A bit frustrated with NHC

[jasons2k]

Maybe I am being overlty critical.......

At 5PM We had a 987 mb storm in the Caribbean and the NHC still called it a TS based on wind profiles from recon (which BTW is merely a sampling of the storm - a tightening 987mb storm with a warm core in the Caribbean Sea IS a Hurricane).

Anyway, then on the 6PM *Special* advisory, they seem almost taken aback by the additional pressure drop and subsequent wind measurement, and saying with rapid intensification Dennis may be a Cat 2. when it hits Jamaica.

OK - here is my frustration. This is all standard stuff with a growing hurricane. No surprises here. Often the winds may relax a bit (we see this a lot with eyewall replacements), then the pressure will drop and we will see a period of significant intensification. Why is the NHC sounding so surprised here? Why the miss at 5PM and the need for a rush advisory at 6? grrrrr. THIS, my friends, is why we see so many people get confused.

That said, overall, I think they do a good job, but IMO they should have called Dennis the Hurricane that it was at 5PM.

[Pebbles]

I don't think they were surprised at all. They even mentioned it was intensifying in the discussion. But for the sake of accuracy they held off on calling it a hurricane until it verified. You have to remember they are also dealing with other countries in the path of the storm which we share information with. I think it was prudent of them to handle it the way they did. Telling what was found earlier...adding in the discussion that it will probably need to be upgraded...and then sending out a special advisory when that time came.

[ALhurricane]

The data from recon was not there yet at 5 pm to support upgrading it to a hurricane. In the discussion, they said that it will likely become a hurricane very soon.

As soon as recon found the winds, they upgraded it. What is wrong with that? I don't think they were surprised in the least.

No matter what they do, somebody will find a reason to gripe.

[HurryKane]

I don't think they were surprised at all. They even mentioned it was intensifying in the discussion. But for the sake of accuracy they held off on calling it a hurricane until it verified. You have to remember they are also dealing with other countries in the path of the storm which we share information with. I think it was prudent of them to handle it the way they did. Telling what was found earlier...adding in the discussion that it will probably need to be upgraded...and then sending out a special advisory when that time came.

Agree completely.

You're still gonna have to claw my eyes out to get Stewart though.

[Pebbles]

I don't think they were surprised at all. They even mentioned it was intensifying in the discussion. But for the sake of accuracy they held off on calling it a hurricane until it verified. You have to remember they are also dealing with other countries in the path of the storm which we share information with. I think it was prudent of them to handle it the way they did. Telling what was found earlier...adding in the discussion that it will probably need to be upgraded...and then sending out a special advisory when that time came.

Agree completely.

You're still gonna have to claw my eyes out to get Stewart though.

Oh I would never claw a fellow Stewart lover! *snuggs* Plus what would my hubby say!!!

[senorpepr]

The data from recon was not there yet at 5 pm to support upgrading it to a hurricane. In the discussion, they said that it will likely become a hurricane very soon.

As soon as recon found the winds, they upgraded it. What is wrong with that? I don't think they were surprised in the least.

No matter what they do, somebody will find a reason to gripe.

Yes, I completely agree. NHC wasn't surprised. They were trying to be accurate. I guess some people hate accuracy.

[jasons2k]

Honestly, I'm not trying to find a reason to gripe.

All I'm saying is this:

There is a long list to checkoff for hurricane criteria.

Out of all of them, wind is probably the least reliable from recon. First of all, you are only hitting a small piece of the storm. Second, the flight path over the eyewall just might be during those few minutes when the winds have relaxed for a bit. So, you cannot make an accurate intensity call based on recon data - at most it's an educated guess based on a formula we use to guestimate the surface winds based on the recon. flight elevation.

Anyway, all I'm saying is that all the other criteria were there. The storm was measured at 987 (which BTW pressure readings are a much better baseline to verify storm intensity). It was already, clearly a Hurricane at that time, and the sudden 'oh guess what, on the way out the plane found some winds in there' was almost a joke.

If the plane didn't do that one last pass over the eyewall, guess what - no 6pm advisory and it'd still be called a TS.

[MGC]

I feel your pain with the NHC. I'm still jacked with their job on Cindy. I guess I should just take a chill pill......MGC

[ALhurricane]

First off, while pressure is a good indicator, there are some things to keep in mind. The pressures on average are running lower in the Caribbean this year, therefore it will take a lower than normal pressure to generate hurricane force winds.

Secondly, recon is the ONLY way we can gather accurate, yes I said accurate, wind reports. I do not know how you can say they are unreliable.

The NHC waited for the data to make the call. We all knew it was about to be a cane and they were professional and waited for the data to make the call. I don't see why this is such a big deal.

[Thunder44]

At very least, they should of not lowered the winds in the 5pm advisory, especially when the pressure was dropping. And the recon obviously didn't finish it's investigation, so there were likely stronger winds that weren't found yet.

[senorpepr]

Honestly, I'm not trying to find a reason to gripe.

All I'm saying is this:

There is a long list to checkoff for hurricane criteria.

Out of all of them, wind is probably the least reliable from recon. First of all, you are only hitting a small piece of the storm. Second, the flight path over the eyewall just might be during those few minutes when the winds have relaxed for a bit. So, you cannot make an accurate intensity call based on recon data - at most it's an educated guess based on a formula we use to guestimate the surface winds based on the recon. flight elevation.

Anyway, all I'm saying is that all the other criteria were there. The storm was measured at 987 (which BTW pressure readings are a much better baseline to verify storm intensity). It was already, clearly a Hurricane at that time, and the sudden 'oh guess what, on the way out the plane found some winds in there' was almost a joke.

If the plane didn't do that one last pass over the eyewall, guess what - no 6pm advisory and it'd still be called a TS.

Wait... winds are the least reliable from recon?! Okay... realize that recon uses flight level winds... the winds from the level of which they are flying. They get these winds continuously as they fly. Pressure is not a prefect way of measuring winds. Background pressures and microscale features can throw that off. Recon is a very reliable way of measuring winds. It was very clear Dennis was not a hurricane at the 5pm advisory. The data didn't support it.

[Cape Verde]

The difference between a Tropical Storm and a hurricane is a pretty arbitrary line. It doesn't suddenly become more deadly because the winds have increased a couple of mph.<P>All we want from them is to candid as to what they know for sure, and candid about what they're guessing at and why.

[Pebbles]

From NHC

The Saffir-Simpson Hurricane Scale is a 1-5 rating based on the hurricane's present intensity. This is used to give an estimate of the potential property damage and flooding expected along the coast from a hurricane landfall. Wind speed is the determining factor in the scale, as storm surge values are highly dependent on the slope of the continental shelf in the landfall region. Note that all winds are using the U.S. 1-minute average.

No where there does it say the Cat of a storm is based on pressure... it is ALWAYS based on windspeed. Scientists have to be accurate or they wouldn't be scientist. This is done because of the how there can be pressure differences in relation to what the wind speeds may be just as Senorpepr explained.

Edit: I mean Senorpepr and ALhurricane explained... sorry about that!

[Pebbles]

The difference between a Tropical Storm and a hurricane is a pretty arbitrary line. It doesn't suddenly become more deadly because the winds have increased a couple of mph.<P>All we want from them is to candid as to what they know for sure, and candid about what they're guessing at and why.

TROPICAL STORM DENNIS DISCUSSION NUMBER 8
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
5 PM EDT WED JUL 06 2005

WHILE 18Z DVORAK CLASSIFICATIONS WERE T4.0/65 KT FROM TAFB AND
SAB...AND THE UNITED STATES AIR FORCE RECONNAISSANCE AIRCRAFT
RECENTLY MEASURED A CENTRAL PRESSURE OF 987 MB...MAXIMUM 700 MB
FLIGHT LEVEL WINDS HAVE THUS FAR BEEN ONLY 58 KT. THE ADVISORY
INTENSITY IS THEREFORE ADJUSTED TO 55 KT...BUT THE RECENT PRESSURE
FALLS AND THE INCREASINGLY ORGANIZED APPEARANCE ON SATELLITE
IMAGERY SUGGEST THAT DENNIS COULD REACH HURRICANE INTENSITY
SHORTLY.

Don't know what more to say...

[Cape Verde]

I don't think there's anything more to say. The NHC told us what they knew and gave adequate explanations.<P>When they knew more, they made a special advisory.<P>We all want more information, not less. I'd far rather them admit the uncertainties than to make a wrong call.<P>If there's one thing I've learned at this forum, it's that tropical storm forecasts all about judging the uncertainties and assigning probabilities. If this science was anything less, then we wouldn't have computer models that often predict wildly different outcomes.<P>We'd have one model and it'd always be right.

[Pebbles]

We all want more information, not less. I'd far rather them admit the uncertainties than to make a wrong call.<P>If there's one thing I've learned at this forum, it's that tropical storm forecasts all about judging the uncertainties and assigning probabilities. If this science was anything less, then we wouldn't have computer models that often predict wildly different outcomes.<P>We'd have one model and it'd always be right.

Couldn't agree more!

[soonertwister]

The NHC is getting better on storms all the time. We haven't gotten any bogus info on Dennis thus far, recon flights are going to be regular as long as Dennis remains a threat, and in a couple of days they may increase the flights to every 3 hours.

Relax. If you are anywhere within the cone, prepare for the worst, hope for the best. There's still a lot of time to prepare, but not a lot of time to waste. Hesitation is the worst decision when a hurricane looms. Please remember that.

[jasons2k]

I can't sum it up any better than what Joe B. said on Accuweather - here is his explanation of why Dennis was a Hurricane @5pm:

Let me explain why Dennis is a hurricane, and I think when reviews are done, we will find out that Cindy was too.

The least reliable measurement from the recon is the wind. Its not that the wind reported is not accurate, its that there is no way he can the recon can find the strongest wind every time. The hurricane, like you and me, has strong and weak points and they are always changing. Its like the person who is stronger lets say on the bench press than he or she may be with squats relative to the body. In a supine position, that person may be able to push more weight and be stronger, given that position than someone who may be stronger with the squat. So in a storm can we rely on the wind.

Take Cindy. I have received dozens of emails out of southeastern Louisiana from people saying they had hurricane force winds measured. Are they all wrong, with a 992 mb pressure and an intensifying storm. And what of the idea that the ship kept reporting those high winds was wrong..until the recon found the same wind. And how did that sustained wind of 85 gust to 99 at 150 feet ( and by the way it was on the west side of the storm, which shoots holes into that whole nonsensical idea of tacking wind speed on to forward movement, since the storm was moving north at 13) how come the plane could not find that? Because it cant find every wind speed everywhere, and the storm pulses.

Think about your life. Arent there times of the day when you are stronger or weaker, blood pressure higher or lower? Well what if you are measured at the wrong time.

Now what is the constant we can look at...Pressure. 987 mb over 85 water in July in the Caribbean is a hurricane. Somewhere in the area there are hurricane force winds. Otherwise we are starting to talk record low pressures for tropical storms south of 20 north. Two of the most vivid examples of such things have occurred to South Carolina. Last year of course was Gaston. The more serious one was Hugo, which at 954mb was called a cat 2 storm since the plane could not find over 90kts. It couldnt find it because the eye was big and the flight pattern was missing it. The problem of course was the eye tightened and the pressure dropped 20 mb and when it did the cat 4 winds showed up at landfall. Of course we saw the same thing with Claudette.


Remember we are not talking about a spreading out dying storm here. We are talking about something that is in the caribbean and is a warm core, forced convergence feature. When has anyone seen a 987 mb pressure at 70 west south of 20 that was not a hurricane.

The point is that pressure is the constant measurement that can be reliable since one can fly right into the eye of the system. One can argue at 995 or 998. We have had storms, Bob in 1985, that was 1000 mb at landfall and was called a hurricane. But I think this is now a hurricane, I will use the pressure to justify the argument, and I have a feeling that just like the higher winds suddenly showed up and the track shifted east with Cindy, the track shift I was speaking about for other sources will show up, and if the recon flies around and hits the right spot at the right time, the hurricane force winds will too.

Again, I am not going to worry about who says this is what or that, or who thinks this is official or that is. Its weather, I will state my opinion, back it up, and let the reader...and the weather, decide what is right or wrong..capice, cumpares and cumares? ciao for now ****

[abajan]

...Take Cindy. I have received dozens of emails out of southeastern Louisiana from people saying they had hurricane force winds measured. Are they all wrong, with a 992 mb pressure and an intensifying storm...

Not that I'm necessarily disagreeing with you, but can you confirm if those were sustained winds or wind gusts?

[LSU2001]

Remember Bastardi/Accuweather has an agenda and would love to downplay the NHC/NWS accuracy.
TIM

Always have a critical eye without being prejudiced.