Hurricane Dean and Bogus Reporting

ted_reshetiloff

Contributing Partner
I am having a very hard time reconciling the 160kt winds reported on the TV news and the actual bouy observations from NOAA. If I go here:

http://www.ndbc.noaa.gov/station_page.php?station=42056

I see the max gust at 2250 gmt as 58.3 kts, At that same time the weather channel is reporting the hurricane to be located just 1.7 miles from this buoy. I compared lat lon of the buoy with lat lon of the hurricane.

I have done this several times for several hurricanes in several locations. Tried to substantiate these claims of 100-150 kt winds with actual observations from NOAA sites. I have never found one that was even close. I look at a 24 hour history of wind gusts and never see anything even approaching the numbers the guys on TV say. Any weather experts out there want to show me where I can see that it actually blew 150kts someplace in the Caribbean during this storm or any other?

I'm not saying these storms are anything to mess with and don't want to trivialize their power but I feel like I am being fed a bunch of crap by the weather jocks looking to sensationalize story.
 

Shadowfax

Member III
Here, Here! I agree. The Weather Channel has been dying for a hurricane and now that they have one they are going nuts 150 mph winds would pick you up and set you down in the next county and these guys are standing on the beach with a camera crew. I think in this case they just can't get close enough to where the center of the storm is/was so they make due with what they can get standing in front of a hotel.

I don't know about the sea buoys, but NOAA published the following, so there is wind out there somewhere.

000
WTNT44 KNHC 210900
TCDAT4
HURRICANE DEAN DISCUSSION NUMBER 33
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL042007
500 AM EDT TUE AUG 21 2007

DEAN MADE LANDFALL ON THE EAST COAST OF THE YUCATAN PENINSULA NEAR
THE CRUISE SHIP PORT OF COSTA MAYA AROUND 0830 UTC...AND THE EYE IS
NOW JUST INLAND. OBSERVATIONS FROM AN AIR FORCE HURRICANE HUNTER
PLANE INDICATE THAT THE HURRICANE WAS INTENSIFYING RIGHT UP TO
LANDFALL. A PEAK FLIGHT-LEVEL WIND OF 165 KT WAS MEASURED JUST
NORTH OF THE EYE. MAXIMUM SURFACE WINDS FROM THE SFMR WERE 124
KT...BUT IT IS HIGHLY LIKELY THAT THE MAXIMUM SURFACE WIND SPEED
WAS NOT REPORTED BY THE SFMR INSTRUMENT. A GPS DROPSONDE IN THE
NORTHERN EYEWALL MEASURED A WIND SPEED OF 178 KT AVERAGED OVER THE
LOWEST 150 METERS OF THE SOUNDING. BASED ON THE DROPSONDE AND THE
FLIGHT-LEVEL WINDS...THE INTENSITY IS SET AT 145 KT. A DROPSONDE
IN THE EYE MEASURED A CENTRAL PRESSURE OF 906 MB JUST PRIOR TO
LANDFALL. SOME HISTORIC NOTES ARE IN ORDER HERE. THE 906 MB
CENTRAL PRESSURE IS THE NINTH LOWEST ON RECORD FOR AN ATLANTIC
BASIN HURRICANE...AND THE THIRD LOWEST AT LANDFALL BEHIND THE 1935
LABOR DAY HURRICANE IN THE FLORIDA KEYS AND HURRICANE GILBERT OF
1988 IN CANCUN MEXICO. DEAN IS ALSO THE FIRST CATEGORY FIVE
HURRICANE TO MAKE LANDFALL IN THE ATLANTIC BASIN SINCE ANDREW OF
1992.

FORECAST POSITIONS AND MAX WINDS

INITIAL 21/0900Z 18.7N 87.8W 145 KT
12HR VT 21/1800Z 19.1N 90.4W 85 KT...INLAND
24HR VT 22/0600Z 19.6N 93.9W 95 KT...OVER BAY OF CAMPECHE
36HR VT 22/1800Z 20.1N 96.8W 105 KT...INLAND
48HR VT 23/0600Z 20.5N 100.0W 25 KT...INLAND...DISSIPATING
72HR VT 24/0600Z...DISSIPATED.

I tend to believe these people over the Weather Channel, even if they can't seem to get the weekend weather right
 

ted_reshetiloff

Contributing Partner
I still dont get it

Why whould the buoy I refereced in my first post not have recorded higher surface winds? The buoy only showed 58 kts and nothing higher over the past 24hours? I can see upper level winds say at the altitude a plane is flying at being 150kts but I have never seen a NOAA buoy record anything even close to that in all the hurricanes I have followed. I still want to see the site that actually observed and recorded 150kts.
 

Shadowfax

Member III
Ted,

I don't propose that I'm any kind of weather expert, so this is just my read of the situation. I'm sure there is a closet weather man, if not a real one, on the list somewhere that can answerer our questions.

It seems to me that the area where the highest winds are is a relativity small area compared to the total size of the storm and then the highest winds are found on an even smaller section of the north side of the eye wall. The farther away from the eye the lesser the winds and these storms are not really that large, maybe a couple to three hundred miles across before you lose the tropical winds designation, and moving 15 to 35 mph in a given heading. I don't know where the sea buoy in question is relative to the eye of the storm, but if it was one or two hundred miles away, this could account for the discrepancy. As we all know from sailing, the wind at the water surface is less then say 50 feet above the surface, this may also account for some of the difference, though I can't believe that much.

I think the TV weather people all went to Cancun in hopes that they would witness another New Orleans and found that the eye of the storm was a couple of hundred miles away, so Cancun was only getting tropical storm winds, which is why I think they where not blown off the beach, but needed the drama to sell soap, so where quoting wind speeds found hundreds of miles away.

Anyhow, that my read on it, flawed as it probably is.
 

NateHanson

Sustaining Member
Well, the dropsondes are recording those super high wind speeds, so I'd believe them (I'm not sure NOAA has any reason to hype the hurricane).

As for why the nav buoys don't match that recording? I don't know. Perhaps the wind exceeds the mechanical limits of those anemometers. I expect they might not be designed for the rare possibility that they would pass right through the eyewall of a cat 5 hurricane!
 

Captron

Member III
Wind Speeds

It drives me to the point of not watching the news or the weather channel. They can't be happy reporting the facts but everything has to be so dramatic.

In all of this hyped up, jacked up reporting from reporters on the scene, I noticed that in the background, the tiki huts were still standing, with their thatched roofs.

One 'live' report from the Yucatan showed the damage to one poor family's house. There was a hole at one end of their thatched roof. Everything else was intact. It's hard to believe they experienced anything over about 50k with that minimal damage.

:confused:

In another live report, a van backed into the background. When asked about the van, the reporter said "oh, it's just another news service trying to get a satellite signal." Apparently there were several news services staying at that hotel. No doubt each had a crew of 5 or 10 plus equipment. They likely got rooms there because everyone else was required to evacuate. There's times you wish the winds were as high as reported.
;)
 

Blue Chip

Member III
Read #33

Sorry, but they are giing you th facts...on a technical level. You afre looking at a hut still standing and saying they are lying??

Anyway, read again NOAA #33 earlier in this thread. it freally tells the story. notice "aloft" and "at the surface, etc.

Sorry I'm a little biased. I retired from all that wx business in 2000 after 43+ years.
 

Gary G

Member II
From a meteorologist

I posed the question asked here regarding the discrepancy between wind speeds being reported by TV weather guys and data we see on NOAA buoys to Tom Skilling, the WGN TV weather guru here in Chicago. Here is his explanation:

Dear Gary,

The handful of buoys available, wonderful and indispensible as they are as data collection devices for meteorologists, offer us only snapshots of weather often many miles and completely removed from the peak winds of a hurricane. A hurricane’s cloud shield can be deceptive, suggesting the storm’s wind field is larger than it actually is and that these winds somehow extend beyond their actual boundaries. The strongest winds of a hurricane are contained in a relatively compact “doughnut” of high winds surrounding the eye beneath the so-called eye wall. Unless this eyewall passes DIRECTLY over (or within 30-60 miles) of a NOAA buoy, the winds you see reported by the buoy will come nowhere near the peak wind speeds observed at the core of the storm.

Hurricane hunter aircraft criss-cross hurricanes, often for 6-8 hours at a time, with onboard equipment which maps the wind field in detail and calculates its strength. Sensors on the aircraft and “dropsondes”---instrument payloads lauched from the aircraft which radio wind, temp, humidity and pressure info back to the plane as they descend to the oceans below----are the primary sources of wind information from hurricanes. There are also satellite borne sensors which induce and plot the storm’s wind field with great detail. In an area as large as the Caribbean, Gulf of Mexico and Atlantic, the chance one of the comparative handful of buoys will find itself in the core of the hurricane’s strongest winds, is more limited than you might think. That’s why the so-called “weather recon flights” and satellite observations are indispensable in understanding a given hurricane’s structure.

Hope this helps! A great question---thanks for e-mailing us!



Regards, Tom Skilling
 

ted_reshetiloff

Contributing Partner
Problem with the above analogy is that the eye of Dean passed with 1.7 NM of the buoy I was watching. I think the discrepany is due to wind readings being taken aloft and not at the surface. 150kt winds would pick up and toss small cars IMHO. I would like to know the altitudes at which these dropsondes are recording the 150kt wind speeds. It would not surprise me one bit to hear a hurricane had 150kt winds at several thousand feet, but I still want to see a surface recorded data point.
 

NateHanson

Sustaining Member
NOAA report above said:
A PEAK FLIGHT-LEVEL WIND OF 165 KT WAS MEASURED JUST
NORTH OF THE EYE. MAXIMUM SURFACE WINDS FROM THE SFMR WERE 124
KT...BUT IT IS HIGHLY LIKELY THAT THE MAXIMUM SURFACE WIND SPEED
WAS NOT REPORTED BY THE SFMR INSTRUMENT. A GPS DROPSONDE IN THE
NORTHERN EYEWALL MEASURED A WIND SPEED OF 178 KT AVERAGED OVER THE
LOWEST 150 METERS OF THE SOUNDING.
This is saying that the average windspeed from 150 meters to 0 meters of altitude was 178 knots. The SFMR is a stepped frequency microwave radiometer carried aboard the Orion aircraft, and it (somehow) measures windspeeds at the surface. In this case 124 knots.

It seems clear to me that the buoy report you're looking at is wrong. I can't say why it didn't give an accurate reading. But a number of other devices reported by NOAA showed wind speeds over 124 knots at the surface. I think it's much more likely that the buoy was wrong, and all the NHC-collected data is fairly accurate, don't you?
 

ted_reshetiloff

Contributing Partner
Yes I agree it is likely that the buoy missed something. I have been trying for years to validate these other readings with actual buoy reports that were close enough during hurricanes nad not had any luck. Mostly done while watching them come up the chesapeake. ie Isabelle. Would 165kt winds not pick up and throw small cars though?
 

Shadowfax

Member III
Would 165kt winds not pick up and throw small cars though?[/QUOTE]

Yes that is very close to what a tornado does, though a tornado 's winds are more circular, whereas a hurricane's winds tend to be more strait line.
 

ted_reshetiloff

Contributing Partner
Any reports of any cars getting thrown around in any of these hurricanes where 165kt winds have come ashore? Katrina? I know the flooding has moved cars all over the place but I am trying to find an instance of 160+ kts of wind coming ashore and the resulting destruction. I would think that kind of force would demolish any building rip out any tree and simply wipe the surface of the earth clean leaving nothing but some dirt behind. Sort of like the effect of blowing compressed air across a piece of dusty wood.
 

Keith Parcells

Sustaining Member
What about the wave effects?

This is a fine discussion about the weather and the reporting of the bouy. Consider also; the waves must have also had a huge effect on what that bouy reported at that time. Check out this wave data and scroll down to 8/20 @ 2300 hours, for example. If I read this correctly, the waves were 9.5 ft with 16 ft wind waves. So combined, 25.5 ft waves. The way NOAA reports waves, that is the height of 2/3rd of the average waves. 1/3rd of the waves may be bigger. So the bouy floats (just like your boat) and spends a significant amount of time down in the trough or riding up and down the face of the swells. It only gets the full effect when at the crest. It also may be leaned over to a large degree by the wind, as it pulls against its mooring. Perhaps these cause the anemometer to register only a fraction of the true windspeed.
 

Shadowfax

Member III
Wind Speed

165 kn. of wind is about 190 MPH. I believe most tornados have wind speeds around 250 MPH and we have all seen what torandos do to cars and trucks. I suspect that 190 MPH sustained winds would effect a VW differently then a Lincoln, but my guess is that neither one would be exactly where you left it after an hour or so of 190 MPH winds if unprotected.

I think a building built to modern codes can, and do survive these kinds of winds perhaps without its windows and roof shingles, but the structure is still there. I think the code for windows is like 120 MPH in large buildings around here, probably higher in true hurricane zones down south.
 
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