WPAC: LIONROCK - Post-Tropical

[euro6208]

TXPQ21 KNES 271523
TCSWNP

A. 12W (LIONROCK)

B. 27/1430Z

C. 24.7N

D. 134.9E

E. ONE/HIMAWARI-8

F. T6.0/6.0/D1.5/24HRS

G. IR/EIR

H. REMARKS...WMG EYE EMBEDDED IN LG AND SURROUNDED BY B FOR DT EQUAL
TO 6.0. MET = 5.5 PT = 6.0. FT IS BASED ON DT.

I. ADDL POSITIONS

NIL


...SALEMI

[euro6208]

Past GFS runs favored CMC...NAVGEM solution which stalls this southeast of Tokyo hence weakening.

Now latest agrees with EURO on a Northern Japan hit...

[euro6208]

WDPN34 PGTW 272100
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TYPHOON 12W (LIONROCK) WARNING NR 40//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
TYPHOON 12W (LIONROCK), LOCATED APPROXIMATELY 305 NM WEST OF IWO
TO, HAS TRACKED NORTHEASTWARD AT 11 KNOTS OVER THE PAST SIX
HOURS. ANIMATED ENHANCED INFRARED SATELLITE IMAGERY DEPICTS
FRAGMENTED BANDING WRAPPING INTO A TIGHTLY WOUND WELL-DEFINED 16 NM
EYE. SATELLITE IMAGERY ALSO SHOWS THE WEAKENED CONVECTION ON THE
NORTHWESTERN PERIPHERY DUE TO SUBSIDENCE PROVIDED BY WEAK RIDGING
POSITIONED BETWEEN THE APPROACHING TROUGH MOVING OVER SOUTHERN
JAPAN. THE INITIAL POSITION IS BASED ON SATELLITE EYE FIXES FROM
PGTW AND RJTD WITH GOOD CONFIDENCE. THE INITIAL INTENSITY IS
ASSESSED AT 105 KNOTS AND IS BASED ON RECENT DVORAK ESTIMATES FROM
RJTD AND PGTW REPORTING T5.5 (102 KNOTS) HEDGED SLIGHTLY HIGHER
FROM KNES ESTIMATE OF T6.0 (115 KNOTS) AT 271500Z. A 271233 METOP-B
ASCAT IMAGE SHOWS THE EXTENT OF GALE FORCE WINDS EXPANDING
SIGNIFICANTLY TO THE SOUTH DUE TO AN INCREASING PRESSURE GRADIENT
FROM THE BUILDING SOUTHERN RIDGE. UPPER-LEVEL ANALYSIS SHOWS STEADY
RADIAL OUTFLOW WITH A VERY STRONG EQUATORWARD CHANNEL AND VERY LOW
VERTICAL WIND SHEAR. SEA SURFACE TEMPERATURES REMAIN FAVORABLE
AROUND 30 CELSIUS. CURRENTLY TY 12W IS TRACKING NORTHEAST ALONG THE
PERIPHERY OF THE NEAR-EQUATORIAL RIDGE (NER) TO THE SOUTHEAST.
3. FORECAST REASONING.
A. NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE PREVIOUS
PROGNOSTIC REASONING MESSAGE.
B. IN THE NEAR-TERM FORECAST TY 12W WILL CONTINUE TRACKING
NORTHEAST ALONG THE NER. ENVIRONMENTAL CONDITIONS WILL REMAIN
FAVORABLE FOR THE NEXT 24 HOURS AND INTENSITY WILL MAINTAIN AROUND
105 KNOTS. GRADUAL OSCILLATIONS IN INTENSITY ARE EXPECTED AS
SUBSIDENCE CONTINUES TO DISRUPT THE CONVECTION STRUCTURE ON THE
NORTHWEST PERIPHERY. BEYOND TAU 24 STEADY WEAKENING IS EXPECTED AS
THE ENVIRONMENT STARTS TO DETERIORATE. BEGINNING AROUND TAU 48 THE
TRACK WILL SHIFT NORTHWEST AS STEERING TRANSITIONS FROM THE NER TO A
RIDGE POSITIONED SOUTH OF KAMCHATKA.
C. IN THE EXTENDED FORECAST THE NORTHERN RIDGE WILL STEER TY 12W
ALONG A NORTHWESTERN TRACK INTO A NEGATIVELY TILTED TROUGH OVER
JAPAN. LANDFALL OVER NORTHERN HONSHU IS EXPECTED AROUND TAU 72.
SOMEWHERE BETWEEN TAU 72 AND 96 TY 12W WILL START TRANSITIONING INTO
AN EXTRATROPICAL SYSTEM BECOMING FULLY EXTRATROPICAL BY TAU 120.
DYNAMIC MODEL GUIDANCE IS SHOWING TWO DIFFERENT SCENARIOS. NAVGEM
AND MESOSCALE SOLUTIONS, COAMPS-TC AND GFDN (BOTH INITIALIZED BY
NAVGEM), ARE SHOWING A WEAKENED NER, RESULTING IN A TRACK MORE
SOUTHWARD IN THE NEAR TERM AND A TRAJECTORY SUFFICIENTLY SOUTH TO
AVOID THE STEERING TRANSITION; ULTIMATELY ENDING IN A QUASI-
STATIONARY SCENARIO NEAR 150 DEGREES EAST. THIS IS AN UNLIKELY
SOLUTION AS THE NER HAS ALREADY SHOWN SIGNIFICANT BUILDING,
EVIDENCED BY THE EXPANDING SOUTHERN WIND FIELD. ALL OTHER SOLUTIONS
IN THE MULTI-MODEL CONSENSUS ARE SHOWING TIGHT GROUPING THROUGH TAU
48 AND A TRANSITION TO THE NORTHWEST INTO THE TROUGH. HWRF IS THE
ONLY EXCEPTION SHOWING AN ABRUPT TURN EAST AROUND 40 DEGREES NORTH;
ALSO AN UNLIKELY SCENARIO DUE TO THE NORTHERN RIDGE. THE FORECAST
TRACK IS CLOSELY POSITIONED TO THE GFS AND ECMWF SOLUTIONS SHOWING A
REALISTIC TURN TO THE NORTHWEST AND EVENTUAL CAPTURE BY THE TROUGH.
DUE TO THE DIFFERENCE IN MODEL SOLUTIONS AND VAST UNCERTAINTY THERE
IS LOW CONFIDENCE IN THE FORECAST TRACK.//
NNNN

[1900hurricane]

Microwave presentation looks as good as it ever has at this point.

[euro6208]

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

----- Current Analysis -----
Date : 28 AUG 2016 Time : 003000 UTC
Lat : 26:04:35 N Lon : 136:47:58 E


CI# /Pressure/ Vmax
6.1 / 928.8mb/117.4kt


Final T# Adj T# Raw T#
6.1 5.8 5.8

Estimated radius of max. wind based on IR :N/A km

Center Temp : -28.7C Cloud Region Temp : -73.5C

Scene Type : EYE

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 : 155km
- Environmental MSLP : 1000mb

Satellite Name : HIM-8
Satellite Viewing Angle : 30.8 degrees

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

[mrbagyo]

Convection is on the increase again. The moat to the north makes it look better in visible than IR

Looks like the upper low to the northeast of Lionrock is beginning to open up a second outflow channel now. After leveling off again, this might give Lionrock the potential for another bump up in intensity since it appeared CDO convection in the northern part of the circulation had begun to struggle.

That ULL might have provided some exhaust but it's now moving west to WSW- away from LionRock.
IMO, their motion no longer compliment each other.

[stormwise]

[shah83]

Looking at historical tracks, what Lionrock is about to do is largely unprecedented. I cannot find one historical typhoon that has hit Japan out of the east. Just little old tropical storm Mac.

If the GFS 00z track and trend holds, the coastal feature around Sendai looks very storm-surge friendly. This could be big, even if not as big as a Tokyo strike.

[wxmann_91]

Looking at historical tracks, what Lionrock is about to do is largely unprecedented. I cannot find one historical typhoon that has hit Japan out of the east. Just little old tropical storm Mac.

If the GFS 00z track and trend holds, the coastal feature around Sendai looks very storm-surge friendly. This could be big, even if not as big as a Tokyo strike.

Unfortunately this looks to affect the same areas as the tsunami did five years ago, many of which are still not yet fully recovered.

[stormwise]

If it goes into Tokyo they are well prepared for flooding.
http://gizmodo.com/tokyo-has-the-larges ... 1696967098

[euro6208]

Up up and up...

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

----- Current Analysis -----
Date : 28 AUG 2016 Time : 050000 UTC
Lat : 27:28:44 N Lon : 137:51:57 E


CI# /Pressure/ Vmax
6.1 / 928.3mb/117.4kt


Final T# Adj T# Raw T#
6.1 6.3 6.3

Estimated radius of max. wind based on IR : 19 km

Center Temp : +3.2C Cloud Region Temp : -71.8C

Scene Type : EYE

Positioning Method : RING/SPIRAL COMBINATION

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 : 155km
- Environmental MSLP : 1000mb

Satellite Name : HIM-8
Satellite Viewing Angle : 32.2 degrees

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

[euro6208]

WDPN34 PGTW 280300
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TYPHOON 12W (LIONROCK) WARNING NR 41//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
TYPHOON 12W (LIONROCK), LOCATED APPROXIMATELY 265 NM WEST-
NORTHWEST OF IWO TO, HAS TRACKED NORTHEASTWARD AT 11 KNOTS OVER
THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY DEPICTS
IMPROVED BANDING STRUCTURE IN THE LAST SIX HOURS WRAPPING INTO A
TIGHTLY WOUND 15 NM EYE. SATELLITE IMAGERY ALSO SHOWS SLIGHTLY
WEAKENED CONVECTION ON THE WESTERN PERIPHERY DUE TO SUBSIDENCE
PROVIDED BY WEAK RIDGING BETWEEN TY 12W AND THE APPROACHING TROUGH
MOVING OVER SOUTHERN JAPAN. THE INITIAL POSITION IS BASED ON
SATELLITE EYE FIXES FROM PGTW AND RJTD WITH GOOD CONFIDENCE. THE
INITIAL INTENSITY IS ASSESSED AT 110 KNOTS AND IS BASED ON DVORAK
ESTIMATES FROM RJTD REPORTING T5.5 (102 KNOTS) AND PGTW REPORTING
T6.0 (115 KNOTS). UPPER-LEVEL ANALYSIS SHOWS STEADY RADIAL OUTFLOW
WITH A VERY STRONG EQUATORWARD CHANNEL AND VERY LOW VERTICAL WIND
SHEAR. SEA SURFACE TEMPERATURES REMAIN FAVORABLE AROUND 30 CELSIUS.
CURRENTLY TY 12W IS TRACKING NORTHEAST ALONG THE PERIPHERY OF THE
NEAR-EQUATORIAL RIDGE (NER) TO THE SOUTHEAST.
3. FORECAST REASONING.
A. NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE PREVIOUS
PROGNOSTIC REASONING MESSAGE.
B. IN THE NEAR-TERM FORECAST TY 12W WILL CONTINUE TRACKING
NORTHEAST ALONG THE NER. ENVIRONMENTAL CONDITIONS WILL REMAIN
FAVORABLE FOR THE NEXT 24 HOURS MAINTAINING THE INTENSITY AROUND
105 KNOTS WITH GRADUAL OSCILLATIONS. BEYOND TAU 24 STEADY WEAKENING
IS EXPECTED AS THE ENVIRONMENT STARTS TO DETERIORATE. BEGINNING
AROUND TAU 48 THE TRACK WILL BEGIN TO SHIFT NORTHWEST AS STEERING
TRANSITIONS FROM THE NER TO A NORTHERN RIDGE POSITIONED SOUTH OF
KAMCHATKA.
C. IN THE EXTENDED FORECAST THE NORTHERN RIDGE WILL STEER TY 12W
ALONG A NORTHWESTERN TRACK INTO A NEGATIVELY TILTED TROUGH OVER
JAPAN. LANDFALL OVER NORTHERN HONSHU IS EXPECTED AROUND TAU 60.
SOMEWHERE AROUND TAU 72 TY 12W WILL START TRANSITIONING INTO
AN EXTRATROPICAL SYSTEM BECOMING FULLY EXTRATROPICAL BY TAU 96.
DYNAMIC MODEL GUIDANCE IS SHOWING TWO DIFFERENT SCENARIOS. NAVGEM
AND MESOSCALE SOLUTIONS, COAMPS-TC AND GFDN (BOTH INITIALIZED BY
NAVGEM), ARE SHOWING A WEAKENED NER, RESULTING IN A TRACK MORE
SOUTHWARD IN THE NEAR TERM AND A TRAJECTORY SUFFICIENTLY SOUTH TO
AVOID THE STEERING TRANSITION; ULTIMATELY ENDING IN A QUASI-
STATIONARY SCENARIO NEAR 150 DEGREES EAST. THIS IS AN UNLIKELY
SOLUTION AS THE NER HAS ALREADY SHOWN SIGNIFICANT BUILDING,
EVIDENCED BY THE EXPANDING SOUTHERN WIND FIELD. ALL OTHER SOLUTIONS
IN THE MULTI-MODEL CONSENSUS ARE SHOWING TIGHT GROUPING THROUGH TAU
48 AND A TRANSITION TO THE NORTHWEST ENTERING THE TROUGH. HOWEVER
DIFFERENCES ARE STILL EVIDENT IN THE POSITION AND TIMING OF THE
WESTWARD TURN BEYOND TAU 48. THE FORECAST TRACK IS CLOSELY
POSITIONED TO THE GFS AND ECMWF SOLUTIONS SHOWING A REALISTIC TURN
TO THE NORTHWEST AND EVENTUAL CAPTURE BY THE TROUGH. THE JGSM AND
HWRF SOLUTIONS SHIFTED RECENTLY SHOWING BETTER AGREEMENT WITH GFS
AND ECMWF. NUMERICAL MODELS ARE STARTING TO COME INTO BETTER
AGREEMENT BUT UNCERTAINTY IS STILL HIGH AS TY 12W MAKES THE
TRANSITION TO THE NORTHWEST AND TRACKS INTO THE TROUGH LENDING LOW
CONFIDENCE TO THE FORECAST TRACK.//
NNNN

[stormwise]

Typhoon No. 10 (Lion Rock)
2016 Aug 28, day 12 hour 50 minute presentation

<Commentary o'clock 28 12>
size -
strength Intense
Presence area South of Japan
Center position North latitude 26 degrees 55 minutes (26.9 degrees)
East longitude 137 degrees 25 minutes (137.4 degrees)
Direction of travel, speed Northeast 25km / h (14kt)
Central pressure 945hPa
Maximum wind speed near the center 45m / s (85kt)
Maximum instantaneous wind speed 60m / s (120kt)
25m / s or more of the storm area The entire 110km (60NM)
15m / s or more of the strong wind area Southeast side 500km (270NM)
Northwest side 390km (210NM)

<Forecast o'clock 29 12>
strength Intense
Presence area Southeast of Hachijojima about 310km
The center of the circle forecast North latitude 30 degrees 55 minutes (30.9 degrees)
East longitude 141 degrees 50 minutes (141.8 degrees)
Direction of travel, speed Northeast 30km / h (15kt)
Central pressure 940hPa
Maximum wind speed near the center 45m / s (85kt)
Maximum instantaneous wind speed 60m / s (120kt)
The radius of the circle forecast 150km (80NM)
Storm warning area The entire 280km (150NM)

<Forecast o'clock 30 09>
strength strong
Presence area Choshi Higashiyaku 220km
The center of the circle forecast North latitude 35 degrees 20 minutes (35.3 degrees)
East longitude 143 degrees 10 minutes (143.2 degrees)
Direction of travel, speed North-northeast 25km / h (14kt)
Central pressure 955hPa
Maximum wind speed near the center 35m / s (70kt)
Maximum instantaneous wind speed 50m / s (100kt)
The radius of the circle forecast 280km (150NM)
Storm warning area The entire 410km (220NM)

<Forecast o'clock 31 09>
strength -
Presence area West of Hokkaido
The center of the circle forecast North latitude 42 degrees 35 minutes (42.6 degrees)
East longitude 139 degrees 00 minutes (139.0 degrees)
Direction of travel, speed North-northwest 35km / h (20kt)
Central pressure 970hPa
Maximum wind speed near the center 30m / s (60kt)
Maximum instantaneous wind speed 45m / s (85kt)
The radius of the circle forecast 410km (220NM)
Storm warning area The entire 540km (290NM)

<Forecast o'clock 01 09>
Presence area Maritime
The center of the circle forecast North latitude 44 degrees 30 minutes (44.5 degrees)
East longitude 131 degrees 55 minutes (131.9 degrees)
Direction of travel, speed WNW 25km / h (14kt)
The radius of the circle forecast 600km (325NM)

[euro6208]

Nice banding on the western side...Looks close to a Cat 5...

[Kazmit]

Appears to have annular characteristics... I think this could be a super typhoon.

[Kingarabian]

Appears to have annular characteristics... I think this could be a super typhoon.
[img]http://i67.tinypic.com/2a8gppg.png[/mg]

I agree that it'll become a ST but it's not close to being annular. Remember an annular storm has little to no banding.

[euro6208]

Impressive...

[stormwise]

looks double eyewall structure

[NotoSans]

115 kt looks reasonable to me, although a case for 120 kt could be made given the slight low bias of Dvorak values (~3-4 kt) on storms at higher latitude.

[euro6208]

WDPN34 PGTW 281500
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TYPHOON 12W (LIONROCK) WARNING NR 43//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
TYPHOON (TY) 12W (LIONROCK), LOCATED APPROXIMATELY 410 NM SOUTH OF
YOKOSUKA, JAPAN, HAS TRACKED NORTHEASTWARD AT 12 KNOTS OVER THE
PAST SIX HOURS. ANIMATED ENHANCED INFRARED SATELLITE IMAGERY AND
RECENT MICROWAVE IMAGERY DEPICT A COMPACT, STRENGTHENING CORE
(APPROXIMATELY 60-NM DIAMETER EYEWALL) WITH A 28-NM ROUND EYE,
WHICH PROVIDES HIGH CONFIDENCE IN THE CURRENT POSITION AND RECENT
TRACK ACCELERATION TO THE NORTHEAST. ANIMATED WATER VAPOR IMAGERY
CONTINUES TO INDICATE RADIAL OUTFLOW, HOWEVER, THE DEEP UPPER-LEVEL
TROUGH OVER WESTERN JAPAN IS JUST BEGINNING TO IMPINGE ON THE
NORTHWEST PERIPHERY OF THE SYSTEM. RECENT MICROWAVE IMAGERY SUGGESTS
THE ONSET OF AN EYEWALL REPLACEMENT CYCLE (ERC) WITH A SECONDARY
EYEWALL AND MOAT FORMING, HOWEVER, CORE CONVECTION REMAINS VIGOROUS
AND DVORAK INTENSITY ESTIMATES FROM ALL AGENCIES HAVE MAINTAINED AT
T6.0 (115 KNOTS). CONSEQUENTLY, THE CURRENT INTENSITY REMAINS
ASSESSED AT 115 KNOTS ALTHOUGH POTENTIAL ERC AND DECREASING SATCON
ESTIMATES OF 109 KNOTS MAY SIGNAL A WEAKENING TREND. TY 12W IS
CURRENTLY TRACKING ALONG A POLEWARD EXTENSION OF THE NEAR-EQUATORIAL
RIDGE (NER) POSITIONED TO THE EAST. RECENT 500MB ANALYSES DEPICT A
DEEPENING LOW OVER THE KOREAN PENINSULA AND ASSOCIATED MAJOR
SHORTWAVE TROUGH DIGGING INTO THE EAST CHINA SEA AND WESTERN JAPAN.
OVERALL, THE DYNAMIC MODELS HAVE DONE AN EXCELLENT JOB IN
FORECASTING THE DEVELOPMENT OF THIS EXPANSIVE, STRONG LOW AND MAJOR
SHORTWAVE TROUGH, AND ARE CURRENTLY ACCURATELY INITIALIZING THIS
SYNOPIC FEATURE, WHICH WILL BECOME THE DOMINANT INFLUENCE ON TY
12W'S TRACK AND INTENSITY AFTER TAU 12.
3. FORECAST REASONING.
A. NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE PREVIOUS
PROGNOSTIC REASONING MESSAGE. THE FORECAST TRACK AND CPA TO
YOKOSUKA REMAIN HIGHLY CONSISTENT WITH THE PREVIOUS JTWC FORECAST
TRACK.
B. TY 12W WILL CONTINUE TO TRACK NORTHEASTWARD ALONG THE
NORTHWEST PERIPHERY OF THE NER THROUGH TAU 24. AFTER TAU 24, THE
AFOREMENTIONED UPPER LOW AND MAJOR SHORTWAVE TROUGH ARE FORECAST TO
REMAIN ENTRENCHED OVER THE EAST SEA AND JAPAN WITH THE PRIMARY
STEERING RIDGE POSITIONED OVER SAKHALIN ISLAND AND THE SEA OF
OKHOTSK, EXTENDING SOUTHEASTWARD ACROSS THE KURIL ISLANDS. TY 12W IS
FORECAST TO RE-CURVE WITHIN THE ENHANCED FLOW BETWEEN THESE TWO
SYNOPTIC FEATURES. FOR THE FIRST TIME ALL CONSENSUS DYNAMIC MODEL
TRACKERS NOW SUPPORT THE RE-CURVE SCENARIO AND SHOW A TRACK OVER
NORTHERN HONSHU THEN A RAPID NORTHWESTWARD TRACK ACROSS THE EAST
SEA. ADDITIONALLY, THE BULK OF THE JGSM AND ECMWF ENSEMBLE MEMBERS
NOW SHOW SOLUTIONS TRACKING OVER NORTHERN HONSHU, WHICH FURTHER
BOLSTERS THE RE-CURVE SCENARIO. DESPITE THE IMPROVED AGREEMENT,
THERE REMAINS SOME UNCERTAINTY IN THE EXACT TRACK EAST OF YOKOSUKA
WITH A 110-NM SPREAD IN SOLUTIONS. ADDITIONALLY, THERE IS A LARGER
DEGREE OF UNCERTAINTY IN THE EXACT RE-CURVE POINT AND TRACK SPEEDS
AFTER TAU 36. THE CURRENT INTENSITY IS ASSESSED AT 115 KNOTS, WHICH,
BASED ON THE ERC SUGGESTED IN MICROWAVE IMAGERY AND IMPINGEMENT OF
POLEWARD FLOW REVEALED IN ANIMATED WATER IMAGERY, MAY BE THE PEAK
INTENSITY. THEREFORE, TY 12W IS FORECAST TO GRADUALLY WEAKEN THROUGH
TAU 24 WITH FURTHER WEAKENING AFTER TAU 24 DUE TO COOLER SST,
INCREASING VWS AND INTERACTION WITH LAND. ADDITIONALLY, TY 12W
SHOULD BEGIN EXTRA-TROPICAL TRANSITION (ETT) JUST AFTER TAU 48, AS
IT BEGINS TO INTERACT WITH THE MAJOR SHORTWAVE TROUGH. AFTER
CROSSING THE MOUNTAINOUS TERRAIN OF NORTHERN HONSHU, A MUCH WEAKER
SYSTEM IS EXPECTED TO RE-EMERGE IN THE EAST SEA AND TO ACCELERATE
NORTHWESTWARD WITHIN THE ENHANCED FLOW BETWEEN THE STRONG BAROCLINIC
LOW AND THE STEERING RIDGE. TY 12W IS FORECAST TO COMPLETE ETT BY
TAU 72 AS IT BECOMES EMBEDDED WITHIN THE BAROCLINIC LOW. DUE TO THE
UNCERTAINTY IN THE RE-CURVE POINT, WHICH IS TIED TO UNCERTAINTY IN
THE DEPTH AND ORIENTATION OF THE STRONG UPPER LOW, THERE IS LOW
CONFIDENCE IN THE FORECAST TRACK.//
NNNN