October 18, 2011

Storm names aren't always alphabetical


Typhoon PhilippinesDon Dobrow, in Baltimore, saw in The Sun that the Philippines recently suffered back-to-back hits by typhoons Nesat and Nalgae: “Two [consecutive] typhoons [starting] with the same letter. Do you know the reason for that?” Sure. Typhoons in the northwest Pacific draw names from non-alphabetical lists compiled from 14 nations. Nesat is Cambodian; Nalgae (two storms later) is North Korean. The Philippines later assigned them local (alphabetical) names, Pedring and Quiel.

(PHOTO: Typhoon flooding in Philippines, Romeo Ranoco, Reuters)

Posted by Frank Roylance at 12:03 AM | | Comments (0)
Categories: From the Sun's print edition, Hurricane background

September 17, 2011

Do the worst hurricanes bear female names?


Hurricane Katrina deadKatrina, Hazel, Camille … all terrible hurricanes, and all female names. Someone asked me whether most of the worst storms had female names.

It’s not a fair question, really, since ALL hurricanes bore female names from 1954 to 1978.

But of the top 10 costliest hurricanes since then, four have had male names (Ike, Andrew, Ivan, Charley). Of the top 52 deadliest, only 18 were named. Of the seven since 1978, four had male names (Floyd, Alberto, Andrew and Ivan).  For more on the deadliest and costliest hurricanes, click here.

(PHOTO: A Katrina casualty, one of 1,200 dead. Barbara Davidson, Dallas Morning News/Getty Images, 2005)

Posted by Frank Roylance at 12:01 AM | | Comments (0)
Categories: From the Sun's print edition, Hurricane background

September 5, 2011

Who picks these storm names, anyway?


Hurricane KatiaJeffrey Brauner, in Baltimore, asks: “Who chooses new hurricane names … and why are there some that are rather irregular forms? Why Gert instead of Gertrude, Katia instead of Kate or Katie?” When names of the most deadly or costly storms are retired, an international committee of the World Meteorological Organization chooses new ones. They favor names drawn from all the region's cultures, that are also short, distinctive and easily communicated in various languages.

(NASA PHOTO: Hurricane Katia seen from the International Space Station)

Posted by Frank Roylance at 12:03 AM | | Comments (0)
Categories: From the Sun's print edition, Hurricane background

August 7, 2011

Don't be lulled by lull in U.S. hurricane strikes


Tropical Storm IsabelIt’s easy to dismiss the risks of hurricane strikes, especially when three years have passed since the last one (Ike) struck the U.S. But the dangers are there every summer, and they’re real. Consider: Eight of the 10 costliest U.S. hurricanes on record have struck in the past 10 years. The third deadliest – Katrina, with at least 1,500 lives lost – was just six years ago. Of the 30 costliest storms, 16 were no stronger than Category 2 hurricanes at landfall, and four were tropical storms.

(SUN PHOTO: Isabel flooding, David Hobby, Sept. 19, 2003)      

Posted by Frank Roylance at 12:00 AM | | Comments (0)
Categories: From the Sun's print edition, Hurricane background

June 13, 2011

Beware those "lesser" hurricanes

We have a natural tendency to discount the "weaker" hurricanes, those Cat. 1 and 2 cyclones that seem so run-of-the-mill compared with the Cat. 4 and 5 beasts that show up from time to time.

But the smaller tempests are sometimes the ones that cause the most destruiction. Here's some food for thought: The top 10 most destructive hurricanes, from Daily Finance via CNN Money:

1. Hurricane Katrina, 2005: Landfall category: 3. Damage: $81 billion.

2. Hurricane Andrew, 1992: Landfall category: 5. Damage: $35 billion.

3. Hurricane Wilma, 2005:  Landfall category: 3. Damage: $20.6 billion.

4. Hurricane Ike, 2008:  Landfall category: 2. Damage:  $18 billion.

5. Hurricane Charley, 2004:  Landfall category: 4.  Damage: $14 billion.

6. Hurricane Ivan, 2004:  Landfall category: 3. Damage: $13 billion.

7. Hurricane Rita, 2005:  Landfall category: 3. Damage: $10 billion.

8. Hurricane Hugo, 1989: Landfall category: 4. Damage:  $9.7 billion.

9. Hurricane Frances, 2004:  Landfall category: 2. Damage: $8.86 billion.

10: Hurricane Agnes, 1972: Landfall category: 1.  Damages: $8.6 billion. 


Posted by Frank Roylance at 2:00 PM | | Comments (0)
Categories: Hurricane background

May 26, 2011

Pronouncing those hurricane names


Weather ChannelIt’s almost June 1, time for TV weatherfolk to brush up on their pronunciation of hurricane names. Happily, few foreign monikers are likely to trip them up in 2011.

But NOAA offers a phonetic guide, just in case. The 11th named storm will be Katia (say “ka-TEE-ah”). The 16th is Philippe (“fee-LEEP”). But how will they fare in 2014 with Isaias (can you say “ees-ah-EE-ahs?”), or Laura (“LOOR-ruh”)?

Tune in again in 2016 when they tackle Gaston (“ga-STAWN”), Hermine (“her-MEEN”) and Tobias (“toh-BEE-uss”).

Posted by Frank Roylance at 12:01 AM | | Comments (1)
Categories: Hurricane background

March 30, 2011

AccuWeather's 2011 hurricane forecast is out

The first spring forecast for the 2011 Atlantic Hurricane Season is out.’s Paul Pastelok expects “an active season with more impact on the U.S. coastline than last year.” 

He predicts 15 named tropical storms, with eight reaching hurricane strength, and three becoming “major” (Cat. 3) storms. That’s more than average, but less than 2010’s third-busiest 19, 12 and 5. Since no hurricane made U.S. landfall in 2010, predicting a “higher potential” this year seems a safe bet.  

The season officially begins June 1 and lasts through November. Here's the 2010 storm track map. Click to enlarge.

Last year,'s Joe Bastardi predicted 16 to 18 named storms, a few short of the final count. He also compared the conditions for 2010 to those preceding the 1964, 1995 and 1998 seasons, all of which, he noted, saw major impacts on the U.S.

Pastelok bases this year's predictions on several factors. These include the El Nino/La Nina cycle in the Pacific. We're currently in a waning La Nina, and Pastelok expects it will be in a neutral phase by summer - not cycling into the warm-water El Nino conditions in the tropical eastern Pacific, which tend to produce stronger westerly winds in the Atlantic.Hurricane Igor

"Stronger westerlies would prohibit major storms, or a lot of storms, so it is a critical factor," he said.

Saharan dust is another factor. When it blows west out over the Atlantic, it can inhibit storm formation. "Current projections ... suggest there will be episodes of dust affecting development, but no more than normal," Pastelok said.

He also factors in the Atlantic Multidecadal Oscillation. This is a long-term cycle of Atlantic surface water temperature and atmospheric factors. It has been in a positive, warm-water phase since 1994, and that has meant generally more active hurricane seasons than the historic average.

Pastelok believes the early part of the season will see the highest risk for the western Gulf of Mexico and the southern Caribbean. By the mid- and late-season months, the risk will shift to the eastern Gulf and Caribbean, as well as the Florida peninsula and the Atlantic coast from Florida to the Carolinas. 

(NASA PHOTO: Hurricane Igor, September 2010)  

Posted by Frank Roylance at 8:00 AM | | Comments (3)
Categories: Hurricane background

August 16, 2009

Hurricane Camille made history 40 years ago

Hurricane Camille 

Forty years ago tomorrow, the most powerful storm ever to visit the U.S. mainland crashed ashore along the Mississippi Gulf Coast. Nearly everything in Camille's path, along the coast from Biloxi west to the Alabama state line, was reduced to splinters. If the 190 mph winds (and higher gusts) didn't get it, the 22-foot storm surge probably did. It was the highest storm surge ever recorded in the U.S. Homes went under water 2 miles from the Gulf shore.

Barometric pressure at Camille's center dropped to 26.85 inches, the second-lowest ever measured in the U.S.

More than 200,000 people fled north. Another 44,000 entered shelters. That, plus the relatively low population and development in the region in 1969, prevented the death and destruction from becoming worse than it was. Even so, an estimated 255 people died, and 8,900 were injured. Property damage totaled $4.2 billion in 1969 dollars. Some 14,000 housing units were damaged, and 6,000 more were totally destroyed.

In hindsight, Hurricane Andrew (1992) caused more property damage, and Hurricane Katrina (2005) killed more people. But in its time, Camille was the biggest single destructive event in U.S. history.

And it didn't end after Camille went ashore in Mississippi. The weakening storm moved inland to Kentucky, then turned toward West Virginia and Virginia. Heavy rains and flash flooding caused more damage and deaths in West Virginia. Flash flooding killed 153 people in Virginia as the storm regained tropical storm strength and dropped 12 to 20 inches of rain there. Destruction and damage were widespread, and totalled more than $140 million in 1969 dollars.

The name Camille was permanently retired from the list of names available for Atlantic hurricanes.

Looking at the old newspaper clips from that week, it's interesting to note what else was going on at the time. The last few hundred thousand music lovers were preparing to leave the site of the Woodstock festival in upstate New York. Lunar astronauts Armstrong, Aldrin and Collins were thinking about whether they would seek new space missions. (Collins was finished; Aldrin wasn't sure, but Armstrong said he was still available to fly.) There was fighting in Vietnam and the Middle East, and the world's longest-surviving heart transplant patient, Dr. Philip Blaiberg, 60, died in a South African hospital 594 days after receiving the world's third heart transplant.

(AP Wirephoto/Parnell McKay, civil defense director for Pass Christian, Miss., surveys the damaged town.)

Posted by Frank Roylance at 11:56 AM | | Comments (1)
Categories: Hurricane background

August 13, 2009

When will we ever learn?

Every time a big hurricane comes ashore and knocks out electric service for a few days or weeks, lots of smart, prepared residents break out (or buy) generators, crank them up and switch their juice back on.

Good for them. The trouble is, every time that happens, a few people place the generators in their basements or their garages. And then someone gets sick or dies from carbon monoxide Sun-Sentinel photo/2008poisoning. 

I've been covering storms for many years, and before every one, public health authorities issue statements and warnings and reminders about this hazard. And every time somebody gets sick or dies.

The same warnings went out before Hurricane Ike struck the Texas Gulf Coast last September. In two languages. And still seven people died, and dozens were treated for CO poisoning, according to a report today by the Centers for Disease Control and Prevention.

More than 80 percent of those injuries were attributed to improper residential use of electric generators. Young people and women seem the most vulnerable, according to the CDC study.

A check of Poison Center calls after Ike found 54 storm-related CO exposure cases. The median age of the victims was 24 years. Nearly two-thirds were female. More than 90 percent were exposed in their homes.

Hyperbaric oxygen chambers were used to treat 15 people. Their median age was 49, and eight were women. Seven people were hospitalized. Thirteen were exposed in their homes, and generators were the source in 13 cases.

Among the dead, the median age was 32 years, with ages ranging from 4 to 76 years. Six were male, and six died due to exposure from a generator placed inside the home or garage. All died within four days of Ike's landfall, the study found.

CDC editors noted that 51 people died from CO exposure after Hurricane Katrina in 2005. All but one of those involved generators. Why can't we learn this lesson? 

When hurricanes threaten, everyone worries about high winds and storms surges. And those things do cause a lot of property damage. But when it comes to killing people, it's the freshwater flooding from heavy rains, and CO poisoning, that kill the most people.

The study's findings, the CDC said, "emphasize the need for effective, storm-related prevention messages concerning proper generator use, and underscore the need for ongoing prevention messages regarding the installation and maintenance of battery-powered CO detectors in homes."


Posted by Frank Roylance at 12:07 PM | | Comments (0)
Categories: Hurricane background

August 7, 2009

Still waiting for the "A" storm

Hurricane Gustav 2002

All these nice names on the shelf and not a single tropical storm to claim them: Ana, Bill, Claudette, Danny and 17 more names for the tropical storms and hurricanes that might pop up in the Atlantic basin this season. And here we are, Aug. 7, and still nothing.

Sure, it's good thing. These storms can wreak terrible damage, kill and maim. But still, it's curious. And the National Hurricane Center says we're not even close to setting a record for the latest-occurring "A" storm.

If you look at all the records dating back to 1851 - before the age of satellite observations - the latest first tropical storm to form took shape on Sept. 15. That was in 1914. The latest first storm to spin to hurricane force was detected on Oct. 8, 1905. They didn't give storms names back then - at least not the way we do today.

If you consider only the years since 1966, when satellite observations became comprehensive - presumably picking up more storms that don't happen to blow past ships at sea or coastal weather stations - the latest first tropical storm to form in the basin was Arlene, which was detected on Aug. 30, 1967. The latest first hurricane was Gustav, which reached hurricane strength on Sept. 11, 2002.

Forecasters say El Nino's likely to blame. The Pacific Ocean phenomenon sets up wind shear patterns in the Atlantic that can cut off hurricane development. (2002 was a "moderate" El Nino year, too. But 1967 was a weak La Nina year.)

So it's quiet. For now.

(NASA PHOTO/Gustav 2002)


Posted by Frank Roylance at 3:41 PM | | Comments (1)
Categories: Hurricane background

April 25, 2008

AccuWeather sees "slightly" more active hurricane season

Yet another crowd of tropical weather forecasters has chimed in with their predictions for the upcoming Atlantic hurricane season. Two weeks ago it was the Colorado State University team of Phil Klotzbach and William Gray, calling for a "well-above average" season.

Now it's's hurricane trackers, led by Joe Bastardi, who's expecting only "slightly more storms than average," with increased risk of U.S. landfalls, during the six-month season that opens, officially, on June 1.

For the record, "average" in the Atlantic basin during the period from 1950 to 2000, means 9.6 named storms, with 5.9 of those growing to hurricane force, and 2.3 of those, on average, reaching Category 3, with sustained winds of 111 mph or more.

Bastardi and his crew say both the waning La Nina conditions in the tropical Pacific Ocean, and a continuing warm-water cycle in the Atlantic argue for slightly more activity than the average, and increase the chances for U.S. landfalls.

More specifically, they note that the warm conditions are not uniform across the basin. "In some areas where hurricanes normally form - the central and eastern tropical Atlantic," Bastardi said, "ocean water temperatures are near or below normal. This should limit the number of storms." So don't expect a blowout season like 2005.

But "the warmest waters relative to normal will be in the northern areas of the Atlantic, especially toward the North American continent. This could potentially increase the threat of major landfalls to the U.S. coast."

Where the spread of storm tracks last year shifted southwest, sending a batch of powerful storms across the northern Caribbean, "this year, early indications show that the spread will move north and east, with a target closer to the Southeast U.S."

In their April 9 forecast, Klotzbach and Gray said there would be a 45 percent chance that a Cat. 3 storm or bigger would make landfall somewhere along the east coast, including Florida. The long-term average for the last century is 31 percent per season.

Bastardi and company say the conditions this year most resemble those in 1955, 1996 and 1999. (Klotzbach and Gray agreed on 1999, but also found analogs in 1950, 1989 and 2000.) NOTE: An earlier version of this post, relying on a release from AccuWeather included inaccurate dates. AccuWeather has since corrected its release, and those fixes are reflected here.)

In 1955, Hurricanes Connie and Diane struck North Carolina. And 1999 saw both Hurricanes Floyd and Dennis strike North Carolina. Here's the storm track for Floyd.


Hurricane season forecasting is, of course, a very young science. Weather and climate are vast, chaotic systems with more variables than even the most advanced computer models can capture with any certainty. These forecasters do their best with the knowledge they have (or think they have). And their efforts get lots of news play because hurricanes are big threats to life and property. There is always some benefit to alerting the public to the risks we face every year, in the hope we will pay attention, and prepare, when storms are on the move.

NOAA - AndrewWhen seasonal forecasts fall short of perfect, as they have in recent years, there's a risk that the public will scoff and pay less attention to the hazard in the future. That would be a mistake. Even a slow storm season can cough up one or two calamitous storms. See Hurricane Andrew in 1992. That's some of Andrew's aftermath at left.

Next up is the National Oceanic and Atmospheric Administration's forecast, due out next month.

Posted by Frank Roylance at 10:48 AM | | Comments (0)
Categories: Hurricane background

September 25, 2007

Summery for now; Fall arrives Saturday

It was a beautiful morning for watching the International Space Station fly over Baltimore and right past a gleaming Venus. But summer resumes this afternoon, with even hotter, muggier weather tomorrow. This early-autumn reprise of summer will be short-lived however.

The big mound of high pressure that's brought us these gorgeous days (which I've enjoyed through the sealed, double-paned windows of the newsroom) will be packing up and heading out to sea shortly. As it departs, Maryland will find itself on the west side of the clockwise circulation around the high. That will bring our air up from the south. Daytime highs today and tomorrow will rise toward 90 degrees and humidities will climb. It's going to feel a whole lot like summer.

As the high moves away, of course, it will be trailed by an approaching cold front and falling barometer. That will bring us increasing clouds and rising chances for rainfall late Wednesday and Thursday. Forecasters out at Sterling have been boosting their estimates. We're looking at 50 to 60 percent rain chances Thursday - showers and even a possible thunderstorm as the front and daytime heating stirs the air. Obviously, we need the rain, so every drop will be welcome. Right now this September ranks as the fourth-driest on record for Baltimore, with just 0.35 inch of rain on the meter at BWI, and 0.42 inch here at Calvert & Centre.

Once the front goes by, pressure will start to rise again Friday and cold air will pour in from the northwest. Skies will clear, and daytime highs will rise only into the mid-70s for the weekend, with sleeping-weather lows in the 50s. That's much more fall-like,  just about exactly in line with the long-term averages for Baltimore at this time of year. 

Posted by Frank Roylance at 9:46 AM | | Comments (0)
Categories: Hurricane background

September 10, 2007

Hurricane season peaks today


Today (Sept. 10) marks the statistical peak of the Atlantic hurricane season. From here, the likelihood that tropical storms will form begins to decline. The season runs through November.

That's not to say we can't still have a busy few months. On the chart above, there's an interesting spike in activity in Mid-October. In fact, forecasters expect the backside of this season will be very active.

So far, we've had 7 named storms, 2 of which became hurricanes - both of them (Dean and Felix) making landfall as Category 5 storms. That's never happened before.

National Weather Service forecasters expect a total of 13 to 16 named storms before the season ends, of which 7 to 9 will become hurricanes. If they're right, we have 6 or 7 more named storms (and 5 to 7 hurricanes) to go. Here's the full report.

Phil Klotzbach and William Gray, at Colorado State University, have predicted 15 names storms and 7 hurricanes this season. That would leave 8 named storms and 5 hurricanes to go. Here's their webpage. A link to their latest report is at the upper left hand corner of their main page.

For now, Gabrielle is the only active tropical system on the charts. There is a disturbance in the Atlantic that forecasters are watching. It could become a tropical storm in the next several days. If so, it will be named Humberto.


Posted by Frank Roylance at 2:36 PM | | Comments (0)
Categories: Hurricane background

September 6, 2007

La Nina coming, with SW drought, SE hurricanes

Federal climatologists say that conditions in the tropical Pacific are shifting toward a full-fledged La Nina event this fall. That could mean a deepening drought in the southwestern United States, and ripening conditions for an active autumn hurricane season.

In a release this morning, the National Oceanic and Atmospheric Administration's Climate Prediction Center said surface waters in the eastern and central Pacific are cooling. The green color in the map, along the equator west of South America show the cooler-than-average sea-surface waters.

"While we can't officially call it a La Nina yet, we expect that this pattern will continue to develop during the next three months, meeting the NOAA definition for a La Nina event later this year," said Mike Halpert, acting deputy director for the Climate Prediction Center, in Camp Springs, Md.

La Nina events typically mean wetter-than-average weather in the Pacific Northwest, and drier-than-average weather in the Southwest. "These conditions also reinforce NOAA's August forecast for an above-normal Atlantic hurricane season," said Gerry Bell, NOAA's lead seasonal hurricane forecaster.

La Nina winters in Baltimore are typically poor snow-producers. But there have been exceptions. Since 1950 there have been 9 winters with moderate-to-strong La Ninas. None produced a storm with 8 inches of snow or more. There were 7 winters with weak La Ninas. They produced only two storms of 8 inches or more. But those were sizable. They included the 22-inch storm in January 1996, and a 15-inch snowfall in January 2000. El Nino winters - when the Pacific is unusually warm - tend to be bigger snow-makers in Baltimore.

La Nina events are declared when average sea surface temperatures in the eastern and central equatorial Pacific, measured over three months, move more than 0.9 degrees Fahrenheit below the average. For months, forecasters have been predicting weak La Nina ocean temperatures for this summer. Those conditions now appear to be developing, with some portions of the east-central Pacific now a degree or two below long-term averages.

Posted by Frank Roylance at 10:12 AM | | Comments (0)
Categories: Hurricane background

September 4, 2007

Is global warming igniting more Cat. 5 storms?

Global warming theory and complex computer climate models predict that a warming ocean will increase the intensity of hurricanes. Both of this year's hurricane to date have made landfall at Category 5 on the Safir-Simpson Scale, the first time that's ever been recorded in the Atlantic basin.

Is there a connection here? Maybe. But it's not as clear as you might think, says Chris Landsea, science and operations officer at the National Hurricane Center.

All the numerical models say we should see increased hurricane intensity as the oceans warm. But Landsea notes that the "sensitivity" of that response is not very impressive - on the order of two percent. In other words, for every one-degree increase in global ocean temperatures, we would expect to see a two-percent increase in hurricane intensity.

Since the tropical oceans are about 1 degree warmer now due to global warming, he said, that means a 160-mph hurricane - the hurricane center's estimate of Felix's top sustained winds at landfall - will instead strike land at 162 mph.

On the other hand, it seems to me, that's an average. Some storms will be more dramatically intensified by warmer oceans, some less so. It's the really bad ones that we worry most about. It's like rising temperatures. The global average is one thing, but the impact is expected to be - and already is - more dramatic in the Arctic and Antarctic. And a seemingly modest rise of a few degrees in the average temperature for Baltimore means some summer days (and some winter days) will be dramatically warmer. And the difference between 95 degrees and 105 degrees on a July afternoon can kill people.

In any case, Landsea said the "real driver" behind the busy hurricane seasons of recent years, and the more numerous Category 5 storms, is a long-term natural cycling of ocean surface temperatures and atmospheric conditions that began in 1995 and is expected to continue for another 10 to 30 years. It's a cycle that looks much like another that began in the 1920s and continued into the 1960s.

"In fact," Landsea said, "there is one year we may have had two Category 5's making landfall."

Those were Hurricane Hilda and Hurricane Janet, in 1955. Both followed the same paths Dean and Felix have this season. "Janet we know was a Category 5," he said. Hilda struck in a sparsely populated region of Central America where measurements were scarce. Hurricane hunter aircraft in those days didn't fly through storms that strong, and there were no satellites to estimate central winds. "We don't have any idea how strong it was," Landsea said. "It could have been a 3, 4 or 5."

We do know it crossed the Yucatan and reintensified in the Gulf of Mexico, becoming a borderline Cat. 3 or 4.

We also know that seasons like this one, in the middle of a multi-decadal upswing in hurricane frequency, and La Nina conditions, the season is "not only busy, but long-lasting," Landsea said. "October and November are quite active as well."

Posted by Frank Roylance at 3:59 PM | | Comments (0)
Categories: Hurricane background

August 21, 2007

Dean was 3rd most intense ever at landfall

Dean at landfall - NOAA

Hurricane Dean had a central barometric pressure of 26.75 inches just before making landfall near the Mexico-Belize border early today. That made it the third-most-intense Atlantic hurricane at landfall since record-keeping began in the 1850s, according to the National Hurricane Center.

The air pressure in the eye of a hurricane is an indicator of a storm's ferocity because it's the low central pressure that powers the winds swirling around the eye, and the storm surge. 

The only storms with lower barometric readings at landfall were the unnamed 1935 Labor Day storm that ravaged the Florida Keys, with a pressure of 26.35 inches; and Hurricane Gilbert, which struck Mexico's Yucatan peninsula in 1988 with a central pressure of 26.22 inches.

The lowest barometric pressure ever recorded in an Atlantic hurricane was 26.05 inches, for Hurricane Wilma while at sea in 2005.

If Dean had made landfall in the United States, it would have ranked as the second-most intense ever to come ashore in the U.S., after the Labor Day storm in 1935. The next-most intense at landfall in the U.S. was Hurricane Camille, a deadly Category 5 storm that tore up the Gulf Coast of Louisiana and Mississippi in 1969. Its pressure at landfall was 26.84 inches.  

In the meantime, a weakened but still deadly Dean continues its trek across the Yucatan. Hurricane warnings are going up along the Mexican Gulf Coast. Here's the latest advisory. Here's the predicted storm track, and here's the satellite view.


Posted by Frank Roylance at 11:11 AM | | Comments (0)
Categories: Hurricane background

July 19, 2007

Is dust over Atlantic stifling hurricanes?

The 2007 Atlantic hurricane season continues to be very tranquil. After an early start that spawned two quick storms in late May and early June, the tropics have settled down quite nicely. (Of course, as soon as I note such trends, they reverse. Beware.) Here's all the National Hurricane Center is watching at the moment.

Saharan dust over E. Atlantic - NASA Terra satelliteOne explanation for the failure of the eastern Atlantic to generate tropical storms at this time of year has been the presence of large clouds of Saharan dust in the atmosphere. Some scientists believe such clouds stifle the formation of the kinds of tropical storms that can eventually reach the Caribbean and the U.S. coast. Here's another shot.

Satellite imagery in recent weeks has been documenting exactly such clouds off West Africa. At left is a shot of the eastern Atlantic, taken Monday by NASA's Terra Earth-observing satellite. Some African dust has been tracked as far west as the Caribbean.

Officially, this has been forecast to be an abnormally active hurricane season - not as busy as the record season of 2005, but busier than last year's unexpectedly quiet summer. Here is the latest National Weather Service estimate for the current season.

Posted by Frank Roylance at 12:49 PM | | Comments (0)
Categories: Hurricane background

May 3, 2007

Katrina costliest, 3rd deadliest U.S. hurricane

With the 2007 hurricane season less than a month away, the National Hurricane Center has updated its listing of the costliest and deadliest hurricanes to strike the U.S.

Not surprisingly, perhaps, Katrina, which struck New Orleans and the Gulf Coast in late August 2005, is ranked as the costliest hurricane in U.S. history, with damages exceeding $81 billion. Even after adjustment for inflation, Hurricane Andrew, which trashed South Florida in 1992, still comes in a distant second, at $42 billion.

In terms of deaths, Katrina ranks third, with an estimated 1,500 dead. The death toll from the 1900 hurricane that ravaged Galveston, Tex. remains the highest at some 8,000. (The true number has never been determined.) In second place is a 1928 storm that killed an estimated 2,500 in South Florida and Lake Okeechobee. 

Katrina also ranks third in storm intensity at landfall, with a barometric reading of 27.17 inches.

For the full report, click here.

It's interesting to note that the 1900 and 1928 storms were both Category 4 storms, while Katrina was a weaker Category 3 at landfall. Andrew - the second-ranking storm in terms of storm damage, does not even rank among the top 50 for storm fatalities.

The standings reflect what hurricane scientists have been saying all along - that while modern early-warning and forecasting skills are saving lives, intense development along our vulnerable coastlines is accelerating the property damage totals from comparatively weaker storms.

Posted by Frank Roylance at 8:10 AM | | Comments (2)
Categories: Hurricane background

April 29, 2007

Hurricane Hunters at Martin Airport

Got the afternoon off Wednesday?  Why not drive out to Martin State Aiport and see the National Oceanic and Atmospheric Administration's "Hurricane Hunter" aircraft? The Orion WP3 will be visiting as part of NOAA's effort to call attention to its role in forecasting the track and power of hurricanes as they approach the U.S. coastline.

The airplane will be open to visitors, and local and state emergency services personnel will have displays on site, too. Here's the lowdown from NOAA. And here's more on NOAA's Hurricane Hunter squadron. They're part of the nation's smallest uniformed service, the NOAA Commissioned Corps., based at MacDill Air Force Base, in Tampa. Here are some of their coolest weather photos.

The NOAA Hurricane Hunters are distinct from the Hurricane Hunters of the 53rd Weather Reconaissance Squadron, part of the Air Force Reserve, based at Keesler AFB, in Biloxi, Miss.

Posted by Frank Roylance at 1:11 PM | | Comments (0)
Categories: Hurricane background

April 3, 2007

East Coast hurricane chances rise

Continuing warmth in Atlantic surface waters and the dissipation of El Nino conditions in the Pacific will combine to bring the U.S. a "very active" hurricane season in 2007, according to hurricane forecasters at Colorado State University. Katrina That is, busier than last year, when no hurricanes made U.S. landfall, but not as active as 2004 and 2005, when storms pummeled Florida and devastated New Orleans and the Gulf Coast. (That's 2005's Katrina at left.)

The CSU forecasting team of Phil Klotzbach and William Gray today boosted the numbers they forecast in December for the upcoming Atlantic hurricane season, citing the faster-than-expected disappearance of the El Nino conditions in the Pacific. They're now anticipating 17 named storms between June and November, besting the long-term average of 9.6. Of those 17 storms, the forecasters expect nine will grow to hurricane strength (The average is 5.9.) Five of those will become Category 3 storms or stronger. (The average is 2.3.)

The CSU forecast also predicts a 74 percent chance one of those major hurricanes will strike somewhere along the U.S. Coast, higher than the average of 52 percent for the past century. There is a 50 percent chance one will hit somewhere on the East Coast, including Florida, more than the 31 percent average for the last century. And, there is a 49 percent chance the Gulf Coast will see a storm that big, the forecast states, up from the long-term average of 30 percent.

Here is the full report. Looking back, Klotzbach and Gray fell far short of predicting 2005's record hurricane season, but so did everyone else. Their forecasts in December 2005, April and June 2006 also badly over-estimated the actual storm counts in last year's season. That season fizzled, meteorologists say, because of the unanticipated development of El Nino conditions in the Pacific, and dust storms from North Africa that blew out over the eastern tropical Atlantic.

This year, Klotzbach and Gray anticipate neutral, or weak-to-moderate La Nina conditions in the Pacific, which would support hurricane formation in the Atlantic. The Atlantic basin also continues to experience unusually warm surface waters, which is another factor supporting hurricane formation. The Atlantic Basin has seen unusually active hurricane seasons in most years since 1995 thanks to warm water conditions there, the CSU team says. That trend, part of a long-term Atlantic climate cycle, is likely to continue for decades to come.

Unlike many climate scientists, Klotzbach and Gray say there is insufficient scientific evidence that global warming is playing a role in the recently heightened hurricane activity in the Atlantic. Their reasoning can be found in their current forecast.

Posted by Frank Roylance at 11:38 AM | | Comments (0)
Categories: Hurricane background

March 28, 2007

Dust or El Nino: What killed the 2006 hurricane season?

Even the nation's top hurricane forecasters were caught off-guard when last year's hurricane season - forecast to be another active one - fizzled. The early explanation was that the development of El Nino Mitch conditions in the central and eastern tropical Pacific Ocean stifled hurricane development in the Atlantic. But some scientists are arguing that dust storms blowing off North Africa were to blame.

As the theory goes, that dust wafts off the desert and out over the eastern Atlantic where many hurricanes are born. It absorbed solar heat and cooled the ocean waters beneath it, cutting off the energy needed to spawn new storms.

Not everyone agrees, of course. This is science, after all. Some say El Nino was a bigger factor. Some say it was mostly the dust. You can read about it for yourself. Just click here.

The 2007 Atlantic hurricane season starts June 1, and the El Nino conditions have ended, so forecasters expect a busier season this time around. The National Hurricane Center's official forecast comes out later this spring. Here's the December prediction from Colorado State University's hurricane forecasting team.

Posted by Frank Roylance at 11:07 AM | | Comments (0)
Categories: Hurricane background

June 12, 2006

Video: 27 storms in 5 minutes

NASA's Goddard Space Flight Center has produced a fascinating video from 2005 Atlantic hurricane season data that recaps the record-smashing six-plus months of storms. It features a speeded-up satellite view of the entire season, tracking each storm as it forms over an overheated ocean, steams toward shore or wanders aimlessly at sea, and then dissipates.

It's very similar to the Science on a Sphere exhibits at the Maryland Science Center and the Goddard visitors center. Nice musical background, too. To watch it, click here.

Posted by Frank Roylance at 1:56 PM | | Comments (0)
Categories: Hurricane background

June 8, 2006

Storms starting later than 2005

OK, so we're ahead of the game, at least so far. On this date last year, meteorologists were already tracking what would become Arlene, the season's first tropical storm in the Atlantic basin. For now, the tropics remain mercifully quiet. Here's a satellite view of the Gulf and the Caribbean and part of the Atlantic.

Arlene was born June 8, 2005 in the western Caribbean Sea, off the coast of Honduras. On June 9th it reached tropical storm strength and received its name. It crossed over western Cuba and headed north across the Gulf of Mexico. About halfway across the gulf it reached its maximum strength, with top winds of about 69 mph.

Arlene made landfall near Pensacola, Fla., with gusts as high as 59 mph. There was little property damage, but one fatality - a Russian exchange student caught in a rip tide at Miami Beach - was blamed on the storm.

What was left of Arlene continued north across Alabama, Tennessee and Illinois, finally merging with other weather systems and passing into hurricane history near Flint, Mich.

But the 2005 season was just getting wound up. Tropical Storm Brett was born on June 28 and became the second named storm. The first hurricane was Cindy, which arrived July 3. Before the season finally wheezed to a close - when Tropical Storm Zeta fell apart in the Atlantic on Jan. 6, 2006 !! - there would be 28 named Atlantic storms - an all-time record.

Posted by Frank Roylance at 4:06 PM | | Comments (0)
Categories: Hurricane background

May 31, 2006

Hurricane forecast unchanged; first storm weakens

The latest pre-season forecast for the 2006 Atlantic hurricane season, which opens tomorrow, was released today. And it shows no change from previous versions. The forecast team led by Phil Klotzbach and William Gray, of  Colorado State University, continues to predict a very active season, with 17 named storms, including 9 hurricanes, of which five are expected to be "major" - meaning Category 3 or higher.

In addition, the Colorado State group is setting an 82 percent chance that at least one major hurricane will make landfall in the United States (the long-term average is 52 percent), and a 69 percent chance it will land on the U.S. East Coast, from Florida northward - more than twice the average. You can read the whole report here.

The good news is that sea surface temperatures across the hurricane-birthing area of the Atlantic, while warmer than average, are cooler than they were at the start of last year's hurricane season. These images from May 2005 and May 2006 tell the tale.

In the meantime, the 2006 Hurricane Season for the Eastern Pacific is already underway, with the first named storm - Aletta - weakening south of Mexico's Pacific coast. Here's the latest (and last) forecast discussion. Here's the satellite view. What's left of Aletta is the mass of clouds at lower right.

Posted by Frank Roylance at 2:59 PM | | Comments (0)
Categories: Hurricane background

May 25, 2006

Tropics calm, for how long?

By now everyone knows we're just a week away from the opening of the 2006 Atlantic hurricane season. Fewer remember that we're just two weeks away from the date, last year, when the first tropical storm of that record season popped up in the western Caribbean.

Tropical Storm Arlene was born June 8, one of the earliest storms on record and the first of a record-shattering 28 named storms last year. It tracked northward across the western tip of Cuba. and across the Gulf of Mexico. It went ashore on the Florida panhandle, near Pensacola. Arlene caused little damage, but a rip current stirred up by the storm was blamed for the death of an exchange student swimming in Miami. Arlene was the first of two tropical storms in June last year. TS Bret formed on June 28, lasted three days and killed one person when it went ashore in Mexico.

Fewer still will remember Tropical Storm Ana, in 2003, which defied the hurricane calendar and emerged in the Atlantic on April 20 - yes, April. It was the first North Atlantic tropical storm ever recorded in April. Ana wandered in the open Atlantic for five days before dissipating.

Forecasters are expecting a very active season this year, with 13 to 16 named storms. Among other factors, the sea surface temperatures in the Atlantic are slightly lower than last year. It's also statistically unlikely that we would see two consecutive record seasons. On the other hand, their pre-season forecast is slightly more pessimistic - calling for slightly more storms - than last year's May forecast (which, at 12 to 15 named storms, turned out to be too conservative by half.) 

Posted by Frank Roylance at 10:04 AM | | Comments (0)
Categories: Hurricane background

May 5, 2006

Northeast hurricane overdue

AccuWeather meteorologists have concluded that the Northeast is overdue for a major hurricane - one like the 1938 storm that ripped across Long Island and tore deep into inland New England. They seem to see a pattern of serious northeast storms following bad Gulf Coast storms by a year. The dense population and the value of development in the Northeast have increased so much since 1938 that a similar strike there today would have huge consequences, perhaps more costly than Hurricane Katrina, the forecasters argue.

One of the best accounts of the 1938 storm was "A Wind to Shake the World," written by the late Everett S. "Joe" Allen. He was a cub reporter on his first assignment for the New Bedford (MA) Standard-Times when the storm struck. He also wrote books about New England whaling and the history of Martha's Vineyard. He was still on the job and a colleague of mine in New Bedford during the 1970s, and one of the finest newspapermen and historians I have ever known. Great beach reading. But keep your NOAA Weather Radio handy.

Posted by Frank Roylance at 12:12 PM | | Comments (0) | TrackBacks (14)
Categories: Hurricane background

May 4, 2006

La Nina ends; fewer hurricanes expected

Residents of hurricane country may catch a break in the upcoming 2006 Atlantic hurricane season. NASA says the La Nina phenomenon, a pattern of cool sea surface temperatures in the tropical Pacific that encouraged Atlantic hurricane formation during the 2005 season, won't be a factor this year. The weak La Nina that prevailed last year has ended, and sea surface temperatures returned to normal in April. Forecasters still expect the coming hurricane season will be more active than the long-term average for other reasons. But they say it's unlikely to be as busy as the record-breaking 2005 season. To read more, click here.

Posted by Frank Roylance at 11:28 AM | | Comments (0) | TrackBacks (17)
Categories: Hurricane background

April 7, 2006

Infamous storm names retired

We won't have Katrina to kick us around anymore. Or Dennis. Or Rita. Or Stan. Or Wilma. All those tropical storm names from the 2005 storm season have been officially retired by the World Meteorological Organization's international hurricane names committee, which includes officials from the National Oceanic and Atmospheric Administration's National Hurricane Center. The decisions came out of their recent meeting in Puerto Rico.

Filling in for the retired names will be Don, Katia, Rina, Sean and Whitney.

The international committee can retire names when storms cause very serious death tolls and damage. Otherwise, the names get recycled and reappear every seventh year in the new list of names. In this case, Katrina, Rita and the others would have popped up and haunted us again in 2011.

Here are the name lists for the upcoming Atlantic Hurricane seasons. The NHC typically assigns 21 names for each season. They run in alphabetical order, skipping Q, U, X, Y and Z, and alternating genders. The names are a mix of names from the languages and cultures of the affected region. If they run through the list, as they did in 2005, the NHC turns to the Greek alphabet.

Last year the busy season ripped right through Alpha, Beta, Gamma, Delta, Epsilon and Zeta before quiet returned to the Atlantic Basin.

Posted by Frank Roylance at 1:41 PM | | Comments (0) | TrackBacks (1)
Categories: Hurricane background

February 23, 2006

The Katrina Report

The White House today released the Bush Administration's critical assessment of its own performance in the aftermath of Hurricane Katrina last August, and the lessons learned (we hope).  Here's a link to the full report.

Posted by Frank Roylance at 12:30 PM | | Comments (0) | TrackBacks (9)
Categories: Hurricane background

December 22, 2005

Katrina struck as Cat. 3, not 4

The National Hurricane Center has concluded that Hurricane Katrina struck the Gulf Coast in August as a Category 3 storm, not a Category 4, as was reported at the time. A more thorough review of the available data indicates the storm's top sustained winds at landfall had fallen below the 131-mph lower threshold for Category 4 storms, as set by the Saffir-Simpson Scale of Hurricane Intensity.

The revision could have an impact on the conclusions of engineers who are studying the failure of New Orleans' levee system. Those dikes were supposedly designed to withstand a Category 3 storm, but not necessarily a Cat. 4.

To read the full NHC Katrina assessment, click here, then scroll down to "Katrina" and click on the file format of your choice.

Posted by Frank Roylance at 11:36 AM | | Comments (0)
Categories: Hurricane background

July 7, 2005

Tis the Season - Some Resources

Hurricane Dennis 1999
Maryland Department of Natural Resources

Hurricane: Surviving the Storm, created by the Maryland Emergency Management Agency

Hurricane Survival Gide from our sister publication, the Orlando Sentinel:

American Red Cross of Central Maryland

Weather Service web cams

Tidal Surge maps for the Bay

Geographic Information Systems and Emergency Management: Lessons Learned During Hurricane Isabel

Posted by Admin at 11:13 AM | | Comments (0)
Categories: Hurricane background

March 23, 2005

Hurricane maps won't feel winds of change

Heavy destruction outside the forecast paths of last year's Florida hurricanes led the National Hurricane Center to consider ways to change its graphics to stress both the uncertainty of the predictions, and the potential for damage far to either side of the central path.

But after consulting with the press and the public, forecasters have decided to stick with the old design. The rest of us will just have to understand that these storms don't always go where they seem to be pointed, and that damage can be terrible far from the storm's center.

Here's the story.

Here's the Weather Service release, with sample graphics.

And here are the Atlantic storm names for the coming years.

Posted by Admin at 6:16 PM | | Comments (0)
Categories: Hurricane background

November 29, 2004

National Hurricane Center wants your help

Forecasters at the National Hurricane Center have worried for some time that the public takes too literally the forecast track maps they publish as storms approach the coast.

The maps show a storm's forecast track as a bold black line, embedded inside a sort of teardrop shape which suggests the range of possible tracks a storm's center might take during the following five days or so. That range grows more uncertain at longer intervals from the time of the forecast.

But meteorologists fret that too many people interpret that bold black centerline as THE forecast storm track, giving it more certainty than forecasters can rightly claim. And because the line is so narrow, it may raise the risk that people on either side of it will relax, or delay storm preparations, even though they remain at considerable risk from hurricane-force, or tropical-storm-force winds.

So, the National Hurricane Center has come up with two prototype alternatives to the old graphic scheme. One simply removes the black centerline, leaving a series of most-likely locations for the storm center, and an "area of uncertainty" - the same teardrop-shaped "bubble" denoting where the storm might go. The other replaces the old graphic with a series of circles encompassing all the most likely locations for the storm's center in the succeeding days.

The NHC is inviting public comment on all three designs. One of them will be adopted for use during the 2005 hurricane season, which begins June 1, 2005.

To me, simply eliminating the centerline, while leaving the dots representing the most likely locations for the storm's center, doesn't solve the problem. The mind's eye can easily connect the dots and sketch in the missing line. The empty circles work better for a storm that's moving fairly steadily, suggesting a wide range of possibilities. But they fail with storms like Jeanne that meander for days in the same region of ocean. It becomes a jumble of circles and conveys much less information.

But that's just me. Have a look, see what you think, come up with something better, and send your ideas along to the NHC.

Posted by Admin at 3:54 PM | | Comments (3)
Categories: Hurricane background

November 3, 2004

Isabel forecasts critiqued by NWS

Storm surge forecasts during Hurricane Isabel gave property owners too little information, according to an internal critique just issued by the National Weather Service. The Sept. 2003 flooding caused extensive damage in Baltimore's Inner Harbor, Fells Point and in many exposed bayside communities. To read the full Isabel "service assessment" click here.

Posted by Admin at 7:20 PM | | Comments (1)
Categories: Hurricane background

September 14, 2004

Saffir-Simpson Hurricane Scale

We've all been reading about the Saffir-Simpson Hurricane Scale. For a complete description, go to this link.

Posted by Admin at 5:57 PM | | Comments (0)
Categories: Hurricane background
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About Frank Roylance
This site is the Maryland Weather archive. The current Maryland Weather blog can be found here.
Frank Roylance is a reporter for The Baltimore Sun. He came to Baltimore from New Bedford, Mass. in 1980 to join the old Evening Sun. He moved to the morning Sun when the papers merged in 1992, and has spent most of his time since covering science, including astronomy and the weather. One of The Baltimore Sun's first online Web logs, the Weather Blog debuted in October 2004. In June 2006 Frank also began writing comments on local weather and stargazing for The Baltimore Sun's print Weather Page. Frank also answers readers’ weather queries for the newspaper and the blog. Frank Roylance retired in October 2011. Maryland Weather is now being updated by members of The Baltimore Sun staff

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