Typhoon Roke

[Somerset Squall]

The eighteenth tropical depression of the West Pacific season has formed, near where TS Kulap began it's life. Convection is deep but does not fully surround the LLC. Intensity is 30kts. Convection is deepest on the eastern side, supressed to the west due to poor outflow causing subsidence. The subsidence is being caused by an ULL which is forecast to persist. Shear will be moderate at strongest, so even with the ULL's presence, some slow strengthening is still likely. 18W is moving westwards along the southern eriphery of a subtropical steering ridge. A trough is forecast to break down the ridge inducing a poleward turn in track, but timing is uncertain. Kadena Airbase looks to be in the path of 18W, but the cyclone is not forecast to be intense at this point.

[onlyME]

The depression relocated its LLCC as seen on image below:

It is forecasted that the depression will move north of Kadena and then start to curve west gently,but cone of uncerntainty is HUGE!

[Konstantinos]

Now, we have Tropical Storm Roke. Please change the topic's title.

[Somerset Squall]

Indeed, intensity has risen to 35kts and 18W is now TS Roke. Roke should continue to intensify over the coming days but only slowly as the ULL I mentioned above continues to impinge on the cyclone. Convection is still deepest in Roke's eastern quadrant giving the storm a lop-sided look. Ridging the the northeast is now in control of Roke after the storm briefly moved northeastwards as an equatorial ridge influenced the steering pattern. As OnlyME says, the cone of uncertainty long term is huge due to a developing complex steering pattern developing in the region. The trough I mentioned before will cause a break to develop in the ridge causing a more northerly turn before another ridge develops behind. Roke could get trapped between the two resulting ridges, causing little or no motion by day 5. This scenario is considered most likely but is in no way set in stone.

[Somerset Squall]

Roke is really suffering at the hands of the ULL today. Convection has diminshed due to the very dry air caused by the ULL, and is showing little signs of regenerating at present. Therefore, Roke has been downgraded to a tropical depression with an intensity of 30kts.

Tropical Depression Roke is expected to re-strengthen as the ULL is forecast to weaken beyond the 24hr timeframe. Low shear and warm sea temps should allow Roke to become at least a strong tropical storm as it approaches Kadena AB. Motion will be slow at this stage, and Roke will head slowly southwestwards in a weak steering environment by day 5.

[cornishbrooksy]

Hey me again!

What are the chances of this one heading towards Hong Kong? Maybe too early to say, but a favourable curve to the southwest is being predicted by both JTWC and HKO.

Obviously only 5 days are up at the moment with a large cone of uncertainty, but after the quiet year this year im willing to hedge my bets on any chances!!

[Konstantinos]

Hello my friend cornishbrooksy. Here is a 5-day-forecast for Tropical Storm Roke:

Also here are two links for 14-day-forecast for Hong Kong:

http://www.accuweather.com/en-us/hk/hong-kong/hong-kong/forecast.aspx

http://www.accuweather.com/en-us/hk/hong-kong/hong-kong/forecast2.aspx

[Somerset Squall]

I think it's unlikely Cornishbrooksy. It would be a very odd track if it did- TC's in the Northern Hemisphere rarely track southwestwards for any length of time. Steering currents will be pretty weak by day 5, and there is a lot of uncertainty. Never say never though I suppose!

Roke has become a weak tropical storm again with intensity rising to 35kts. A small area of persistant convection has developed near the LLC. Slow intensification is foreast as shear remains low, waters moderately warm, but outflow poor to the northwest due to the ULL. Roke is heading slowly westwards for now but the tracking of this storm is so uncertain at the moment it could literally turn in any direction afterwards!

[onlyME]

Looks like a pinhole eye.

Is RI(rapid intensification)possible?

On microwave image I see that eyewall is forming.

Any chances that Roke goes to Cat3?

[Somerset Squall]

Roke has turned towards the south very slowly in weak steering currents. The ULL has weakened leaving Roke in a favourable environment. Accordingly, Roke has finally strengthened, with intensity now at 60kts. It won't be long before Roke becomes a typhoon, as a small eye is emerging within the central dense overcast. Just how strong Roke will get is difficult to say, depends on the persistance of the eye.

Roke is trapped between a ridge to the west and a ridge to the east. Therefore, Roke has moved very little (just a small southward drift as previously described). The ridge to the eaast is expected to win out forcing Roke to the north then northeast as it rounds the northwestern periphery of the eastern ridge. Extratropical transition is expected to begin in about 72hrs and be complete between 96-120hrs in southeastern Japan.

[Somerset Squall]

Roke has moved northwestwards today completing a small anti-clockwise loop. Intensity has fallen to 55kts as some dry air has impacted the storm. Now the storm has completed the loop, it will finally lift out to the northeast and brush Japan as it begins extratropical transition.

Edited September 18, 2011 by Somerset Squall

[Somerset Squall]

Roke has become a 70kt, cat 1 typhoon. Roke has developed a small eye within a small central dense overcast and looks rather similar to Typhoon Sonca at it's peak. Poleward outflow is improving and equatorward outflow remains good, so I think further intensification is likely before Roke turns northeastwards and clses in on Tokyo, Japan. Roke will have weakened considerably by this point as shear will rise and waters are signifcantly cooler to Roke's north.

[Somerset Squall]

Roke has rapidly strengthened this evening and intensity has risen to 100kts, making Roke a cat 3. Roke's eye has become very well defined over the last few hours and is embedded in a deep central dense overcast. Poleward outflow into the westerlies has facilitated this rapid intensification, and it is possible that Roke could further intensify tonight before shear increases and sea temps cool along track.

[chottom]

I started a blog with video updates for the Typhoons which hit us here in Kansai area (Kobe), Japan. So if you want to watch typhoon Roke in (almost) real time updates here is the address:

http://chottomatte.net/typhoonwatch/

I am posting the videos on my youtube channel but there are and some typhoon uprelated videos as well:

http://www.youtube.com/user/chottomattenet

ROKE will hit us in the middle of night but I will try to take a few short movies (if possible). Today was raining very heaviky and some of the underground streets in the city are flooded but no serious damages yet.

[Somerset Squall]

Thanks for those links Chottom, will be worth viewing over the next couple of days.

Roke has strengthened further today, and intensity has risen to 115kts, making the typhoon a cat 4 on the SS scale. Roke maintains a well defined eye but may be close to beginning an eyewall replacement cycle (EWRC) as evidenced by a possible secondary eyewall on satellite imagery. This means Roke has likely peaked, as when the EWRC is complete Roke will have likely collided with the upper level westerlies which will weaken the typhoon and initiate extratropical transition. Roke clearly shows however, that small storms really can ramp up quickly.

[Konstantinos]

ROKE will hit us in the middle of night but I will try to take a few short movies (if possible).

Thank you my friend. But you must have your attention.

[Cookie]

[yamkin]

Part of the Updates.....A powerful typhoon has struck disaster-ravaged Japan, bringing heavy rains and floods that have killed four people.....................http://www.bbc.co.uk...acific-14998561

Edited September 21, 2011 by yamkin

[Cookie]

http://www.youtube.com/watch?v=IURwh5y72LY&feature=player_embedded

[yamkin]

1 Million Evacuated, Typhoon Battered Japan

Japan has been hit by one natural disaster after another, since a powerful earthquake and tsunami killed more than 20,000 people. Typhoon Roke comes just weeks after Typhoon Talas killed 67 people, and left dozens of others injured in central Japan.....http://abcnews.go.co...lion-evacuated/

Edited September 21, 2011 by yamkin

[Somerset Squall]

Not good news at all, Roke has packed quite a punch!

Roke has cleared eastern Japan and is now almost completely extratropical. JTWC have issued their final advisory.

[Coast]

http://www.youtube.com/watch?v=S3BvtQO9D5U

TOKYO — A powerful typhoon struck Japan’s main island on Wednesday, stranding thousands of commuters in Tokyo and poured heavy rain on the stricken Fukushima Daiichi nuclear plant in the nation’s tsunami-ravaged northeast. Evacuation advisories went out to more than one million people across the main island of Honshu as torrential downpours caused flash floods in low-lying areas. As of Wednesday evening, six people had been found dead and seven others were missing, according to Japan’s national broadcaster, NHK. The storm, called Typhoon Roke, directly hit greater Tokyo, briefly shutting down Japan’s commercial and political center.

Strong winds and rains brought most subways and commuter trains to at least a temporary halt, stranding tens of thousands at stations. Bullet train and airline service was canceled. Even so, most of Tokyo continued to have electric power even as the eye of the storm passed through the city on Wednesday evening, a testament to Japan’s generally robust basic infrastructure. According to Tokyo Electric Power, about 20,000 homes lost electricity in Tokyo, a city of almost 13 million residents.

Roke was the second powerful typhoon to strike Japan in the last month. Typhoon Talas, which made landfall in western Japan on Sept. 2, left 106 people dead or missing, the worst toll in decades. Roke’s path was expected to take it over the Fukushima plant, which was crippled by the massive earthquake and tsunami on March 11. The storm’s approach raised concerns that heavy rains could increase the risk of a leak of contaminated water from the crippled reactor buildings into the nearby Pacific Ocean.

But Takeo Iwamoto, a spokesman for Tokyo Electric, the plant’s operator, said before the storm hit that the plant could weather it without further damage or risk of a leak. Company spokesmen could not be reached on Thursday morning. The storm also threatened to flood coastal areas damaged by the tsunami and earthquake, which lowered the level of the ground by as much as two or three feet in some areas, and to wash radioactivity from the evacuated area around the plant into the sea.

http://www.nytimes.com/2011/09/22/world/asia/typhoon-roke-hits-japan-headed-for-stricken-nuclear-plant.html#h[]