Typhoon Roke bears down on Japan; 98L continues to grow more organized

By: Dr. Jeff Masters , 6:48 PM GMT on September 20, 2011

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Powerful Category 3 Typhoon Roke is bearing down on Japan, and is expected to hit the main island of Honshu on Wednesday morning, local time. Roke is on a dangerous track for Japan, one that would take the storm over some of the most heavily populated areas of the country. Heavy rains from Roke have already reached the coast of Japan, as seen on Japanese radar. However, Roke is starting to weaken, as seen in latest satellite imagery. The eye is no longer apparent, the cloud tops have warmed, and a slot of dry air has gotten wrapped into the storm's northwest side. Wind shear should continue to weaken Roke as it approaches landfall; shear is currently a high 20 knots, and will increase to 30 knots by Wednesday morning. Given the current weakening trend, I expect Roke is most likely to be a Category 2 typhoon at landfall.

Typhoon's Roke's storm surge, winds, and heavy rains will all be a concern. A damaging storm surge is likely to the right of where the center makes landfall, since Roke is a large storm whose winds are spread out over a wide area. If Roke tracks farther to the east than expected, a large storm surge may affect Tokyo Bay. Perhaps the biggest concern from the storm is heavy rain. The soils over much of Japan are saturated from the passage of Tropical Storm Talas during the first week of September. Talas was a very slow moving storm, and brought extreme rainfall amounts of over six feet to some portions of Japan. Roke is expected to bring up to 20 more inches of rain along its path. Roke could bring winds of 30 - 40 mph and heavy rains of 3 - 5 inches to the damaged Fukishima-Dai-Iche nuclear plant northeast of Tokyo.


Figure 1. MODIS image of Typhoon Roke taken at 1:45 pm local time (4:45 UTC) on Tuesday, September 20, 2011. At the time, Roke was a Category 2 storm with 110 mph winds. Image credit: NASA Earth Observatory.

Invest 98L continues to grow more organized
A tropical wave midway between Africa and the Lesser Antilles (Invest 98L) has increased in organization this afternoon, but still lacks a well-defined surface circulation. Satellite imagery shows a number of curved spiral bands have formed this afternoon, and the area covered by heavy thunderstorms has steadily increased. An ASCAT pass from 8:21 am EDT this morning did not capture the full circulation of the storm, but did show winds of 30 mph on the east side of the center. Wind shear as diagnosed by the SHIPS model has increased to a moderate 10 - 15 knots, and is predicted to stay moderate through Friday. Ocean temperatures are 28 - 28.5°C, well above the threshold typically needed for a tropical storm to spin up. Water vapor satellite images show 98L is embedded in a moist environment, but there is dry air to the system's northwest. Given that the shear has now increased to the moderate level, this dry air may begin to hinder development on Wednesday. An analysis of upper level winds from the University of Wisconsin CIMMS group shows a pattern favorable for development, with an outflow channel open to both the north and south available to ventilate the storm and allow 98L to efficiently lift plenty of moisture to high levels.


Figure 2. Afternoon satellite image of 98L.

The latest 8 am EDT (12Z) runs of the computer models show either no development of 98L, or development of 98L into a tropical depression or weak tropical storm by Saturday. 98L's westward motion of 5 - 10 mph should bring the storm into the Lesser Antilles Islands by Saturday, though the models are not in strong agreement about the forward speed of the storm. The GFDL model brings 98L into the islands on Friday, while the HWRF model keeps the storm east of the islands through Sunday. If 98L takes a more west-northwesterly path through northern Lesser Antilles, which has been the preferred track for tropical systems this year, the disturbance should encounter high wind shear in excess of 20 knots due to strong upper-level winds out of the west. This shear should make it difficult for 98L to intensify as it moves though the islands. However, if 98L takes a more southerly path across Barbados, as predicted by the GFDL model, the storm will miss seeing the high shear area that lies over the northern islands, and the storm would have more opportunity to strengthen. The most likely scenario I see at this point is for 98L to be a weak tropical storm on Saturday as it moves through the Lesser Antilles--but there is more than the usual amount of uncertainty in both the track and intensity forecast. NHC gave the disturbance a 70% chance of developing into a tropical depression by Thursday in their 2 pm Tropical Weather Outlook.

September temperatures return to normal over the U.S.
The summer of 2011 was the second hottest in U.S. history, but September of 2011 is so far shaping up to be an average one for temperature. A series of cold fronts and cold-cored low pressure systems have moved southwards out of Canada this month, bringing typical amounts of cool air to the country. If you want to select dates for the start and end of the U.S. heat wave of 2011, the dates to pick would be May 20 - September 4. During the period May 20 - September 4, 2011, the number of daily record high temperatures at the 515 major airports in the U.S. exceeded the number of daily low temperature records every day but one. That's an astonishing 107 out of 108 days! Only July 15 had more record daily lows than highs during that 108-day period. I doubt one could find a similar stretch of days anytime in U.S. weather history where such a lopsided ratio of high temperature to low temperature records existed. For the 3-month summer period of June, July, and August, 2703 daily high temperature records were set, compared to 300 daily low temperature records--a ratio of 9-to-1. Not surprisingly, the summer of 2011 wound up as the hottest summer in 75 years in the U.S., and was only 0.1°F cooler than the all-time record hottest summer, during the Dust Bowl year of 1936. But so far this September, the ratio of high temperature records to low temperature records has been close to 1-to-1. There were 283 daily high temperature records set during the first sixteen days of September, and 246 low temperature records. Eight of the first sixteen days of September have seen the lows outnumber the highs, and eight have seen the highs outnumber the lows. The latest 2-week forecast from the GFS model shows a continuation of pretty normal weather over the U.S. for the rest of the month, and September temperatures will end up close to average.

Jeff Masters

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Thank you all it was confusing at first because I had not kept up...


OK, we have TS Ophelia...

is it suppose to curve out to sea like all the ones before her this year???


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Quoting seflagamma:


HUH???? What.. where did TS Ophelia form??

is it 98?




ATCF had a renumber gam, we've got Ophelia out of 98L.
AL, 16, 2011092100, , BEST, 0, 120N, 396W, 35, 1007, LO, 34, NEQ, 150, 0, 0, 120, 1012, 175, 100, 0, 0, L, 0, , 0, 0, OPHELIA, M,
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Now the discussion can turn to NHC track.
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Quoting seflagamma:


HUH???? What.. where did TS Ophelia form??

is it 98?


Yes mam
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661. SLU
HI OPHELIA.

Just to add my piece on the closed circulation discussion a while ago ...

The circulation was always closed. The only issue today was that it did not have a well defined center which is different from not having a closed circulation. That was the only reason why it wasn't renumbered since morning.
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Quoting TropicalAnalystwx13:
TROPICAL STORM OPHELIA HAS FORMED


HUH???? What.. where did TS Ophelia form??

is it 98?


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Tropical Storm Ophelia.
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Quoting seflagamma:


Thank you, Tom, for answering my question...
I have not been around a lot but I figured this invest would have been a TD by now if not a TS..

Appreciate your taking the time to answer my question.

Gams
Well, it's a tropical storm now. Tropical Storm Ophelia.
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well i missed her by about 2 hrs
Member Since: September 19, 2005 Posts: 2 Comments: 4066
Quoting MiamiHurricanes09:
Damn it. I take back what I said, LOL.
WE GOT OPHELIA, WU.
Member Since: August 18, 2011 Posts: 0 Comments: 994
Quoting Neapolitan:
Happy?

AL, 16, 2011092100, , BEST, 0, 120N, 396W, 35, 1007, LO, 34, NEQ, 150, 0, 0, 120, 1012, 175, 100, 0, 0, L, 0, , 0, 0, OPHELIA, M,
Well there it is lol

15-3-2
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For those keeping up at home.

That's 15-3-2.
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Quoting Neapolitan:
AL, 16, 2011092100, , BEST, 0, 120N, 396W, 35, 1007, LO, 34, NEQ, 150, 0, 0, 120, 1012, 175, 100, 0, 0, L, 0, , 0, 0, OPHELIA, M,
Damn it. I take back what I said, LOL.
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Quoting TomTaylor:
A partial ASCAT pass revealed NE to SW winds associated with 98L. Since this was only a partial pass, the circulation may have been closed at the time, however, there was no conclusive evidence to say that it was in fact closed. There were no westerly winds on the pass.

The reason for the strong winds is because of the intense thunderstorm activity around the storm.


Thank you, Tom, for answering my question...
I have not been around a lot but I figured this invest would have been a TD by now if not a TS..

Appreciate your taking the time to answer my question.

Gams
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Quoting Neapolitan:
Happy?

AL, 16, 2011092100, , BEST, 0, 120N, 396W, 35, 1007, LO, 34, NEQ, 150, 0, 0, 120, 1012, 175, 100, 0, 0, L, 0, , 0, 0, OPHELIA, M,


I can sleep tight now.
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TROPICAL STORM OPHELIA HAS FORMED
Member Since: July 6, 2010 Posts: 108 Comments: 30237
Quoting interstatelover7165:
Anybody think Five? Huh? Huh?
five what?
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We got the renumber... Ophelia.
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Happy?

AL, 16, 2011092100, , BEST, 0, 120N, 396W, 35, 1007, LO, 34, NEQ, 150, 0, 0, 120, 1012, 175, 100, 0, 0, L, 0, , 0, 0, OPHELIA, M,
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Quoting seflagamma:
'tap tap tap on the glass interruption'



What the heck is going on..


Invest 98 is 40 mph winds, has a spin and not even a TD much less a TS???


Please someone explain and I will come back to see what you have said.




A partial ASCAT pass revealed NE to SW winds associated with 98L. Since this was only a partial pass, the circulation may have been closed at the time, however, there was no conclusive evidence to say that it was in fact closed at the time of the pass. There were no westerly winds on the pass.

The reason for the strong winds is because of the intense thunderstorm activity around the storm.
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Anybody think Five? Huh? Huh?
Member Since: August 18, 2011 Posts: 0 Comments: 994
Quoting MiamiHurricanes09:
Looks like no renumber again.

Would be nice to see some consistency on the NHC's part.
edit, nevermind.
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'tap tap tap on the glass interruption'
I don't have time to read back..




What the heck is going on..


Invest 98 has 40 mph winds, has a spin and not even a TD much less a TS???


Please someone explain and I will come back to see what you have said.




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gfs 18z shows what the 12z showed a hurricane hitting florida this time stronger. 982mb but in reality thats about 20mb less so a cat2/3. the carribean and eastern gulf can spin up majors so florida better watch out...
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Quoting MiamiHurricanes09:
Maybe we can throw some trolls in a lake during a lightning storm?




oh how fun oh sould we start with 1st
Member Since: May 21, 2006 Posts: 5089 Comments: 114024
Quoting sunlinepr:
Well, they are in concensus....
They agree that they don't agree....



the great majority agree on a NE pass of PR
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Quoting sunlinepr:
Well, they are in concensus....
They agree that they don't agree....

THEY'RE FIGHTINGduh duh duh. but seriously this has happened before a million billion times.
Member Since: August 18, 2011 Posts: 0 Comments: 994
Quoting MiamiHurricanes09:
Looks like no renumber again.

Would be nice to see some consistency on the NHC's part.


LOL.
Member Since: July 6, 2010 Posts: 108 Comments: 30237
I could stay up all night and watch 98L but I won't.
It sure does look like it means business though.
manana
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Looks like no renumber again.

Would be nice to see some consistency on the NHC's part.
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Quoting hurricanejunky:
NHC NOT READY TO UPGRADE YET...
SHOWERS AND THUNDERSTORMS ASSOCIATED WITH THE LARGE LOW PRESSURE SYSTEM LOCATED ABOUT 1400 MILES EAST OF THE WINDWARD ISLANDS CONTINUE TO SHOW SIGNS OF ORGANIZATION...BUT RECENT SATELLITE IMAGERY INDICATES THAT THIS SYSTEM DOES NOT YET HAVE A WELL-DEFINED CIRCULATION CENTER. CONDITIONS ARE EXPECTED TO REMAIN CONDUCIVE FOR A TROPICAL DEPRESSION TO FORM IN THIS AREA TONIGHT OR WEDNESDAY...AND THIS SYSTEM HAS A HIGH CHANCE...70 PERCENT...OF BECOMING A TROPICAL CYCLONE DURING THE NEXT 48 HOURS AS IT MOVES WESTWARD AT 5 TO 10 MPH.


That's from the 8pm EDT TWO.
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Quoting Chicklit:


I hope this isn't too dumb a question, but why wouldn't it burn up coming into our atmosphere?


There are many pieces that are too dense to completely burn up. I heard, have not verified, that the largest piece expected to hit the earth will be about 300 lbs.
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Latest CIMSS low level convergence map still shows a very elongated convergence zone. Although, the convergence has significantly improved over the last day if you click back through the previous images.

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Quoting Chicklit:


I hope this isn't too dumb a question, but why wouldn't it burn up coming into our atmosphere?



one would think so but i have seen mentioned a piece as big as a bus
Member Since: September 19, 2005 Posts: 2 Comments: 4066
now the models show recurvuture. wow lol this season has been all about recurvutures except for irene :P ophelia wont get too strong if shear remains this high
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Quoting Chicklit:


I hope this isn't too dumb a question, but why wouldn't it burn up coming into our atmosphere?


Most of it will but some of it will survive, similar to when the old space station came down. Since the satellite is much smaller, less should survive.
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NHC NOT READY TO UPGRADE YET...
SHOWERS AND THUNDERSTORMS ASSOCIATED WITH THE LARGE LOW PRESSURE SYSTEM LOCATED ABOUT 1400 MILES EAST OF THE WINDWARD ISLANDS CONTINUE TO SHOW SIGNS OF ORGANIZATION...BUT RECENT SATELLITE IMAGERY INDICATES THAT THIS SYSTEM DOES NOT YET HAVE A WELL-DEFINED CIRCULATION CENTER. CONDITIONS ARE EXPECTED TO REMAIN CONDUCIVE FOR A TROPICAL DEPRESSION TO FORM IN THIS AREA TONIGHT OR WEDNESDAY...AND THIS SYSTEM HAS A HIGH CHANCE...70 PERCENT...OF BECOMING A TROPICAL CYCLONE DURING THE NEXT 48 HOURS AS IT MOVES WESTWARD AT 5 TO 10 MPH.
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Well, they are in concensus....
They agree that they don't agree....

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98L center has relocated and tightened slightly south and west , and this is a TS if I ever saw one, jmo
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Quoting JLPR2:
The blog had a little burst of activity. This place has been a ghost town the last several days, comparing it to the usual activity.

Also, 98L still has some work to do, needs deep convection, shallow convection just doesn't do it.
Yeah, that's what a debate will do.

And if the storm had good surface convergence around the center we would see cool cloud tops over the center, however, these intense thunderstorms are spread out and removed from the center as a result of the monsoonal/ITCZ nature of the storm making it hard for air to pile up in one location.
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The convective bursts in 98L in the feeder bands are looking rather deep and impressive.

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Quoting mossyhead:
CAPE CANAVERAL, Florida (AP) — NASA scientists are doing their best to tell us where a plummeting six-ton satellite will fall later this week. It's just that if they're off a little bit, it could mean the difference between hitting Florida or landing on New York. Or, say, Iran or India.

Pinpointing where and when hurtling space debris will strike is an imprecise science. For now, scientists predict the earliest it will hit is Thursday U.S. time, the latest Saturday. The strike zone covers most of Earth.


I hope this isn't too dumb a question, but why wouldn't it burn up coming into our atmosphere?
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Quoting BahaHurican:
Hey.... do u have internet back at ur house yet?


Yes....

and then last Friday I lost it (DSL that is) for 24 hours
...am a couple pages behind now and reading up to current.

-------------
....oh yes, now I remember I was on at the pharmacy when it was out this last time...

surprisingly it was resstored after 5pm Saturday
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Hey Beel-- good to see you. I hate to see so many longtime members go to "lurk mode". Somehow it how it seems wrong. Watching 98L closely, I have plans and do not want to see it heading into the GOM.
Quoting beell:


I have for the most part. From a purely personal/selfish/over-inflated-sense-of-my-own-val ue standpoint, posting here is no longer a good use of my time. But I could not resist a post for the left-coasters!

; - )
Quoting beell:


I have for the most part. From a purely personal/selfish/over-inflated-sense-of-my-own-val ue standpoint, posting here is no longer a good use of my time. But I could not resist a post for the left-coasters!

; - )
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Quoting mossyhead:
Wrong, that is the worse thing you can do other than be on or in the water.
Maybe we can throw some trolls in a lake during a lightning storm?
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Quoting JLPR2:
Well I'll be on and off for awhile. Got to do some homework and an essay. :\
Just finished mine.
Member Since: August 18, 2011 Posts: 0 Comments: 994
Quoting Drakoen:
I'm arrogant? LOL. I need to go back to lurking.


Don't let anyone run you off Drak! We need ya man!
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Quoting TomTaylor:

is that a joke?


I don't think he is really cocky, but I do occasionally get that vibe coming off his posts. No offense to him, I have plenty of flaws my self, just a casual observation.
speaking of flaws, there's a nice typo.
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About JeffMasters

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