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 violet312s:


WRAL. Greg Fishel. It's that huge low that will keep us rather damp for the next week.


Yeah.

I'd switch from WRAL to WECT though, much better IMO ;)
Member Since: July 6, 2010 Posts: 113 Comments: 34461
I can hear them coming.:) Much needed rain.:) thx

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Quoting TropicalAnalystwx13:


Who were you watching?


WRAL. Greg Fishel. It's that huge low that will keep us rather damp for the next week.
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Quoting violet312s:
Our NC met said that 98L's path depends on its speed. The huge low that is going to be spinning in the Ohio valley will inhibit anything from being able to come ashore on the East coast for at least 7 days. Then once it moves off shore might make anything do that Katia curve.

Only time will tell this far out.


Who were you watching?
Member Since: July 6, 2010 Posts: 113 Comments: 34461
Complete Update

TS BUSTED FORECAST ALIBI





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Our NC met said that 98L's path depends on its speed. The huge low that is going to be spinning in the Ohio valley will inhibit anything from being able to come ashore on the East coast for at least 7 days. Then once it moves off shore might make anything do that Katia curve.

Only time will tell this far out.
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the one the GFS shows hitting FLA is comming out of the

Caribbean
Member Since: September 19, 2005 Posts: 2 Comments: 4266
Quoting RussianWinter:

Minimal is not good enough. It needs to be zero.


No, it doesn't. There is always a chance =P

0.000000000000001%
Member Since: July 6, 2010 Posts: 113 Comments: 34461
Quoting TropicalAnalystwx13:


We're talking about a storm forming in the Caribbean. Obviously, there is a very minimal chance of 98L affecting Florida. =P


Minimal is not good enough. It needs to be zero.
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Quoting indianrivguy:


ahhh, you saw Levi's video too. He does a great job.


I've supported his idea of a Caribbean for what...A week and a half now? We're getting late in the season, so Caribbean development naturally comes anyways. Additionally, the upcoming pattern favors Caribbean trouble.
Member Since: July 6, 2010 Posts: 113 Comments: 34461
Quoting TropicalAnalystwx13:


That's definitely NOT true.

If anything develops in the Caribbean, Florida is right in the bulls-eye.

Cough*Cough*WILMA*Cough*Cough*
I'm talking about the east coast.Everyone knows Florida can still get struck during October.
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Quoting BOGUSFORCASTAGAIN:
all the tv weather staions here in miami channel 2 channel 3 chanel 6 and channel 9 all just said on the 6pm weather that if 98l should develop it will go around the bermuda high and stay was out to sea thats comming from the news channels


We're talking about a storm forming in the Caribbean. Obviously, there is a very minimal chance of 98L affecting Florida. =P

Member Since: July 6, 2010 Posts: 113 Comments: 34461
Quoting TropicalAnalystwx13:


That's definitely NOT true.

If anything develops in the Caribbean, Florida is right in the bulls-eye.

Cough*Cough*WILMA*Cough*Cough*


ahhh, you saw Levi's video too. He does a great job.
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Quoting washingtonian115:
Um that run is not belivabls because the jet stream is suppose to stay in place and basically block any storm that even decides to look at the U.S.


That's definitely NOT true.

If anything develops in the Caribbean, Florida is right in the bulls-eye.

Cough*Cough*WILMA*Cough*Cough*
Member Since: July 6, 2010 Posts: 113 Comments: 34461
Quoting prweatherwatcher:



The track should be more like Irene when she approach the NE Carr. The uncertany is with the wind speed.
If this gets up and goes, it does look more likely to do it like Irene, as opposed to Katia. OTOH, this may indeed be our first genuine Caribbean tracker, if it doesn't get going soon enough. There's still a lot of room for variation with this one.
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Quoting Tazmanian:
the 18Z at the end of the run has this for FL and look where it makes land fall lol



Um that run is not belivable because the jet stream is suppose to stay in place and basically block any storm that even decides to look at the U.S.
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Quoting Tazmanian:
the 18Z at the end of the run has this for FL and look where it makes land fall lol





I had to enlarge it a bunch before I could see it well enough.. cracked me up. They've had it easy since Easy.
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Quoting Tazmanian:
the 18Z at the end of the run has this for FL and look where it makes land fall lol





Florida is safe. It's official lol.
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Quoting TropicalAnalystwx13:
How the heck do you get that 98L will follow a similar path to Katia?! Do you not see that 98L is WELL south of where Katia was at this point?!




The track should be more like Irene when she approach the NE Carr. The uncertany is with the wind speed.
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Quoting Tazmanian:
the 18Z at the end of the run has this for FL and look where it makes land fall lol





DOOM!!!

Member Since: July 6, 2010 Posts: 113 Comments: 34461
Quoting washingtonian115:
Won't be long now till we see a depression....


agree she is looking bad now
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the 18Z at the end of the run has this for FL and look where it makes land fall lol



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Quoting BDADUDE:
It will join up with Katias track, just wait and see.


We'll see...
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Quoting WoodyFL:
It becomes now to look better.

Won't be long now till we see a depression....
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Quoting TropicalAnalystwx13:
How the heck do you get that 98L will follow a similar path to Katia?! Do you not see that 98L is WELL south of where Katia was at this point?!

It will join up with Katias track, just wait and see.
Member Since: September 3, 2008 Posts: 0 Comments: 605
How the heck do you get that 98L will follow a similar path to Katia?! Do you not see that 98L is WELL south of where Katia was at this point?!

Member Since: July 6, 2010 Posts: 113 Comments: 34461
Quoting BDADUDE:
?? The tracks are going to be very similiar dude.


Oh man...
Member Since: July 6, 2010 Posts: 113 Comments: 34461
Quoting WeatherNerdPR:

Not at all.
?? The tracks are going to be very similiar dude.
Member Since: September 3, 2008 Posts: 0 Comments: 605
Quoting Neapolitan:

Yeah, your comment is nearly identical to my comment #171 in the previous blog. How often have we heard comments here along the lines of, "I'm not going to evacuate; there's a shield over us". Optimism bias indeed...


You hear that about Tampa time to time. It just means they are overdo and more will likely get hurt when it DOES happen. :(
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Quoting violet312s:


The report also said that the majority of people IGNORED the first siren sounding. Their conclusion was that sirens need to have 2 sounds. First sound is take cover. Second sound is WE WEREN'T KIDDING!

I wonder how many lives in Joplin would have been saved if people would have taken cover at the sound of the first siren.
For hurricanes we have watches and warnings.... different but related signals. Maybe they need something like that.... the regular three minute warning saying a tornado or bad straight line winds are possible in the area, and another siren, maybe a "beeping" one, that says "it's going to hit YOU - right now!". So people know to stay alert, even if they don't immediately take cover.

Tornados just seem so much more complex to deal with, not just because of the speed issue....
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Quoting WoodyFL:


I am sorry, I was not here much for Katia. Are they of a similar direction?

Not at all.
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Quoting violet312s:


I wonder if they'll give TS Lee the credit and add the damage totals at Bastrop to the overall Lee cost. Lee clearly caused the high winds.

Glad it's nearly fully contained.

So far, the official cause of the fire is still listed as "under investigation".
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Quoting Neapolitan:

Yeah, your comment is nearly identical to my comment #171 in the previous blog. How often have we heard comments here along the lines of, "I'm not going to evacuate; there's a shield over us". Optimism bias indeed...
The sad thing is, it's really obvious from a few of the comments that the reporters believe this kind of bias, combined with ignorance or confusion about what was happening with the storm, likely led to at least some of the deaths in this tornado.

The other thing that struck me is that lots of Joplin residents, for whatever reason, didn't have basements. [I wonder if it has something to do with being relatively near the River.] So even though some people took shelter, the buildings they were in couldn't withstand the EF5 winds. I'm assuming most survivors were in better structures or in basements.
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Member Since: September 19, 2005 Posts: 2 Comments: 4266
Quoting BDADUDE:
So 98 is following in the wake of Katia i see.


I am sorry, I was not here much for Katia. Are they of a similar direction?
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Burn Bans REMAIN IN EFFECT 98% of Texas. The ground has already dried up from recent rainfall. NO BURNING!

For those Texans who had some rain don't let your guard down, especially near any large group of trees or brush.
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Quoting WoodyFL:
Does it look like thunder storms are trying to form on the southwest maybe


So 98 is following in the wake of Katia i see.
Member Since: September 3, 2008 Posts: 0 Comments: 605
Quoting Neapolitan:

Yeah, your comment is nearly identical to my comment #171 in the previous blog. How often have we heard comments here along the lines of, "I'm not going to evacuate; there's a shield over us". Optimism bias indeed...


The report also said that the majority of people IGNORED the first siren sounding. Their conclusion was that sirens need to have 2 sounds. First sound is take cover. Second sound is WE WEREN'T KIDDING!

I wonder how many lives in Joplin would have been saved if people would have taken cover at the sound of the first siren.
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It becomes now to look better.

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Quoting violet312s:


I wonder if they'll give TS Lee the credit and add the damage totals at Bastrop to the overall Lee cost. Lee clearly caused the high winds.

Glad it's nearly fully contained.
Not sure about that but Lee sure did contribute to our Hell, LOL. Texas needs a Strong front to come thru and Cool it off, 97 today? We are still at least 95 after fronts come thru, they are very weak when they come thru South Central Texas and their effects are minimal. One coming thru thursday will drop us a degree or 2.
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Quoting BahaHurican:
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.

Yeah, your comment is nearly identical to my comment #171 in the previous blog. How often have we heard comments here along the lines of, "I'm not going to evacuate; there's a shield over us". Optimism bias indeed...
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Quoting bohonkweatherman:
Downed power line from winds gusting over 45 mph was the cause of the Bastrop fire, FYI. 95 percent contained as of today.


I wonder if they'll give TS Lee the credit and add the damage totals at Bastrop to the overall Lee cost. Lee clearly caused the high winds.

Glad it's nearly fully contained.
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Does it look like thunder storms are trying to form on the southwest maybe


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Quoting washingtonian115:
Why don't we just say the "T" world.
Very good idea.
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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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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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