WPAC: KHANUN - Post-Tropical

[cycloneye]

WDPN32 PGTW 050300
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 06W (KHANUN) WARNING NR
036//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
INITIAL POSITION: 27.7N 126.9E
INITIAL INTENSITY: 55 KTS
GEOGRAPHIC REFERENCE: 87 NM NORTHWEST OF KADENA AB
MOVEMENT PAST 6 HOURS: EASTWARD AT 04 KTS
SIGNIFICANT WAVE HEIGHT: 28 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED MULTISPECTRAL SATELLITE IMAGERY LOOP INDICATES THERE HAS
BEEN LITTLE CHANGE IN THE APPEARANCE OF TS 06W OVER THE PAST SIX
HOURS, WITH TIGHTLY-CURVED BANDING CONTINUING TO WRAP INTO A
DEFINED LOW-LEVEL CIRCULATION CENTER (LLCC) OF THIS BROAD SYSTEM. A
042136Z RCM-3 SAR PASS REVEALS A BROAD SWATH OF 50 TO 55 KNOT OCEAN
SURFACE WINDS APPROXIMATELY 50 NM FROM THE LLCC, WITH A FEW PIXELS
OF POTENTIAL 60 KNOT VALUES. THE OUTER WIND FIELD EXTENT OF 06W WAS
TOO LARGE TO FIT WITHIN THE EXTRA-WIDE SENSOR SWATH, BUT THE DATA
PROVIDES GOOD ESTIMATES TO UPDATE THE R34 AND R50 VALUES. THE RAW
SAR RADAR RETURNS ALONG WITH MULTI-AGENCY FIX AGREEMENT PROVIDES
GOOD CONFIDENCE FOR THE ANALYZED INITIAL POSITION, WHICH INDICATES
TS 06W IS TRACKING ALMOST DUE EAST UNDER THE STEERING INFLUENCE OF
A NEAR EQUATORIAL RIDGE (NER) ANCHORED OVER THE CENTRAL
PHILIPPINES. PEAK 10 MIN WIND MEASUREMENTS OBSERVED FROM REPORTING
STATIONS IN THE AREA ARE BETWEEN 40 TO 45 KNOTS. THE INITIAL
INTENSITY WAS HELD AT 55 KNOTS BASED ON THE SAR DATA, WITH
AGREEMENT BY THE RJTD CURRENT INTENSITY T3.5 VALUE, AS WELL AS
DMINT, DPRINT, AND SATCON ESTIMATES. ENVIRONMENTAL CONDITIONS
ARE MARGINALLY FAVORABLE DUE PRIMARILY TO THE UPWELLING OF 22-24
DEGREE WATERS IN KHANUNS WAKE, BUT VALUES ARE INCREASING ALONG THE
DIRECTION OF MOTION. KHANUN HAS MANAGED TO MAINTAIN ITS INTENSITY
LARGELY THANKS TO GOOD OUTFLOW INTO A UPPER LEVEL SUB-TROPICAL LOW
TO THE NORTHEAST AND LOW VERTICAL WIND SHEAR.

INITIAL WIND RADII BASIS: SAR DATA

CURRENT STEERING MECHANISM: NER TO THE SOUTH

AGENCY DVORAK AND AUTOMATED FIXES:
PGTW: T3.0 - 45 KTS
RJTD: T3.5 - 55 KTS
KNES: T3.0 - 45 KTS
CIMSS SATCON: 58 KTS AT 042010Z
CIMSS ADT: 32 KTS AT 042330Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: MARGINALLY FAVORABLE
VWS: 5-10 KTS
SST: 26-28 CELSIUS
OUTFLOW: STRONG POLEWARD
OTHER FACTORS: UPPER-LEVEL LOW TO THE EAST ENHANCING OUTFLOW,
IMPROVING SST GRADIENT ALONG THE DIRECTION OF MOTION

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: TROPICAL STORM (TS) 06W IS EXPECTED TO
CONTINUE A PREDOMINANTLY EASTWARD MOTION WITHIN THE NER FLOW OVER
THE NEXT 36 HOURS. DURING THIS TIME, HWRF FIELDS INDICATE KHANUN WILL
MAINTAIN ITS LARGE RADIUS OF MAXIMUM WINDS AND SHALLOW CORE
CONVECTION. AFTER TAU 36, RIDGING WILL BUILD AND REORIENT TO A MORE
ZONAL AXIS AHEAD OF THE TRACK RESULTING IN A POLEWARD TURN. WARMER
WATERS WILL HELP DRIVE A SHORT PERIOD OF RE-INTENSIFICATION PRIOR TO
LANDFALL, WITH HFWF SUGGESTING A BRIEF RETURN TO TYPHOON INTENSITY
NEAR TAU 72 AHEAD OF LANDFALL. ONCE OVER KYUSHU, A 500MB SHORTWAVE
TROUGH SHOULD CAPTURE THE SYSTEM, FURTHER ENHANCING THE POLEWARD
MOTION AND BEGINNING AN EXTRATROPICAL TRANSITION PHASE. HOWEVER, WARM
27 DEGREE C WATERS OVER THE SEA OF JAPAN MAY PROLONG THE TRANSITION
AND HELP MAINTAIN STORM FORCE WINDS THROUGHOUT THE REMAINDER OF THE
FORECAST PERIOD. THE FORECAST TRACK WAS PLACED VERY CLOSE TO THE
PRIOR FORECAST.

MODEL DISCUSSION: MULTI-MODEL CONSENSUS AGREEMENT IS GOOD THROUGH
TAU 48, AFTER WHICH TWO MEMBERS BECOME OUTLIERS, NAVGEM TO THE EAST
AND UKMET ENSEMBLE MEAN TO THE WEST. HOWEVER, THE REMAINING MEMBERS
ALL TRACK OVER KYUSHU. THE 18Z OFF-CYCLE ECMWF RUN HOWEVER IS
MAKING A SHARPER TURN PASSING OFF THE WEST OF KYUSHU AT TAU 96.
STANDING BY TO SEE IF THIS TREND CONTINUES IN THE 00Z RUN.
INTENSITY GUIDANCE IS IN MODERATE AGREEMENT, WITH STEADY STATE
UNTIL JUST PRIOR TO LANDFALL WHEN A SHORT RE-INTENSIFICATION
OCCURS.

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

[Sciencerocks]

 https://twitter.com/LckyTuba/status/1687654182638022656

[cycloneye]

WDPN32 PGTW 050900
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 06W (KHANUN) WARNING NR
037//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
INITIAL POSITION: 27.8N 127.6E
INITIAL INTENSITY: 55 KTS
GEOGRAPHIC REFERENCE: 79 NM NORTH OF KADENA AB
MOVEMENT PAST 6 HOURS: EASTWARD AT 06 KTS
SIGNIFICANT WAVE HEIGHT: 30 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) DEPICTS A LARGE
TROPICAL STORM FORCE CIRCULATION WITH DEEP CONVECTIVE BANDING
FEATURES IN ALL QUADRANTS. A 050143Z ASCAT-C SCATTEROMETERY PASS
REVEALS A SIZABLE CIRCULATION WITH AN RMW APPROACHING 80NM AND AN
ASYMMETRIC WIND FIELD UNFORTUNATELY FAVORING THE SOUTHEASTERN
QUADRANT. THE INITIAL POSITION IS PLACED WITH HIGH CONFIDENCE BASED
ON MSI AND ASCAT-C DATA. THE INITIAL INTENSITY OF 55 KTS IS
ASSESSED WITH HIGH CONFIDENCE BASED ON THE PREPONDERANCE OF
EVIDENCE, INCLUDING AGENCY DVORAK INTENSITY ESTIMATES, CIMSS
D-PRINT AND SATCON SUPPORTING THE JTWC INITIAL INTENSITY, WHILE
CIMSS ADT AND AIDT REMAIN MUCH LOWER.

INITIAL WIND RADII BASIS: SCATTEROMETER DATA

CURRENT STEERING MECHANISM: NEAR-EQUATORIAL RIDGE (NER) TO THE
SOUTH

AGENCY DVORAK AND AUTOMATED FIXES:
PGTW: T3.0 - 45 KTS
RJTD: T3.5 - 55 KTS
RCTP: T3.5 - 55 KTS
KNES: T3.0 - 45 KTS
CIMSS SATCON: 61 KTS AT 050220Z
CIMSS ADT: 32 KTS AT 050530Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: MARGINALLY FAVORABLE
VWS: 0-5 KTS
SST: 28-29 CELSIUS
OUTFLOW: MODERATE EASTWARD
OTHER FACTORS: IMPROVING SST GRADIENT ALONG THE DIRECTION OF
MOTION

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: TROPICAL STORM (TS) 06W (KHANUN) IS FORECAST
TO CONTINUE TRACKING GENERALLY EASTWARD OVER THE NEXT 36 HOURS
UNDER THE STEERING INFLUENCE OF THE NER TO THE SOUTH. AS TRACK
SPEEDS INCREASE, UPWELLING BECOMES MUCH LESS OF A FACTOR, THOUGH
LOW VERTICAL WIND SHEAR AND WARMING SSTS WILL STILL STRUGGLE TO
FUEL ANY SUBSTANTIAL INTENSIFICATION DUE IN PART TO THE SYSTEMS
LARGE RMW AND SHALLOW CORE CONVECTION. BY TAU 48, THE NER TO THE
SOUTH SHIFTS NORTHEASTWARD AND FORCES 06W TO EXECUTE A NORTHWARD
COURSE CHANGE. BETWEEN TAUS 48 AND 72, 06W IS FORECAST TO ONCE
AGAIN REACH TYPHOON STRENGTH AS IT APPROACHES SOUTHERN JAPAN. AS
THE SYSTEM MAKES LANDFALL, IT WILL QUICKLY TRAVERSE THE ISLAND OF
KYUSHU, PASSING ROUGHLY 75NM EAST OF SASEBO AND EVENTUALLY SPILLING
OUT INTO THE SEA OF JAPAN. BY TAU 120, THE SYSTEM WILL INTERACT
WITH A PASSING 500MB TROUGH AND ASSOCIATED BAROCLINIC ZONE WHICH
WILL INITIATE EXTRA-TROPICAL TRANSITION (ETT), WHILE AT THE SAME
TIME PROVIDING A ROBUST OUTFLOW CHANNEL. THIS ENHANCED OUTFLOW,
WHEN COMBINED WITH WARM SSTS MAY PROLONG OR SLIGHTLY ENHANCE THE
DURATION OF STORM FORCE WINDS, WHILE AT THE SAME TIME DELAYING THE
EXTRA-TROPICAL TRANSITION.

MODEL DISCUSSION: WITH THE EXCEPTION OF A FEW TROUBLE MAKERS TO
EITHER SIDE OF THE MULTI-MODEL CONSENSUS, THE BULK OF THE MODEL
GUIDANCE IS IN GOOD AGREEMENT. NVGM AND COAMPS-TC (NVGM VERSION)
REPRESENT THE EXTREME EASTWARD TRACK FORECASTS, WHILE UK-MET
ENSEMBLE IS THE LONE MEMBER TO THE FAR WEST. THE BULK OF THE MODELS
TRACK EASTWARD THROUGH TAUS 36-48 AFTERWARDS MAKING A SHARP
NORTHWARD TURN THROUGH THE FORECAST PERIOD. BASED ON THE PERSISTENT
CROSS TRACK SPREADING, THE JTWC TRACK FORECAST IS PLACED WITH
OVERALL MEDIUM CONFIDENCE. RELIABLE MODEL INTENSITY GUIDANCE IS IN
FAIR AGREEMENT THROUGH THE FORECAST PERIOD WITH A 15KT SPREAD IN
SOLUTIONS BY TAU 120. SIMILAR TO THE TRACK FORECAST, BASED ON THE
PERSISTENT SPREAD IN INTENSITY GUIDANCE, THE JTWC INTENSITY
FORECAST IS PLACED WITH OVERALL MEDIUM CONFIDENCE.

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

[InfernoFlameCat]

Massive eye. Wow. That’s crazy

[cycloneye]

WDPN32 PGTW 051500
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 06W (KHANUN) WARNING NR
038//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
INITIAL POSITION: 27.8N 128.5E
INITIAL INTENSITY: 55 KTS
GEOGRAPHIC REFERENCE: 86 NM NORTH-NORTHEAST OF KADENA AB
MOVEMENT PAST 6 HOURS: EASTWARD AT 08 KTS
SIGNIFICANT WAVE HEIGHT: 32 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY DEPICTS A LARGE
TROPICAL STORM FORCE CIRCULATION WITH DEEP CONVECTIVE BANDING
FEATURES IN ALL QUADRANTS. A 050940Z SSMIS 91GHZ MICROWAVE IMAGE
REVEALS A ROUGHLY 80NM CONVECTIVE DOUGHNUT WITH MINIMAL CORE
CONVECTION. A SERIES OF SCALAR WIND PRODUCTS, SOIL MOISTURE ACTIVE
PASSIVE (SMAP) AND SYNTHETIC APERTURE RADAR (SAR) BOTH INDICATE A
ROUGHLY 80NM RMW WITH VMAX NEAR 55KTS AND SPURIOUS POCKETS OF 60KT
WINDS. THE INITIAL POSITION IS PLACED WITH HIGH CONFIDENCE BASED ON
EIR AND SSMIS IMAGERY. THE INITIAL INTENSITY OF 55 KTS IS ASSESSED
WITH MEDIUM CONFIDENCE BASED ON SAR AND SMAP PASSES GENERALLY
SUPPORTING 55KTS ALONG WITH AGENCY DVORAK INTENSITY ESTIMATES AND
CIMSS D-PRINT.

INITIAL WIND RADII BASIS: SAR DATA

CURRENT STEERING MECHANISM: NEAR-EQUATORIAL RIDGE (NER) TO THE
SOUTH

AGENCY DVORAK AND AUTOMATED FIXES:
PGTW: T3.5 - 55 KTS
RJTD: T3.5 - 55 KTS
RCTP: T3.0 - 45 KTS
KNES: T3.0 - 45 KTS
CIMSS ADT: 32 KTS AT 051130Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: MARGINALLY FAVORABLE
VWS: 0-5 KTS
SST: 28-29 CELSIUS
OUTFLOW: MODERATE EASTWARD
OTHER FACTORS: IMPROVING SST GRADIENT ALONG THE DIRECTION OF
MOTION

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

3. FORECAST REASONING.

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

FORECAST DISCUSSION: TROPICAL STORM (TS) 06W (KHANUN) IS FORECAST
TO CONTINUE TRACKING GENERALLY EASTWARD OVER THE NEXT 36 HOURS
UNDER THE STEERING INFLUENCE OF THE NER TO THE SOUTH. AS TRACK
SPEEDS INCREASE, UPWELLING BECOMES MUCH LESS OF A FACTOR, THOUGH
LOW VERTICAL WIND SHEAR AND WARMING SSTS WILL STILL STRUGGLE TO
FUEL ANY SUBSTANTIAL INTENSIFICATION DUE IN PART TO THE SYSTEMS
LARGE RMW AND SHALLOW CORE CONVECTION. BY TAU 48, THE NER TO THE
SOUTH SHIFTS NORTHEASTWARD AND FORCES 06W TO EXECUTE A SHARP
NORTHWARD COURSE CHANGE. BETWEEN TAUS 48 AND 72, 06W IS FORECAST TO
ONCE AGAIN REACH TYPHOON STRENGTH AS IT APPROACHES SOUTHERN JAPAN.
AS THE SYSTEM MAKES LANDFALL, IT WILL QUICKLY TRAVERSE THE ISLAND
OF KYUSHU, PASSING ROUGHLY 70NM EAST OF SASEBO AND EVENTUALLY
SPILLING OUT INTO THE SEA OF JAPAN. BY TAU 120, THE SYSTEM WILL
INTERACT WITH A PASSING 500MB TROUGH AND ASSOCIATED BAROCLINIC ZONE
WHICH WILL INITIATE EXTRA-TROPICAL TRANSITION (ETT), WHILE AT THE
SAME TIME PROVIDING A ROBUST OUTFLOW CHANNEL. THIS ENHANCED
OUTFLOW, WHEN COMBINED WITH WARM SSTS MAY PROLONG OR SLIGHTLY
ENHANCE THE DURATION OF STORM FORCE WINDS, WHILE AT THE SAME TIME
DELAYING THE EXTRA-TROPICAL TRANSITION.

MODEL DISCUSSION: WITH THE EXCEPTION OF A FEW PERSISTENT TROUBLE
MAKERS TO EITHER SIDE OF THE MULTI-MODEL CONSENSUS, THE BULK OF THE
MODEL GUIDANCE IS IN FAIR AGREEMENT. NVGM AND COAMPS-TC (NVGM
VERSION) REPRESENT THE EXTREME EASTWARD TRACK FORECASTS, WHILE
UK-MET ENSEMBLE AND ECMWF ENSEMBLE REPRESENT THE EXTREME WESTWARD
TRACK FORECAST. THE BULK OF THE REMAINING MODELS TRACK EASTWARD
THROUGH TAUS 36-48 AFTERWARDS MAKING A SHARP NORTHWARD TURN THROUGH
THE FORECAST PERIOD. BASED ON THE PERSISTENT CROSS TRACK SPREADING,
THE JTWC TRACK FORECAST IS PLACED WITH OVERALL MEDIUM CONFIDENCE.
RELIABLE MODEL INTENSITY GUIDANCE IS IN FAIR AGREEMENT THROUGH THE
FORECAST PERIOD WITH A 15KT SPREAD IN SOLUTIONS BY TAU 120. SIMILAR
TO THE TRACK FORECAST, BASED ON THE PERSISTENT SPREAD IN INTENSITY
GUIDANCE, THE JTWC INTENSITY FORECAST IS PLACED WITH OVERALL MEDIUM
CONFIDENCE.

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

[Sciencerocks]

[somethingfunny]

How long do y'all figure the cool upwelling pool from Khanun might stick around in a way meaningful enough to impact future landfall threats moving up that corridor? That section of ocean has definitely been drained of fuel for now, Khanun ate it all.

[Sciencerocks]

[cycloneye]

WDPN32 PGTW 060300
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 06W (KHANUN) WARNING NR
040//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
INITIAL POSITION: 27.5N 129.5E
INITIAL INTENSITY: 55 KTS
GEOGRAPHIC REFERENCE: 109 NM NORTHEAST OF KADENA AB
MOVEMENT PAST 6 HOURS: SOUTHEASTWARD AT 07 KTS
SIGNIFICANT WAVE HEIGHT: 36 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) AND ANIMATED RADAR
DATA FROM JMA SHOW THAT TS 06W (KHANUN) TOOK A SHARP DIVE TO THE
SOUTHEAST AFTER PASSING JUST NORTH OF TOKUNOSHIMA ISLAND. THE MOST
RECENT IMAGERY SUGGEST THE SYSTEM IS NOW TRACKING DUE EAST OR
SLIGHTLY EAST-NORTHEAST, BUT ALSO SHOWS DEVELOPMENT OF A SECOND
VORTEX THAT LOOKS TO TRACK BETWEEN TOKUNOSHIMA AND WADOMARI
ISLANDS. THE RADAR AND MSI ALSO SHOW A VERY TIGHT INNER LOW LEVEL
CIRCULATION CENTER (LLCC), SURROUNDED BY A BAND OF MODERATELY
INTENSE CONVECTION WHICH EXTENDS FROM THE NORTHWEST QUADRANT TO THE
SOUTHEAST QUADRANT AT ABOUT 85-90NM DISTANT. OVER THE PAST FEW
HOURS, A SERIES OF MICROWAVE IMAGES AND THE MSI INDICATE CONVECTION
HAS INTENSIFIED ALONG THE CONVECTIVE BAND TO THE EAST OF OKINAWA
AND IS BEGINNING TO WRAP FURTHER UP THE EAST SIDE. HOWEVER, CIRA
ADVECTED LAYER PRECIPITABLE WATER IMAGERY AS WELL AS THE LATEST
SOUNDING FROM KAGOSHIMA INDICATE A WELL-ENTRENCHED WEDGE OF DRY AIR
IS PUNCHING INTO THE CORE FROM THE NORTHEAST, INHIBITING CONVECTIVE
DEVELOPMENT IN THAT SECTOR. A HOT OFF THE PRESSES 052112Z RCM-1 SAR
PASS SHOWS A MAXIMUM 1-MIN WIND OF 59 KNOTS IN THE CONVECTIVE BAND
TO THE SOUTH, WITH A AN RMW OF 95NM. IN GENERAL, THIS SUPPORTS THE
INITIAL INTENSITY WITH HIGH CONFIDENCE, HEDGED SLIGHTLY HIGHER THAN
THE BULK OF THE AGENCY DVORAK CURRENT INTENSITY ESTIMATES AND FAR
ABOVE THE OBJECTIVE ESTIMATES. THE ENVIRONMENT REMAINS MARGINAL,
WITH LOW VWS OFFSET BY MID-LEVEL DRY AIR, LIMITED UPPER-LEVEL
OUTFLOW AND WEAK UPWELLING KEEPING SSTS RELATIVELY COOL. THE SYSTEM
IS EXHIBITING SOME TROCHOIDAL MOTION BUT OVERALL IS TRACKING
TOWARDS THE EAST ALONG THE NORTH SIDE OF A DEEP NEAR EQUATORIAL
RIDGE (NER) TO THE SOUTHEAST.

INITIAL WIND RADII BASIS: SAR DATA

CURRENT STEERING MECHANISM: NORTHERN PERIPHERY OF THE DEEP-LAYER
NER TO THE SOUTHEAST.

AGENCY DVORAK AND AUTOMATED FIXES:
PGTW: T3.0 - 45 KTS
RJTD: T3.5 - 55 KTS
KNES: T3.0 - 45 KTS
CIMSS ADT: 27 KTS AT 052330Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: MARGINALLY FAVORABLE
VWS: 10-15 KTS
SST: 29-30 CELSIUS
OUTFLOW: WEAK EQUATORWARD
OTHER FACTORS: MID-LEVEL DRY AIR, UPWELLING OF COOLER WATERS.

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

3. FORECAST REASONING.

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

FORECAST DISCUSSION: THE RECENT DEVELOPMENT OF A SECONDARY VORTEX
TO THE WEST OF THE PRIMARY LLCC WILL COMPOUND THE ALREADY ERRATIC
AND TROCHOIDAL MOTION EXHIBITED EARLIER TODAY AS THESE TWO VORTICES
ESSENTIALLY UNDERGO A SMALL-SCALE FUJIWHARA TYPE INTERACTION. THIS
COMPLEX DANCE AND ERRATIC MOTION IS EXPECTED TO CONTINUE FOR THE
NEXT 24 TO 36 HOURS AS THE OVERALL LARGER CIRCULATION TRACKS
GENERALLY TOWARDS THE EAST. DURING THIS TIMEFRAME THE DIAMETER OF
THE CIRCULATION IS FORECAST TO SLOWLY SHRINK AS THE SYSTEM MOVES
INTO WARMER WATERS AND AWAY FROM THE INFLUENCE OF LAND BUT OVERALL
INTENSITY IS FORECAST TO REMAIN STEADY THROUGH TAU 24. BY TAU 36
THE SYSTEM SLOWS, BECOMING NEARLY QUASI-STATIONARY AS IT ENTERS A
WEAK STEERING PATTERN FOR A BRIEF PERIOD OF TIME. BY TAU 48 THE
SUBTROPICAL RIDGE (STR) TO THE NORTHEAST WILL ASSUME THE DOMINATE
STEERING ROLE AND TS 06W WILL KICK OUT TO THE NORTH-NORTHWEST ALONG
THE WESTERN SIDE OF THIS RIDGE. THE SYSTEM BEGINS TO ACCELERATE
AFTER TAU 48 AS THE STEERING RIDGE BUILDS AND MOVES WESTWARD,
STRENGTHENING THE STEERING GRADIENT. THE CURRENT FORECAST SHIFTS
THE TRACK FURTHER TO THE WEST, WITH THE SYSTEM NOW EXPECTED REMAIN
OFF THE COAST OF KYUSHU THROUGH THE FORECAST PERIOD. LANDFALL IS
NOW EXPECTED NEAR BUSAN, SOUTH KOREA JUST AFTER TAU 96, FOLLOWED BY
AN INLAND TRACK OVER EASTERN SOUTH KOREA AND BRIEF EXCURSION BACK
OVER WATER JUST EAST OF WONSON, NORTH KOREA BY TAU 120. AFTER
TURNING POLEWARD, THE SYSTEM IS FORECAST TO INTENSIFY BACK TO
TYPHOON STRENGTH AS IT CROSSES THE DEEP, WARM WATERS OF THE
KUROSHIO AND TAPS INTO STRONG POLEWARD OUTFLOW AHEAD OF A
UPPER-LEVEL TROUGH PASSING BY TO THE NORTH. SOME SLIGHT WEAKENING
IS EXPECTED PRIOR TO LANDFALL IN KOREA DUE TO THE PROXIMITY TO THE
RUGGED TERRAIN OF SOUTHWEST KYUSHU AND ENTRAINMENT OF LOW-LEVEL DRY
AIR DESCENDING FROM THE ISLAND INTO THE CORE OF THE SYSTEM. BY TAU
120, THE SYSTEM BEGINS EXTRATROPICAL TRANSITION AS IT INTERACTS
WITH A 500MB TROUGH AND ASSOCIATED BAROCLINIC ZONE.

MODEL DISCUSSION: DETERMINISTIC TRACK GUIDANCE IS VERY CONSISTENT
WITH THE PREVIOUS CYCLE IN OVERALL SHAPE AND MODEL TENDENCIES,
THOUGH THE ENTIRE ENVELOPE CONTINUES TO SHIFT WESTWARD WITH EACH
SUCCESSIVE RUN. THE NAVGEM AND COAMPS-TC CONTINUE INSISTING ON A
TRACKING OVER FAR SOUTHWEST HONSHU AND INTO THE EASTERN SEA OF
JAPAN, WHILE THE UKMET AND SHOWS A TRACK OVER CHEJU DO THEN UP TO
NEAR PYONGYANG. THE REMAINDER OF THE CONSENSUS MEMBERS ARE CONFINED
TO AN ENVELOPE OF 60NM AT TAU 48, WHICH EXPANDS TO 150NM BY TAU 96,
ROUGHLY CENTERED ON BUSAN, SOUTH KOREA. OF NOTE, THE GFS HAS
CONTINUED TO TREND FURTHER AND FURTHER WEST WITH EACH MODEL RUN AND
NOW IS THE LEFT-MOST TRACKER AFTER TAU 72, SHOWING THE CENTER
TRACKING OVER SEOUL AND INTO NORTHEAST CHINA BY TAU 120. THE ENTIRE
MODEL ENVELOPE EXPANDS TO OVER 800NM BY TAU 120, PROVIDING A HINT
AT THE HIGH LEVELS OF UNCERTAINTY IN THE TRACK FORECAST AFTER TAU
72. A SIMILARLY LARGE SPREAD IS EVIDENT IN THE ENSEMBLE MODELS,
RESULTING IN LOW CONFIDENCE IN THE JTWC FORECAST AFTER TAU 72.
INTENSITY GUIDANCE IS IN GOOD AGREEMENT ON THE OVERALL FORECAST
TREND, THOUGH THE BULK OF THE CONSENSUS PEAKS THE SYSTEM AT AROUND
60-65 KNOTS, WITH THE JTWC FORECAST BEING A SHADE HIGHER, HEDGED
TOWARDS THE HAFS-A SOLUTION.

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

[cycloneye]

WDPN32 PGTW 060900
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 06W (KHANUN)
WARNING NR 041//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
INITIAL POSITION: 27.8N 130.1E
INITIAL INTENSITY: 55 KTS
GEOGRAPHIC REFERENCE: 319 NM SOUTH OF SASEBO, JAPAN
MOVEMENT PAST 6 HOURS: EAST-NORTHEASTWARD AT 06 KTS
SIGNIFICANT WAVE HEIGHT: 36 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
TROPICAL STORM (TS) 06W HAS MAINTAINED INTENSITY AT 55 KNOTS OVER
THE PAST SIX HOURS WITH A SOMEWHAT ERRATIC TRACK OVER THE PAST 12
HOURS DUE TO THE PRESENCE OF MULTIPLE MESOVORTICES ROTATING WITHIN
A BROAD, EXPOSED CENTER. ANIMATED MULTISPECTRAL SATELLITE IMAGERY
(MSI) CONTINUES TO SHOW AN EXPOSED BUT DOMINANT LOW-LEVEL
CIRCULATION (LLC) WITH EXTENSIVE DEEP CONVECTIVE BANDING PERSISTING
OVER THE SOUTHERN SEMICIRCLE. A 060430Z AMSR2 89GHZ MICROWAVE IMAGE
REVEALS A NARROW BAND OF DEEP CONVECTION WRAPPING AROUND A VERY
BROAD, CONVECTION-FREE CENTER (APPROXIMATELY 200-225NM DIAMETER).
THE INITIAL POSITION IS PLACED WITH MEDIUM CONFIDENCE BASED ON THE
MSI AND AMSR2 IMAGERY AS WELL AS JMA HOURLY RADAR FIXES.
ENVIRONMENTAL CONDITIONS REMAIN MARGINALLY FAVORABLE WITH
SIGNIFICANT DRY AIR IN THE MID- TO UPPER-LEVELS INDICATED IN THE
RECENT KAGOSHIMA AND NAZE SOUNDINGS. HOWEVER, THE DEEP CONVECTIVE
STRUCTURE HAS MAINTAINED DUE TO LOW VERTICAL WIND SHEAR (VWS), WARM
SST (29C) AND MODERATE EQUATORWARD VENTING. THERE IS HIGH CONFIDENCE
IN THE INITIAL INTENSITY BASED ON THE 060430Z AMSR2 WINDSPEED DATA
AND RANGE OF DVORAK ESTIMATES.

INITIAL WIND RADII BASIS: SCATTEROMETER DATA AND AMSR2 DATA

CURRENT STEERING MECHANISM: WEAK SUBTROPICAL RIDGE (STR) POSITIONED
TO THE EAST AND NORTHEAST

AGENCY DVORAK AND AUTOMATED FIXES:
PGTW: T3.0 - 45 KTS
RJTD: T3.5 - 55 KTS
RCTP: T3.0 - 45 KTS
KNES: T3.5 - 55 KTS
CIMSS SATCON: 45 KTS AT 060120Z
CIMSS ADT: 30 KTS AT 060230Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: MARGINALLY FAVORABLE
VWS: 10-15 KTS
SST: 29-30 CELSIUS
OUTFLOW: MODERATE EQUATORWARD
OTHER FACTORS: DRY AIR ENTRAINMENT

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

3. FORECAST REASONING.

SIGNIFICANT FORECAST CHANGES: DUE TO THE PROLONGED TRACK OVER THE
KOREAN PENINSULA, THE FORECAST PHILOSOPHY HAS BEEN SWITCHED FROM
EXTRA-TROPICAL TRANSITION TO DISSIPATION.

FORECAST DISCUSSION: TS 06W IS WOBBLING SLOWLY EAST-NORTHEASTWARD
ALONG THE NORTHWESTERN PERIPHERY OF THE WEAK STR AND IS EXPECTED TO
SLOWLY TURN POLEWARD WITHIN THE NEXT 12 HOURS. TRACK SPEEDS REMAIN
SLOW DUE TO A DEVELOPING TROPICAL DISTURBANCE TO THE EAST, WHICH IS
DISRUPTING THE STR. THE SYSTEM'S SLOW TRACK MOTION IS RESULTING IN
PERSISTENT HEAVY RAINBANDS AND GALE-FORCE WINDS SUSTAINING OVER
OKINAWA. AFTER TAU 12, TS 06W WILL TURN NORTH-NORTHWESTWARD AND
GRADUALLY INTENSIFY DUE PRIMARILY TO IMPROVING POLEWARD OUTFLOW TO
A PEAK OF 65 TO 70 KNOTS BY TAU 72. AS THE LARGE (600NM DIAMETER)
SYSTEM TRACKS PARALLEL TO THE WESTERN COAST OF KYUSHU, IT WILL
GRADUALLY WEAKEN DUE TO FRICTIONAL EFFECTS WITH MORE SIGNIFICANT
WEAKENING AS IT APPROACHES THE BUSAN REGION WITH LANDFALL
ANTICIPATED NEAR TAU 96. AFTER TAU 96, TS KHANUN WILL TRACK ALONG
THE EASTERN PORTION OF THE KOREAN PENINSULA AND BEGIN INTERACTING
WITH THE LEADING EDGE OF A SUBTROPICAL SHORTWAVE TROUGH AND WEAK
BAROCLINIC ZONE. DESPITE THE BAROCLINIC INFLUENCE, THE SYSTEM IS
FORECAST TO DISSIPATE AS IT TRACKS INTO NORTH KOREA AND NORTHEAST
CHINA.

MODEL DISCUSSION: NUMERICAL MODEL GUIDANCE REMAINS IN FAIR AGREEMENT
WITH A 150NM CROSS-TRACK SPREAD IN SOLUTIONS AT TAU 84 (NEAR SASEBO)
DIVERGING TO 250NM AT TAU 96 (NEAR BUSAN). IN GENERAL, NUMERICAL
GUIDANCE IS IN POOR AGREEMENT AFTER TAU 72 WITH LOW CONFIDENCE (HIGH
UNCERTAINTY) IN THE JTWC FORECAST TRACK OVER THE KOREAN PENINSULA.
THIS UNCERTAINTY IS ALSO REFLECTED IN THE 060000Z GEFS AND EPS
PROBABILISTIC GUIDANCE. OVERALL, THERE IS MEDIUM CONFIDENCE IN THE
JTWC INTENSITY FORECAST WITH THE 060000Z COAMPS-TC ENSEMBLE SHOWING
AN 80 TO 100 PERCENT PROBABILITY OF REINTENSIFICATION THROUGH TAU 48.

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

[Sciencerocks]

[Sciencerocks]

 https://twitter.com/zoom_earth/status/1688279063201304576

[cycloneye]

WDPN32 PGTW 062100
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 06W (KHANUN) WARNING NR
043//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
INITIAL POSITION: 27.9N 130.7E
INITIAL INTENSITY: 55 KTS
GEOGRAPHIC REFERENCE: 176 NM EAST-NORTHEAST OF KADENA AB
MOVEMENT PAST 6 HOURS: NORTHWARD AT 05 KTS
SIGNIFICANT WAVE HEIGHT: 35 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
TROPICAL STORM (TS) 06W (KHANUN) CONTINUES TO EXHIBIT MULTIPLE
VORTICES EMBEDDED WITHIN A LARGE, ROUGHLY 85NM WIDE CIRCULATION.
BASED ON ANIMATED JMA RADAR AND SHORTWAVE INFRARED (SWIR) IMAGERY
INDICATES THAT THE PRIMARY VORTEX CONTINUES TO WOBBLE AND FUJIWHARA
WITH ONE OR MORE SECONDARY VORTICES, LEADING TO A VERY ERRATIC
TRACK MOTION OVER THE PAST 12 HOURS. OVER THE PAST SIX HOURS, THE
PRIMARY VORTEX HAS TRACKED TOWARDS THE NORTH, BUT THE MOST RECENT
IMAGERY SUGGEST IT IS NOW MOVING TOWARDS THE WEST. HENCE PLACEMENT
OF THE INITIAL POSITION AND SUBSEQUENTLY, THE INITIAL MOTION
VECTOR, IS ASSESSED WITH ONLY MEDIUM CONFIDENCE. A 061637Z AMSR2
89GHZ IMAGE REVEALS SHALLOW BANDING ACROSS THE SOUTHERN HEMISPHERE
OF THE CIRCULATION, WITH ENHANCED CONVECTION IN THE NORTHERN
PORTION OF THE PRIMARY BANDING FEATURE. CONVECTION REMAINS
FRAGMENTED ACROSS THE MAJORITY OF THE CIRCULATION, STILL UNABLE TO
CONSOLIDATE EFFECTIVELY. AN EARLIER SENTINEL-1A SAR PASS REVEALED
MAXIMUM WINDS NEAR 65 KNOTS, WHILE THE AMSR2 WINDSPEED MEASUREMENT
FROM 061632Z SHOWED A MAX BETWEEN 50 TO 55 KNOTS IN THE NORTHEAST
QUADRANT, SUPPORTING THE INITIAL INTENSITY WITH HIGH CONFIDENCE. NO
SIGNIFICANT CHANGE IS NOTED IN THE ENVIRONMENTAL CONDITIONS; SHEAR
REMAINS LOW, SSTS WARM BUT THE LONGER THE SYSTEM LINGERS IN THIS
AREA THE COOLER THEY WILL GET DUE TO UPWELLING. THE ONLY MAJOR
CHANGE IS THE SLOWLY IMPROVING OUTFLOW. THE SYSTEM HAS STALLED DUE
TO THE DEVELOPMENT OF A SUBTROPICAL RIDGE (STR) NEAR 20N 140E,
WHICH IS BUILDING TO THE NORTH, EFFECTIVELY BLOCKING MUCH IN THE
WAY OF EASTWARD MOVEMENT.

INITIAL WIND RADII BASIS: AMSR2 WINDSPEED DATA.

CURRENT STEERING MECHANISM: WEAK STEERING PATTERN AS STEERING
INFLUENCE IS SHIFTING.

AGENCY DVORAK AND AUTOMATED FIXES:
PGTW: T3.0 - 45 KTS
RJTD: T3.5 - 55 KTS
KNES: T3.5 - 55 KTS
CIMSS SATCON: 47 KTS AT 061325Z
CIMSS ADT: 35 KTS AT 061450Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: MARGINALLY FAVORABLE
VWS: 5-10 KTS
SST: 27-28 CELSIUS
OUTFLOW: MODERATE POLEWARD AND EQUATORWARD

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

3. FORECAST REASONING.

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

FORECAST DISCUSSION: AS DISCUSSED ABOVE, THE EMERGENCE OF A
BUILDING STR TO THE SOUTHEAST OF TS 06W HAS EFFECTIVELY BLOCKED THE
SYSTEM FROM MOVING MUCH FURTHER TO THE EAST. RECENT IMAGERY
SUGGESTS THE PRIMARY VORTEX WILL PIROUETTE COUNTER-CLOCKWISE AND THEN
KICK OUT TO THE NORTHEAST OVER THE NEXT 12 HOURS, SUCH THAT THE
CENTER POSITION IS NOT EXPECTED TO MOVE MUCH FROM THE CURRENT
POSITION. BY TAU 12, THE STR TO THE SOUTHEAST IS EXPECTED TO
STRENGTHEN AND ORIENT TO A NORTH-SOUTH AXIS, AND PUSH TS 06W ONTO A
NORTHWARD TRACK. BY TAU 24, THE STRONG STR CENTERED FAR OUT INTO
THE NORTH PACIFIC WILL TAKE OVER AS THE PRIMARY STEERING MECHANISM,
AND PUSH TS 06W ONTO A NORTH-NORTHWEST TRACK, WHICH WILL CONTINUE
THROUGH THE REMAINDER OF THE FORECAST PERIOD. LANDFALL IS EXPECTED
TO THE WEST OF BUSAN AROUND TAU 84, WITH THE SYSTEM RAPIDLY MOVING
INTO NORTHEASTERN CHINA BY TAU 120. IN TERMS OF INTENSITY, THE
LARGE RADIUS OF MAXIMUM WINDS (RMW), WEAK UPWELLING, AND RESTRICTED
(THOUGH IMPROVING) OUTFLOW ALOFT ARE INHIBITING CONSOLIDATION AND
INTENSIFICATION AT THE MOMENT. AS THE SYSTEM BEGINS TO MOVE OFF TO
THE NORTH, IT WILL MOVE OVER THE DEEP, WARM WATERS OF THE KUROSHIO
CURRENT. AT THE SAME TIME, OUTFLOW WILL STEADILY IMPROVE, AND THESE
TWO FACTORS SHOULD COMBINE TO ENABLE INCREASED CONVECTIVE
CONSOLIDATION AFTER TAU 24, ALLOWING THE SYSTEM TO SLOWLY BUT
STEADILY INTENSIFY TO A PEAK OF 65 TO POTENTIALLY 70 KNOTS BY TAU
48. THE ULTIMATE INTENSITY WILL IN LARGE PART BE DRIVEN BY
INTERPLAY BETWEEN THE SIZE OF THE CIRCULATION AND THE PROXIMITY TO
KYUSHU. THE LARGER THE CIRCULATION AND CLOSER TO LAND THE SYSTEM
IS, THE LOWER THE PEAK INTENSITY WILL BE. AFTER LANDFALL, TS 06W
WILL RAPIDLY WEAKEN AS IT CROSSES OVER THE RUGGED TERRAIN OF THE
KOREAN PENINSULA, AND ULTIMATELY DISSIPATE OVER NORTHEASTERN CHINA
BY AROUND TAU 120.

MODEL DISCUSSION: DETERMINISTIC TRACK GUIDANCE IS CONSISTENT WITH
THE PREVIOUS MODEL RUN, WITH NO MAJOR CHANGES IN THE CONSENSUS
TRACK OR THE ENVELOPE SIZE AND MAKEUP. THE NAVGEM AND UKMET
ENSEMBLE CONTINUE TO MARK THE EASTERN AND WESTERN OUTLIERS
RESPECTIVELY, THE REMAINDER OF THE CONSENSUS MEMBERS HOLDING FIRM
IN A TRACK ENVELOPE THAT MEASURES 95 NM ACROSS AT TAU 72. THE
ENVELOPE EXPANDS TO OVER 400NM BY TAU 120 THOUGH THE BULK OF THE
CONSENSUS MEMBERS LIE IN A MUCH SMALLER ENVELOPE OF JUST 125 NM. THE
JTWC FORECAST REMAINS CONSISTENT WITH THE PREVIOUS FORECAST AND
LIES ON THE EASTERN SIDE OF THE GUIDANCE PACKAGE. WHILE CONFIDENCE
IN THE OVERALL TRACK IS FAIRLY HIGH, THE ERRATIC TROCHOIDAL MOTION
EXPECTED FOR THE FIRST 12 TO 24 HOURS INTRODUCES A MODEST AMOUNT OF
UNCERTAINTY IN THE EXACT FORECAST TRACK. INTENSITY GUIDANCE IS IN
GOOD AGREEMENT, WITH ALL AVAILABLE MODELS INDICATING
INTENSIFICATION AFTER TAU 12, WITH A PEAK INTENSITY RANGE BETWEEN
55-70 KNOTS. THE JTWC FORECAST IS ON THE HIGHER END OF THE GUIDANCE
THROUGH THE ENTIRE FORECAST PERIOD.

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

[cycloneye]

WDPN32 PGTW 070300
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 06W (KHANUN) WARNING NR
044//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
INITIAL POSITION: 27.8N 131.1E
INITIAL INTENSITY: 55 KTS
GEOGRAPHIC REFERENCE: 326 NM SOUTH-SOUTHEAST OF SASEBO, JAPAN
MOVEMENT PAST 6 HOURS: EAST-SOUTHEASTWARD AT 04 KTS
SIGNIFICANT WAVE HEIGHT: 34 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
TROPICAL STORM (TS) 06W (KHANUN) REMAINS QUITE LARGE, WITH THE
INNER CORE BECOMING INCREASINGLY DISORGANIZED AS MULTIPLE VORTICES
ARE SPINNING AROUND THE INNER-EDGE OF THE DONUT-LIKE BAND OF
CONVECTION SITUATED ABOUT 85 NM OUT FROM THE ASSESSED CENTER. THE
LOW-LEVEL STRUCTURE IS MUCH IMPROVED BASED ON AN ANALYSIS OF A
062159Z SSMIS 37GHZ MICROWAVE IMAGE, WHICH SHOWED WELL-DEFINED
LOW-LEVEL BANDING FEATURES SURROUNDING THE LARGE CORE LOW
EMISSIVITY REGION. THE MSI DEPICTS DEEP CONVECTION IS FLARING
ACROSS ALL QUADRANTS EXCEPT FOR THE NORTHEAST, WHERE SOME MID-LEVEL
DRY AIR CONTINUES TO LINGER. ANIMATED MSI AND WATER VAPOR IMAGERY
SHOWS RADIAL OUTFLOW CONTINUES TO EXPAND OUTWARD BUT REMAINS
RELATIVELY CONFINED AND IS NOT YET CONNECTING TO ANY OUTFLOW
CHANNELS. THE INITIAL POSITION IS PLACED IN A CENTROID POSITION,
CONSCIOUSLY NOT FOLLOWING ANY OF THE PERIPHERAL VORTICIES. THE
INITIAL INTENSITY REMAINS SET AT 55 KNOTS, SET ON THE HIGHER END OF
THE AGENCY DVORAK CURRENT INTENSITY ESTIMATES, AND CONSISTENT WITH
EARLIER SAR AND AMSR2 MEASUREMENTS. WHILE THE SYSTEM IS NOT MOVING
VERY QUICKLY, IT IS LEAVING THE REGION OF UPWELLING IN ITS WAKE,
AND MOVING INTO DEEPER, WARMER WATERS. COMBINED WITH THE STEADILY
IMPROVING OUTFLOW AND MOISTENING OF THE AIRMASS DOWN TRACK, THE
BOTTOM LINE IS THAT THE ENVIRONMENT IS STEADILY IMPROVING.

INITIAL WIND RADII BASIS: PERSISTENCE

CURRENT STEERING MECHANISM: WEAK STEERING PATTERN.

AGENCY DVORAK AND AUTOMATED FIXES:
PGTW: T2.5 - 35 KTS
RJTD: T3.5 - 55 KTS
KNES: T3.0 - 45 KTS
CIMSS ADT: 33 KTS AT 062040Z

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

ANALYSIS CONFIDENCE:
INITIAL POSITION: MEDIUM
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: INDEPENDENT OF THE MESO-VORTICES RIDING AROUND
THE EASTERN PERIPHERY OF THE CIRCULATION, THE CENTROID OF THE
SYSTEM HAS LIKELY REACHED ITS EASTERN-MOST POINT AS IT IS RUNNING
FACE-FIRST INTO A BUILDING RIDGE EXTENDING TO THE NORTH ALONG THE
14O3 LONGITUDE LINE. THE SYSTEM IS EXPECTED TO MAKE A GRADUAL TURN
TO THE NORTH OVER THE NEXT FEW HOURS AS THE RIDGE CONTINUES TO
EXTEND TO THE NORTH. AFTER TAU 24, THE STRONG SUBTROPICAL RIDGE
(STR) TO THE NORTHEAST BUILDS IN AND ASSUMES THE DOMINANT STEERING
ROLE, PUSHING TS 06W ONTO A MORE NORTH-NORTHWEST TRACK, WHICH IS
EXPECTED TO CONTINUE THROUGH THE REMAINDER OF THE FORECAST PERIOD.
THE SYSTEM IS FORECAST TO PASS WEST OF KYUSHU PASSING THROUGH THE
GOTO ISLANDS, ON ITS WAY TOWARDS EVENTUAL LANDFALL IN KOREA. EVEN
THOUGH THE ENVIRONMENT CONTINUES TO IMPROVE, THE LACK OF A STRONG
OUTFLOW CHANNEL AND THE BROAD NATURE OF THE SYSTEM WILL CONTINUE TO
SLOW THE PACE OF INTENSIFICATION THROUGH THE FIRST 48 HOURS OF THE
FORECAST. ONCE THE SYSTEM REACHES SOUTHERN KYUSHU, IT WILL BEGIN TO
TAP INTO THE RIGHT ENTRANCE REGION OF A 200MB JET MAX OVER FAR
NORTHEASTERN CHINA, WHICH WILL KICK THE SYSTEM INTO HIGH GEAR,
UNLEASHING A MORE RAPID PACE OF INTENSIFICATION. THE CURRENT
FORECAST CALLS FOR A PEAK OF 70 KNOTS, THOUGH A SLIGHTLY HIGHER
PEAK IS POSSIBLE, DEPENDING ON HOW FAR WEST OF KYUSHU THE SYSTEM
PASSES, AND THE WIDTH OF THE RADIUS OF MAXIMUM WINDS (RMW) AT THAT
TIME. THE SYSTEM IS FORECAST TO MAKE LANDFALL ALONG THE SOUTHERN
COAST OF KOREA TO THE WEST OF BUSAN AROUND TAU 72. AFTER LANDFALL,
THE SYSTEM WILL TRACK NORTHWARD THROUGH THE CENTER OF THE KOREAN
PENINSULA WHILE RAPIDLY WEAKENING DUE TO THE EFFECTS OF THE RUGGED
TERRAIN OF THE KOREA PENINSULA AND INCREASING SHEAR, ULTIMATELY
DISSIPATING BY TAU 120 OVER NORTHEASTERN CHINA.

MODEL DISCUSSION: TRACK GUIDANCE HAS COME INTO BETTER AGREEMENT
WITH THIS RUN, WITH THE NAVGEM NOW JOINING THE REST OF THE
CONSENSUS PACK. THE UKMET AND UKMET ENSEMBLE ON THE OTHER HAND,
STUBBORNLY PERSIST IN TRACKING THE SYSTEM OVER THE YELLOW SEA AND
INTO THE BOHAI GULF. THE REMAINDER OF THE GUIDANCE PACKAGE IS
CONFINED TO A TRACK ENVELOPE, WHICH IS BASICALLY CONFINED TO THE
WIDTH OF THE KOREAN PENINSULA. THE JTWC FORECAST REMAINS CONSISTENT
WITH THE PREVIOUS FORECAST AND LIES ON THE EASTERN EDGE OF THE
GUIDANCE THROUGH THE BULK OF THE FORECAST PERIOD. CONFIDENCE IS
MEDIUM, PRIMARILY IN LIGHT OF THE UNCERTAINTY IN THE INITIAL
POSITION AND TROCHOIDAL MOTION ANTICIPATED THROUGH THE FIRST 12 TO
24 HOURS OF THE FORECAST. INTENSITY GUIDANCE IS IN GOOD AGREEMENT
WITH THE OVERALL INTENSITY SCENARIO, WITH THE HAFS-A, AND GFS
PEAKING THE SYSTEM AT 70 KNOTS WHILE THE CONSENSUS PEAK IS ABOUT
FIVE KNOTS LOWER. OVERALL CONFIDENCE IN THE INTENSITY FORECAST IS
MEDIUM TO HIGH.

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

[cycloneye]

WDPN32 PGTW 070900
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 06W (KHANUN)
WARNING NR 045//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
INITIAL POSITION: 28.0N 131.2E
INITIAL INTENSITY: 55 KTS
GEOGRAPHIC REFERENCE: 316 NM SOUTH-SOUTHEAST OF SASEBO, JAPAN
MOVEMENT PAST 6 HOURS: NORTH-NORTHEASTWARD AT 02 KTS
SIGNIFICANT WAVE HEIGHT: 34 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) DEPICTS DEEP
CONVECTIVE BANDING WRAPPING INTO A BROAD, EXPOSED CENTER WITH
MULTIPLE MESOVORTICES ROTATING CYCLONICALLY AROUND A DEFINED
CENTROID. ANIMATED RADAR IMAGERY ALSO REVEALS A DEFINED CENTER WITH
WEAK BANDING AND FRAGMENTED CLOUD ELEMENTS ROTATING AROUND A
DEFINED CENTER. THERE IS MEDIUM CONFIDENCE IN THE INITIAL POSITION,
WHICH IS BASED ON THE CENTROID LOCATION. BASED ON HOURLY JMA RADAR
FIXES, THE CENTER APPEARS TO BE DRIFTING SLOWLY POLEWARD. ALTHOUGH
MODEST, A 070715Z SSMIS 37GHZ MICROWAVE IMAGE INDICATES IMPROVING
ORGANIZATION WITH DEEP CONVECTIVE BANDING WRAPPING TIGHTLY INTO A
DEFINED LOW-LEVEL CIRCULATION CENTER. ENVIRONMENTAL CONDITIONS HAVE
IMPROVED WITH EXPANDING RADIAL OUTFLOW, LOW VERTICAL WIND SHEAR
AND WARM SST (29C). HOWEVER, MID-LEVEL TO UPPER-LEVEL DRY AIR
ENTRAINMENT IS LIKELY HINDERING DEVELOPMENT AT THIS TIME.

INITIAL WIND RADII BASIS: PERSISTENCE BUT ADJUSTED SLIGHTLY USING
SURFACE OBSERVATIONS FROM THE RYUKYU ISLANDS

CURRENT STEERING MECHANISM: WEAK SUBTROPICAL RIDGE (STR) POSITIONED
TO THE EAST AND NORTHEAST

AGENCY DVORAK AND AUTOMATED FIXES:
PGTW: T2.5 - 35 KTS
RJTD: T3.5 - 55 KTS
RCTP: T2.5 - 35 KTS
KNES: T3.0 - 45 KTS
CIMSS SATCON: 48 KTS AT 070438Z
CIMSS ADT: 34 KTS AT 070540Z
CIMSS AIDT: 56 KTS AT 070710Z
D-PRINT: 45 KTS AT 070700Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: MARGINALLY FAVORABLE
VWS: 5-10 KTS
SST: 29-30 CELSIUS
OUTFLOW: MODERATE RADIAL
OTHER FACTORS: DRY AIR ENTRAINMENT

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

3. FORECAST REASONING.

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

FORECAST DISCUSSION: TS 06W IS DRIFTING SLOWLY POLEWARD BASED ON A
SERIES OF RECENT JMA RADAR FIXES AND IS FORECAST TO TRACK SLOWLY
NORTHWARD TO NORTH-NORTHWESTWARD OVER THE NEXT 48 HOURS WHILE STEADILY
INTENSIFYING TO 65 KNOTS NEAR SASEBO. TS 06W SHOULD INTENSIFY TO A
PEAK OF 70 KNOTS BY TAU 60 PRIOR TO LANDFALL WEST OF BUSAN DUE TO
IMPROVING, ROBUST POLEWARD OUTFLOW AND WARM SST VALUES. THE SYSTEM IS
FORECAST TO GRADUALLY RE-MOISTEN, WHICH WILL ALSO AID IN THE
REINTENSIFICATION PHASE. AFTER TAU 72, TS KHANUN WILL ACCELERATE OVER
THE KOREAN PENINSULA AND BEGIN INTERACTING WITH THE LEADING EDGE OF A
SUBTROPICAL SHORTWAVE TROUGH AND WEAK BAROCLINIC ZONE. DESPITE THE
BAROCLINIC INFLUENCE, THE SYSTEM IS FORECAST TO DISSIPATE AS IT TRACKS
INTO NORTH KOREA AND NORTHEAST CHINA.

MODEL DISCUSSION: WITH THE EXCEPTION OF THE UKMET ENSEMBLE MEAN, WHICH
IS THE WESTERNMOST OUTLIER, AND NAVGEM, WHICH IS THE EASTERNMOST
OUTLIER, NUMERICAL MODEL GUIDANCE SHOWS A TIGHT GROUPING OVER THE
CENTRAL TO WESTERN KOREAN PENINSULA. THEREFORE, THERE IS MEDIUM
OVERALL CONFIDENCE IN THE JTWC FORECAST TRACK. THIS UNCERTAINTY IS
ALSO REFLECTED IN THE 070000Z GEFS AND EPS PROBABILISTIC GUIDANCE.
OVERALL, THERE IS MEDIUM CONFIDENCE IN THE JTWC INTENSITY FORECAST
WITH THE 070000Z COAMPS-TC ENSEMBLE SHOWING AN 80 TO 100 PERCENT
PROBABILITY OF MODERATE INTENSIFICATION THROUGH TAU 30 DECREASING TO
40 PERCENT PROBABILITY THROUGH TAU 54.

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

[cycloneye]

WDPN32 PGTW 071500
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 06W (KHANUN)
WARNING NR 046//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
INITIAL POSITION: 28.4N 131.2E
INITIAL INTENSITY: 55 KTS
GEOGRAPHIC REFERENCE: 292 NM SOUTH-SOUTHEAST OF SASEBO, JAPAN
MOVEMENT PAST 6 HOURS: NORTHWARD AT 03 KTS
SIGNIFICANT WAVE HEIGHT: 34 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED PROXYVIS SATELLITE IMAGERY DEPICTS DEEP CONVECTIVE BANDING
WRAPPING INTO A BROAD, EXPOSED CENTER WITH MULTIPLE MESOVORTICES
ROTATING CYCLONICALLY AROUND A DEFINED CENTROID. ANIMATED RADAR
IMAGERY REVEALS CONVECTIVE BANDING WRAPPING INTO A BROAD, ILL-DEFINED
CENTER. A 070847Z SMAP IMAGE SHOWS A LARGE, SYMMETRIC CORE OF WEAK
WINDS, ABOUT 90 NM DIAMETER, WITH A REGION OF 55-60 KNOT WINDS (1-
MINUTE AVERAGE) OVER THE EAST AND SOUTH QUADRANTS. DUE TO THE BROAD
NATURE OF THE CENTER, THERE IS MEDIUM CONFIDENCE IN THE INITIAL
POSITION. OVER THE PAST SIX HOURS, THE TRACK MOTION HAS REMAINED SLOW
TOWARD THE NORTH. A 070917Z SSMIS 37 GHZ COLOR COMPOSITE IMAGE
SUGGESTS SLIGHTLY IMPROVED CONVECTIVE STRUCTURE WITH BANDING WRAPPING
INTO A DEFINED CENTER. ENVIRONMENTAL CONDITIONS HAVE IMPROVED WITH
EXPANDING RADIAL OUTFLOW, LOW VERTICAL WIND SHEAR AND WARM SST (29C).
HOWEVER, MID-LEVEL TO UPPER-LEVEL DRY AIR ENTRAINMENT IS LIKELY
HINDERING DEVELOPMENT AT THIS TIME. THE INITIAL INTENSITY IS BASED ON
THE RECENT SMAP DATA HEDGED CLOSER TO THE RJTD CURRENT INTENSITY
ESTIMATE OF 55 KNOTS. A 070907Z RCM-2 SAR IMAGE INDICATES MAXIMUM
WINDS OF 69 KNOTS BUT APPEARS TO BE TOO HIGH.

INITIAL WIND RADII BASIS: SMAP DATA ADJUSTED WITH SURFACE
OBSERVATIONS OVER THE RYUKYU ISLANDS.

CURRENT STEERING MECHANISM: WEAK SUBTROPICAL RIDGE (STR) POSITIONED
TO THE EAST AND NORTHEAST

AGENCY DVORAK AND AUTOMATED FIXES:
PGTW: T3.0 - 45 KTS
RJTD: T3.5 - 55 KTS
RCTP: T2.5 - 35 KTS
KNES: T3.0 - 45 KTS
CIMSS SATCON: 47 KTS AT 071034Z
CIMSS ADT: 39 KTS AT 071140Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: FAVORABLE
VWS: 5-10 KTS
SST: 29-30 CELSIUS
OUTFLOW: MODERATE RADIAL
OTHER FACTORS: DRY AIR ENTRAINMENT

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

3. FORECAST REASONING.

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

FORECAST DISCUSSION: TS 06W IS DRIFTING SLOWLY POLEWARD BASED ON A
SERIES OF RECENT JMA RADAR FIXES AND IS FORECAST TO TRACK SLOWLY
NORTHWARD TO NORTH-NORTHWESTWARD OVER THE NEXT 48 HOURS WHILE
STEADILY INTENSIFYING TO 65-70 KNOTS NEAR SASEBO DUE TO IMPROVING,
ROBUST POLEWARD OUTFLOW AND WARM SST VALUES. THE SYSTEM IS FORECAST
TO GRADUALLY RE-MOISTEN, WHICH WILL ALSO AID IN THE REINTENSIFICATION
PHASE. AFTER TAU 72, TS KHANUN WILL ACCELERATE OVER THE KOREAN
PENINSULA AND BEGIN INTERACTING WITH THE LEADING EDGE OF A
SUBTROPICAL SHORTWAVE TROUGH AND WEAK BAROCLINIC ZONE. DESPITE THE
BAROCLINIC INFLUENCE, THE SYSTEM IS FORECAST TO DISSIPATE AS IT
TRACKS INTO NORTH KOREA AND NORTHEAST CHINA.

MODEL DISCUSSION: NUMERICAL GUIDANCE HAS SHIFTED FURTHER WEST OVER
THE WESTERN KOREAN PENINSULA AND WEST SEA. CONSEQUENTLY, THE JTWC
TRACK FORECAST WAS SHIFTED SLIGHTLY WEST OF THE PREVIOUS WARNING. DUE
TO THE BROAD CENTER AND UNCERTAINTY IN THE INITIAL POSITION AND TRACK
MOTION, THE JTWC TRACK FORECAST IS POSITIONED ALONG THE EASTERN EDGE
OF THE AIDS ENVELOPE CLOSE TO THE ECMWF TRACK. SEVERAL MODELS
INCLUDING GFS, UKMET AND NAVGEM TRACK THE SYSTEM NORTH-NORTHWESTWARD
OVER THE WEST SEA INTO THE UPPER LEVEL WESTERLIES, WHICH APPEARS
UNLIKELY. HOWEVER, THE 070600Z GEFS AND EPS PROBABILISTIC GUIDANCE
SHOWS INCREASING UNCERTAINTY WITH A LARGE SPREAD AFTER TAU 48.
OVERALL, THERE IS MEDIUM CONFIDENCE IN THE JTWC INTENSITY FORECAST
WITH THE 070000Z COAMPS-TC ENSEMBLE SHOWING AN 80 TO 100 PERCENT
PROBABILITY OF MODERATE INTENSIFICATION THROUGH TAU 24 DECREASING TO
40 PERCENT PROBABILITY THROUGH TAU 48.

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

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[cycloneye]

WDPN32 PGTW 080900
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 06W (KHANUN) WARNING NR
049//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
INITIAL POSITION: 29.4N 130.7E
INITIAL INTENSITY: 45 KTS
GEOGRAPHIC REFERENCE: 228 NM SOUTH-SOUTHEAST OF SASEBO, JAPAN
MOVEMENT PAST 6 HOURS: NORTH-NORTHWESTWARD AT 04 KTS
SIGNIFICANT WAVE HEIGHT: 25 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) AND ANIMATED RADAR
IMAGERY DEPICTS DEEP CONVECTIVE BANDING WRAPPING INTO A BROAD
EXPOSED CENTER. A 080418Z AMSR2 37GHZ MICROWAVE IMAGE SHOWS
TIGHTLY-CURVED DEEP CONVECTIVE BANDING WRAPPING TIGHTLY INTO A
DEFINED LOW-LEVEL CIRCULATION CENTER AND ALSO SUPPORTS THE INITIAL
POSITION. INITIAL INTENSITY IS ALSO PLACED WITH MEDIUM CONFIDENCE
BASED ON A COMBINATION OF AGENCY AND AUTOMATED DVORAK
ESTIMATES. ENVIRONMENTAL ANALYSIS INDICATES A MARGINAL ENVIRONMENT
WITH STRONG EQUATORWARD OUTFLOW, LOW VERTICAL WIND SHEAR AND WARM
SST (29C) OFFSET BY DRY AIR ENTRAINMENT.

INITIAL WIND RADII BASIS: PERSISTENCE

CURRENT STEERING MECHANISM: SUBTROPICAL RIDGE (STR) POSITIONED TO
THE EAST AND NORTHEAST.


AGENCY DVORAK AND AUTOMATED FIXES:
PGTW: T2.5 - 35 KTS
RJTD: T3.5 - 55 KTS
RCTP: T2.5 - 35 KTS
KNES: T3.0 - 45 KTS
CIMSS SATCON: 42 KTS AT 080143Z
CIMSS ADT: 32 KTS AT 080530Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: MARGINAL
VWS: 5-10 KTS
SST: 29-30 CELSIUS
OUTFLOW: STRONG EQUATORWARD

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

3. FORECAST REASONING.

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

FORECAST DISCUSSION: TS 06W IS FORECAST TO TRACK
NORTH-NORTHWESTWARD OVER THE NEXT 36 HOURS AS A SUBTROPICAL RIDGE
(STR) POSITIONED TO THE EAST AND NORTHEAST WILL TAKE OVER AS THE
PRIMARY STEERING MECHANISM, THROUGH THE REMAINDER OF THE FORECAST
PERIOD. LANDFALL IS EXPECTED TO THE WEST OF BUSAN AFTER TAU 36,
WITH THE SYSTEM RAPIDLY MOVING INTO NORTHEASTERN CHINA BY TAU 96.
IN REGARD TO INTENSITY, THE SYSTEM IT WILL MOVE OVER WARM SEA
SURFACE TEMPERATURES (SSTS), AT THE SAME TIME, OUTFLOW WILL
STEADILY IMPROVE, WITH INCREASED POLEWARD OUTFLOW, WHICH WILL
ENABLE INCREASED CONVECTION. THESE COMBINE FACTORS SHOULD ALLOW THE
SYSTEM TO INTENSITY TO A PEAK OF 55 KNOTS BY TAU 36. AFTERWARD
INTERACTION WITH THE KOREAN PENINSULA WILL LEAD TO GRADUAL
DETERIORATION TO 45 KNOTS AND THEN TO EVENTUAL DISSIPATION BY TAU
96.


MODEL DISCUSSION: NUMERICAL MODEL GUIDANCE REMAINS IN GOOD
AGREEMENT WITH A 130NM CROSS-TRACK SPREAD IN SOLUTIONS AT TAU 72
DIVERGING TO 200NM AT TAU 96. OVERALL, THERE IS MEDIUM CONFIDENCE IN
THE JTWC INTENSITY FORECAST WITH INTENSITY GUIDANCE INDICATING A BRIEF
REINTENSIFICATION THROUGH TAU 36, AFTERWARD INTENSITY GUIDANCE
SHOWS A STEADY DECREASING TREND.


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

[cycloneye]

WDPN32 PGTW 081500
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 06W (KHANUN) WARNING NR
050//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
INITIAL POSITION: 30.0N 130.4E
INITIAL INTENSITY: 50 KTS
GEOGRAPHIC REFERENCE: 189 NM SOUTH OF SASEBO, JAPAN
MOVEMENT PAST 6 HOURS: NORTH-NORTHWESTWARD AT 07 KTS
SIGNIFICANT WAVE HEIGHT: 25 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY DEPICTS DEEP
CONVECTIVE BANDING WRAPPING INTO A BROAD EXPOSED CENTER. PROXY
VISIBLE IMAGERY AND A 080926Z GMI MICROWAVE PASS SHOW MULTIPLE
CONCENTRIC BANDS AROUND THE LLCC. ENVIRONMENTAL ANALYSIS INDICATES
A MARGINAL ENVIRONMENT WITH STRONG EQUATORWARD OUTFLOW, LOW (5-10
KNOTS) VERTICAL WIND SHEAR (VWS) AND WARM (29-30C) SEA SURFACE
TEMPERATURES (SSTS) OFFSET BY DRY AIR ENTRAINMENT. THE INITIAL
INTENSITY IS ASSESSED AT 50 KTS, A BLEND BETWEEN SUBJECTIVE DVORAK
ESTIMATES OF 45 KTS FROM PGTW AND RCTP, SATCON ESTIMATES OF 48 KTS,
AND A 080915Z SAR PASS SHOWING WINDS OF 50-55 KTS IN THE
NORTHEASTERN SEMICIRCLE.

INITIAL WIND RADII BASIS: PERSISTENCE

CURRENT STEERING MECHANISM: SUBTROPICAL RIDGE (STR) POSITIONED TO
THE EAST AND NORTHEAST.

AGENCY DVORAK AND AUTOMATED FIXES:
PGTW: T3.0 - 45 KTS
RCTP: T3.0 - 45 KTS
KNES: T3.5 - 55 KTS
CIMSS SATCON: 48 KTS AT 080814Z
CIMSS ADT: 33 KTS AT 081130Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: MARGINAL
VWS: 5-10 KTS
SST: 29-30 CELSIUS
OUTFLOW: MODERATE POLEWARD AND EQUATORWARD

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: TS 06W (KHANUN) CONTINUES TO TRACK AROUND THE
WESTERN PERIPHERY OF THE SUBTROPICAL RIDGE (STR) POSITIONED TO THE
EAST AND NORTHEAST, AND WILL CONTINUE TO ACCELERATE NORTHWESTWARD
AS THE STR TAKES OVER AS THE PRIMARY STEERING MECHANISM, THROUGH
THE REMAINDER OF THE FORECAST. BY TAU 24, 06W WILL PASS TO THE WEST
OF KYUSHU BEFORE MAKING LANDFALL TO THE WEST OF BUSAN BY TAU 36.
AFTER WHICH THE SYSTEM WILL RAPIDLY MOVE NORTHWARD INTO
NORTHEASTERN CHINA BY TAU 96. IN TERMS OF INTENSITY, THE SYSTEM
WILL MOVE OVER WARM SSTS, AT THE SAME TIME, OUTFLOW WILL STEADILY
IMPROVE, WITH INCREASED POLEWARD OUTFLOW, WHICH WILL ENABLE
INCREASED CONVECTION. THESE COMBINED FACTORS SHOULD ALLOW THE SYSTEM
TO INTENSIFY TO A PEAK OF 60 KNOTS BY TAU 24. AFTER TAU 36, 06W
WILL SUCCUMB TO THE AFFECTS OF LAND INTERACTION WITH THE KOREAN
PENINSULA AND WILL DECREASE IN INTENSITY TO 30 KTS BY TAU 72. BY
TAU 96, 06W IS EXPECTED TO MOVE OVER LAND IN SOUTHERN CHINA WHERE
DISSIPATION WILL OCCUR.

MODEL DISCUSSION: TRACK GUIDANCE IS IN GOOD AGREEMENT, WITH THE
MINIMAL SPREAD THROUGH THE FORECAST PERIOD. THE JTWC REMAINS
CONSISTENT WITH THE PREVIOUS FORECAST AND LIES NEAR THE MULTI-MODEL
CONSENSUS WITH MEDIUM CONFIDENCE. INTENSITY GUIDANCE IS ALSO IN
RELATIVELY GOOD AGREEMENT, WITH THE MAJORITY OF THE GUIDANCE
SHOWING A PEAK OF 60-65 KNOTS BY TAU 24. OVERALL, THERE IS MEDIUM
CONFIDENCE IN THE JTWC INTENSITY FORECAST WITH INTENSITY GUIDANCE
INDICATING A BRIEF REINTENSIFICATION PHASE THROUGH TAU 24,
AFTERWARD INTENSITY GUIDANCE SHOWS A STEADY DECREASING TREND.


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