahrain.

Thursday, July 7, 2011

Outflow boundary ... a storm's footprint

A dying thunderstorm leaves a piece of itself behind in the atmosphere.

Like one of those horror movies, where a supposedly dead monster comes back to life, sprouting from a small piece of itself, thunderstorms can regenerate along their outflow boundary.

In fact, the outflow boundary sometimes is an effective tool for predicting where storms might form the next day.

The outflow boundary is an area of storm-cooled air that moves into much warmer surrounding air.

That boundary also is called a gust front, because a brief period of gusty winds is observed as the area passes by.

The concept isn't difficult to understand. If you jump into a swimming pool, a wave is sent out in all directions. When a blast of cold air comes roaring to the ground in a thunderstorm downdraft, it reaches the earth and is sent out in all directions.

Meteorologists can locates these outflow boundaries by looking for density changes in the atmosphere. And they've learned that the boundaries can persist for 24 or more hours -- long after the storms that created them dissipated.

They've also learned that new thunderstorms often form on the outflow boundaries.

On Wednesday, we had a couple areas of thunderstorms in the Carolinas. One cluster was southeast of Charlotte, around Camden, S.C. Another moved across Cabarrus and Stanly counties. Today, we can look for storms to form somewhere on the edges (or maybe 25 miles out) from Wednesday's storms.

Incidentally, an outflow boundary (or gust front) was responsible for setting off that habob (sand storm) earlier this week in Phoenix. Strong wind gusts from dying thunderstorms that formed in the tropical air off the Gulf of California roared across the flat desert land, kicking up a monster sand storm.

Tuesday, July 5, 2011

Weather warning experiment doesn't work

Give the City of Gastonia credit ... they tried to do something a little different with weather warnings.

Unfortunately, it didn't work. And the failure is another reminder of the dislike (and even anger) that some people have about the way the National Weather Service issues its watches and warnings.

Gastonia launched an automated phone service June 1, in which the issuance of a weather warning would trigger an automated phone call to about 27,000 phones in the city. It worked much the same as the Connect-Ed system used by the Charlotte-Mecklenburg and other school systems. When there's news, a computer-generated phone call is placed to homes, and when people answer the phone, they hear a taped message.

Gastonia officials were using NOAA's All Hazards Radio, which many people have in their homes. When a watch or warning is issued, the radio activates with a tone, and then a message -- delivered by a computerized voice -- reads the warning's details.

Apparently, the service wasn't a big hit in Gastonia. City officials pulled the plug on the calls before the end of June, after getting a couple dozen complaints from residents. Some residents said the warning came after the storm had passed. Others complained that the computerized voice was too difficult to understand.

Doug Outlaw, of the National Weather Service office in Greer, S.C., said his office has nine transmitters across the western Carolinas and northeast Georgia.

The Charlotte area is served by a transmitter at Spencer Mountain in Gaston County, which covers Alexander, Cabarrus, Caldwell, Catawba, Cleveland, Gaston, Iredell, Lincoln, Mecklenburg, Rowan and Union counties.

CMS requires all schools to have working weather radios, and school system officials conduct random checks to insure that the radios are operating.

Gastonia took the idea one step farther, but it didn't work.

It's much like the furor that is raised when TV stations interrupt their programming for weather alerts. Brad Panovich, Eric Thomas, Steve Udelson and their television meteorological counterparts draw scathing criticism in some quarters when they break into a program for live tornado coverage.

Yet many of the people who survived the killer tornadoes this spring in Alabama, Georgia, Tennessee, Mississippi and Missouri say they are alive because of the warnings. Survivors said they were able to find shelter because they knew the storms were coming.

Not everyone has a NOAA All Hazards Radio in their house, and Gastonia was trying to cover that gap.

The idea was admirable, but it apparently needs some tinkering. Here's hoping the concept isn't dropped.