Tropical Depression HUMBERTO Discussion & Images

[KWT]

drezee, I was lucky enough to see it pretty much at its peak when the flight level winds of 98kts were found. I had to admit I nearly went into shock when I saw this topic titled "Hurricane Humberto" I was expecting it to be a 65mph tropical storm, not a 85mph cat-1 hurricane. Just hope the damage wasn't too severe.

first USA hurricane landfalling since Wilma in 05.

[Derek Ortt]

I screwed up as much, if not more than, the NHC did with Humberto

No reason why on nwhhc at 4 p.m. I did not have a TS Warning/cane watch recommended (I did at 7 p.m.... a little too late) and should have recommended a cane warning at 10 p.m., not 12:10 a.m.

[PhillyWX]

Does anybody have radar and satelitte shots of it's landfall?

http://philadelphiaweather.blogspot.com ... texas.html

The radar shot is just after landfall but the eye is well-defined. Satellite is from 0701 UTC on MSFC. That's the closest I could find.

Hope that helps.

[Ed Mahmoud]

JB suspects Humberto moves offsahore near/just East of NOLA, comes back to Texas, but won't make an official prediction, like he did last Friday for Humberto I, for Humberto the Sequel until tomorrow.

[perk]

JB suspects Humberto moves offsahore near/just East of NOLA, comes back to Texas, but won't make an official prediction, like he did last Friday for Humberto I, for Humberto the Sequel until tomorrow.

Did J.B. actually say that.

[tailgater]

Is it me or does it look like the CDO it's had, is now being blown off to the NE of the LLC?
http://radar.weather.gov/radar.php?prod ... e&loop=yes
http://www.ssd.noaa.gov/goes/flt/t1/loop-wv.html

The LLC doesn't seem to being moving much on the Visible loop IMHO.

http://weather.msfc.nasa.gov/GOES/goeseastconus.html

[Ed Mahmoud]

JB suspects Humberto moves offshore near/just East of NOLA, comes back to Texas, but won't make an official prediction, like he did last Friday for Humberto I, for Humberto the Sequel until tomorrow.

Did J.B. actually say that.

I watched his "Big Dog" video during lunch. But he may predict a second Texas landfall of Humberto tomorrow.

[Chris_in_Tampa]

From reading a lot of the posts from last night I noticed a lot of confusion over if the storm should have been upgraded to a higher wind speed than it was. The data did support 85 mph winds. People often read off the peak 10 second flight level winds or the 10 second SFMR surface estimated winds, but often neglect the 30 second sustained flight level wind or to see if data was suspect. (This is still not even the 1 minute sustained that the NHC reports.)

Last night two observations right together, meaning over a continuous 1 minute period, had a 30 second flight level (About 1,443 meters) sustained wind of 93 knots followed by one of 94 knots. (The one right after was 92 knots.) The data was not suspect. So averaging the two together the storm had sustained one minute flight level winds of 93.5 knots, or about 107.5 mph. However, this is not the whole story. The highest non suspect SFMR reported 10 second peak surface winds were 74 knots or about 85.1 mph at this point. The estimated reduction factor turns out to be about 78%. The estimated 30 second sustained surface winds would be about 73.2 knots or about 84.2 mph, which is not suspect. The next highest value next to this one was suspect for the SFMR instrument, so we don't know for sure about what the 1 minute sustained wind might be. Using non suspect data over a continuous interval, the next observation, you would get 1 minute sustained surface winds estimated to be 70.4 knots or about 80.9 mph. This is a little low since the preceding reading, though suspect, indicated based on flight level winds that were not suspect, that the SFMR reading would be higher. Using that suspect data, we might estimate the 1 minute sustained surface winds to be about 71.7 knots or about 82.5 mph, meaning even with the suspect data considered, the winds are between 80 and 85 mph sustained in the storm. Given the fact that the highest winds may not have been sampled, it makes sense that the advisory intensity could be set at 75 knots or around 85 mph.

You can view a decoded view of this report here:
http://www.tropicalatlantic.com/recon/a ... 730-22--94
Click the "About" link for info on how I determined the estimated reduction factor.

And a note, the 102 knot SFMR wind from an earlier ob last night was suspect and looking at the winds around it, was wildly off.

[Air Force Met]

I wonder whether the rapid development can also explain the amount of lightning that this system had in it last night. If I remember recon saw a heck of a lot of lightning in the eyewall of Felix when it bombed out.
Wonder if thats a trademark of really explosive systems?

I was at the sea wall on GLS island last night and there was an incredible lightning show going on right off the coast in the eyewall.

[perk]

JB suspects Humberto moves offshore near/just East of NOLA, comes back to Texas, but won't make an official prediction, like he did last Friday for Humberto I, for Humberto the Sequel until tomorrow.

Did J.B. actually say that.

I watched his "Big Dog" video during lunch. But he may predict a second Texas landfall of Humberto tomorrow.

Thanks i appreciate the reply.

[Derek Ortt]

The 10 second winds are used to estimate the 1 minute surface winds... NOT the 30 second winds

I could see this being upgraded to 80KT on BT... outside chance at 75KT due to a dropsonde, but 85KT likely was not representative

the 102KT SFMR was considered suspect and discarded

[CrazyC83]

From reading a lot of the posts from last night I noticed a lot of confusion over if the storm should have been upgraded to a higher wind speed than it was. The data did support 85 mph winds. People often read off the peak 10 second flight level winds or the 10 second SFMR surface estimated winds, but often neglect the 30 second sustained flight level wind or to see if data was suspect. (This is still not even the 1 minute sustained that the NHC reports.)

Last night two observations right together, meaning over a continuous 1 minute period, had a 30 second flight level (About 1,443 meters) sustained wind of 93 knots followed by one of 94 knots. (The one right after was 92 knots.) The data was not suspect. So averaging the two together the storm had sustained one minute flight level winds of 93.5 knots, or about 107.5 mph. However, this is not the whole story. The highest non suspect SFMR reported 10 second peak surface winds were 74 knots or about 85.1 mph at this point. The estimated reduction factor turns out to be about 78%. The estimated 30 second sustained surface winds would be about 73.2 knots or about 84.2 mph, which is not suspect. The next highest value next to this one was suspect for the SFMR instrument, so we don't know for sure about what the 1 minute sustained wind might be. Using non suspect data over a continuous interval, the next observation, you would get 1 minute sustained surface winds estimated to be 70.4 knots or about 80.9 mph. This is a little low since the preceding reading, though suspect, indicated based on flight level winds that were not suspect, that the SFMR reading would be higher. Using that suspect data, we might estimate the 1 minute sustained surface winds to be about 71.7 knots or about 82.5 mph, meaning even with the suspect data considered, the winds are between 80 and 85 mph sustained in the storm. Given the fact that the highest winds may not have been sampled, it makes sense that the advisory intensity could be set at 75 knots or around 85 mph.

You can view a decoded view of this report here:
http://www.tropicalatlantic.com/recon/a ... 730-22--94
Click the "About" link for info on how I determined the estimated reduction factor.

And a note, the 102 knot SFMR wind from an earlier ob last night was suspect and looking at the winds around it, was wildly off.

There was a 98 kt FL (78 kt surface at 80%, 83 kt at 85%, 88 kt at 90%) wind measurement, along with another 83 kt SFMR estimate. Those might support an 80 kt (90 mph) wind estimate at landfall, maybe even 85 kt (100 mph) although that might be a bit high.

The 102 was clearly suspect (that would be a Cat 3) and was probably a gust.

Based on the data available, my landfall estimate is 80 kt.

[Category 5]

IMO one of the most dangerous types of Hurricanes is the ones that strengthen into Category 1's before landfall when they weren't forecasted to. People get caught off guard.

Claudette and Humberto are perfect examples.

[KWT]

Derek, isn't Humberto's max strength at 75kts, or 85mph anyway?
By the way Chris, good post, i agree with most of what you say, other then to say the surface stimates are just that, surface estimates and the standard reduction should really apply rather then using the based surface estimate which has been a little inaccurate at times.

[Ed Mahmoud]

What was the highest recorded sustained wind on land or at a buoy?

[Steve]

>>IMO one of the most dangerous types of Hurricanes is the ones that strengthen into Category 1's before landfall when they weren't forecasted to. People get caught off guard.

That's one type. Another type is where the expert-anticipated steering is off and the storm goes its own way (see Katrina Friday 26th early 18z guidance) not providing requisite time for people to get out of harm's way. We still did it mostly (80-85% evacuation), but almost 2,000 people died.

Both of these elements of unpredictability (to whatever degree) between track and intensity are just things we have to live with. Again, good thing Humberto didn't get any stronger than a Cat 1 because it could have been really, really nasty.

Steve

[Category 5]

>>IMO one of the most dangerous types of Hurricanes is the ones that strengthen into Category 1's before landfall when they weren't forecasted to. People get caught off guard.

That's one type. Another type is where the expert-anticipated steering is off and the storm goes its own way (see Katrina Friday 26th early 18z guidance) not providing requisite time for people to get out of harm's way. We still did it mostly (80-85% evacuation), but almost 2,000 people died.

Both of these elements of unpredictability (to whatever degree) between track and intensity are just things we have to live with. Again, good thing Humberto didn't get any stronger than a Cat 1 because it could have been really, really nasty.

Steve

The most dangerous part about it is that people don't evacuate when they're told it's going to only be a Tropical Storm.

[green eyed girl]

>>IMO one of the most dangerous types of Hurricanes is the ones that strengthen into Category 1's before landfall when they weren't forecasted to. People get caught off guard.

That's one type. Another type is where the expert-anticipated steering is off and the storm goes its own way (see Katrina Friday 26th early 18z guidance) not providing requisite time for people to get out of harm's way. We still did it mostly (80-85% evacuation), but almost 2,000 people died.

Both of these elements of unpredictability (to whatever degree) between track and intensity are just things we have to live with. Again, good thing Humberto didn't get any stronger than a Cat 1 because it could have been really, really nasty.

Steve

I completely agree. There is also a human element with forecasting storms and sometimes that human element can be wrong!
CHECK YOUR PM

[Chris_in_Tampa]

"The 10 second winds are used to estimate the 1 minute surface winds... NOT the 30 second winds"

Why wouldn't they want to use the 30 second sustained flight level winds to estimate the 1 minute sustained winds? It would seem to be a more accurate comparison?

Or perhaps you misunderstood what I am saying. I am not saying the NHC looks at the 10 second winds to get the 30 second winds so they can put those out there as the advisory intensity.

Three obs are measured or estimated:
10 second flight level wind
30 second flight level wind
SMFR estimated 10 second surface wind

Assuming none of the data is suspect.. Using that you can estimate what the 30 second surface winds might be. You can now take two of those observations which are directly next to each other and average them out to get what the 1 minute sustained surface wind might be. From that you would need to know if the highest winds have been sampled and make possible increases. Making the assumption that you will never find the absolute highest winds, even if you think you have sampled the highest winds, a small increase upward may be necessary.

[JtSmarts]

Just watched a report on CNN from High Island. They had some pretty bad damage, some houses lost roofs, and a Gas Station was "completely destroyed".