WPAC: KHANUN - Post-Tropical

[cycloneye]

WDPN32 PGTW 301500
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TYPHOON 06W (KHANUN) WARNING NR 014//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
INITIAL POSITION: 20.4N 132.4E
INITIAL INTENSITY: 90 KTS
GEOGRAPHIC REFERENCE: 445 NM SOUTHEAST OF KADENA AB
MOVEMENT PAST 6 HOURS: NORTH-NORTHWESTWARD AT 08 KTS
SIGNIFICANT WAVE HEIGHT: 31 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
TYPHOON (TY) 06W HAS RAPIDLY INTENSIFIED 40 KNOTS OVER THE PAST 24
HOURS FROM 50 KNOTS AT 291200Z TO THE INITIAL INTENSITY OF 90
KNOTS. ANIMATED ENHANCED INFRARED SATELLITE IMAGERY DEPICTS A ROUND
15NM EYE, WHICH SUPPORTS THE INITIAL POSITION WITH HIGH CONFIDENCE.
A 301103Z GMI 89GHZ MICROWAVE IMAGE DEPICTS AN OBLONG EYEWALL WITH
A BREAK OVER THE NNW QUADRANT AND TIGHTLY-CURVED SPIRAL BANDING.
THE GMI 37GHZ MICROWAVE IMAGE SHOWS A MORE SYMMETRIC MICROWAVE EYE
FEATURE AND ALSO SUPPORTS THE INITIAL POSITION. ANIMATED WATER
VAPOR IMAGERY CONTINUES TO SHOW STRONG EQUATORWARD OUTFLOW AND
ROBUST POLEWARD OUTFLOW, WHICH HAS ALLOWED CORE CONVECTION TO
CONSOLIDATE RAPIDLY OVER THE PAST 12 HOURS. THE INITIAL INTENSITY
IS ASSESSED AT 90 KNOTS WITH MEDIUM CONFIDENCE AND IS BASED ON THE
PGTW, RCTP DVORAK ESTIMATES, THE CIMSS ADT ESTIMATE AS WELL AS A
PARTIAL 300905Z RCM-3 SAR IMAGE SHOWING 87 KNOT WINDS OVER THE
EASTERN QUADRANT. THE KNES DVORAK ESTIMATE OF T5.5 (102 KNOTS) IS
WITHIN THE RANGE OF UNCERTAINTY WITH THE 301330Z ADT ESTIMATES UP
TO 5.3 (97 KNOTS) AND THE RAW ADT ESTIMATES STEADY AT ABOUT T6.0
(115 KNOTS); THESE ESTIMATES SUGGEST THE INTENSITY COULD JUMP
HIGHER WITHIN THE NEXT SIX TO TWELVE HOURS.

INITIAL WIND RADII BASIS: PERSISTENCE

CURRENT STEERING MECHANISM: DEEP-LAYERED SUBTROPICAL RIDGE (STR)
CENTERED SE OF TOKYO WITH RIDGE EXTENDING SOUTHWARD.

AGENCY DVORAK AND AUTOMATED FIXES:
PGTW: T5.0 - 90 KTS
RJTD: T4.0 - 65 KTS
RCTP: T5.0 - 90 KTS
KNES: T5.5 - 102 KTS
CIMSS SATCON: 87 KTS AT 301035Z
CIMSS ADT: 92 KTS AT 301200Z
D-PRINT: 96 KTS AT 301400Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: HIGHLY FAVORABLE
VWS: 0-5 KTS
SST: 29-30 CELSIUS
OUTFLOW: STRONG RADIAL

ANALYSIS CONFIDENCE:
INITIAL POSITION: HIGH
INITIAL INTENSITY: MEDIUM
INITIAL WIND RADII: MEDIUM

3. FORECAST REASONING.

SIGNIFICANT FORECAST CHANGES: PEAK INTENSITY HAS BEEN INCREASED TO
115 KNOTS. FORECAST TRACK SPEEDS HAVE BEEN SLOWED SIGNIFICANTLY AFTER
TAU 72.

FORECAST DISCUSSION: THE JTWC TRACK FORECAST REMAINS HIGHLY
CONSISTENT WITH THE PREVIOUS JTWC TRACK FORECAST WITH NO SIGNIFICANT
CHANGE TO THE CPA AND CPA DISTANCE TO KADENA AB. OVERALL, OVER THE
PAST 3.5 DAYS, JTWC FORECASTS HAVE REMAINED WITHIN A 50NM ENVELOPE
JUST TO THE SOUTH OF OKINAWA. TY 06W WILL TURN GRADUALLY WEST-
NORTHWESTWARD AFTER TAU 24 AND CONTINUE TRACKING WEST-NORTHWESTWARD
THROUGH TAU 72 UNDER THE STEERING INFLUENCE OF THE STR POSITIONED TO
THE NORTH AND NORTHEAST. BASED ON THE HIGHLY FAVORABLE ENVIRONMENTAL
CONDITIONS AND AFOREMENTIONED RAW ADT ESTIMATES, THE PEAK INTENSITY
HAS BEEN INCREASED TO 115 KNOTS AT TAU 36. AFTER TAU 72, THE SYSTEM
IS NOW FORECAST TO SLOW SIGNIFICANTLY AS IT APPROACHES THE EASTERN
COAST OF CHINA WITH LANDFALL EXPECTED NEAR TAU 96. DUE TO THE LARGE
SIZE OF THE SYSTEM AND ITS EXPANSIVE GALE-FORCE WINDS, NEAR GALE-
FORCE WINDS MAY PERSIST AFTER THE SYSTEM TRACKS WEST OF OKINAWA.

MODEL DISCUSSION: THE 300600Z ECMWF (EPS) AND GFS (GEFS) ENSEMBLES
INDICATE A BIFURCATION IN PROBABILISTIC GUIDANCE WITH TWO DISTINCT
CLUSTERS. THE FIRST CLUSTER SUPPORTS A WNW TRACK INTO EAST CENTRAL
CHINA AND DISSIPATION SCENARIO. THE SECOND CLUSTER REVEALS A SLOW
POLEWARD TRACK OVER THE EAST CHINA SEA TOWARD THE KOREAN PENINSULA
(NOTE: THIS COVERS THE NEXT 5 DAYS ONLY). DETERMINISTIC GUIDANCE
REMAINS IN TIGHT AGREEMENT THROUGH TAU 48 WITH A CROSS-TRACK
SPREAD NEAR OKINAWA RANGING FROM 50NM AT TAU 36 TO 80 NM AT TAU 48.
RAPID INTENSIFICATION (RI) WILL LIKELY CONTINUE FOR THE NEXT 24 TO 36
HOURS WITH RI GUIDANCE TRIGGERED AND THE 300600Z COAMPS-TC ENSEMBLE
INDICATING A 20 TO 30 PERCENT PROBABILITY OF RI. AFTER TAU 48,
DETERMINISTIC GUIDANCE DIVERGES WITH A VERY NOTICEABLE DECREASE IN
TRACK SPEEDS OVER EASTERN CHINA OR OFF THE COAST. CONSEQUENTLY,
CONFIDENCE IS LOW IN THE EXTENDED PERIOD. THE GFS DETERMINISTIC
SOLUTION IS PARTICULARLY PROBLEMATIC WITH GFS QUICKLY BREAKING DOWN
THE STR AND SHOWING A STALL NEAR 125E; THIS SCENARIO WILL BE WATCHED
CAREFULLY SINCE IT COULD IMPACT OKINAWA. THE JTWC FORECAST PHILOSOPHY
CONTINUES TO FAVOR THE WNW MODEL GROUPING AND THE ECMWF ENSEMBLE
(EPS) SINCE GFS CONTINUES TO TRACK THE SYSTEM DIRECTLY INTO THE STR
TO THE NORTH WITH NO DYNAMIC SHORTWAVE TROUGH EVIDENT IN THE ZONAL
MIDLATITUDE FLOW.

FORECAST CONFIDENCE:
TRACK 0 - 72 HR: MEDIUM
TRACK 72-120 HR: LOW
INTENSITY 0 - 72 HR: MEDIUM
INTENSITY 72-120 HR: LOW//
NNNN

[cycloneye]

6.0

TXPQ26 KNES 301759
TCSWNP

A. 06W (KHANUN)

B. 30/1730Z

C. 21.0N

D. 132.2E

E. ONE/HIMAWARI-9

F. T6.0/6.0

G. IR/EIR/SWIR

H. REMARKS...OW EYE SURROUNDED BY W AND EMBEDDED IN B RESULTS IN A DT
OF 6.0 AFTER ADDING A 0.5 EYE ADJUSTMENT. MET IS 5.0 BASED ON RAPID 24HR
DEVELOPMENT. PT IS 5.5. THE FT IS BASED ON THE DT.

I. ADDL POSITIONS

NIL

[cycloneye]

Cat 3.

06W KHANUN 230730 1800 21.1N 132.2E WPAC 105 948

[Hayabusa]

Models were in tight agreement in tracking towards China but now it became a mess...

[cycloneye]

WDPN32 PGTW 302100
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TYPHOON 06W (KHANUN) WARNING NR 015//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
INITIAL POSITION: 21.1N 132.2E
INITIAL INTENSITY: 105 KTS
GEOGRAPHIC REFERENCE: 404 NM SOUTHEAST OF KADENA AB, OKINAWA,
JAPAN
MOVEMENT PAST 6 HOURS: NORTH-NORTHWESTWARD AT 07 KTS
SIGNIFICANT WAVE HEIGHT: 48 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY SHOWS A LARGE
SYSTEM THAT CONTINUES TO RAPIDLY INTENSIFY AND CONSOLIDATE WITH
FEEDER BANDS FROM ALL QUADRANTS WRAPPING TIGHTER INTO THE CENTRAL
DENSE OVERCAST THAT MAINTAINED A RAGGED 15-NM EYE. OUTFLOW, BOTH
POLEWARD AND EQUATORWARD ARE VIGOROUS AND PROVIDING EFFICIENT
VENTILATION TO THE ASSOCIATED CONVECTION. THE INITIAL POSITION IS
PLACED WITH HIGH CONFIDENCE BASED ON THE EYE FEATURE. THE INITIAL
INTENSITY OF 105KTS IS ALSO PLACED WITH HIGH CONFIDENCE BASED ON AN
OVERALL ASSESSMENT OF AGENCY AND AUTOMATED DVORAK ESTIMATES (SEE
BELOW) AND REFLECTS THE IMPROVED EIR STRUCTURE. ANALYSIS INDICATES A
HIGHLY FAVORABLE ENVIRONMENT WITH WARM SSTS IN THE PHILIPPINE SEA,
LOW VWS, AND STRONG DUAL OUTFLOW ALOFT.

INITIAL WIND RADII BASIS: PERSISTENCE.

CURRENT STEERING MECHANISM: DEEP-LAYER SUBTROPICAL RIDGE (STR) TO
THE NORTHEAST, EAST OF JAPAN.

AGENCY DVORAK AND AUTOMATED FIXES:
PGTW: T5.5 - 102 KTS
RJTD: T5.0 - 90 KTS
KNES: T6.0 - 115 KTS
CIMSS SATCON: 106 KTS AT 301705Z
CIMSS ADT: 112 KTS AT 301730Z
CIMSS D-PRINT: 94 KTS AT 301800Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: HIGHLY FAVORABLE
VWS: 0-5 KTS
SST: 29-30 CELSIUS
OUTFLOW: STRONG POLEWARD AND EQUATORWARD

ANALYSIS CONFIDENCE:
INITIAL POSITION: HIGH
INITIAL INTENSITY: HIGH
INITIAL WIND RADII: MEDIUM

3. FORECAST REASONING.

SIGNIFICANT FORECAST CHANGES: FORECAST PEAK INTENSITY RAISED TO
125KTS AND EXTENDED PORTION OF FORECAST CHANGED TO A
QUASI-STATIONARY STORM MOTION.

FORECAST DISCUSSION: TY KHANUN WILL CONTINUE ON A NORTHWESTWARD
TRACK UNDER THE STEERING INFLUENCE OF THE STR TO THE NORTHEAST
TOWARD OKINAWA, PASSING APPROXIMATELY 58 NM SOUTHWEST OF KADENA AB
AROUND TAU 48 PRIOR TO DRIFTING SLOWLY INTO THE EAST CHINA SEA
(ECS). AFTER TAU 72, A SECONDARY STR, CURRENTLY ANCHORED IN THE
GULF OF POHAI, WILL COMPETE FOR STEERING AND FORCE A
QUASI-STATIONARY (QS) STORM MOTION IN THE ECS. THE HIGHLY FAVORABLE
ENVIRONMENT WILL FUEL A SECONDARY RAPID INTENSIFICATION TO A PEAK
OF 125KTS BY TAU 36. AFTERWARD, SUBSIDENCE CAUSED BY A MID-
LATITUDE TROUGH TO THE NORTH AND BEHIND THE CURRENT STR WILL STIFLE
FURTHER INTENSIFICATION. INCREASING VWS AND COOLING SST DUE TO
UPWELLING INDUCED BY THE SYSTEM QS MOTION WILL MORE RAPIDLY ERODE
THE SYSTEM DOWN TO 65 KTS BY TAU 120.

MODEL DISCUSSION: NUMERICAL MODELS ARE IN VERY GOOD AGREEMENT WITH
A GRADUAL SPREAD TO A MERE 194 NM BY TAU 72. AFTERWARD, ALL MEMBERS
INDICATE A SLOW POLEWARD RECURVATURE, ALBEIT IN A VERY WIDE SPREAD
TO 598 NM BY TAU 120. IN VIEW OF THIS, THERE IS HIGH CONFIDENCE IN
THE JTWC FORECAST TRACK UP TO TAU 72 THEN LOW CONFIDENCE AFTERWARD.


FORECAST CONFIDENCE:
TRACK 0 - 72 HR: HIGH
TRACK 72-120 HR: LOW
INTENSITY 0 - 72 HR: MEDIUM
INTENSITY 72-120 HR: LOW//
NNNN

[Sciencerocks]

[Mob1]

GFS stalls this near Okinawa for a couple of days, depending on exactly how this plays out it could be devastating to one of the islands.

[cycloneye]

At least at 00z BT, it has not gone higher than 105kt.

06W KHANUN 230731 0000 22.0N 132.0E WPAC 105 948

[cycloneye]

TXPQ26 KNES 302350
TCSWNP

A. 06W (KHANUN)

B. 30/2330Z

C. 22.0N

D. 131.9E

E. ONE/HIMAWARI-9

F. T5.5/6.0

G. IR/EIR/VIS

H. REMARKS...OW EYE IS EMBEDDED IN LG AND SURROUNDED BY B RESULTING
IN A DT OF 5.5 AFTER ADDING 0.5 FOR AN EYE ADJUSTMENT. MET AND PT ARE
5.5. THE FT IS BASED ON THE DT.

I. ADDL POSITIONS

NIL


...TURK

[cycloneye]

[cycloneye]

WDPN32 PGTW 310300
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TYPHOON 06W (KHANUN) WARNING NR 016//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
INITIAL POSITION: 22.0N 132.0E
INITIAL INTENSITY: 105 KTS
GEOGRAPHIC REFERENCE: 354 NM SOUTHEAST OF KADENA AB, OKINAWA,
JAPAN
MOVEMENT PAST 6 HOURS: NORTHWARD AT 09 KTS
SIGNIFICANT WAVE HEIGHT: 50 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) SHOWS A LARGE SYSTEM
THAT HAS MAINTAINED ITS CONVECTIVE STRUCTURE WITH DEEP FEEDER BANDS
FROM ALL QUADRANTS WRAPPING INTO THE CENTRAL DENSE OVERCAST WITH AN
EYE THAT HAS ENLARGED TO 27-NM. OUTFLOW, BOTH POLEWARD AND
EQUATORWARD ARE STRONG AND PROVIDING EFFICIENT VENTILATION TO THE
ASSOCIATED CONVECTION. THE INITIAL POSITION IS PLACED WITH HIGH
CONFIDENCE BASED ON THE EYE FEATURE. THE INITIAL INTENSITY OF
105KTS IS ALSO PLACED WITH HIGH CONFIDENCE BASED ON THE OVERALL
ASSESSMENT OF AGENCY AND AUTOMATED DVORAK ESTIMATES AND REFLECTS THE
SUSTAINED CONVECTIVE STRUCTURE. ANALYSIS INDICATES A HIGHLY FAVORABLE
ENVIRONMENT WITH WARM SSTS IN THE PHILIPPINE SEA, LOW VWS, AND
STRONG DUAL OUTFLOW ALOFT.

INITIAL WIND RADII BASIS: PERSISTENCE.

CURRENT STEERING MECHANISM: DEEP-LAYER SUBTROPICAL RIDGE (STR) TO
THE NORTHEAST, EAST OF JAPAN.

AGENCY DVORAK AND AUTOMATED FIXES:
PGTW: T5.5 - 102 KTS
RJTD: T5.0 - 90 KTS
RCTP: T5.5 - 102 KTS
KNES: T6.0 - 115 KTS
CIMSS ADT: 107 KTS AT 302330Z
CIMSS D-PRINT: 106 KTS AT 310100Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: HIGHLY FAVORABLE
VWS: 5-10 KTS
SST: 29-30 CELSIUS
OUTFLOW: STRONG POLEWARD AND EQUATORWARD

ANALYSIS CONFIDENCE:
INITIAL POSITION: HIGH
INITIAL INTENSITY: HIGH
INITIAL WIND RADII: MEDIUM

3. FORECAST REASONING.

SIGNIFICANT FORECAST CHANGES: THERE ARE NO SIGNIFICANT CHANGES TO
THE FORECAST FROM THE PREVIOUS WARNING.

FORECAST DISCUSSION: TY KHANUN WILL TRACK MORE NORTHWESTWARD UNDER
THE STEERING INFLUENCE OF THE BUILDING STR TO THE NORTHEAST
TOWARD OKINAWA, PASSING APPROXIMATELY 66 NM SOUTHWEST OF KADENA AB
ON 011700Z PRIOR TO DRIFTING SLOWLY INTO THE EAST CHINA SEA (ECS).
AFTER TAU 72, A SECONDARY STR, CURRENTLY ANCHORED IN THE GULF OF
POHAI, WILL COMPETE FOR STEERING AND FORCE A QUASI-STATIONARY (QS)
STORM MOTION IN THE ECS. THE HIGHLY FAVORABLE ENVIRONMENT WILL FUEL
RAPID INTENSIFICATION TO A PEAK OF 125KTS BY TAU 36. AFTERWARD,
SUBSIDENCE CAUSED BY A MID-LATITUDE TROUGH TO THE NORTH AND BEHIND
THE CURRENT STR WILL PREVENT FURTHER INTENSIFICATION. IN THE ECS,
INCREASING VWS AND COOLING SST DUE TO UPWELLING INDUCED BY THE SYSTEM
QS MOTION WILL MORE RAPIDLY ERODE THE SYSTEM DOWN TO 65 KTS BY TAU
120.

MODEL DISCUSSION: NUMERICAL MODELS ARE IN OVERALL GOOD AGREEMENT
BUT NOW WITH A MORE PRONOUNCED SPREAD TO 310 NM BY TAU 72 WITH GFS
THE EXTREME RIGHT-OF-TRACK OUTLIER DEVIATING FROM THE MODEL PACK AS
EARLY AS TAU 36. AFTER TAU 72, ALL MEMBERS INDICATE A SLOW
POLEWARD TRAJECTORY, ALBEIT IN A VERY WIDE SPREAD SPANNING OVER 500
NM BY TAU 120. IN VIEW OF THIS, THERE IS MEDIUM CONFIDENCE IN THE
JTWC FORECAST AND INTENSITY TRACKS UP TO TAU 72 THEN LOW CONFIDENCE
AFTERWARD.

FORECAST CONFIDENCE:
TRACK 0 - 72 HR: MEDIUM
TRACK 72-120 HR: LOW
INTENSITY 0 - 72 HR: MEDIUM
INTENSITY 72-120 HR: LOW//
NNNN

[1900hurricane]

 https://twitter.com/1900hurricane/status/1685881432021848065

[Sciencerocks]

[Hayabusa]

00z

[Foxfires]

06W KHANUN 230731 0600 22.8N 131.6E WPAC 115 937
06W KHANUN 230731 0000 22.0N 132.0E WPAC 110 948

[Hurricane2022]

Likely will be a STY later today.

[cycloneye]

WDPN32 PGTW 310900
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TYPHOON 06W (KHANUN) WARNING NR 017//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
INITIAL POSITION: 22.8N 131.6E
INITIAL INTENSITY: 115 KTS
GEOGRAPHIC REFERENCE: 304 NM SOUTHEAST OF KADENA AB
MOVEMENT PAST 6 HOURS: NORTH-NORTHWESTWARD AT 09 KTS
SIGNIFICANT WAVE HEIGHT: 48 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
TYPHOON (TY) 06W HAS RAPIDLY INTENSIFIED 45 KNOTS OVER THE PAST 24
HOURS FROM 70 KNOTS AT 300600Z TO THE INITIAL INTENSITY OF 115
KNOTS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) DEPICTS A
SYMMETRIC EYEWALL SURROUNDING A 20-25NM ROUND EYE (EYE TEMPERATURE
ABOUT PLUS 16.2C) WITH INTENSE CONVECTIVE BURSTS PRODUCING A
GRAVITY WAVE PROPAGATING POLEWARD. THIS IMPROVED CORE STRUCTURE IS
CLEARLY EVIDENT IN A 310705Z SSMIS 91GHZ COLOR COMPOSITE MICROWAVE
IMAGE WITH SPIRAL BANDING PREDOMINANTLY OVER THE SOUTHERN
SEMICIRCLE. THE INITIAL POSITION IS PLACED WITH HIGH CONFIDENCE
BASED ON THE MSI AND SSMIS IMAGERY. TY 06W HAS TURNED
NORTH-NORTHWESTWARD AS IT COMES UNDER THE STEERING INFLUENCE OF THE
DEEP-LAYER SUBTROPICAL RIDGE (STR) POSITIONED TO THE NORTH AND
NORTHEAST WHILE MAINTAINING A FORWARD MOTION OF 09 KNOTS. THE
310000Z 500MB UPPER-AIR SOUNDINGS OVER WESTERN JAPAN AND SOUTH
KOREA INDICATE EAST-SOUTHEASTERLY TO EASTERLY WINDS AT 15 TO 25 KNOTS
WITH THE RIDGE AXIS EXTENDING FROM WESTERN JAPAN TO SOUTH KOREA. THE
INITIAL INTENSITY OF 115 KTS IS ASSESSED WITH HIGH CONFIDENCE BASED
ON THE PGTW, KNES AND RJTD DVORAK ESTIMATES. THE RECENT AIDT AND ADT
ESTIMATES RANGE FROM 113 TO 119 KNOTS.

INITIAL WIND RADII BASIS: PERSISTENCE

CURRENT STEERING MECHANISM: DEEP-LAYER STR POSITIONED TO THE NORTH
AND NORTHEAST.

AGENCY DVORAK AND AUTOMATED FIXES:
PGTW: T6.0 - 115 KTS
RJTD: T6.0 - 115 KTS
RCTP: T5.5 - 102 KTS
KNES: T6.0 - 115 KTS
CIMSS SATCON: 111 KTS AT 310142Z
CIMSS ADT: 119 KTS AT 310530Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: HIGHLY FAVORABLE
VWS: 10-15 KTS
SST: 29-30 CELSIUS
OUTFLOW: STRONG RADIAL

ANALYSIS CONFIDENCE:
INITIAL POSITION: HIGH
INITIAL INTENSITY: HIGH
INITIAL WIND RADII: LOW

3. FORECAST REASONING.

SIGNIFICANT FORECAST CHANGES: THERE ARE NO SIGNIFICANT CHANGES TO
THE FORECAST FROM THE PREVIOUS WARNING.

FORECAST DISCUSSION: TY 06W WILL TRACK WEST-NORTHWESTWARD THROUGH
TAU 72 PASSING TO THE SOUTH OF OKINAWA WITH A PEAK INTENSITY OF
120-125 KNOTS BY TAU 24. GRADUAL WEAKENING SHOULD OCCUR AS THE
SYSTEM PASSES OKINAWA WITH MORE PRONOUNCED WEAKENING AS IT SLOWS
AND STALLS NORTHWEST OF OKINAWA AND UPWELLS COOLER WATER. DUE TO
THE SYSTEM'S LARGE SIZE AND CLOSE PROXIMITY TO OKINAWA AFTER CPA,
THERE REMAINS A HIGH PROBABILITY OF GALE-FORCE WINDS OR HIGHER IF
THE SYSTEM DRIFTS CLOSER WITHIN THE WEAK STEERING ENVIRONMENT. AS
DISCUSSED BELOW, THERE IS HIGH UNCERTAINTY (LOW CONFIDENCE) IN THE
JTWC FORECAST TRACK AFTER TAU 48.

MODEL DISCUSSION: DETERMINISTIC MODEL GUIDANCE REMAINS IN GOOD
AGREEMENT ONLY THROUGH TAU 48 WITH A 41NM CROSS-TRACK SPREAD AT TAU
36 AND A 51NM CROSS-TRACK SPREAD AT TAU 48 LENDING HIGH CONFIDENCE TO
THIS PORTION OF THE JTWC FORECAST TRACK. JTWC FORECAST TRACKS HAVE
REMAINED WITHIN A TIGHT, 50NM ENVELOPE JUST TO THE SOUTH OF OKINAWA
OVER THE PAST FOUR DAYS. HOWEVER, ALONG-TRACK SPEEDS HAVE REMAINED
INCONSISTENT RESULTING IN A SIGNIFICANT CHANGE IN THE CPA TIMING
OVER THE PAST 12 HOURS. AFTER TAU 48, BOTH DETERMINISTIC AND
PROBABILISTIC GUIDANCE CONTINUE TO INDICATE A VERY LARGE SPREAD
(433NM SPREAD AT TAU 96 AND A 514NM SPREAD AT TAU 120) AND A HIGH
DEGREE OF UNCERTAINTY DUE TO THE RAPID WEAKENING OF THE STEERING
RIDGE TO THE NORTH. THIS RAPID WEAKENING OF THE STEERING RIDGE IS
DUE TO A COMBINATION OF THE WESTERLIES ACROSS THE KOREAN PENINSULA
AND THE UNUSUALLY LARGE SIZE OF TY 06W, WHICH IS CURRENTLY
ESTIMATED AT A 700-780NM DIAMETER. AFTER TAU 48, TY 06W WILL BE
POSITIONED WITHIN A COMPETING STEERING ENVIRONMENT WITH A STR TO
THE EAST AND ANOTHER WEAK STR TO THE WEST THUS A SLOW, POSSIBLY
ERRATIC TRACK THROUGH TAU 120. THIS UNCERTAIN SCENARIO IS EVIDENT IN
THE 310000Z ECMWF (EPS) AND GFS (GEFS) ENSEMBLE SOLUTIONS.

FORECAST CONFIDENCE:
TRACK 0 - 48 HR: HIGH
TRACK 48 - 120 HR: LOW
INTENSITY 0 - 48 HR: HIGH
INTENSITY 48 - 120 HR: MEDIUM//
NNNN

[cycloneye]

WP, 06, 2023073112, , BEST, 0, 234N, 1311E, 115, 936, TY

[cycloneye]

WDPN32 PGTW 311500
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TYPHOON 06W (KHANUN) WARNING NR 018//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
INITIAL POSITION: 23.4N 131.1E
INITIAL INTENSITY: 115 KTS
GEOGRAPHIC REFERENCE: 258 NM SOUTHEAST OF KADENA AB
MOVEMENT PAST 6 HOURS: NORTHWESTWARD AT 08 KTS
SIGNIFICANT WAVE HEIGHT: 48 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
AFTER A PERIOD OF RAPID INTENSIFICATION, TYPHOON (TY) 06W HAS
MAINTAINED INTENSITY AT 115 KNOTS. ANIMATED ENHANCED INFRARED
SATELLITE IMAGERY (EIR) DEPICTS A SYMMETRIC EYEWALL SURROUNDING A
27NM ROUND EYE (EYE TEMPERATURE ABOUT PLUS 18.4C), WHICH SUPPORTS THE
INITIAL POSITION AND RECENT TRACK MOTION WITH HIGH CONFIDENCE. THIS
IMPROVED CORE STRUCTURE IS CLEARLY EVIDENT IN A 310908Z SSMIS 91GHZ
COLOR COMPOSITE MICROWAVE IMAGE WITH SPIRAL BANDING PREDOMINANTLY
OVER THE SOUTHERN SEMICIRCLE. TY 06W HAS TURNED NORTHWESTWARD AS IT
COMES UNDER THE STEERING INFLUENCE OF THE DEEP-LAYER SUBTROPICAL
RIDGE (STR) POSITIONED TO THE NORTH AND NORTHEAST WHILE MAINTAINING A
FORWARD MOTION OF 08 KNOTS. THE 310000Z 500MB UPPER-AIR SOUNDINGS
OVER WESTERN JAPAN AND SOUTH KOREA INDICATE EAST-SOUTHEASTERLY TO
EASTERLY WINDS AT 15 TO 25 KNOTS WITH THE RIDGE AXIS EXTENDING FROM
WESTERN JAPAN TO SOUTH KOREA. THE INITIAL INTENSITY OF 115 KTS IS
ASSESSED WITH HIGH CONFIDENCE BASED ON AGENCY DVORAK ESTIMATES AS
WELL AS THE CIMSS ADT ESTIMATE AND A 311200Z D-PRINT ESTIMATE OF 116
KNOTS.

INITIAL WIND RADII BASIS: SMAP DATA (WESTERN SEMICIRCLE),
SCATTEROMETER DATA (BULLSEYE) AND LIMITED SURFACE OBSERVATIONS.

CURRENT STEERING MECHANISM: DEEP-LAYER STR POSITIONED TO THE NORTH
AND NORTHEAST.

AGENCY DVORAK AND AUTOMATED FIXES:
PGTW: T6.0 - 115 KTS
RJTD: T6.0 - 115 KTS
RCTP: T6.0 - 115 KTS
KNES: T6.0 - 115 KTS
CIMSS SATCON: 118 KTS AT 311011Z
CIMSS ADT: 117 KTS AT 311130Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: HIGHLY FAVORABLE
VWS: 10-15 KTS
SST: 29-30 CELSIUS
OUTFLOW: STRONG RADIAL

ANALYSIS CONFIDENCE:
INITIAL POSITION: HIGH
INITIAL INTENSITY: HIGH
INITIAL WIND RADII: MEDIUM

3. FORECAST REASONING.

SIGNIFICANT FORECAST CHANGES: THERE ARE NO SIGNIFICANT CHANGES TO
THE FORECAST FROM THE PREVIOUS WARNING.

FORECAST DISCUSSION: TY 06W WILL TRACK WEST-NORTHWESTWARD THROUGH
TAU 72 PASSING TO THE SOUTH OF OKINAWA WITH A PEAK INTENSITY OF
120 KNOTS BY TAU 12. GRADUAL WEAKENING SHOULD OCCUR AS THE SYSTEM
PASSES OKINAWA WITH MORE PRONOUNCED WEAKENING AS IT SLOWS AND STALLS
NORTHWEST OF OKINAWA AND UPWELLS COOLER WATER. THE 310600Z HAFS-A RUN
INDICATES SIGNIFICANT UPWELLING OCCURRING WITH SEA SURFACE
TEMPERATURES COOLING DOWN TO 21-22C NEAR THE CENTER, WHICH SHOULD
PRODUCE A FAIRLY SHARP WEAKENING TREND. DUE TO THE SYSTEM'S LARGE
SIZE AND CLOSE PROXIMITY TO OKINAWA AFTER CPA, THERE REMAINS A HIGH
PROBABILITY OF GALE-FORCE WINDS OR HIGHER IF THE SYSTEM DRIFTS CLOSER
WITHIN THE WEAK STEERING ENVIRONMENT. AS DISCUSSED BELOW, THERE IS
HIGH UNCERTAINTY (LOW CONFIDENCE) IN THE JTWC FORECAST TRACK AFTER
TAU 48.

MODEL DISCUSSION: DETERMINISTIC MODEL GUIDANCE REMAINS IN GOOD
AGREEMENT ONLY THROUGH TAU 48 WITH A 44NM CROSS-TRACK SPREAD AT TAU
36 AND A 50NM CROSS-TRACK SPREAD AT TAU 48 LENDING HIGH CONFIDENCE
TO THIS PORTION OF THE JTWC FORECAST TRACK. JTWC FORECAST TRACKS HAVE
REMAINED WITHIN A TIGHT, 50NM ENVELOPE JUST TO THE SOUTH OF
OKINAWA OVER THE PAST FOUR DAYS. HOWEVER, ALONG-TRACK SPEEDS HAVE
REMAINED INCONSISTENT RESULTING IN A SIGNIFICANT CHANGE IN THE CPA
TIMING OVER THE PAST 18 HOURS. AFTER TAU 48, BOTH DETERMINISTIC AND
PROBABILISTIC GUIDANCE CONTINUE TO INDICATE A VERY LARGE SPREAD
(345NM SPREAD AT TAU 96 AND A 450NM SPREAD AT TAU 120) AND A HIGH
DEGREE OF UNCERTAINTY DUE TO THE RAPID WEAKENING OF THE STEERING
RIDGE TO THE NORTH. THIS RAPID WEAKENING OF THE STEERING RIDGE IS
DUE TO A COMBINATION OF THE WESTERLIES ACROSS THE KOREAN PENINSULA
AND THE UNUSUALLY LARGE SIZE OF TY 06W, WHICH IS CURRENTLY
ESTIMATED AT A 700-780NM DIAMETER. AFTER TAU 48, TY 06W WILL BE
POSITIONED WITHIN A COMPETING STEERING ENVIRONMENT WITH A STR TO
THE EAST AND ANOTHER WEAK STR TO THE WEST THUS A SLOW, POSSIBLY
ERRATIC TRACK THROUGH TAU 120. THIS UNCERTAIN SCENARIO IS EVIDENT
IN THE 310600Z ECMWF (EPS) AND GFS (GEFS) ENSEMBLE SOLUTIONS.

FORECAST CONFIDENCE:
TRACK 0 - 48 HR: HIGH
TRACK 48 - 120 HR: LOW
INTENSITY 0 - 48 HR: HIGH
INTENSITY 48 - 120 HR: MEDIUM//
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