Restoring confidence in NHC

By: Dr. Jeff Masters , 12:24 PM GMT on July 11, 2007

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There are no threat areas in the tropical Atlantic to discuss, and none of the computer models are forecasting tropical storm formation over the coming week. In the Pacific, an exceptionally large Category 4 typhoon, Man-Yi, will pass close to Okinawa on Friday, and hit Japan on Saturday. Winds at Okinawa have been as high as 50 mph with gusts to 70 mph.

Some links on Man-Yi, sent to me by Jim Edds:

Live camera feed from Southern Okinawa:

click on the pic arrow on the bottom right.

Okinawa radar.
click on Okinawa to zoom in - awesome shot

Camera feed with some audio.
click on the first "no image" box then select "report 17/66"

Latest satellite image of Typhoon Man-Yi, courtesy of NOAA.

Restoring confidence in the NHC
Interim National Hurricane Director Dr. Ed Rappaport has two immediate tasks--restoring morale fractured by Bill Proenza's turbulent 6-month tenure, and restoring public confidence in the Hurricane Center's ability to do their job. With the steadying influence of Dr. Rappaport, a highly respected and talented hurricane scientist, I expect that the staff of NHC will put out their best hurricane forecasts ever this season. Aiding in this endeavor will be the availability of a new hurricane tracking, intensity, and storm surge model called the HWRF--Hurricane Weather and Research Forecast Model. In addition, several of the other reliable models used by the forecasters, such as the GFS and GFDL, have had upgrades since last hurricane season. Furthermore, the Air Force Hurricane Hunters will be carrying the SFMR instrument for the first time, which can measure winds speeds at the ocean surface everywhere the aircraft fly.

Forecasters at the National Hurricane Center made their best track forecasts ever for storms in the Atlantic in 2006. The mean track errors for 12 to 72 hour forecasts were 15% - 20% lower than during 2001-2005. Track errors for Atlantic storms have improved about 50% in the past 15 years (Figure 1), a remarkable achievement that has undoubtedly saved lives and hundreds of millions of dollars. The track error in 2006 for a 24 hour forecast was 58 miles; 112 miles for a 48 hour forecast; and 171 miles for a 72 hour forecast. Track errors for 96 and 120 hour forecasts were 236 miles and 305 miles--the second best on record (2003 set the record). NHC's long-range 120 hour forecasts had a significant bias to the west of 94 miles--about double the bias of what the computer models were forecasting. Thus, when the models correctly called for systems to recurve out to sea, NHC human forecasters tended to resist following what the models were saying.

Figure 1. Track forecast skill since 1990 in the Atlantic for the official NHC forecasts. Track errors are given in nautical miles (100 n mi = 115 miles). Skill is rated compared to a "zero skill" forecast using NHC's CLIPER5 model. The CLIPER model (short for CLImatology and PERsistence) is a model that makes a forecast based on historical paths hurricane have taken, along with the fact that hurricanes tend to keep moving in the direction they are going (i.e., their current motion persists).

Intensity forecasts
Intensity forecasts since 1990 have shown little or no improvement, and 2006 was no exception (Figure 2). One encouraging result was the emergence of the GFDL's intensity model as the best intensity model for 2006. This is the first time that a non-statistical model has made the best intensity forecasts. With the major improvements that were added for the 2007 version of the GFDL, plus the availability of the HWRF model, I am hopeful that this year will see the first noticeable improvement in intensity forecasts since 1990.

Figure 2. Intensity forecast skill since 1990 of the official NHC Atlantic forecasts. Intensity errors are given in knots (10 knots = 11.5 mph).

Jeff Masters

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488. benirica
11:12 PM GMT on July 11, 2007
should the 35w wave be taken as a whole system or two or is the "organized" western part the actual area or... what?
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487. K8eCane
11:03 PM GMT on July 11, 2007
Posted By: swFLboy at 10:02 PM GMT on July 11, 2007.

is anyone else surprised that system trailing that front in the atl. didn't get any type of recognition, granted it isn't any threat to anything but boats

not surprised at all flboy
after all , it was in the atlantic and not the gulf
watch and learn as i have said before.....
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486. stormybil
10:59 PM GMT on July 11, 2007
wave at 35 is looking a little bit better at this hour
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485. ustropics
10:44 PM GMT on July 11, 2007
This is a very healthy storm. From looking at Cyclone's two images it appears that an ERC is in fact occuring, hence the expanding of the cold top clouds from the center (the dark red you see in the images) especially to the northwest. Another sign of an ERC occuring is the size of the eye decreasing, which is evident from the two images above. The outflow is incredible.

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484. Altestic87
6:37 PM EDT on July 11, 2007
Eyewall replacement cycle time for manyi...seems like it's about to be turning annular. Scary.

As for the wave/low/sytem east of 37W, will it have a chance as the shear relaxes a little bit?

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483. CycloneQld
10:25 PM GMT on July 11, 2007
As you can see Man-Yi is really consolidating its eyewall, particularly on the poleward side.

Man-Yi 2007 07 12 a

Man-Yi 2007 07 12 b

Once the eye itself clears up again, another period of rapid intensification can be expected while it remains over relatively low shear for the next day.

Also note the outflow development on the eastern side of the storm in the second image.
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481. RL3AO
5:26 PM CDT on July 11, 2007
Eyewall replacement cycle?
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480. nash28
10:23 PM GMT on July 11, 2007
Ok guys... Gotta fire up the grill. Looking forward to steak, but not the heat:-)

Have a good one:-)
Member Since: July 11, 2005 Posts: 190 Comments: 16972
478. CJ5
10:16 PM GMT on July 11, 2007
Man-Yi eye is becoming somewhat ragged than it was a few hours ago but the heaviest convection band around the center has greatly increased. This is a nice one to watch. (or bad, depending on your perspective)
Member Since: July 4, 2007 Posts: 0 Comments: 1755
477. groundman
10:13 PM GMT on July 11, 2007
Posted By: swFLboy at 10:05 PM GMT on July 11, 2007.
it's coordinates being 37n, 58w

That's the one off of the Carolinas right?? I don't know if anyone was surprised or not, we discussed it yesterday or the day before and the fact it wouldn't pose any threat to land.
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476. pottery2
6:07 PM AST on July 11, 2007
Good afternoon, ye WUBAband members.
Whats the scoop in the tropics?
Its been a showery day here, and the plants are in bliss.
So, all is well in the world.
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473. IKE
5:02 PM CDT on July 11, 2007
New Orleans extended...looks like a heavy rain event is possible....

"Long term...

By Friday night...the full force a deep cold pool and strong cold
front swinging down from the northern plains on the back side of
the deep trough over the eastern portion of Canada and the Great
Lakes will begin to be felt in the County Warning Area. At this appears
that a strong mesoscale convective system may from over Oklahoma
and Arkansas and race southward into the lower Mississippi Valley
as it follows the 850 winds and Theta-E axis. If this
happens...there could be some severe weather toward daybreak on
Saturday. This situation will have to be monitored. In any
event...the main front will sweep through the County Warning Area Saturday
afternoon into Saturday evening...which should set off another
line of strong to severe thunderstorms. It appears that strong
winds and hail will be the main threat from these thunderstorms
based off model soundings. also appears that just as the front gets into
our forecast will begin to lose any dynamic forcing as
the upper level trough axis pulls northeastward. Thus...the front
will slam into the deep ridge axis over the Gulf and Florida and
stall on top of our area on Sunday. Southerly flow will redevelop
across the area as the upper level ridge in the western Atlantic
pushes westward...which will interact with the frontal boundary in
place. As a result...periods of showers and thunderstorms are
expected Sunday into Monday. On top of this...deep tropical
moisture should also overspread the region Monday into a weak tropical wave moves up from the Yucatan. This
deep tropical moisture...combined with the surface boundary should
allow for some very heavy rainfall over the County Warning Area Monday through
Wednesday. In fact...flooding may be a concern by the middle of
next week given the pattern expected."
Member Since: June 9, 2005 Posts: 23 Comments: 37860
472. sunshineandshowers
10:02 PM GMT on July 11, 2007

Man-yi's dvorak plummet has slowed and looks like it's reversing temporarily.
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470. groundman
9:57 PM GMT on July 11, 2007
StormW, I still get an "Error opening map overlay memory map /web/www/Satellite/G8HURRLALOMAP1.BIN"

No biggie though. THANKS
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467. TayTay
9:49 PM GMT on July 11, 2007
Man-yi is still not completely organised. It has plenty of time to, though. I really think this will become an intense Cat. 5 storm.
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466. stoormfury
9:41 PM GMT on July 11, 2007
The area of convection around 32W is a bit too south. it hac no rotation. even if it were to
move up in lat ,it would have endure hostile conditions near iat 45W.
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465. groundman
9:44 PM GMT on July 11, 2007
Is anyone else having problems with the lat/long overlays on the Nasa Interactive Maps??


I've been having trouble for weeks now and just thought it would go away? I'm using Foxfire
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463. IKE
4:39 PM CDT on July 11, 2007
I know the NAM model is unreliable...not a tropical model of choice...but notice on the link below at the 84 hour mark of the latest model run.

Wonder if thats what the CMC and GFS are hinting at? My guess is yes.

Member Since: June 9, 2005 Posts: 23 Comments: 37860
462. moonlightcowboy
9:33 PM GMT on July 11, 2007
Stormfury...Nash, has been preaching that gospel for a week now. It should be no suprise finally hearing it from Masters.

Gotcha, StormW...I see what you mean. Thanks for the enlightenment...again!
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460. stoormfury
9:32 PM GMT on July 11, 2007

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459. stoormfury
9:25 PM GMT on July 11, 2007

href="" target="_blank">Link
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457. nash28
9:27 PM GMT on July 11, 2007
LOL Hurricane Mean!!!

Seriously though, pray for those in the path. It is a monster!
Member Since: July 11, 2005 Posts: 190 Comments: 16972
456. nash28
9:26 PM GMT on July 11, 2007
Good point on the MJO StormW. It doesn't mean 30-60 days of straight upward or downward pulses...

It's a tough oscillation to pin down.
Member Since: July 11, 2005 Posts: 190 Comments: 16972
455. moonlightcowboy
9:25 PM GMT on July 11, 2007
Thanks, StormW. Now, that sounds like we may only have a few weeks (maybe last week July, first week August) for optimum convection and development?
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452. groundman
9:19 PM GMT on July 11, 2007
Posted By: randommichael at 8:35 PM GMT on July 11, 2007.
Being nice to FEMA and contractors...does that get you anywhere? What about insurance agents?

Michael, my husband works for FEMA, it was sort of a joke.

I have a whole complete philosophy about the survival of a hurricane mentally. And you unlucky people are going to hear it, possibly for the 2nd or 3rd time. I KNOW I haven't lost everything as many people have but I also know in order to be with my husband I can't see our "home" more than one month a year, ditto for most relatives (I could go back to the midwest more but it's a hassel and I do work occasionally). I sort of know what it is like to leave everything if not loose it. "Things" are nice, they are great and I have become quite the accomplished shopper don't get me wrong, they know me by name @ wal-mart, but things in the long run are not important. The only things that can't be replaced are heirlooms which will disintegrate anyway or get broken and photographs. If you have the memories from the photographs, your friends and family that is when you are truly rich and blessed. If you do loose everything materially and have the means to replace it you are fortunate but if you don't, life goes on. That is what I have learned from the people of the Gulf Coast.
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451. moonlightcowboy
9:18 PM GMT on July 11, 2007
Good afternoon, all.

StormW, was reading your blog. I didn't think we were getting the upward motion from the MJO until starting about the it early? Doesn't that also run for 30-60 days? And, wouldn't that take an upward motion for convectivity even through August? That's not what I think I read in your blog...not doubting, just curious. TIA

...btw, Man-yi is looking wicked!
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450. weatherblog
9:16 PM GMT on July 11, 2007
Yes, some very slow development is quite possible...convection--of course-- would need to remain and an evident surface low too.

But shear, could be a small problem when/if it gains some degrees north...but shear may diminish in the next 24-48 hours.

An invest is quite possible also...but as of now it's, I know, another wait and see situation...
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448. HurricaneMyles
8:50 PM GMT on July 11, 2007
Bringing up the wind-pressure relationship with Wilma compared to the W. Pacific; she/it had the lowest recorded pressure because at the time conditions in the SW Carribea were like the those normally in the W. Pacific. The W. Pac generally has lower avg surface pressures so storms attain lower pressure and the Atlantic vice-versa; higher avg pressure, higher storm pressure. It's not a reason to say she was some how stronger or lower in pressure then she was.
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447. Chicklit
9:01 PM GMT on July 11, 2007
What do you think about the system around 35L?
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445. Tropicnerd13
8:52 PM GMT on July 11, 2007
what happened to all the systems behind man yi? did it eat them?
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444. Drakoen
8:55 PM GMT on July 11, 2007
I'm gone as well.
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443. Crisis57
8:53 PM GMT on July 11, 2007
Hey Drak how is the shear and dust looking around that area
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442. Tropicnerd13
8:46 PM GMT on July 11, 2007
drak, you nevre know with it being so close to africa still. it could organize in the next 3 days and we could see a larger version of 96l that actually makes it. ok im gone now.
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441. StormHype
8:45 PM GMT on July 11, 2007
From St. Pete times. Archive article and pics from 1985 Elena. This shows there's only so much importance to where the storm actually ends up making landfall. It has a lot to do with how long it persists in an area. Frances also demonstrated this in 2004 on the east coast.
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440. Drakoen
8:49 PM GMT on July 11, 2007
Compare this to MichaelSTL pic of Wilma. Wilma is obviously stronger.
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438. Drakoen
8:47 PM GMT on July 11, 2007
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Dr. Masters co-founded wunderground in 1995. He flew with the NOAA Hurricane Hunters from 1986-1990. Co-blogging with him: Bob Henson, @bhensonweather

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