Hurricane Humberto

[rdale]

The METAR obs are NOT hourly, BPT issued many updates during that hour. So your basis is completely incorrect.

What I'm saying is not only did no station report hurricane force winds, for the next 8 hours as it moved inland and still reportedly had > 60mph winds, no station reported anything more than 30-40mph. That's an awful large number of ob sites to pass over...

 

[rdale]

No idea. It's a pretty common occurrence these days, where the winds in the bulletin are never as strong as the actual obs.

 

[Justin E. Reed]

Official wind obs form NWS LCH

ok rdale, maybe this will satisfy you. NWS Lake Charles is still collecting data, but it clearly shows KBPT had an 84mph gust. and a TCEQ had one of 75mph. Now if you have any further doubts over this, I suggest you take it up with them. This is clear data, and if you try and discredit this, then IMO your a little crazy. Just my observation, but dont try and discredit everyone on here.

http://www.srh.noaa.gov/lch/tropical/humberto.php

 

[rdale]

Justin - sorry you just got in... We already noted that on page 1 of this thread (actually, I posted that information.)

NHC said sustained winds were 85mph with gusts to 110mph. If you can find ANY evidence of anything CLOSE to that, I will bow to your clear data.

I don't know why people try to discredit hard data with "I think"s. Meteorology is at its core a science, and science requires evidence. All evidence shows that the storm did not cross the Texas coast with 85mph sustained winds, and it also shows that the storm did not continue into LA with 65mph winds. Yet that's what NHC said, even as the observations proved otherwise...

 

[Jonathan.Brazzell]

The METAR obs are NOT hourly, BPT issued many updates during that hour. So your basis is completely incorrect.

What I'm saying is not only did no station report hurricane force winds, for the next 8 hours as it moved inland and still reportedly had > 60mph winds, no station reported anything more than 30-40mph. That's an awful large number of ob sites to pass over...

I think the most important thing we have to take into account is that the NHC uses 1 minute sustained. ASOS and AWOS measure 2 minute sustained. Differences to be expected in the two measurements. And if you look at the McFadin RAWS station across the western part of Jefferson County shortly after it came ashore, those winds are 10 minute average with sustained 60 at 20 foot level.

 

[Justin E. Reed]

Well, he did come ashore in a relatively lowly populated area, so he may have at some point on the coast, just not for long, we will probably never know the max landfall point, but some of the damage pictures show some good winds.

 

[rdale]

I understand all that... But at L+10 hours NHC still had it at 60mph, and all obs it was passing over were 30-40mph. And even those were very isolated.

And sustained 60mph is STILL not even close to sustained 85mph. That's a pretty big error range.

 

[rdale]

...and I will agree with you in part, however at NO point during the path of H.H. did ANY observation match up with ANY "NHC" wind. And that's where my question is... It supposedly had sustained 60+mph winds from landfall (3am CT) for a good 6-8 hours, covering a LOT of ground. Yet nobody reported anything close to that, and it happens frequently, and it just makes me question...

 

[rdale]

I agree... NHC will continue to spew out numbers that aren't matched by measurements, and I don't expect to change their processes, but in the interest of keeping meteorology a "science" instead of a "feeling" I'll probably bring this up on the next landfall...

 

[rdale]

HGX says damage in their area corresponds with 60-70mph sustained winds.

 

[Derrick Herndon]

The METAR obs are NOT hourly, BPT issued many updates during that hour. So your basis is completely incorrect.

What I'm saying is not only did no station report hurricane force winds, for the next 8 hours as it moved inland and still reportedly had > 60mph winds, no station reported anything more than 30-40mph. That's an awful large number of ob sites to pass over...

Ahh yes, I see them now. I pulled the obs from FSU's archive and they do not contain the specials.

At the time of landfall NHC had to go with the data they had including the recon and WSR-88D data along with the surface obs. At the end of the season they will look over all the data including some obs after the fact. Actually if anything I would not be surprised to see the winds upgraded slightly just prior to landfall. Perhaps the post landfall winds will be dropped some. We'll see. It's not uncommon for revisions to made to the intensities at the end of the season.

 

[rdale]

I can see "time of landfall" errors - but it crossed a LOT of ground over the 6-10 hours it was moving inland and NHC numbers were NOTABLY higher than ALL of the obs. That's where my bigger question lies.

 

[Justin E. Reed]

HGX says damage in their area corresponds with 60-70mph sustained winds.

It made landfall in the NWS Lake Charles Warning Area., which includes Beaumont, High Island, Port Arthur, Ornage, and up to Toledo Bend Resevoir and then east into LA. We'll see what they spit out.

 

[Jack Beven]

Justin - sorry you just got in... We already noted that on page 1 of this thread (actually, I posted that information.)

NHC said sustained winds were 85mph with gusts to 110mph. If you can find ANY evidence of anything CLOSE to that, I will bow to your clear data.

I don't know why people try to discredit hard data with "I think"s. Meteorology is at its core a science, and science requires evidence. All evidence shows that the storm did not cross the Texas coast with 85mph sustained winds, and it also shows that the storm did not continue into LA with 65mph winds. Yet that's what NHC said, even as the observations proved otherwise...

I think a little perspective is needed here. The reconnaissance aircraft in Humberto at landfall fixed the center at 29 degrees 32 minutes North 94 degrees 21 minutes West. At 29 degrees 32 minutes North 94 degrees 11 minutes west - 9 nautical miles to the east - it measured a 850 mb flight-level wind of 98 kt. At 29 degrees 38 minutes North 93 degrees 57 minutes West - 14 nautical miles father to the east-northeast - the flight-level winds dropped below 65 kt. The surface winds probably dropped below 65 kt before then.

The only surface station on the coast in that area is the Sea Rim State Park C-MAN station at 29 degrees 40 minutes North 94 degrees 3 minutes west, which reported two 10-minute average winds of 60 kt. Now, we've not had the time to analyze the data in detail, but I would say there is a possibility the strongest winds passed just west of that station. Hopefully a detailed study of the WSR-88D winds will tell us if that was actually the case.

Now, a few miles doesn't sound like much. But in a tight-cored system such as Humberto a few miles can make a tremendous difference in the experienced winds. The flight-level winds in Humberto decreased about 10 kt over a 5 nautical mile distance out from the maximum measured wind, while in Wilma (an extreme example) the flight-level winds decreased about 70 kt over a 5 nautical mile distance out from the maximum measured wind.

The eye passed over the Beaumont airport, so the eyewall and the radius of maximum winds passed over the station. However, the strongest winds in the storm at the time could have been in the part of the eyewall that did not pass over the station - possibly off to the east. Radar data and damage surveys may tell us more about that.

As for after landfall, I was the duty hurricane specialist during that time. I didn't get any core surface wind observations between Beaumont and Alexandria, so I was relying mainly on WSR-88D data. (The winds in Lake Charles, for example, were probably not representative of the core winds.) Do you have any such observations that were taken in the radius of maximum winds? If so, could you please pass them along for our post-analysis?

We'll be doing some extensive post-analysis of this storm before we settle on a final set of intensities.

Jack Beven

 

[Justin E. Reed]

I think about the only direct pass over of the eye over a ASOS was DeRidder-Beauregard Parish Airport, far inland an the winds never got over 50mph, not much help, but that's the only other one I know of. Like I said earlier, this isn't the most heavily populated area of the Gulf Coast, it's highly likely the max winds shifted in the eye wall around stations, just slamming the pine and oak forests of SE Texas and SW Louisiana. But I'd say from the damage pics from High Island, especially the high school, easily 65-80 mph sustained, maybe a mini-swirl hit the school, I don't know but thats my thinking. Now, a good image of the winds moving around in the eyewall is a radar loop of Hurricane Charley. You can se the deep red core move from the SE side of the eyewall, to the N part as it approached land, and as it moved over the peninsula. Either way Humberto was a surprise and something to really study for years to come, he proved many a meteorologist wrong, thank God it didn't have 2-3 more hours over the water, we could've had a strong cat1 or weak cat2!