WPAC: DUJUAN - Post-Tropical

[1900hurricane]

JMA is now expecting to name 97W within 24 hours.

TD
Issued at 13:30 UTC, 21 September 2015
<Analyses at 21/12 UTC>
Scale -
Intensity -
TD
Center position N14°50'(14.8°)
E142°25'(142.4°)
Direction and speed of movement W Slowly
Central pressure 1000hPa
Maximum wind speed near the center 15m/s(30kt)
Maximum wind gust speed 23m/s(45kt)

<Forecast for 22/12 UTC>
Intensity -
Center position of probability circle N15°25'(15.4°)
E140°35'(140.6°)
Direction and speed of movement WNW Slowly
Central pressure 998hPa
Maximum wind speed near the center 18m/s(35kt)
Maximum wind gust speed 25m/s(50kt)
Radius of probability circle 220km(120NM)

[supercane]

WTPQ20 RJTD 211200
RSMC TROPICAL CYCLONE ADVISORY
NAME TD
ANALYSIS
PSTN 211200UTC 14.8N 142.4E POOR
MOVE W SLOWLY
PRES 1000HPA
MXWD 030KT
GUST 045KT
FORECAST
24HF 221200UTC 15.4N 140.6E 120NM 70%
MOVE WNW SLOWLY
PRES 998HPA
MXWD 035KT
GUST 050KT =

[1900hurricane]

The circulation is still elongated some on a WSW/ENE axis, but not as badly as it has been. The biggest issue right now is where the center is in relation to the convection. 97W looks like it could be a named storm if the center was under/near the eastern portion of the main convective cluster. However, it's not. The circulation is actually just north of the smaller eastern cluster, far removed from the larger cluster. Every time so far that convection has started to fire near the center (as is the case right now), easterly shear has helped propigate the cluster westwards faster than the actual storm motion. It's yet to be seen if the current budding convection near the center will stick around this time.

[1900hurricane]

RSCAT shows wind barbs up to 40 kt, but still that elongated center.

[euro6208]

Expecting another Category 3...

WTPN31 PGTW 212100
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE WARNING//
RMKS/
1. TROPICAL DEPRESSION 21W (TWENTYONE) WARNING NR 001
01 ACTIVE TROPICAL CYCLONE IN NORTHWESTPAC
MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
WIND RADII VALID OVER OPEN WATER ONLY
---
WARNING POSITION:
211800Z --- NEAR 15.6N 141.7E
MOVEMENT PAST SIX HOURS - 275 DEGREES AT 10 KTS
POSITION ACCURATE TO WITHIN 060 NM
POSITION BASED ON CENTER LOCATED BY SATELLITE
PRESENT WIND DISTRIBUTION:
MAX SUSTAINED WINDS - 025 KT, GUSTS 035 KT
WIND RADII VALID OVER OPEN WATER ONLY
REPEAT POSIT: 15.6N 141.7E
---
FORECASTS:
12 HRS, VALID AT:
220600Z --- 16.1N 139.8E
MAX SUSTAINED WINDS - 030 KT, GUSTS 040 KT
WIND RADII VALID OVER OPEN WATER ONLY
VECTOR TO 24 HR POSIT: 290 DEG/ 09 KTS
---
24 HRS, VALID AT:
221800Z --- 16.7N 138.1E
MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT
WIND RADII VALID OVER OPEN WATER ONLY
VECTOR TO 36 HR POSIT: 285 DEG/ 07 KTS
---
36 HRS, VALID AT:
230600Z --- 17.1N 136.6E
MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 034 KT WINDS - 055 NM NORTHEAST QUADRANT
050 NM SOUTHEAST QUADRANT
050 NM SOUTHWEST QUADRANT
055 NM NORTHWEST QUADRANT
VECTOR TO 48 HR POSIT: 295 DEG/ 06 KTS
---
EXTENDED OUTLOOK:
48 HRS, VALID AT:
231800Z --- 17.6N 135.4E
MAX SUSTAINED WINDS - 055 KT, GUSTS 070 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 050 KT WINDS - 025 NM NORTHEAST QUADRANT
025 NM SOUTHEAST QUADRANT
025 NM SOUTHWEST QUADRANT
025 NM NORTHWEST QUADRANT
RADIUS OF 034 KT WINDS - 085 NM NORTHEAST QUADRANT
080 NM SOUTHEAST QUADRANT
075 NM SOUTHWEST QUADRANT
085 NM NORTHWEST QUADRANT
VECTOR TO 72 HR POSIT: 330 DEG/ 06 KTS
---
72 HRS, VALID AT:
241800Z --- 19.6N 134.1E
MAX SUSTAINED WINDS - 070 KT, GUSTS 085 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 064 KT WINDS - 025 NM NORTHEAST QUADRANT
025 NM SOUTHEAST QUADRANT
020 NM SOUTHWEST QUADRANT
025 NM NORTHWEST QUADRANT
RADIUS OF 050 KT WINDS - 045 NM NORTHEAST QUADRANT
045 NM SOUTHEAST QUADRANT
045 NM SOUTHWEST QUADRANT
045 NM NORTHWEST QUADRANT
RADIUS OF 034 KT WINDS - 120 NM NORTHEAST QUADRANT
115 NM SOUTHEAST QUADRANT
105 NM SOUTHWEST QUADRANT
115 NM NORTHWEST QUADRANT
VECTOR TO 96 HR POSIT: 340 DEG/ 07 KTS
---
LONG RANGE OUTLOOK:
---
96 HRS, VALID AT:
251800Z --- 22.3N 133.1E
MAX SUSTAINED WINDS - 095 KT, GUSTS 115 KT
WIND RADII VALID OVER OPEN WATER ONLY
VECTOR TO 120 HR POSIT: 340 DEG/ 07 KTS
---
120 HRS, VALID AT:
261800Z --- 24.8N 132.1E
MAX SUSTAINED WINDS - 105 KT, GUSTS 130 KT
WIND RADII VALID OVER OPEN WATER ONLY
---
REMARKS:
212100Z POSITION NEAR 15.7N 141.2E.
TROPICAL DEPRESSION 21W (TWENTYONE), LOCATED APPROXIMATELY 214 NM
NORTHWEST OF NAVSTA GUAM, HAS TRACKED WESTWARD AT 10 KNOTS OVER
THE PAST SIX HOURS. MAXIMUM SIGNIFICANT WAVE HEIGHT AT 211800Z IS 10
FEET. NEXT WARNINGS AT 220300Z, 220900Z, 221500Z AND 222100Z.//
NNNN

[euro6208]

UW - CIMSS
ADVANCED DVORAK TECHNIQUE
ADT-Version 8.2.1
Tropical Cyclone Intensity Algorithm

----- Current Analysis -----
Date : 21 SEP 2015 Time : 193000 UTC
Lat : 15:38:54 N Lon : 141:26:30 E


CI# /Pressure/ Vmax
1.5 /1008.1mb/ 25.0kt


Final T# Adj T# Raw T#
1.5 1.5 1.5

Center Temp : -39.4C Cloud Region Temp : -33.8C

Scene Type : USER DEFINED INITIAL CLASSIFICATION
Maximum CURVED BAND with 0.40 ARC in LT GRAY
at Lat: 15:38:24 N Lon: 140:50:23 E

Positioning Method : FORECAST INTERPOLATION

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

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

C/K/Z MSLP Estimate Inputs :
- Average 34 knot radii : N/A
- Environmental MSLP : 1010mb

Satellite Name : MTSAT2
Satellite Viewing Angle : 18.8 degrees

[euro6208]

WDPN31 PGTW 212100
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL DEPRESSION 21W (TWENTYONE)
WARNING NR 01//
RMKS//
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
TROPICAL DEPRESSION (TD) 21W (TWENTYONE), LOCATED APPROXIMATELY
214 NM NORTHWEST OF NAVSTA GUAM, HAS TRACKED WESTWARD AT 10 KNOTS
OVER THE PAST SIX HOURS. ANIMATED ENHANCED IR SATELLITE SHOWS
PERSISTENT SYMMETRICAL DEEP CONVECTION AS WELL AS A LOW LEVER
SPINNER TO THE EAST. DUE TO THE MULTIPLE VORTICES PRESENT, THERE IS
LOW CONFIDENCE IN THE INITIAL POSITIONING OF THE SYSTEM WHICH IS
PLACED AT THE CENROID OF THE VORTICES. HOWEVER, DUE TO THE
CONVECTIVE STRUCTURE AND AN OLDER 211246Z RSCAT IMAGE, THERE IS GOOD
CONFIDENCE IN THE INITIAL INTENSITY OF 25 KNOTS. UPPER LEVEL
ANALYSIS SHOWS THAT THERE IS 10 TO 20 KNOTS OF VWS OFFSET BY GOOD
DIVERGENCE ALOFT. THE SYSTEM IS CURRENTLY TRACKING ON THE SOUTHERN
SIDE OF A STR TO THE NORTH.
3. FORECAST REASONING.
A. THIS IS THE INITIAL PROGNOSTIC REASONING AND SETS THE FORECAST
PHILOSOPHY.
B. TD 21W WILL CONTINUE TO TRACK TO THE WEST UNDER THE INFLUENCE
OF THE STR THROUGH TAU 36. BEYOND THAT, A SHORTWAVE THROUGH WILL
CAUSE A SMALL BREAK IN THE STR AND ALLOW TD 21W TO TAKE A MORE
POLEWARD TRACK. EXPECT MARGINAL INTENSIFICATION THROUGH TAU 48 AS
THE SYSTEM CONTINUES TO CONSOLIDATE. HOWEVER THE SYSTEM IS EXPECTED
TO EXCEED TYPHOON STRENGTH BY TAU 72.
C. IN THE EXTENDED FORECAST, TD 21W WILL CONTINUE TO INTENSIFY AS
POLEWARD OUTFLOW IMPROVES. THE SYSTEM WILL CONTINUE TO TRACK TO THE
NORTHWEST THROUGH A BREAK IN THE RIDGE. DYNAMIC MODEL GUIDANCE IS
VARIED WITH REGARD TO BOTH THE SPEED OF TRACK AND THE POINT AT WHICH
THE BREAK IN THE RIDGE DEVELOPS. AS SUCH, THERE IS LIMITED
CONFIDENCE IN THE JTWC FORECAST TRACK AT THIS TIME.//
NNNN

[1900hurricane]

21W's circulation still looks like a barred spiral galaxy.

[euro6208]

000
WTPQ31 PGUM 220910
TCPPQ1

BULLETIN
TROPICAL DEPRESSION 21W ADVISORY NUMBER 3
NATIONAL WEATHER SERVICE TIYAN GU WP202015
800 PM CHST TUE SEP 22 2015

...TROPICAL DEPRESSION 21W RELOCATED...MOVING NORTHWEST...

CHANGES WITH THIS ADVISORY
--------------------------
NONE.

WATCHES AND WARNINGS
--------------------
NONE.

SUMMARY OF 700 PM CHST...0900 UTC...INFORMATION
-----------------------------------------------
LOCATION...17.6N 140.5E

ABOUT 350 MILES WEST-SOUTHWEST OF AGRIHAN
ABOUT 385 MILES WEST-NORTHWEST OF SAIPAN
ABOUT 400 MILES NORTHWEST OF GUAM

MAXIMUM SUSTAINED WINDS...30 MPH
PRESENT MOVEMENT...NORTHWEST...320 DEGREES AT 10 MPH

DISCUSSION AND OUTLOOK
----------------------
AT 700 PM CHST...0900 UTC...THE POORLY-DEFINED CENTER OF TROPICAL
DEPRESSION 21W WAS RELOCATED NEAR LATITUDE 17.6 NORTH AND LONGITUDE
140.5 EAST. MOVEMENT IS ESTIMATED TO BE TOWARD THE NORTHWEST AT
10 MPH. TROPICAL DEPRESSION 21W IS EXPECTED TO MOVE WEST-NORTHWEST
TONIGHT AND WEDNESDAY...THEN TURN SLOWLY NORTH-NORTHWEST ON
THURSDAY AND FRIDAY.

MAXIMUM SUSTAINED WINDS REMAIN AT 30 MPH. SLOW INTENSIFICATION IS
FORECAST...AND TROPICAL DEPRESSION 21W WILL LIKELY BECOME A TROPICAL
STORM BY LATE WEDNESDAY.

NEXT ADVISORY
-------------
THE NEXT SCHEDULED ADVISORY WILL BE ISSUED BY THE NATIONAL WEATHER
SERVICE AT 200 AM WEDNESDAY MORNING.

$$

MIDDLEBROOKE

[euro6208]

WDPN31 PGTW 222100
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL DEPRESSION 21W (DUJUAN)
WARNING NR 05//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
TROPICAL DEPRESSION (TD) 21W (DUJUAN), LOCATED APPROXIMATELY 469
NM SOUTH-SOUTHWEST OF IWO TO, HAS TRACKED WESTWARD AT 12 KNOTS OVER
THE PAST SIX HOURS. ANIMATED ENHANCED IR (EIR) SATELLITE IMAGERY
DEPICTS PERSISTENT CONVECTION THAT IS ASYMMETRIC, WITH A CLEAR LOW
LEVEL CIRCULATION TO THE EAST OF THE DEEP CONVECTION. A 211735Z SSMI
IMAGE SHOWS VERY FRAGMENTED BANDING WITH THE DEEP CONVECTION ON THE
WESTERN SIDE OF THE SYSTEM. THE INITIAL POSITION IS BASED ON THE
PARTIAL LLCC IN THE AFOREMENTIONED MICROWAVE IMAGE AND THE EIR LOOP
WITH LOW CONFIDENCE. THE CURRENT INTENSITY HAS BEEN MAINTAINED AT 30
KNOTS BASED ON THE PREVIOUS ASCAT PASS, SLIGHTLY HIGHER THAN THE
DT1.5 REPORTED FROM KNES, RJTD AND PGTW. ENVIRONMENTAL ANALYSIS
INDICATES A MARGINAL ENVIRONMENT WITH 20 TO 25 KNOTS OF EASTERLY VWS
BEING PARTIALLY OFFSET BY DIVERGENCE ALOFT AND HIGH SSTS. TD 21W IS
TRACKING ALONG THE SOUTHERN PERIPHERY OF A DEEP LAYERED STR.
3. FORECAST REASONING.
A. THERE IS A SLIGHT CHANGE IN THE JTWC FORECAST PHILOSOPHY WITH
A MORE FLAT TRACK IN THE NEAR TERM AND RECURVING AROUND THE STR
BEYOND TAU 36.
B. TD DUJUAN WILL CONTINUE TO TRACK WEST-NORTHWESTWARD OVER THE
NEXT 36 HOURS AS THE STR REMAINS TO THE NORTH OF THE SYSTEM. DURING
THIS TIMEFRAME, EXPECT MARGINAL INTENSIFICATION DUE TO MODERATE VWS
AFFECTING THE SYSTEM. BEYOND TAU 36, EXPECT A SHORTWAVE MID-LATITUDE
TROUGH TO CREATE A SMALL BREAK IN THE STR, ALLOWING A STRONGER TD
21W TO GAIN A MORE POLEWARD TRAJECTORY. ADDITIONALLY, EXPECT
IMPROVED OUTFLOW TO ALLOW FOR NEAR RAPID INTENSIFICATION FOR THE
SYSTEM THROUGH TAU 72.
C. IN THE EXTENDED FORECAST, TD 21W WILL CONTINUE TO INTENSIFY
DUE TO FAVORABLE ENVIRONMENTAL CONDITIONS. HOWEVER, DUE TO LOWER
SSTS AND OCEAN HEAT CONTENT, TD DUJAUN'S INTENSIFICATION WILL BE AT
A SLOWER RATE. DYNAMIC MODEL GUIDANCE CONTINUES TO DISPLAY A WIDE
SPREAD OF SOLUTIONS REGARDING THE TIMING AND EXTENT OF THE RECURVE,
WITH GFS NOW DEPICTING A MORE FLAT TRACK, COMING INTO BETTER
ALIGNMENT WITH THE NAVGEM SUITE. THE JTWC TRACK HAS FLATTENED
SIGNIFICANTLY IN THE EARLY STAGES OF THE FORECAST TO TAKE INTO
CONSIDERATION HOW SLOWLY THE SYSTEM HAS CONSOLIDATED, NOT ALLOWING
THE SYSTEM TO TRACK INTO THE STR. DUE TO THE CONTINUED WIDE SPREAD
IN DYNAMIC MODEL GUIDANCE, THERE REMAINS LOW CONFIDENCE IN THE JTWC
TRACK FORECAST.//
NNNN

[euro6208]

UW - CIMSS
ADVANCED DVORAK TECHNIQUE
ADT-Version 8.2.1
Tropical Cyclone Intensity Algorithm

----- Current Analysis -----
Date : 22 SEP 2015 Time : 193000 UTC
Lat : 17:32:47 N Lon : 138:02:40 E


CI# /Pressure/ Vmax
2.3 /1000.5mb/ 33.0kt


Final T# Adj T# Raw T#
2.3 2.2 2.3

Center Temp : -11.5C Cloud Region Temp : -21.5C

Scene Type : CURVED BAND with 0.29 ARC in MD GRAY
Maximum CURVED BAND with 0.44 ARC in MD GRAY
at Lat: 18:32:24 N Lon: 137:14:24 E

Positioning Method : FORECAST INTERPOLATION

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

Tno/CI Rules : Constraint Limits : 0.7T/6hr
Weakening Flag : OFF
Rapid Dissipation Flag : OFF

C/K/Z MSLP Estimate Inputs :
- Average 34 knot radii : N/A
- Environmental MSLP : 1007mb

Satellite Name : MTSAT2
Satellite Viewing Angle : 22.0 degrees

[supercane]

WTPQ50 RJTD 221800
RSMC TROPICAL CYCLONE ADVISORY
NAME TS 1521 DUJUAN (1521) UPGRADED FROM TD
ANALYSIS
PSTN 221800UTC 17.7N 138.2E FAIR
MOVE W 09KT
PRES 996HPA
MXWD 035KT
GUST 050KT
30KT 210NM WEST 150NM EAST
FORECAST
24HF 231800UTC 18.7N 134.9E 70NM 70%
MOVE WNW 08KT
PRES 992HPA
MXWD 040KT
GUST 060KT
48HF 241800UTC 19.8N 133.7E 110NM 70%
MOVE NW SLOWLY
PRES 985HPA
MXWD 050KT
GUST 070KT
72HF 251800UTC 21.7N 133.1E 160NM 70%
MOVE NNW SLOWLY
PRES 975HPA
MXWD 060KT
GUST 085KT
96HF 261800UTC 24.8N 133.6E 240NM 70%
MOVE N 08KT
120HF 271800UTC 27.8N 134.7E 300NM 70%
MOVE NNE 08KT =

[1900hurricane]

Well, the circulation of Dujuan looks like it has outgrown its ellipticalness, now it just needs to get under some convection.

[Alyono]

EC flipped from well south of Tokyo to a direct hit on Taipei. Model is worth less than the Canadian model this year

Also, this does not qualify as a TC right now given its convective structure

[Alyono]

those wind barbs are contaminated by the convection. They are also not related to the circulation given how far away from the center they are

[euro6208]

Great discussion.

WDPN31 PGTW 230900
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 21W (DUJUAN) WARNING NR
07//
RMKS//
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
TROPICAL STORM (TS) 21W (DUJUAN), LOCATED APPROXIMATELY 655 NM
SOUTHEAST OF KADENA AB, JAPAN HAS TRACKED WEST-NORTHWESTWARD
AT 12 KNOTS OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL
SATELLITE IMAGERY DEPICTS SMALLER VORTICES ROTATING AROUND A LARGER
CIRCULATION CENTROID WITH DEEP SYMMETRIC CONVECTION ALONG THE
WESTERN PERIPHERY OF THE LARGER CIRCULATION. ENHANCED INFRARED
SATELLITE IMAGERY SHOWS POSSIBLE MID-LEVEL TURNING WITHIN THE DEEP
CONVECTION. DUE TO THE LARGE CIRCULATION AND MULTIPLE VORTICES
WITHIN THE SYSTEM, THERE IS LOW CONFIDENCE IN THE INITIAL POSITION.
THE HORIZONTAL EXTENT OF THE CIRCULATION IS FURTHER EVIDENT IN A
230136Z ASCAT PASS THAT MISSED THE CENTER OF THE CIRCULATION BUT
SHOWED THE ELONGATED NATURE OF THE PERIPHERY WINDS. A 230234Z AMSR-2
89GHZ MICROWAVE IMAGE SHOWS VERY BROAD SHALLOW BANDING WRAPPING INTO
THE ELONGATED CIRCULATION WITH THE DEEP CONVECTION CONFINED TO THE
WESTERN QUADRANT. THE CURRENT INTENSITY IS HELD AT 40 KNOTS BASED ON
AN OLDER WINDSAT PASS AND SUPPORTS THE UNCHANGED STRUCTURE OF THE
SYSTEM. UPPER LEVEL ANALYSIS INDICATES A MARGINAL ENVIRONMENT WITH
20 TO 25 KNOT EASTERLY VERTICAL WIND SHEAR (VWS) PREVENTING THE
STORM FROM ALIGNING VERTICALLY. HOWEVER, GOOD DIVERGENT OUTFLOW IS
MAINTAINING THE CURRENT CONVECTION. TS DUJUAN IS TRACKING ALONG THE
SOUTHERN PERIPHERY OF A DEEP LAYERED SUB-TROPICAL RIDGE (STR).
3. FORECAST REASONING.
A. THE EXTENDED FORECAST HAS BEEN ADJUSTED TO SHOW A CONTINUED
NORTHWESTWARD TRACK PASSING JUST NORTH OF OKINAWA. THIS IS FURTHER
EXPLAINED IN PARA 3.C.
B. TS 21W WILL CONTINUE TO TRACK WEST-NORTHWESTWARD OVER THE NEXT
36 HOURS AS THE STR REMAINS TO THE NORTH OF THE SYSTEM.
CONCURRENTLY, EXPECT MARGINAL INTENSIFICATION DUE TO MODERATE VWS
CONTINUING TO PREVENT THE SYSTEM FROM FULLY CONSOLIDATING. BEYOND
TAU 36, A SHORTWAVE MID-LATITUDE TROUGH WILL CREATE A SMALL BREAK IN
THE STR, ALLOWING TS 21W TO TURN MORE NORTHWESTWARD. DECREASED VWS
AND AN IMPROVED POLEWARD OUTFLOW CHANNEL WILL INCREASE THE RATE OF
INTENSIFICATION.
C. IN THE EXTENDED FORECAST, TS 21W WILL CONTINUE TO TRACK
TOWARDS THE WEAK BREAK IN THE STEERING STR AND INTENSIFY DUE TO
FAVORABLE ENVIRONMENTAL CONDITIONS. DYNAMIC MODEL GUIDANCE HAS BEEN
INCREASINGLY UNSTABLE AS THEY CONTINUE TO DISPLAY A WIDE RANGE OF
SOLUTIONS; NOW SHOWING A TRIFURCATION. NAVGEM AND THE EUROPEAN
MODELS SHOW A WEAKER SYSTEM PASSING THROUGH THE SOUTHERN RYUKYU
ISLANDS. ENVIRONMENTAL CONDITIONS WILL SUPPORT AN INTENSIFICATION
MAKING THESE SOLUTIONS LESS REALISTIC. HWRF AND THE JAPANESE MODELS
SHOW A SHARP RECURVE BEFORE THE SYSTEM REACHES THE RYUKYU ISLANDS.
TS DUJUAN IS CURRENTLY AND NOT FORECASTED TO BE STRONG ENOUGH TO
BREAK THROUGH THE STEERING STR AND SUPPORT A SOONER RECURVE. GFS,
COAMPS-TC, AND GFDN SHOW A STRAIGHT NORTHWESTWARD TRACK PASSING OVER
OKINAWA WITH THE POSSIBILITY OF A LATER RECURVE. THIS SOLUTION IS
DEEMED MOST FEASIBLE AT THIS TIME BASED ON THE EXPECTED DEVELOPMENT
OF THE SYSTEM AND SUPPORTS THE CURRENT FORECAST TRACK. THE OVERALL
MODEL UNCERTAINTY IS FURTHER EVIDENT IN THE NAVGEM AND ECMWF
ENSEMBLE CLUSTERS WHICH SHOW ALL THREE SCENARIOS AS POSSIBILITIES
AND DO NOT PROVIDE ANY SUPPORT FOR THEIR DETERMINISTIC MODEL TRACKS.
DUE TO THE CONTINUED WIDE SPREAD INSTABILITY IN ALL MODEL GUIDANCE,
THERE IS LOW CONFIDENCE IN THE JTWC FORECAST.//
NNNN

[Alyono]

I wouldn't say the JT discussion was good. They said the initial position was low confidence. It is very high confidence as the low level center was very visible on visible imagery. Wasn't a cloud near it! Thus, we could easily see the position

Based upon ensembles, the GFS track is the least likely solution. Going between two bifurcated outcomes is simply bad science as that is the one thing that likely will not happen. For the record, my latest track did the same. However, I did not have the ensemble probabilities until after I issued it

The ECMWF takes a fairly intense typhoon into Taipei, so not sure why JTWC was saying it is a weak system.

Overall, I am negatively impressed

[Alyono]

this may be even more poorly organized than Ida is. The LLC does not appear to be as well defined

[1900hurricane]

ASCAT got a good hit earlier. I wonder if the swirl that looked to be escaping to the north twelve hours ago was a cast-away vort, since it seems back to the south a bit.

[1900hurricane]

Track-wise, guidance is starting to agree that the Southern Ryukyus/Taiwan/Eastern China is the most likely outcome. Models are also still bullish with intensification after hour 24. We'll see, but as of right now, the center and the convection are still struggling to find each other.