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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1538. HadesGodWyvern (Mod)
12:31 AM GMT on July 13, 2007
Current Observation from Naha, Okinawa

9am JST
Temp 26.9C
Precip: 29.5mm
Wind Direction SE
Wind speed: 25m/s
Humidity 91 percent
Barametric Pressure 941.5 hPa
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1537. Drakoen
12:30 AM GMT on July 13, 2007

Member Since: October 28, 2006 Posts: 57 Comments: 30490
1536. StormJunkie
12:29 AM GMT on July 13, 2007
Good points Us
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1535. pottery2
8:26 PM AST on July 12, 2007
Yeah, but every wave that comes off above 10 n , must also help to reduce the SAL. ??
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1533. Drakoen
12:28 AM GMT on July 13, 2007
Something to watch over the next few days. Should move to the WNW within time.
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1532. ustropics
12:27 AM GMT on July 13, 2007
Ustropics unless it moves South it won't be of much interest. Due to the SAL.

Oh I know. But the ITCZ establishing itself north of 10N can't be good with the MJO pulse expected in the next 2 weeks and neutral ENSO. It should sweep some of that SAL out and add moisture to the Atlantic.
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1531. hurricane23
20:28 EDT le 12 juillet 2007
Good evening...

No big deal but the ramsdis floater is now on the wave approaching the islands...

floater
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1530. Drakoen
12:25 AM GMT on July 13, 2007
Ustropics unless it moves South it won't be of much interest. Due to the SAL.
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1529. philliesrock
8:24 PM EDT on July 12, 2007
Watch the SAL tear that wave apart.
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1528. ClearH2OFla
8:24 PM EDT on July 12, 2007
LOL your right it seems almost every Thursday nite we are having this same Conversation and then on Monday Poof its gone lol
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1527. Drakoen
12:22 AM GMT on July 13, 2007
Posted By: ClearH2OFla at 12:22 AM GMT on July 13, 2007.

Hey Drake we might have a situation in about 5 days. Doubt the west coast feels it but hey maybe we can get some rain at least.


Maybe. way too far out to tell.
Member Since: October 28, 2006 Posts: 57 Comments: 30490
1526. ustropics
12:19 AM GMT on July 13, 2007
Impressive wave coming off Africa above 10N for a change.

Atlantic
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1525. pottery2
8:21 PM AST on July 12, 2007
LOL CRS. Have an umbrella around, just in case.............
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1524. ClearH2OFla
8:19 PM EDT on July 12, 2007
Hey Drake we might have a situation in about 5 days. Doubt the west coast feels it but hey maybe we can get some rain at least.
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1523. Drakoen
12:21 AM GMT on July 13, 2007
Looking at the CMC loop it should start doing something at 100 hours or so North of the D.R. moving WNW.
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1522. StormJunkie
12:21 AM GMT on July 13, 2007
Thanks CRS ☺
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1521. CaicosRetiredSailor
12:09 AM GMT on July 13, 2007
I'll look out my front door Monday afternoon and let you guys know if the CMC model was right...
CRS
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1520. Drakoen
12:18 AM GMT on July 13, 2007
Posted By: StormJunkie at 12:17 AM GMT on July 13, 2007.

lol Drak, we are on it tonight ~)


Apparently so....lol
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1519. groundman
12:05 AM GMT on July 13, 2007
Posted By: catastropheadjuster at 11:56 PM GMT on July 12, 2007.
Groundman I went to your link you put up and kept hitting next and next and it shows it coming into the GOM close to Ala with 1001 reading. But i may be wrong.I am fairly new at looking at this stuff. I just usually read a lot.
Sheri


That's the graphical CMC which is the GEM. It does show a low coming close to AL but it's the same thing as the first link, it just takes it further in time but shows it in less detail.

I just learned there WAS a GEM this morning so don't feel bad. We are ALL learning, I think?
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1518. StormJunkie
12:17 AM GMT on July 13, 2007
lol Drak, we are on it tonight ~)
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1517. pottery2
8:15 PM AST on July 12, 2007
Whats the conditions at Okinawa now ??
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1516. StormJunkie
12:15 AM GMT on July 13, 2007
It's all good Anti, I have seen where that road leads :~)

The CMC is often over zealous.
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1515. Drakoen
12:14 AM GMT on July 13, 2007
Posted By: jphurricane2006 at 12:13 AM GMT on July 13, 2007.

but looking at the loop how do we know that system by the bahamas in 5 days comes from this area in the central atlantic


Look at the 850mb vorticy. It shows that same area traveling across the CATL.
Member Since: October 28, 2006 Posts: 57 Comments: 30490
1514. StormJunkie
12:14 AM GMT on July 13, 2007
850mb vorticity on the CMC seems to say so jp, but I could be wrong, I really am not watching the wave itself.
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1510. Drakoen
12:12 AM GMT on July 13, 2007
Posted By: jphurricane2006 at 12:10 AM GMT on July 13, 2007.

what up people


well i got nothing better to say right now so I will lurk lol


LOL.nothing much going on just discussing the CMC run.
Member Since: October 28, 2006 Posts: 57 Comments: 30490
1509. pottery2
8:11 PM AST on July 12, 2007
Lurk away, JP......
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1508. StormJunkie
12:12 AM GMT on July 13, 2007
lol jp

good to see ya
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1507. Drakoen
12:10 AM GMT on July 13, 2007
Posted By: JoshNHurricanes at 12:08 AM GMT on July 13, 2007.

well drak, it should be labeled an invest by this weekend right?


I doubt that unless it takes advantage of its diurnal max phases.If it were to develop i would expect an invest by Wednesday or Thursday. The CMC does really do much with the wave untill that point. Maybe dveloping a closed low level circulation at best. Right now i will stick to the more reliable models and call for moisture in Florida next week, untill i see more model agreement.
Member Since: October 28, 2006 Posts: 57 Comments: 30490
1506. StormJunkie
12:09 AM GMT on July 13, 2007
Maybe JNH, but not real likely. The CMC does not show much development before the 78-102hr time frame.
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1504. pottery2
8:08 PM AST on July 12, 2007
Makes sense, Nash.
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1503. Drakoen
12:08 AM GMT on July 13, 2007
yea Nash, the CMC was right on target with Barry. I need about 3 days of consistency with more models jumping aboard to believe this. The models will have a better read on this Tuesdays. Usually i trust model runs 2-3 days out.
Member Since: October 28, 2006 Posts: 57 Comments: 30490
1501. StormJunkie
12:06 AM GMT on July 13, 2007
The GFS and Ukmet are major models, and as for the CMC, it does not have the best track record with formation. Gonna have to see some more models jump on board before I buy it.
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1500. nash28
12:04 AM GMT on July 13, 2007
Guys, regarding the CMC solution from 12z, I need another two straight unwavered days from it to really begin to believe it... Other models jumping on board helps, but in the case of TS Barry, the CMC was really the only one that made it stronger than a wave and they hit a homerun with it, almost standing alone until the final runs when it was already a TS...

If the CMC sticks with it for several more runs, then we have something to watch...
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1499. Drakoen
12:03 AM GMT on July 13, 2007
Josh Look here at the position and time frame
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1497. Drakoen
12:03 AM GMT on July 13, 2007
Posted By: msuwxman at 12:00 AM GMT on July 13, 2007.

What's the forecast shear for this wave.


Low to moderate shear.
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1496. StormJunkie
12:02 AM GMT on July 13, 2007
Welcome lbg ☺
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1495. pottery2
7:58 PM AST on July 12, 2007
Yes Drak, I saw that too. There is a fair amount of moisture ahead of it, and Water temp is good.
I hope it swings north before it gets to 11 n 61 w in any event. We have had loads of rain here the past week.
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1494. msuwxman
11:59 PM GMT on July 12, 2007
What's the forecast shear for this wave.
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1493. Drakoen
11:58 PM GMT on July 12, 2007
Posted By: JoshNHurricanes at 11:55 PM GMT on July 12, 2007.

well if the cmc model is to be correct then it should be a depression by monday correct.


No. Somewhere around the 120 hours time frame which is 5 days from now.By that time it should be west Cuba.
Member Since: October 28, 2006 Posts: 57 Comments: 30490
1492. catastropheadjuster
11:56 PM GMT on July 12, 2007
Lowerbamagirl, Where are you at in (LA) lower bama? And Welcome. I am in Satsuma,Al
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1491. StormJunkie
11:54 PM GMT on July 12, 2007
Anti, 8 runs of the GFS and UKmet are only two days. Basically they will interest me a little more if they get consistency over the next two days.
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1490. Drakoen
11:56 PM GMT on July 12, 2007
the system doesn't have much SAL to contend with. This is noted by not only looking at the SAL charts but the water vapor in the upper and mid levels.
Member Since: October 28, 2006 Posts: 57 Comments: 30490
1489. CaicosRetiredSailor
11:55 PM GMT on July 12, 2007
Posted By: StormJunkie
Welcome CRS


Thanks CRS
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1488. catastropheadjuster
11:46 PM GMT on July 12, 2007
Groundman I went to your link you put up and kept hitting next and next and it shows it coming into the GOM close to Ala with 1001 reading. But i may be wrong.I am fairly new at looking at this stuff. I just usually read a lot.
Sheri
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About

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