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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338. Tazmanian
7:48 PM GMT on July 11, 2007
it is 7.0 all most there we are now at 6.9
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337. weatherboykris
7:47 PM GMT on July 11, 2007
Ike,that chart basically agrees with climatology,anyway.
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336. weathersp
7:46 PM GMT on July 11, 2007
RED = Not favorable for hurricanes right Drako?
Member Since: January 14, 2007 Posts: 17 Comments: 4140
335. IKE
2:45 PM CDT on July 11, 2007
I know some call them inaccuweather, but this chart seems almost believable....

Link
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334. Drakoen
7:45 PM GMT on July 11, 2007
Taz it need to get to 7.0 which it probably will reach.
Member Since: October 28, 2006 Posts: 57 Comments: 30689
333. hurricane23
3:44 PM EDT on July 11, 2007
Posted By: weatherboykris at 3:43 PM EDT on July 11, 2007. (hide)
Adrian,that is...in particular bad news given the amazingly high TCHP in the GUlf and Carribean.

Yea kris the switch might indeed go off in a few weeks and when it does...

Cant wait for that monday blog.
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332. Drakoen
7:45 PM GMT on July 11, 2007

Member Since: October 28, 2006 Posts: 57 Comments: 30689
331. CJ5
7:43 PM GMT on July 11, 2007
Nice wave at 35W but I see no circulation right now at all.

ManYi is looking classic with a well defined eye, dropping pressure and plenty of convection.

Nash, Drak and others beat Masters to the call. :hatsoff:
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330. weathersp
7:41 PM GMT on July 11, 2007
Here come the sun do do do do.. Here comes the sun and I say it's alright..
Sun Sun Sun here it comes!
Member Since: January 14, 2007 Posts: 17 Comments: 4140
329. Tazmanian
7:44 PM GMT on July 11, 2007
by looking at that it is at Super Typhoon
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328. weatherboykris
7:43 PM GMT on July 11, 2007
Perhaps...when we look back at the end of this season,we will be saying "Why couldn't we have a had the ridges last year and the troughs this year?"
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327. weatherboykris
7:43 PM GMT on July 11, 2007
Adrian,that is...in particular bad news given the amazingly high TCHP in the GUlf and Carribean.
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326. Drakoen
7:42 PM GMT on July 11, 2007
hurricane23 the pressure is at 902 mb form the DVORAK.
Member Since: October 28, 2006 Posts: 57 Comments: 30689
325. RL3AO
2:42 PM CDT on July 11, 2007
The new JTWC update is about in 75 minutes. Can't wait to see what they have it as.
324. Drakoen
7:41 PM GMT on July 11, 2007
Man Yi is almost Super Typhoon Strength.
Member Since: October 28, 2006 Posts: 57 Comments: 30689
323. hurricane23
3:39 PM EDT on July 11, 2007
Yes i know guys but to here this from jeff masters who does not like to make alarm of any situation really got my attention.

Pressure down to 935mb with this monster typhoon.
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322. Tazmanian
7:41 PM GMT on July 11, 2007
UW - CIMSS
ADVANCED DVORAK TECHNIQUE
ADT-Version 7.2.1
Tropical Cyclone Intensity Algorithm

----- Current Analysis -----
Date : 11 JUL 2007 Time : 183300 UTC
Lat : 20:00:07 N Lon : 129:40:50 E


CI# /Pressure/ Vmax
6.9 / 902.5mb/137.4kt



6hr-Avg T# 3hr-Avg T# Adj T# Raw T#
6.8 6.9 7.2 7.6

Latitude bias adjustment to MSLP : +1.3mb

Estimated radius of max. wind based on IR : 25 km

Center Temp : +10.3C Cloud Region Temp : -81.3C

Scene Type : EYE

Positioning Method : RING/SPIRAL COMBINATION

Ocean Basin : WEST PACIFIC
Dvorak CI > MSLP Conversion Used : PACIFIC

Tno/CI Rules : Constraint Limits : 1.7T/6hr
Weakening Flag : OFF
Rapid Dissipation Flag : OFF
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321. MichaelSTL
2:39 PM CDT on July 11, 2007
By the way, here is a chart to convert JMA's readings to 1 minute readings:

T-num_____JMA__________US__________SS_Cat
__________(10_min)_____(1_min)

Tropical Depression
1.0______25_kt___________25_kt
1.5______30_kt___________30_kt
2.0______30_kt___________35_kt__________
Tropical Storm
2.5______35_kt___________40_kt__________
3.0______45_kt___________50_kt__________
Severe Tropical Storm
3.5______55_kt___________55_kt__________
Typhoon
4.0______65_kt___________65_kt__________1
4.5______70_kt___________75_kt__________1-2
5.0______80_kt__________ 90_kt__________2-3
5.5______90_kt__________100_kt__________3
6.0______95_kt__________115_kt__________4
6.5_____100_kt__________130_kt__________4
Super Typhoon
7.0_____110_kt__________140_kt__________5
7.5_____115_kt__________155_kt__________5
8.0_____120_kt__________170_kt__________5
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320. IKE
2:37 PM CDT on July 11, 2007
FROM: JeffMasters FAVORITES BLOCKED
TO: hurricane23
DATE: 2007-07-11 14:14:39 (14:14 EDT) NEW MESSAGE
SUBJECT: Re: Hey Dr.Masters Iam looking for your thoughts on something...
The last 2 days of runs from the GFS show the 2006-like steering pattern breaking down and a pattern less favorable for recurvature setting up by July 23. I'll say more on this on Monday when I issue my bi-weekly outlook. By then, we'll have data from the ECMWF to see if it goes along with this idea.



I thought so...that's bad news.
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319. wanzewurld
7:34 PM GMT on July 11, 2007
I'm looking at the water temperatures in the Gulf of Mexico... Great day in the morning! Looks like we're almost out of colors! Any way of finding out record temperatures in the past? This is looking like the month before Katrina, Heaven forbid.
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318. hurricane23
3:38 PM EDT on July 11, 2007
Ok guys dont mean to scare anybody but i just got another email from jeff masters and he states that the pattern of recurvature may becoming to an end.Iam really going to watch this in the coming weeks as we get closer to the heart of the season.He will have more details on this on his next july update.

This is what he says...

FROM: JeffMasters FAVORITES BLOCKED
TO: hurricane23
DATE: 2007-07-11 14:14:39 (14:14 EDT) NEW MESSAGE
SUBJECT: Re: Hey Dr.Masters Iam looking for your thoughts on something...
The last 2 days of runs from the GFS show the 2006-like steering pattern breaking down and a pattern less favorable for recurvature setting up by July 23. I'll say more on this on Monday when I issue my bi-weekly outlook. By then, we'll have data from the ECMWF to see if it goes along with this idea.

Jeff
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317. weatherboykris
7:38 PM GMT on July 11, 2007
Adrian,that's what I've been saying,man,LOL.Nash,we are vindicated,LOL.
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316. Drakoen
7:37 PM GMT on July 11, 2007
Hurricane23 thats what we have been saying. the pattern is going to change. Strong high and weaker troughs.
Member Since: October 28, 2006 Posts: 57 Comments: 30689
315. RL3AO
2:36 PM CDT on July 11, 2007
Yes. But in the Atlantic it is only 1 minute sustained for it to be official.

Right now there are two agencies issuing advisories.

The JMA has Man-yi at 80 kts (Cat 1) (10 minute sustained)

The JTWC has Man-yi at 100 kts (Cat 3) (1 minute sustained). And that was 5 hours ago.
314. MichaelSTL
2:36 PM CDT on July 11, 2007
I know this is a crazy question, but how do they determine the "official" top wind speed in a storm? Is it the sustained MPH for 1 minute? So lets say a storm has 140 mph winds...that is the 1 minute sustained wind. So lets say the majority of the time the winds are only 90 mph... is that possible. Am I making any sense?

"Maximum sustained winds" are just that - the highest winds anywhere in the storm, usually confined to a very small area near the eyewall on the right side. That is why you are lucky to see gusts that are anywhere near what the NHC has for sustained winds for a landfalling storm (plus friction from land).
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313. Drakoen
7:35 PM GMT on July 11, 2007
This tropical wave big. Extending from 40W to 30W
Member Since: October 28, 2006 Posts: 57 Comments: 30689
312. hurricane23
3:36 PM EDT on July 11, 2007
Ok guys dont mean to scare anybody but i just got another email from jeff masters and he states that the pattern of recurvature may becoming to an end.Iam really going to watch this in the coming weeks as we get closer to the heart of the season.He will have more details on this on his next july update.

This is what he says...

FROM: JeffMasters FAVORITES BLOCKED
TO: hurricane23
DATE: 2007-07-11 14:14:39 (14:14 EDT) NEW MESSAGE
SUBJECT: Re: Hey Dr.Masters Iam looking for your thoughts on something...
The last 2 days of runs from the GFS show the 2006-like steering pattern breaking down and a pattern less favorable for recurvature setting up by July 23. I'll say more on this on Monday when I issue my bi-weekly outlook. By then, we'll have data from the ECMWF to see if it goes along with this idea.

Jeff

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310. RL3AO
2:35 PM CDT on July 11, 2007
Yep.
308. Drakoen
7:34 PM GMT on July 11, 2007
There is nothing in the Northern Caribbean or GOM to talk about. Also you can see that shear is low in the ITCZ.
Member Since: October 28, 2006 Posts: 57 Comments: 30689
307. Starwoman
3:25 PM EDT on July 11, 2007
Looking at those pictures of Man-Yi... the Phillipines musst get a lot of rain and wind already.

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306. RL3AO
2:33 PM CDT on July 11, 2007
Everywhere except the Atlantic, it it 10 minutes sustained.
305. Drakoen
7:32 PM GMT on July 11, 2007
randomichael i think you are talking about wind gust. Usually wind gust are 5-15 mph above the sustained wind speed.
Member Since: October 28, 2006 Posts: 57 Comments: 30689
304. Thundercloud01221991
7:32 PM GMT on July 11, 2007
that is exactly what happens
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302. weathersp
7:29 PM GMT on July 11, 2007
I made a mistake...

I know It's ok I am just pokin fun at ya..

Drako.. a mistake? Get outta here.. Really? ;)
Member Since: January 14, 2007 Posts: 17 Comments: 4140
300. Drakoen
7:29 PM GMT on July 11, 2007
Member Since: October 28, 2006 Posts: 57 Comments: 30689
299. IKE
2:28 PM CDT on July 11, 2007
Note the pressure in Okinawa...

"Observed at: Okinawa, JP
Elevation: 148 ft
[Scattered Clouds]
84 F
Scattered Clouds
Humidity: 88%
Dew Point: 80 F
Wind: 14 mph from the ENE
Pressure: 29.57 in (Falling)
Heat Index: 97 F
Visibility: 6.2 miles
UV: 0 out of 16
Clouds: Scattered Clouds 1700 ft
(Above Ground Level)
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298. Drakoen
7:28 PM GMT on July 11, 2007
I made a mistake...
Member Since: October 28, 2006 Posts: 57 Comments: 30689
297. RL3AO
2:27 PM CDT on July 11, 2007
The official advisories (the Japan Meteorological Agency) has Man-yi at 80kts sustained (10-min avg). The JTWC (1-min avg) has it at 100kts.
296. Thundercloud01221991
7:26 PM GMT on July 11, 2007
Check out my image for sale here

just type severe in the search and it is the 4th image

Link

If you want to register here please do so by closing out of the page with my image on it and coming back here and clicking on this link then registering
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295. Drakoen
7:25 PM GMT on July 11, 2007
Member Since: October 28, 2006 Posts: 57 Comments: 30689
294. Fshhead
7:25 PM GMT on July 11, 2007
Yea I think Okinawa & sw part of island going to get a cat 5 or a REAL strong cat4.
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293. weathersp
7:25 PM GMT on July 11, 2007
Posted By: Drakoen at 7:24 PM GMT on July 11, 2007.

should hit Okinawa as a Cat 4 maybe Cat 5. Should Hit mainland china as a Cat 3.


Drako... what grade did you get in World Geography class?
Member Since: January 14, 2007 Posts: 17 Comments: 4140
292. weathermanwannabe
2:23 PM CDT on July 11, 2007
Don't know anything about West Pacific waters/currents to even speculate a guess on intensification issues; problem with our Florida/Gulf storms and this issue has always been the Gulf Stream (on those approaching the Fl east coast) and Loop Current and Gulf Eddys (on those coming through the Yucatan Channel into the Gulf).....
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291. tropicfreak
3:21 PM EDT on July 11, 2007
So, how high is the shear in the atlantic?
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290. Drakoen
7:23 PM GMT on July 11, 2007
should hit Okinawa as a Cat 4 maybe Cat 5. Should Hit mainland japan as a Cat 3.
Member Since: October 28, 2006 Posts: 57 Comments: 30689
289. IKE
2:22 PM CDT on July 11, 2007
It's suppose to be extratropical in 96 hours....

"The storm will become fully extratropical by tau 96."
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288. weathersp
7:20 PM GMT on July 11, 2007
It's a Buz Saw!

Man-Yi
Member Since: January 14, 2007 Posts: 17 Comments: 4140

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Jeff co-founded the Weather Underground in 1995 while working on his Ph.D. He flew with the NOAA Hurricane Hunters from 1986-1990.

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