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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Quoting BDADUDE:
Dont talk anymore about trolls. All that does is encourage them. If everyone here never mentioned the word troll and ignored troll like posters then they would have no audience. All who respond to trolls are in effect no better than them. This is the last time I personally will ever say the world troll, except for when i'm reading the troll under the bridge story with my kids. Thanks for your time.
Why don't we just say the "T" world.
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Here is an interesting quote from the Joplin tornado response.

Similarly, familiarity with seasonal weather in southwest Missouri played a major role in risk perception and warning response. Most individuals commented that severe weather in southwest Missouri during spring is common; however, tornadoes never affect Joplin or themselves personally. It was common in the interviews to hear residents refer to "storms always blowing over and missing Joplin", or that there seemed like there was a "protective bubble" around Joplin, or "there is rotation all the time, but never in Joplin". One city employee stated, "… don't think it can't happen in your community, because that‘s what I thought". This sense in which people believe their personal risk from a hazard is less than the risk faced by others is referred to as optimism bias and can lead to diminished perceptions of threat and influence response.

I have seen / heard pple in this blog use this kind of expression [can I get a witness, Tampa?], and I have heard it said on the streets of Nassau, Bahamas.
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Good afternoon.
Quoting TropicalAnalystwx13:

That makes us special, lol.

lol
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Quoting aquak9:
Wise men talk because they have something to say; fools talk because they have to say something.
-- Plato
nice!! ..jury is out on me, but I'm thinking 98L stands a good chance at getting to minimal TS in the next 24hrs. i think convection will kick in and the closed circulation draw tighter. not much to support except my read on it, so take as a man's opinion only..
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Downed power line from winds gusting over 45 mph was the cause of the Bastrop fire, FYI. 95 percent contained as of today.
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Wise men talk because they have something to say; fools talk because they have to say something.
-- Plato
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Quoting Tazmanian:




good thinking POOF


Point proven....nuff said.
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Dont talk anymore about trolls. All that does is encourage them. If everyone here never mentioned the word troll and ignored troll like posters then they would have no audience. All who respond to trolls are in effect no better than them. This is the last time I personally will ever say the world troll, except for when i'm reading the troll under the bridge story with my kids. Thanks for your time.
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Quoting KEEPEROFTHEGATE:
same here wash some not all but you can see it changing its coming 505am friday morning the sun crosses the line heading south for the winter and with it the start of fall summer has 2 more days
The squirrels are going nuts to(Again don't shoot me no bad pun intended).There gathering food and what not and it seems the birds are also active.I've never seen them this active this time of year except for September of 09.Maybe the animals know something we don't?
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Quoting CaribBoy:
Convection starting to cool with 98L
thats a good thing at least its operating on the correct cycle for thius time of day should rebuild after o lets say 10 pm or there abouts
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Post99L threatening the Leeward... with rains
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Convection starting to cool with 98L
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my adjuster just left. looks like insurance company gonna get hit by about 8 grand from Irene
Member Since: September 19, 2005 Posts: 2 Comments: 4266
Quoting MiamiHurricanes09:
Maturity is of the mind.
Quoting hurricanehunter27:
The troll? Im in the 9th grade and i dont act like that.
Quoting wxgeek723:


But the bulk of the teenage populace does.

That makes us special, lol.
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Its getting there.

Recent observations of Cleveland volcano show that the current eruption, characterized by effusion of lava within the summit crater continues. The size of the lava dome is now about 165 m (540 ft) in diameter compared to 150 m (490 ft) in diameter on September 9,2011. The growing lava dome remains entirely contained within the summit crater but is now approximately 20 meters below the eastern rim.
Member Since: July 22, 2010 Posts: 1 Comments: 3851
Quoting will40:



he is just trying to plug that site he did it twice yesterday


As a matter fact no i am not trying to plug the site..just was needing some clarification thats all since i got no response yesterday...
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i think she will be TD at the 8:00 update
Member Since: September 19, 2005 Posts: 2 Comments: 4266
Quoting Tazmanian:



it has a closed circulation


so it needs a well defined LLC
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Quoting washingtonian115:
Yeah.The trees are turning yellow and orange.I was sorta surprised.Over the last week.The trees have really changed color.
same here wash some not all but you can see it changing its coming 505am friday morning the sun crosses the line heading south for the winter and with it the start of fall summer has 2 more days
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As long as blogs will exist so will trolls. Just go right by their posts and don't give them the time of day. I don't have anyone on ignore and, except for this one time, they don't exist. Just simply move on to posts that matter and the ones who frequent this blog will know who is full of garbage or just someone giving an opinion whether it is baseless or not. The more bandwidth wasted on acknowledging them, the happier they are.

Same goes for global warming or not global warming. Just fly right by those posts if they are not to your liking or pertinent to what you want to find on this forum.

This is the only bandwidth I will waste with my 2 cents on this.
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Quoting washingtonian115:
Invest 98L has winds of 35mph all it needs now is a closed circulation.



it has a closed circulation
Member Since: May 21, 2006 Posts: 5091 Comments: 115435
To everyone : PEACE :) :) :) :) To much bad things in the world.. so let's love each of us!
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Invest 98L has winds of 35mph all it needs now is a closed circulation.
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Quoting wxgeek723:


Really? In Washington? I live by Philadelphia and the trees here are as green as ever, lol.
Yeah.The trees are turning yellow and orange.I was sorta surprised.Over the last week.The trees have really changed color.
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One of the coolest sat loops of northern hemisphere

Link
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Quoting hurricanehunter27:
The troll? Im in the 9th grade and i dont act like that.
Maturity is of the mind.
Member Since: September 2, 2009 Posts: 130 Comments: 21194
Quoting washingtonian115:
KOTG I see your not banned that's good.Anywho fall is showing it's colors(don't shoot me not pun inteded).Yep yep.The trees are turning yellow and orange along with red.The acorns are falling off of the trees now and there are below average tempetures now.It's been a rainy and gloomy september thus far.Mmmmm last time we had a September this rainy was in 09.


Really? In Washington? I live by Philadelphia and the trees here are as green as ever, lol.
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Quoting GainesvilleGator:


There was a center relocation yesterday evening. I believe it was mentioned in the 8:00 PM NHC Advisory. The COC moved a couple of degrees East and a little to the South.



he is just trying to plug that site he did it twice yesterday
Member Since: September 19, 2005 Posts: 2 Comments: 4266
Quoting koolkiddvc:
I notice that WU has 98L at 12 North but Storm pulse still has the system down at 10.8 north, it has more than a degree south of the WU points in the past few days...can anyone explain this?


There was a center relocation yesterday evening. I believe it was mentioned in the 8:00 PM NHC Advisory. The COC moved a couple of degrees East and a little to the South.
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Quoting hurricanehunter27:
The troll? Im in the 9th grade and i dont act like that.


But the bulk of the teenage populace does.
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KOTG I see your not banned that's good.Anywho fall is showing it's colors(don't shoot me not pun inteded).Yep yep.The trees are turning yellow and orange along with red.The acorns are falling off of the trees now and there are below average tempetures now.It's been a rainy and gloomy september thus far.Mmmmm last time we had a September this rainy was in 09.
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Quoting hurricanehunter27:
The troll? Im in the 9th grade and i dont act like that.


Some 9th graders are a lot more mature than adults. It's just a blog, we need to sift out those who aren't mature and not let them get under our skin. They really win if we do.
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Quoting TropicalAnalystwx13:
Yep, its a high schooler.

Probably in 11th or 12th grade.
The troll? Im in the 9th grade and i dont act like that.
Member Since: July 22, 2010 Posts: 1 Comments: 3851
Quoting DFWjc:


but for how long? my sanity can't take it honestly...


Its okay, you can calm down. (nods)
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Quoting Gearsts:
Alot of shear to the north, dry air to the west and down MJO... No


So why do you to ignore me if actually you think like me about 98L. Lol
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174. DFWjc
Quoting docrod:
Finally


but for how long? my sanity can't take it honestly...
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Finally
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Quoting wxgeek723:


Lol only to a teenage mind inclined to perversion :p


:P
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Quoting TropicalAnalystwx13:


That sounds bad on so many levels...


Lol only to a teenage mind inclined to perversion :p
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KEEPER WANTS HOS KY IINSTEAD OF VASELINE POOR BABY
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.
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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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