WPAC: JELAWAT - Post-Tropical

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Re: WPAC: JELAWAT - Typhoon

#261 Postby Laplacian » Sat Sep 29, 2012 7:31 pm

dexterlabio wrote:http://www.wunderground.com/blog/JeffMasters/comment.html?entrynum=2244


One interesting discussion about Jelawat and the mysterious "boundary" off its eye.


I believe this "boundary" was actually a limiting streamline associated with a cyclonically curved, mesoscale jet streak. Such mesoscale jet streaks form in concert with horizontal gradients in latent heating (thermal wind arguments).

I "attached" the 18Z GFS model analysis at 250 mb on September 25, 2012. Couldn't get my software to print out values associated with color key, but 250-mb wind speeds clearly exceeded 100 knots around Jelawat (yes, wind speeds are expressed in knots). Quite unusual, in my opinion. So, in my view, this was a cyclonically curved, meso-beta jet streak induced by large horizontal gradients in latent heating probably in the middle to upper troposphere.

http://imageshack.us/photo/my-images/25 ... 25201.gif/

I've seen such mesoscale jet streaks form in concert with MCSs or MCCs here in the U.S.

Here's an example of a mesoscale jet streak associated with an MCS:

http://cimss.ssec.wisc.edu/goes/misc/980721.html
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#262 Postby brunota2003 » Sat Sep 29, 2012 7:46 pm

:uarrow: Would that be helpful or hurtful, in terms of maintaining intensity or strengthening? I would assume not many studies have been conducted about those with TCs...but maybe an educated guess?
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Re: WPAC: JELAWAT - Typhoon

#263 Postby ozonepete » Sun Sep 30, 2012 3:18 am

I believe they are neither helpful nor hurtful but rather an indication of a really severe tropical cyclone, i.e. it takes an unusually strong TC with intense outflow at or above 250mb to produce a jet streak like that.
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Re: WPAC: JELAWAT - Typhoon

#264 Postby Laplacian » Sun Sep 30, 2012 7:03 am

ozonepete wrote:I believe they are neither helpful nor hurtful but rather an indication of a really severe tropical cyclone, i.e. it takes an unusually strong TC with intense outflow at or above 250mb to produce a jet streak like that.


That's pretty much wrong...the mesoscale jet streak looks like it was cyclonically curved...not associated with anticyclonic outflow at all (250 mb is too low an altitude to observe anticyclonic outflow in most cases). If I'm correct, the jet streak formed as a result of a large horizontal gradient in latent heating (thermal wind equation). With latent heating in mind, I suspect it might be a footprint of strengthening, but the earlier post above is correct...I'm not sure there's been much research on this topic, so my strengthening theory is an educated guess. To be honest, I've never observed the phenomenon on satellite imagery that Jeff Masters observed...he has a great eye (no pun intended) to have pointed this out.
Last edited by Laplacian on Sun Sep 30, 2012 7:10 am, edited 3 times in total.
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#265 Postby Hurricane_Luis » Sun Sep 30, 2012 7:04 am

TS Jelawat making landfall in Mie Province, Japan

Image
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Re:

#266 Postby Laplacian » Sun Sep 30, 2012 7:13 am

Forgive me if this is a stupid question, but how did you insert your image in your post? Many thanks for your patience.
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Re: WPAC: JELAWAT - Typhoon

#267 Postby Typhoon Hunter » Sun Sep 30, 2012 8:22 am

The ugliest and worst side of a typhoon happened today on Okinawa, many hours after Jelawat had passed the island. I filmed a man swept away to his death at Cape Zanpa on the west coast of Okinawa near Kadena Airbase. I hope this tragic footage goes someway to highlight the extreme dangers of the ocean before, during and after a hurricane or typhoon:

[youtube]http://www.youtube.com/watch?v=hwgJ0egdGeA[/youtube]
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Re: WPAC: JELAWAT - Typhoon

#268 Postby Laplacian » Sun Sep 30, 2012 8:56 am

Tragic and very surreal. Thank you for posting this video.
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#269 Postby RobWESTPACWX » Sun Sep 30, 2012 9:11 am

Lots of footage has come in today, sadly there was the one death as well that James was there to document. Over 100 injures and wide spread travel havoc across Japan. Here is a link to my latest update.

http://www.westernpacificweather.com/20 ... -in-tokyo/
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Re: WPAC: JELAWAT - Typhoon

#270 Postby euro6208 » Sun Sep 30, 2012 10:15 am

Laplacian wrote:
ozonepete wrote:I believe they are neither helpful nor hurtful but rather an indication of a really severe tropical cyclone, i.e. it takes an unusually strong TC with intense outflow at or above 250mb to produce a jet streak like that.


That's pretty much wrong...the mesoscale jet streak looks like it was cyclonically curved...not associated with anticyclonic outflow at all (250 mb is too low an altitude to observe anticyclonic outflow in most cases). If I'm correct, the jet streak formed as a result of a large horizontal gradient in latent heating (thermal wind equation). With latent heating in mind, I suspect it might be a footprint of strengthening, but the earlier post above is correct...I'm not sure there's been much research on this topic, so my strengthening theory is an educated guess. To be honest, I've never observed the phenomenon on satellite imagery that Jeff Masters observed...he has a great eye (no pun intended) to have pointed this out.


could this be a new era for category 6 typhoons? :lol:
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Re: WPAC: JELAWAT - Typhoon

#271 Postby euro6208 » Sun Sep 30, 2012 10:16 am

Typhoon Hunter wrote:The ugliest and worst side of a typhoon happened today on Okinawa, many hours after Jelawat had passed the island. I filmed a man swept away to his death at Cape Zanpa on the west coast of Okinawa near Kadena Airbase. I hope this tragic footage goes someway to highlight the extreme dangers of the ocean before, during and after a hurricane or typhoon:



this video is surreal...what was he there for? fishing? photos?
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#272 Postby Typhoon Hunter » Sun Sep 30, 2012 10:22 am

Local man out fishing, severely underestimated the conditions and tragically paid with his life. His wife was there and witnessed the whole thing.
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Re: Re:

#273 Postby Hurricane_Luis » Sun Sep 30, 2012 3:52 pm

Laplacian wrote:Forgive me if this is a stupid question, but how did you insert your image in your post? Many thanks for your patience.


i just uploaded it via imageshak then put the embed code in, like this= [img]http//:www.exapmle.co.uk[img]

or have a read of this, https://groups.google.com/forum/#!topic ... BLAaBDJl_0 its written by me so if it dosent make any sense you can blame me (Im english but still cant write it :D )
Last edited by Hurricane_Luis on Sun Sep 30, 2012 4:13 pm, edited 1 time in total.
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Re: Re:

#274 Postby brunota2003 » Sun Sep 30, 2012 3:56 pm

Hurricane_Luis wrote:
Laplacian wrote:Forgive me if this is a stupid question, but how did you insert your image in your post? Many thanks for your patience.


i just uploaded it via imageshak then put the embed code in, like this= [img]http//:www.exapmle.co.uk[img]

Yep...when you click the reply button, all you have to do is click the Img button above the reply box and put the URL between the two tags that appear!
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Re: WPAC: JELAWAT - Typhoon

#275 Postby ozonepete » Sun Sep 30, 2012 4:46 pm

Laplacian wrote:
ozonepete wrote:I believe they are neither helpful nor hurtful but rather an indication of a really severe tropical cyclone, i.e. it takes an unusually strong TC with intense outflow at or above 250mb to produce a jet streak like that.


That's pretty much wrong...the mesoscale jet streak looks like it was cyclonically curved...not associated with anticyclonic outflow at all (250 mb is too low an altitude to observe anticyclonic outflow in most cases). If I'm correct, the jet streak formed as a result of a large horizontal gradient in latent heating (thermal wind equation). With latent heating in mind, I suspect it might be a footprint of strengthening, but the earlier post above is correct...I'm not sure there's been much research on this topic, so my strengthening theory is an educated guess. To be honest, I've never observed the phenomenon on satellite imagery that Jeff Masters observed...he has a great eye (no pun intended) to have pointed this out.


My bad on the outflow region. You are the maestro on such things as thermal wind and TC outflow dynamics. :wink: But would it be safe to say that this feature would only be seen in very strong TCs?
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Re: WPAC: JELAWAT - Typhoon

#276 Postby greenkat » Sun Sep 30, 2012 9:57 pm

Typhoon Hunter wrote:The ugliest and worst side of a typhoon happened today on Okinawa, many hours after Jelawat had passed the island. I filmed a man swept away to his death at Cape Zanpa on the west coast of Okinawa near Kadena Airbase. I hope this tragic footage goes someway to highlight the extreme dangers of the ocean before, during and after a hurricane or typhoon:

[youtube]http://www.youtube.com/watch?v=hwgJ0egdGeA[/youtube]


Tragic :cry: :cry: :cry:
Keep up the excellent videos! :)
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Re: WPAC: JELAWAT - Tropical Storm

#277 Postby euro6208 » Sun Sep 30, 2012 10:34 pm

Image

FINAL WARNING


WTPN31 PGTW 302100
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE WARNING//
RMKS/
1. TROPICAL STORM 18W (JELAWAT) WARNING NR 042
02 ACTIVE TROPICAL CYCLONES IN NORTHWESTPAC
MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
WIND RADII VALID OVER OPEN WATER ONLY
---
WARNING POSITION:
301800Z --- NEAR 38.6N 140.9E
MOVEMENT PAST SIX HOURS - 030 DEGREES AT 39 KTS
POSITION ACCURATE TO WITHIN 040 NM
POSITION BASED ON CENTER LOCATED BY A COMBINATION OF
SATELLITE AND RADAR
PRESENT WIND DISTRIBUTION:
MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT
WIND RADII VALID OVER OPEN WATER ONLY
BECOMING EXTRATROPICAL
REPEAT POSIT: 38.6N 140.9E
---
FORECASTS:
12 HRS, VALID AT:
010600Z --- 44.0N 149.3E
MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT
WIND RADII VALID OVER OPEN WATER ONLY
EXTRATROPICAL
RADIUS OF 034 KT WINDS - 055 NM NORTHEAST QUADRANT
045 NM SOUTHEAST QUADRANT
040 NM SOUTHWEST QUADRANT
035 NM NORTHWEST QUADRANT
VECTOR TO 24 HR POSIT: 060 DEG/ 44 KTS
---
24 HRS, VALID AT:
011800Z --- 48.0N 160.6E
MAX SUSTAINED WINDS - 030 KT, GUSTS 040 KT
WIND RADII VALID OVER OPEN WATER ONLY
EXTRATROPICAL
---
REMARKS:
302100Z POSITION NEAR 40.0N 143.0E.
TROPICAL STORM 18W (JELAWAT), LOCATED, APPROXIMATELY 105 NM SOUTH
OF MISAWA, JAPAN, HAS ACCELERATED NORTH-NORTHEASTWARD AT 39 KNOTS
OVER THE PAST SIX HOURS. THE INITIAL POSITION IS BASED ON ANIMATED
RADAR REFLECTIVITY IMAGERY FROM JAPAN METEOROLOGICAL AGENCY WITH
HIGH CONFIDENCE. THE INITIAL INTENSITY IS EXTRAPOLATED FROM NEARBY
SURFACE OBSERVATIONS. TS 18W IS NOW EMBEDDED IN THE BAROCLINIC ZONE
AND ALMOST VOID OF CONVECTION AS THE LOW LEVEL CIRCULATION CENTER
HAS UNRAVELED AND BECOME RAGGED. THE SYSTEM WILL BECOME A COLD CORE
LOW AFTER IT EXITS HONSHU INTO THE COLD SEA OF JAPAN OVER THE NEXT
FEW HOURS. THIS IS THE FINAL WARNING ON THIS SYSTEM BY THE JOINT
TYPHOON WRNCEN PEARL HARBOR HI. THE SYSTEM WILL BE CLOSELY MONITORED
FOR SIGNS OF REGENERATION. //
NNNN
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Re: WPAC: JELAWAT - Typhoon

#278 Postby Laplacian » Mon Oct 01, 2012 5:39 am

ozonepete wrote:
Laplacian wrote:
ozonepete wrote:
My bad on the outflow region. You are the maestro on such things as thermal wind and TC outflow dynamics. :wink: But would it be safe to say that this feature would only be seen in very strong TCs?


No biggie. It would seem that way, ozonepete, but I hesitate to state definitively that it's so until I read some research on this topic.
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Re: Re:

#279 Postby Laplacian » Mon Oct 01, 2012 6:05 am

Hurricane_Luis wrote:
Laplacian wrote:Forgive me if this is a stupid question, but how did you insert your image in your post? Many thanks for your patience.


i just uploaded it via imageshak then put the embed code in, like this= [img]http//:www.exapmle.co.uk[img]

or have a read of this, https://groups.google.com/forum/#!topic ... BLAaBDJl_0 its written by me so if it dosent make any sense you can blame me (Im english but still cant write it :D )


You did very well. Thank you. Much appreciated.
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#280 Postby RobWESTPACWX » Mon Oct 01, 2012 6:09 am

One for the record books, Here is some videos of this storm, good thing it is well documented, I suggest most of you take a look at these videos.

http://www.westernpacificweather.com/20 ... m-footage/
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