WPAC: Typhoon KROSA

[CrazyC83]

Wow... Rapid intensification is kind of a theme this year, it seems.

It's not uncommon in the WPAC though.

[apocalypt-flyer]

It's not the only thing. Intensity forecasts for WPAC Systems are often quite off-track. They often classify TSs too late or don't pick up on strong intensification hints. Which leads to 'rapid intensification' but in reality they just aren't upgraded as quickly as they should be.

[wxmann_91]

Can't believe this is already classified a Cat 4. The inner core is still loosely organized at best. Dry air entrainment is still affecting the circulation. Maybe low end 3 right now. Could strengthen to a 4 in the next 24 hours if dry air entrainment ceases.

[CrazyC83]

03/2030 UTC 18.4N 128.4E T6.0/6.0 KROSA

[wxmann_91]

Can't believe this is already classified a Cat 4. The inner core is still loosely organized at best. Dry air entrainment is still affecting the circulation. Maybe low end 3 right now. Could strengthen to a 4 in the next 24 hours if dry air entrainment ceases.

Here's MIMIC

http://cimss.ssec.wisc.edu/tropic/real- ... npage.html

2007-10-03 00:00 -- 2007-10-03 23:45 loop clearly shows that an inner core did consolidate earlier today, but renewed dry air entrainment has pwned it.

[Coredesat]

[Coredesat]

WTJP22 RJTD 040000
WARNING 040000.
WARNING VALID 050000.
WARNING IS UPDATED EVERY 6 HOURS.
TYPHOON WARNING.
TYPHOON 0715 KROSA (0715) 940 HPA
AT 18.5N 128.0E SEA EAST OF PHILIPPINES MOVING WESTNORTHWEST 09
KNOTS.
POSITION GOOD.
MAX WINDS 90 KNOTS NEAR CENTER.
RADIUS OF OVER 50 KNOT WINDS 90 MILES.
RADIUS OF OVER 30 KNOT WINDS 400 MILES SOUTHEAST SEMICIRCLE AND 270
MILES ELSEWHERE.
FORECAST POSITION FOR 050000UTC AT 20.9N 125.5E WITH 90 MILES RADIUS
OF 70 PERCENT PROBABILITY CIRCLE.
935 HPA, MAX WINDS 90 KNOTS NEAR CENTER.
EXTENDED OUTLOOK.
FORECAST POSITION FOR 060000UTC AT 23.1N 123.0E WITH 150 MILES RADIUS
OF 70 PERCENT PROBABILITY CIRCLE.
940 HPA, MAX WINDS 85 KNOTS NEAR CENTER.
FORECAST POSITION FOR 070000UTC AT 25.5N 121.1E WITH 220 MILES RADIUS
OF 70 PERCENT PROBABILITY CIRCLE.
960 HPA, MAX WINDS 75 KNOTS NEAR CENTER.

JAPAN METEOROLOGICAL AGENCY.=

[CrazyC83]

Current Intensity Analysis




UW - CIMSS
ADVANCED DVORAK TECHNIQUE
ADT-Version 7.2.1
Tropical Cyclone Intensity Algorithm

----- Current Analysis -----
Date : 04 OCT 2007 Time : 015700 UTC
Lat : 18:44:00 N Lon : 127:40:26 E


CI# /Pressure/ Vmax
6.4 / 918.3mb/124.6kt


6hr-Avg T# 3hr-Avg T# Adj T# Raw T#
6.4 6.4 6.7 6.8

Latitude bias adjustment to MSLP : +1.7mb

Estimated radius of max. wind based on IR : 31 km

Center Temp : +13.7C Cloud Region Temp : -72.9C

Scene Type : EYE

Positioning Method : RING/SPIRAL COMBINATION

Ocean Basin : WEST PACIFIC
Dvorak CI > MSLP Conversion Used : PACIFIC

Tno/CI Rules : Constraint Limits : 3.7T/24hr
Weakening Flag : OFF
Rapid Dissipation Flag : OFF

****************************************************

[HURAKAN]

IMPRESSIVE:

[Typhoon Hunter]

I am flying to Taiwan tomorrow to intercept typhoon Krosa. I arrive at 2120 local time via Macau and then will move into position.

Looks like there's going to be a big hit on Taiwan. JMA holding Krosa at 90kts, expecting it to intensify further to 95kts.

Here's the latest forecast:

WTPQ21 RJTD 041200
RSMC TROPICAL CYCLONE ADVISORY
NAME TY 0715 KROSA (0715)

ANALYSIS
PSTN 041200UTC 19.9N 126.7E GOOD
MOVE NW 09KT
PRES 940HPA
MXWD 090KT
GUST 130KT
50KT 90NM
30KT 350NM SOUTHEAST 300NM NORTHWEST

FORECAST
24HF 051200UTC 22.4N 124.4E 80NM 70%
MOVE NW 08KT
PRES 935HPA
MXWD 095KT
GUST 135KT
48HF 061200UTC 24.1N 122.0E 150NM 70%
MOVE NW 07KT
PRES 950HPA
MXWD 085KT
GUST 120KT
72HF 071200UTC 26.4N 120.6E 220NM 70%
MOVE NNW 07KT
PRES 970HPA
MXWD 070KT
GUST 100KT =

[Chacor]

The following post is NOT an official bulletin and should not be used as such. However, it is written using official WMO information. They are NOT endorsed by any professional institution or storm2k.org. For official information, please refer to the relevant JMA and JTWC products. Windspeeds listed here are 10-minute averages.

BULLETIN
TYPHOON KROSA ADVISORY
11 PM JST... 1400Z... THU OCT 4 2007

...LARGE TYPHOON KROSA OFF NORTHEASTERN LUZON...

AT 9 PM JST...1200Z...THE CENTRE OF TYPHOON KROSA WAS LOCATED NEAR
LATITUDE 19.9 NORTH...LONGITUDE 126.7 EAST...OR ABOUT 485 MILES...780 KM
SOUTHEAST OF TAIPEI...AND ABOUT 520 MILES...840 KM NORTHEAST OF MANILA.

KROSA IS MOVING TO THE NORTHWEST NEAR 10 MPH...17 KM/H. A SLIGHT
INCREASE IN FORWARD SPEED IS POSSIBLE OVER THE NEXT 24 HOURS.

MAXIMUM SUSTAINED WINDS ARE NEAR 105 MPH...165 KM/H...WITH HIGHER
GUSTS. SOME STRENGTHENING IS POSSIBLE OVER THE NEXT 24 HOURS AS
KROSA CONTINUES TOWARDS TAIWAN.

30-KT WINDS EXTEND OUTWARD UP TO 400 MILES...650 KM FROM THE CENTRE...
50-KT WINDS EXTEND OUTWARD UP TO 105 MILES...165 KM FROM THE CENTRE.

ESTIMATED MINIMUM CENTRAL PRESSURE IS 940 HPA...27.76 INCHES.

REPEATING THE 9 PM JST POSITION...NEAR 19.9 NORTH 126.7 EAST. MOVEMENT
TOWARD NORTHWEST...NEAR 17 KM/H. MAXIMUM SUSTAINED WINDS...165 KM/H.
MINIMUM CENTRAL PRESSURE...940 HPA.

[Typhoon Hunter]

Someone needs to updates the Active Storms sub-heading please. It still states Tropical Storm Krosa and STS Lekim.

The jog to the west is pretty clear now that the 3 hourly 15z position update from JMA is out. At 12z centre of Krosa was at 19.9N 126.7E. Over the last 3 hours it hasn't gained much latitude but is charging WNW westward at 10kts - 20.1N 126.1E.

If this picks up a bit of speed and hit central Taiwan may just snag a daylight evening landfall...

[CrazyC83]

Now up to 95 kt (10-min)/935mb.

[whereverwx]

The eye is gradually becoming more defined and it's also warming. Some dry air does appear to have entrained itself into its core, though.

[HurricaneBill]

Where would be the worst place for a typhoon to hit Taiwan? The northern part?

[Matt-hurricanewatcher]

UW - CIMSS
ADVANCED DVORAK TECHNIQUE
ADT-Version 7.2.1
Tropical Cyclone Intensity Algorithm

----- Current Analysis -----
Date : 04 OCT 2007 Time : 223000 UTC
Lat : 20:23:17 N Lon : 125:19:24 E


CI# /Pressure/ Vmax
6.7 / 908.8mb/132.2kt


6hr-Avg T# 3hr-Avg T# Adj T# Raw T#
6.6 6.6 6.8 6.8

Latitude bias adjustment to MSLP : +1.2mb

Estimated radius of max. wind based on IR : 34 km

Center Temp : +17.2C Cloud Region Temp : -73.6C

Scene Type : EYE

Positioning Method : RING/SPIRAL COMBINATION

Ocean Basin : WEST PACIFIC
Dvorak CI > MSLP Conversion Used : PACIFIC

Tno/CI Rules : Constraint Limits : NO LIMIT
Weakening Flag : ON
Rapid Dissipation Flag : OFF

[HURAKAN]

I LIVE FOR THIS!



04/2030 UTC 20.2N 125.5E T7.0/7.0 KROSA -- West Pacific Ocean

[CrazyC83]

7.0 warrants an upgrade to Super Typhoon Krosa...I'd say 135 kt right now.

[CrazyC83]

Where would be the worst place for a typhoon to hit Taiwan? The northern part?

Correct, and that is the current forecast track, putting the eastern eyewall over Taipei. However, the cone of uncertainty could mean it could miss Taiwan completely or go farther south...

[Typhoon Hunter]

Yup, northern Taiwan would be worse place for Krosa to hit in terms of disruption to largest number of people. Big citues up there apart from Tapei include Taoyuan, Jilong and Damshui. The forecast track is swinging all over the place at the moment and the latest JMA forecast has this passing just offshore northern Taiwan in about 40 hours.

Latest JMA has also just upped Krosa to 100kts...big and bad!

TY 0715 (Krosa)
Issued at 00:50 UTC, 5 October 2007
<Analyses at 05/00 UTC>
Scale Large
Intensity Very Strong
Center position N20°25'(20.4°)
E125°20'(125.3°)
Direction and speed of movement WNW Slowly
Central pressure 930hPa
Maximum wind speed near the center 50m/s(100kt)
Maximum wind gust speed 70m/s(140kt)
Area of 50kt winds or more Wide 190km(100NM)
Area of 30kt winds or more SE650km(350NM)
NW560km(300NM)