Article on Wilma's winds:

[jasons2k]

Believe it or not: Wilma packed weak winds
By Robert P. King

Palm Beach Post Staff Writer

Monday, November 07, 2005

Hurricane Wilma tossed railroad cars off the tracks near Clewiston, blasted the windows of high-rise condos on State Road A1A, leveled a beloved church in Lake Worth, sank boats in the Intracoastal Waterway and left millions of Floridians without electricity.

Just imagine what a major hurricane would do.

Despite the shredded trees, wrecked homes and widespread disruption left in Wilma's wake, meteorologists say their wind measurements and the storm's impact across Palm Beach County mostly match what would be expected from the lowest tiers of hurricanes: Category 1 or, perhaps, Category 2.

Not an Andrew. Not a Katrina. Not even a Charley.

"It shows you don't need a major hurricane — you don't need a Category 4 or 5 hitting you — to produce disruption," said Robert Molleda, a meteorologist at the National Weather Service's office near Miami.

Officially, the weather service and the National Hurricane Center say Wilma was a Category 3 storm when it hit Southwest Florida near Naples the morning of Oct. 24, and a Category 2 when its eye exited the state near Hobe Sound a few hours later. But after flying over the region, Molleda said he saw mostly evidence of Category 1 damage, with pockets of more severe havoc.

"Most of the damage we saw was minor: a few shingles and a few tiles loose from the roofs, trees down, fences down... damage that you would typically see in a Category 1 storm," he said.

But some communities, including parts of Delray Beach and Boynton Beach, showed more extensive roof and structural damage, possibly indicating Category 2 winds.

Official and unofficial wind measurements tell a similar tale, according to the weather service, the South Florida Water Management District and other agencies that gather wind speeds.

Aside from two sites on Lake Okeechobee — one blowing at 103 mph — no location in Palm Beach County appeared to have exceeded the 82 mph sustained wind reading taken at Palm Beach International Airport, based on initial data. Sustained winds last for at least a minute.

Meanwhile, communities from the Miami suburbs to Boynton Beach and north Palm Beach County felt gusts harsher than 110 mph, according to a National Weather Service compilation of wind readings. The state's fiercest unofficial gust measurements might have been 135 mph at Marco Island and 133 mph near Stuart.

Such gusts can be especially devastating, but they are not unheard of in a Category 1 storm, meteorologists said.

The overall diagnosis sounded accurate to Kurt Gurley, an engineering professor at the University of Florida, who was part of a team that installed five mobile wind gauges along Wilma's path.

"Every one of those instruments recorded essentially Category 1 sustained winds across the state of Florida," Gurley said, although he cautioned that the hurricane's overall strength could have been higher. But even Category 1 power was enough to surprise many residents, he said.

Some wonder whether Wilma was even stronger.

Florida Power & Light is trying to figure out how Wilma snapped up to 10,000 of its concrete and wooden poles while shredding thousands of miles of power lines. That damage caused power failures across South and Southwest Florida, forcing FPL to rebut accusations of shoddy maintenance.

"It's definitely perplexing," utility spokeswoman Pat Davis said. "Based on the damage that we had, the company will say we had more than Category 1 or 2 damage."

Similarly, Palm Beach County Public Safety Director Paul Milelli said the damage in south county, where Wilma destroyed something like 150 homes, appears to be "greater than what a 100 mph wind would do." He suspects that much of the damage came from tornadoes.

Such debates can take years and set off fierce controversy. It took 12 years for the National Hurricane Center to conclude that Andrew, which ravaged south Miami-Dade County in 1992, was a 165-mph Category 5 storm at landfall. Federal researchers already are debating evidence that Katrina was a Category 3 hurricane when it struck the Gulf Coast, not the Category 4 monster official estimates proclaimed.

Meteorologists agree on this, however: Neither of those hurricanes' most infamous victims — Homestead and New Orleans, respectively — felt those storms' strongest winds. Much the same appears to be true for Wilma, which probably unleashed its harshest power at the western end of Everglades National Park.

That kind of news often displeases the victims, said Mark Powell, an atmospheric scientist at the federal Hurricane Research Division in Miami.

"Anyone who got any damage, they want to believe they got the worst possible (hurricane), that there wasn't anything they possibly could have done," he said.

The hurricane center and Powell's agency eventually will release firmer estimates of Wilma's wind speeds, but after such a record-setting hurricane season, it won't be quick.

Hampering the debate is a series of gaps in wind measurements.

No gauge on land in Florida measured sustained wind speeds anywhere close to the 125 mph, Category 3 figure that the hurricane center estimated for Wilma's landfall, which probably inflicted its harshest winds on uninhabited mangrove islands south of Naples. Only two official sites — Lake Okeechobee's south end and Biscayne Bay — recorded even Category 2 winds, according to the weather service's preliminary reports.

Even where readings exist, weather service wind gauges at airports typically stop recording data when the electricity goes out, despite more than a decade of suggestions for hurricane-proofing them.

Federal buoys and weather stations at the Lake Worth pier, part of the Keys and the Dry Tortugas are out of commission from previous storms. Gauges operated by hobbyists and other agencies might be too high, too low, blocked by buildings or otherwise ill-equipped to take accurate measurements.

The upshot: Readings are placed too sparsely to pick up the bands, "mini-swirls" and other variations in a hurricane winds.

Besides those readings, the weather service and hurricane center rely on wind estimates from satellites, airplanes, ground-based radar and instruments that scientists drop into the storm. But the planes typically don't fly into storms over land, and the satellite wind readings work only over water.

Meanwhile, rumors abound.

In Clewiston, United States Sugar Corp. spokeswoman Judy Sanchez said the scuttlebutt has it that someone near Lake Okeechobee measured 150 mph gusts. But she, the weather service and the hurricane center do not have any evidence to support that.

Meteorologists say the data they have supports their general understanding of Wilma: It struck Florida as a Category 3 storm, then weakened as it crossed the state.

"We're confident enough about the observations we received," the weather service's Molleda said. "We're not going to doubt those."

[WxGuy1]

Pretty nice article, and I agree with much of it. It's nice to see an article about how the winds weren't as bad as many folks thought/think they were, since the media seem to over-sensationalize weather events much more frequently... Yes, Cat 1-2 winds CAN cause the destruction seen from Wilma across Florida. This just goes to show how few people usually see the advisory winds from most hurricanes -- the large eye in this case meant that many more people were affected by hurricane force winds.

[quandary]

In the article:

Not an Andrew. Not a Katrina. Not even a Charley.

What type of ordering principle is this? By pressure, it is Katrina, Andrew, Charley. By winds, it is Andrew, Charley, Katrina. No one will dare argue that Katrina's winds were higher than Charley's. By damage, it is Katrina, Andrew, Charley.

[x-y-no]

After the damage that marginal Cat-1 Katrina did in parts of Dade, nobody should be surprised that a mature storm like Wilma, with a large windfield (and recently a Cat-3 thus with high winds aloft to cause gusts) would do substantial damage as a high Cat-1.

[f5]

Katrina:A CAT 3 with a pressure between andrew and Camille that a record i think

[tallywx]

Article is good but the title sucks.

"WEAK" winds? Better title would have been "...category 1 winds" or "Wilma demonstrates the STRENGTH of category 1 winds"

All the title does is reinforce the notion that category 1 winds are somehow "weak," which is totally inconsistent with the article's content.

[jasons2k]

Article is good but the title sucks.

"WEAK" winds? Better title would have been "...category 1 winds" or "Wilma demonstrates the STRENGTH of category 1 winds"

All the title does is reinforce the notion that category 1 winds are somehow "weak," which is totally inconsistent with the article's content.

I agree.

[T'Bonz]

I've been all over Broward county, and from what I have seen, the damage exactly fits what a cat 2 storm would do.

[fci]

Article is good but the title sucks.

"WEAK" winds? Better title would have been "...category 1 winds" or "Wilma demonstrates the STRENGTH of category 1 winds"

All the title does is reinforce the notion that category 1 winds are somehow "weak," which is totally inconsistent with the article's content.

I agree.

"Weak" is a subjective word.
Weak when compared to a Katrina (Gulf coast version), Andrew et al.
NOT weak when compared to Florida's Katrina, Rita .....

It's just good, given the threads saying the media has not told everyone that this was NOT a major hurricane and that many could be worse.
Here, the media does just that; warn that this pales in comparison to what a real major could do.

[Valkhorn]

No gauge on land in Florida measured sustained wind speeds anywhere close to the 125 mph

I always felt this was a terrible argument. It's very difficult for a weather station to report or operate without power - which most in any decent hurricane will lose.

In fact, in Katrina, no station reported even category 1 winds in MS on the coast because the power knocked out or the station was just gone.

In fact, Bay St. Louis's weather station is still missing.

[HurricaneBill]

No gauge on land in Florida measured sustained wind speeds anywhere close to the 125 mph

I always felt this was a terrible argument. It's very difficult for a weather station to report or operate without power - which most in any decent hurricane will lose.

In fact, in Katrina, no station reported even category 1 winds in MS on the coast because the power knocked out or the station was just gone.

In fact, Bay St. Louis's weather station is still missing.

It's also been said many times that the maximum sustained winds in a hurricane are almost always NEVER recorded.

One of the few times I have seen peak maximum sustained winds recorded was during Claudette in 2003. And the recorded winds showed Claudette was stronger at landfall than she was operationally.

Operationally, Claudette was listed as 70 kts at landfall. But she was upgraded to 80 kts in best track.

[hookemfins]

Here is an explanation from Brian Norcross http://www.wfor.com/

Go to the bottom and look for "Hurricane Winds: "the Truth about Wilma"-Bryan Norcross". I'd hurry as to not sure when it will fall off the list.

Basically he claims equipment failure and more research is needed

[Valkhorn]

Also, with Katrina, I'm very skeptical to the SMFR readings on landfall. How well is it able to cope with 30 feet of storm surge on top of land? Wouldn't debris sort of hinder an accurate reading?

Oh well, I think the NHC should have a final say, and frankly I dont see how they will downgrade Wilma to a category 1 at landfall, nor Katrina a category 3 in Louisiana.

[T'Bonz]

Here is an explanation from Brian Norcross http://www.wfor.com/

Go to the bottom and look for "Hurricane Winds: "the Truth about Wilma"-Bryan Norcross". I'd hurry as to not sure when it will fall off the list.

Basically he claims equipment failure and more research is needed

I saw that the night it aired.

And it makes sense. I remember looking all over for stats during the hurricane and during the strongest part, very little was recorded, instrument failure.

What the hell is the use of having instruments if they're going to fail during a minor (not major, being under a cat 3) hurricane?

Here is cat 1 damage as per the NHC:

Damage primarily to unanchored mobile homes, shrubbery, and trees. Some damage to poorly constructed signs. Also, some coastal road flooding and minor pier damage

Here is cat 2 damage as per the NHC:

Storm surge generally 6-8 feet above normal. Some roofing material, door, and window damage of buildings. Considerable damage to shrubbery and trees with some trees blown down. Considerable damage to mobile homes, poorly constructed signs, and piers. Coastal and low-lying escape routes flood 2-4 hours before arrival of the hurricane center.

I've been all over the county in the normal course of my life in the past few weeks, and I'm seeing cat 2 damage all over. I'm seeing tarp after tarp and my own roof sustained minor damage. I've also seen window damage, which I've never seen through Andrew, Katrina, Rita, Frances or Jeanne. Andrew was a cat 1 up here back in 92 (Dade took the brunt.) As strong as Andrew was up here, all it did was knock down trees and blow out signs. Exactly cat 1 damage as per the NHC. During Andrew in 1992, I only saw ONE damaged roof. One. And I was looking. I can see 1 right now after Wilma if I go outside of my front door, my own. :p And I've seen many more than that.

I can't imagine what the folks went through in Andrew in 1992, which was either a 4 or 5. If a 1 or 2 can do what this did, I'm not hanging around for the big boys.

[sponger]

T Bonz, I saw for myself as well (Family in Margate and brother in Western Coral Springs) and saw Cat 2 damage wide spread. It amazes me how many look at a wind reading from 1000 miles away and say look, cat 1!

I do agree the majority of S Fl experienced Cat 1 winds. But anyone who drove through Monday night will know the true story in Western Broward and Southern Palm Beach.

[f5]

Also, with Katrina, I'm very skeptical to the SMFR readings on landfall. How well is it able to cope with 30 feet of storm surge on top of land? Wouldn't debris sort of hinder an accurate reading?

Oh well, I think the NHC should have a final say, and frankly I dont see how they will downgrade Wilma to a category 1 at landfall, nor Katrina a category 3 in Louisiana.

if the NHC downgrades Katrina to a CAT 3 with a 918,920 mb storm everyone will like at that wind/presssure relationship like

[Zackiedawg]

Saffir Simpson descriptions:

Category One Hurricane:
Winds 74-95 mph (64-82 kt or 119-153 km/hr). Storm surge generally 4-5 ft above normal. No real damage to building structures. Damage primarily to unanchored mobile homes, shrubbery, and trees. Some damage to poorly constructed signs. Also, some coastal road flooding and minor pier damage.

Category Two Hurricane:
Winds 96-110 mph (83-95 kt or 154-177 km/hr). Storm surge generally 6-8 feet above normal. Some roofing material, door, and window damage of buildings. Considerable damage to shrubbery and trees with some trees blown down. Considerable damage to mobile homes, poorly constructed signs, and piers. Coastal and low-lying escape routes flood 2-4 hours before arrival of the hurricane center. Small craft in unprotected anchorages break moorings.

Category Three Hurricane:
Winds 111-130 mph (96-113 kt or 178-209 km/hr). Storm surge generally 9-12 ft above normal. Some structural damage to small residences and utility buildings with a minor amount of curtainwall failures. Damage to shrubbery and trees with foliage blown off trees and large trees blown down. Mobile homes and poorly constructed signs are destroyed. Low-lying escape routes are cut by rising water 3-5 hours before arrival of the center of the hurricane. Flooding near the coast destroys smaller structures with larger structures damaged by battering from floating debris. Terrain continuously lower than 5 ft above mean sea level may be flooded inland 8 miles (13 km) or more. Evacuation of low-lying residences with several blocks of the shoreline may be required.

Certainly the damage seen in Southern Palm Beach County and much of Broward county sounds reasonably closer to Category 2 than Category 1...though probably the larger portion of South Florida experienced Category 1 or less. Small pockets of damage may match the Category 3 description...but those could be isolated incidents of microbursts or tornadoes.

It would seem better to emphasize the severity of even a Category 1 storm rather than desribe it as 'weak'...so people can better prepare for the possibility of a strong blow. Maybe the Saffir/Simpson scale should include other facts, such as 'widespread power outages for 3-7 days' for Cat 1, '7-14 days' for Cat 2, etc. Mention of the weight or size of flying debris in each category.

And less emphasis on the 'sustained' winds when describing the hurricanes, since too many people seem to use that measurement to decide how much they need to prepare. While obviously sustained winds are what will wear down a particular structure or tree, the maximum gusts are often responsible for the pockets of more severe damage, and are often the reason for the loss of large trees, signs, and roof tiles. Knowing that even in a Category 1, the maximum gusts can reach 120MPH, people might be more inclined to respect the smaller storms as well.

I had the privelege of watching Frances, Jeanne, and Wilma through hurricane glass, unlike many who shuttered up and couldn't watch the blow-by-blow. And I can verify that in Frances it was the slowness of the storm that wore down trees in our area...after more than 24 hours of sustained 60-90MPH winds, many trees eventually gave up and fell. However Wilma was quite different. The benefit of watching the storm in daylight revealed how the most intense gusts caused 80% or more of the damage in my neighborhood. I watched trees flex, and roof shingles bend, but hold on through the sustained winds. But when a large gust arrived, I watched a 30-year old Banyan drop into my swimming pool, my 25 year old cactus get thrown to the ground, my neighbor's roof shingles peel off 10 at a time, and screen patio enclosures collapse in seconds. While Boca may have only seen sustained winds around 90MPH, it seemed to receive maximum gusts reaching up to 120MPH plus (unscientific...just observed). I had a non-professional home weather station (Davis) which was supposed to be good for measurements to 175MPH...it was reading between 88-95MPH most of the time during the storm, and occasionally would burst higher. The highest reading I saw was 112MPH...but unfortunately the readings all turned to little dashed lines when the back eye wall was raging through. After the storm, I found the outside sensor and anemometer in the dirt and leaves under the hedges at the back of the yard, having been torn off the wall it was mounted to.

[Blown Away]

I've surveyed the damage in Palm Beach & Martin Counties. The damage I saw in South Palm Beach County & Glades was similar to the damage seen in Martin & St. Lucie counties last year after Frances. Frances took care of all the tree overgrowth, weak structures, fences, old roofs, etc in this area. What Frances missed was picked up by Jeanne. N Broward & S Palm Beach Counties got prunned by Wilma. N Palm Beach County & Martin got their prunning last year and alot of people had new roofs, I think that's why you didn't see the damge in N Palm Beach like you saw in S Palm Beach County & Broward. The winds & gusts in N Palm Beach & S Martin were very similar if not higher in some areas than they were in S Palm Beach County.

[Aslkahuna]

The anemometer is supposed to withstand winds up to 175 mph but that goes only for the sensor head and not the attachment to the structure which obviously was not able to withstand winds that strong. That brings up a point about sensors. It matters not how good the sensors are if where and how they are mounted doesn't meet the same level of robustness-the will fail at the lower level by being simply blown off or down. 90 mph winds are high Cat 1 winds and you could conceivably have gusts as high as 130 mph with sustained 90 mph winds overland.

Steve

[f5]

i hear people sometimes refer to 160mph as a weak CAT 5.there is nothing weak about a CAT 5 the damage on the saffir simpson scale is Catastrophic there no such thing a weak catastrophic or super catastrophic.catastrophic means catastrophic period