WPAC: KHANUN - Post-Tropical

[cycloneye]

WP, 06, 2023072712, , BEST, 0, 125N, 1384E, 25, 1003, TD

[Sciencerocks]

[cycloneye]

WP, 06, 2023072718, , BEST, 0, 133N, 1361E, 25, 1002, TD

[Hayabusa]

T2306(Khanun)
Issued at 2023/07/27 19:25 UTC
Analysis at 07/27 18 UTC
Grade TS
Scale -
Intensity -
Center position N12°20′ (12.3°)
E138°10′ (138.2°)
Direction and speed of movement WNW 15 km/h (7 kt)
Central pressure 1000 hPa
Maximum sustained wind speed near center 18 m/s (35 kt)
Maximum wind gust speed 25 m/s (50 kt)
Radius of 30-kt wind area 440 km (240 NM)
Forecast for 07/28 18 UTC
Grade TS
Intensity -
Center position of probability circle N15°30′ (15.5°)
E136°00′ (136.0°)
Direction and speed of movement NNW 20 km/h (10 kt)
Central pressure 998 hPa
Maximum sustained wind speed near center 20 m/s (40 kt)
Maximum wind gust speed 30 m/s (60 kt)
Radius of probability circle 120 km (65 NM)
Forecast for 07/29 18 UTC
Grade TS
Intensity -
Center position of probability circle N19°25′ (19.4°)
E134°40′ (134.7°)
Direction and speed of movement NNW 20 km/h (10 kt)
Central pressure 990 hPa
Maximum sustained wind speed near center 23 m/s (45 kt)
Maximum wind gust speed 35 m/s (65 kt)
Radius of probability circle 210 km (115 NM)
Forecast for 07/30 18 UTC
Grade STS
Intensity -
Center position of probability circle N24°00′ (24.0°)
E131°30′ (131.5°)
Direction and speed of movement NNW 25 km/h (14 kt)
Central pressure 980 hPa
Maximum sustained wind speed near center 30 m/s (60 kt)
Maximum wind gust speed 45 m/s (85 kt)
Radius of probability circle 260 km (140 NM)
Radius of storm warning area 330 km (180 NM)
Forecast for 07/31 18 UTC
Grade TY
Intensity -
Center position of probability circle N27°05′ (27.1°)
E126°20′ (126.3°)
Direction and speed of movement NW 25 km/h (14 kt)
Central pressure 965 hPa
Maximum sustained wind speed near center 40 m/s (75 kt)
Maximum wind gust speed 55 m/s (105 kt)
Radius of probability circle 320 km (175 NM)
Radius of storm warning area 440 km (235 NM)
Forecast for 08/01 18 UTC
Grade TY
Intensity -
Center position of probability circle N29°55′ (29.9°)
E122°05′ (122.1°)
Direction and speed of movement NW 20 km/h (12 kt)
Central pressure 955 hPa
Maximum sustained wind speed near center 40 m/s (80 kt)
Maximum wind gust speed 60 m/s (115 kt)
Radius of probability circle 330 km (180 NM)
Radius of storm warning area 470 km (255 NM)

[cycloneye]

WDPN32 PGTW 272100
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL DEPRESSION 06W (SIX) WARNING
NR 003//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
INITIAL POSITION: 13.3N 136.1E
INITIAL INTENSITY: 25 KTS
GEOGRAPHIC REFERENCE: 919 NM SOUTH-SOUTHEAST OF KADENA AB
MOVEMENT PAST 6 HOURS: WEST-NORTHWESTWARD AT 14 KTS
SIGNIFICANT WAVE HEIGHT: 18 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY VERIFIES
DEEPENING CONVECTION AND A LITTLE CONSOLIDATION OVER THE PAST SIX
HOURS. THE DEEPEST CONVECTION REMAINS TO THE SOUTH OF THE
LOW LEVEL CIRCULATION CENTER (LLCC) IN THE CONVERGENT
SOUTH WESTERLIES WHILE THE ACTUAL LLCC REMAINS EXTREMELY DIFFICULT
TO DISCERN DUE TO SLOPPY CLOUD COVER IN THE CENTER OF THE
SYSTEM. FORTUNATELY THERE WAS A DIRECT OVERHEAD SCATTEROMETRY PASS
NEAR 12Z THAT ALLOWS FOR REASONABLE CERTAINTY IN PLACEMENT ALONG A
CONSTANT BEARING AND SPEED OF ADVANCE. ANIMATED WATER VAPOR IMAGERY
SHOWS SUBSIDENCE AND 30 PLUS KNOTS OF VERTICAL WIND SHEAR (VWS)
NORTH OF THE 18TH LATITUDE BUT OVER THE SYSTEM THERE IS A NARROW
BAND OF GOOD POLEWARD OUTFLOW OVER THE NORTHEAST QUADRANT AND
EXCELLENT EQUATORWARD OUTFLOW. THE CURRENT INTENSITY IS BASED ON
THE JTWC AND KNES DVORAKS OF T1.5 AND SUPPORTED BY THE EARLIER
SCATTEROMETRY. THE SYSTEM HAS A WAYS TO GO BUT WE HAVE SEEN THE
EARLY INDICATIONS OF CONSOLIDATION VIA CONTRACTION IN THE
RADIUS OF MAXIMUM WINDS AND MORE COHERENT TURNING AROUND THE LLCC
IN THE SATELLITE ANIMATION. ANIMATED TOTAL PRECIPITABLE WATER LOOPS
AND 700-300MB MOISTURE PROFILES INDICATE A NARROW TONGUE OF DRY AIR
BEING DRAWN INTO THE NORTHWEST QUADRANT BUT OTHERWISE THE ALONG
TRACK ENVIRONMENT IS SATURATED WITH DEEP MOISTURE.

INITIAL WIND RADII BASIS: NOT APPLICABLE (THERE ARE NO INITIAL WIND
RADII).

CURRENT STEERING MECHANISM: THE SOUTHWESTERN PERIPHERY OF AN
850-500MB REFLECTION OF THE SUBTROPICAL RIDGE, WHICH IS ANCHORED
IN AN ANTICYCLONE NEAR 32N 152E.

AGENCY DVORAK AND AUTOMATED FIXES:
PGTW: T1.5 - 25 KTS
RJTD: T2.0 - 30 KTS
KNES: T1.5 - 25 KTS
CIMSS ADT: 33 KTS AT 271730Z

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

ANALYSIS CONFIDENCE:
INITIAL POSITION: LOW
INITIAL INTENSITY: MEDIUM
INITIAL WIND RADII: NOT APPLICABLE

3. FORECAST REASONING.

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

FORECAST DISCUSSION: TD 06W WILL CONTINUE ORGANIZING AND
DEEPENING ALONG A NORTHWESTERLY BEARING FOR THE NEXT 12 HOURS, THEN
SHIFT TO A MORE POLEWARD TRACK AS IT LEAVES THE INFLUENCE OF THE
SUBTROPICAL RIDGE AND GETS A NUDGE FROM THE BOTTOM VIA THE NEAR
EQUATORIAL RIDGE. A STRONG ANTICYCLONE ALOFT BUILDING OVER TOKYO
WILL EVENTUALLY BLOCK THE POLEWARD MOVEMENT AND TURN THE SYSTEM
TOWARDS THE SOUTHERN PORTION OF THE RYUKYU ISLANDS, WITH A NEAR-
DIRECT PASSAGE TO OKINAWA. ALTHOUGH RECENT MODEL RUNS INDICATE
PASSAGE NEAR OR JUST SOUTH OF THE ISLAND IT BEARS REITERATION THAT
OPERATORS SHOULD NOT FIXATE ON THE VORTEX BUT RATHER THE WIND FIELDS
AROUND IT, AS CPA ESTIMATES WILL OSCILLATE UNDER THE MOST MUNDANE
PATTERNS, AND WITH THREE DIFFERENT STEERING FORCES AND 1000 MILES TO
GO THERE WILL BE MORE THAN THE USUAL VARIATION IN CPAS. OPERATORS ARE
REMINDED TO USE THE CAC-ENABLED DECISION SUPPORT PORTAL TO SEE WIND
FIELD PROBABILITIES AND ONSET TIMES. AS TD 06W CROSSES THE TROPIC OF
CANCER AND MAKES THE DOGLEG TOWARDS THE RYUKYUS THE ENVIRONMENT WILL
BECOME EXTREMELY FAVORABLE AND THE SYSTEM WILL LIKELY TOP 100 KNOTS
AS IT TRACKS INTO THE EAST CHINA SEA.

MODEL DISCUSSION: BOTH DETERMINISTIC AND ENSEMBLE GUIDANCE HAS BEEN
TIGHTER THAN USUAL DURING THE FORMATION OF THIS STORM. TRACK
GUIDANCE IS TIGHT AND UNANIMOUS ABOUT THE TIMING AND LOCATION OF
THE DOGLEG TO THE NORTHWEST NEAR 30JUL18Z AND CROSS-TRACK SPREAD IS
FAR LESS THAN AVERAGE. INTENSITY AIDS ARE IN BETTER THAN AVERAGE
AGREEMENT AS WELL. THE JTWC FORECAST STAYS ABOVE THE PACK AND
CLOSER TO THE MESOSCALE GUIDANCE ESPECIALLY THE HHFI. THE COAMPS-TC
GUIDANCE IS ALSO TRIGGER RI INDICATORS IN THE 48-120 HR RANGE. THUS
THE JTWC TRACK FORECAST STAYS TIGHT ON THE CONSENSUS BUT THE
INTENSITY FORECAST IS MUCH HIGHER THAN THE MEAN GUIDANCE.

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

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[cycloneye]

06W SIX 230728 0000 13.1N 135.9E WPAC 30 1001

[cycloneye]

WDPN32 PGTW 280300
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL DEPRESSION 06W (KHANUN)
WARNING NR 004//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
INITIAL POSITION: 13.1N 135.9E
INITIAL INTENSITY: 30 KTS
GEOGRAPHIC REFERENCE: 924 NM SOUTH-SOUTHEAST OF KADENA AB
MOVEMENT PAST 6 HOURS: WESTWARD AT 09 KTS
SIGNIFICANT WAVE HEIGHT: 20 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) CONFIRMS TD 06W
(KHANUN) IS SLOWLY CONSOLIDATING AND ORGANIZING AROUND A LOW LEVEL
CIRCULATION CENTER (LLCC). THE LLCC SITS AT THE POLEWARD TIP OF
THE BIGGEST AND DEEPEST CONVECTIVE SHIELD, WHICH EXTENDS ALONG THE
SOUTHERN PERIPHERY OF A RELATIVELY CLOUD-FREE CENTROID. THREE
COMPLEXES OF DEEP CONVECTION ARE ROTATING AROUND THE CENTROID AND
CLOSING IN ON THE CENTROID. RECENT SCATTEROMETRY THAT COVERED THE
WESTERN SEMICIRCLE DOES NOT SHOW GALE FORCE WINDS OUTSIDE OF THE
DEEPEST CONVECTION AND SUPPORTS THE JTWC DVORAK ASSESSMENT OF T2.0.
ANIMATED WATER VAPOR IMAGERY SHOWS SUBSTANTIAL SUBSIDENCE AND
ASSOCIATED DRYING TO THE DISTANT NORTHWEST OF THE SYSTEM BUT THE
ENVIRONMENT IN THE IMMEDIATE VICINITY OF THE STORM IS RICH IN DEEP
MOISTURE. THE WATER VAPOR ALSO SHOWS THAT EQUATORWARD OUTFLOW TO THE
SOUTHWEST IS PARTICULARLY ROBUST. TOTAL PRECIPITABLE WATER LOOPS
ALSO INDICATE THAT THE SYSTEM IS COCOONING ITSELF FROM THE DRIER
POLEWARD ENVIRONMENT AND SATELLITE ANIMATION CONFIRMS THAT THE
EARLY STAGES OF CONSOLIDATION AND DEEPENING ARE UNDERWAY.

INITIAL WIND RADII BASIS: NOT APPLICABLE (THERE ARE NO INITIAL WIND
RADII).

CURRENT STEERING MECHANISM: THE SOUTHWESTERN PERIPHERY OF AN
850-500MB REFLECTION OF THE SUBTROPICAL RIDGE, WHICH IS ANCHORED IN
AN ANTICYCLONE NEAR 32N 152E.

AGENCY DVORAK AND AUTOMATED FIXES:
PGTW: T2.0 - 30 KTS
RJTD: T2.0 - 30 KTS
RCTP: T2.0 - 30 KTS
KNES: T2.0 - 30 KTS
CIMSS ADT: 35 KTS AT 272330Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: FAVORABLE
VWS: 20-25 KTS
SST: 29-30 CELSIUS
OUTFLOW: MODERATE EQUATORWARD
OTHER FACTORS: THERE IS ALSO A NARROW AND COMPRESSED BUT VIABLE
POLEWARD OUTFLOW CHANNEL OVER THE NORTHEAST QUANDRANT.

ANALYSIS CONFIDENCE:
INITIAL POSITION: MEDIUM
INITIAL INTENSITY: HIGH
INITIAL WIND RADII: NOT APPLICABLE

3. FORECAST REASONING.

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

FORECAST DISCUSSION: CONSOLIDATION AND DEEPENING OF TD 06W (KHANUN)
WILL CONTINUE AS THE SYSTEM TURNS TO A NORTHWESTERLY BEARING DURING
THE NEXT 12 HOURS. THE STEERING INFLUENCE OF AN EXTENSION OF THE
SUBROPICAL RIDGE IS WANING AND THE NEAR-EQUATORIAL RIDGE IS TAKING
OVER AS THE DOMINANT STEERING FORCE. AS THE SYSTEM CROSSES THE
TROPIC OF CANCER A STRONG ANTICYCLONE ALOFT THAT IS SETTING UP OVER
THE KANTO PLAIN REGION WILL BLOCK POLEWARD MOVEMENT AND DRIVE THE
SYSTEM TOWARDS THE SOUTHERN RYUKUS. AS THAT OCCURS IT WILL FORCE A
DOGLEG TOWARDS THE RYUKYUS AND TAKE THE SYSTEM INTO AN EXTREMELY
FAVORABLE ENVIRONMENT AND THE SYSTEM WILL LIKELY TOP 100 KNOTS
BEFORE IT TRACKS INTO THE EAST CHINA SEA. THE LATEST GUIDANCE HAS
SUBTLY SHIFTED THE TRACK TO JUST SOUTH OF OKINAWA BUT THE GUIDANCE
ENVELOPE HAS SPREAD A LITTLE. STILL, AT THIS EARLY JUNCTURE, THE
TRACK CERTAINTY IS HIGHER THAN AVERAGE. IT BEARS REPEATING THAT
OPERATORS SHOULD NOT FIXATE ON THE VORTEX BUT RATHER THE WIND
FIELDS AROUND IT, AS CPA ESTIMATES WILL OSCILLATE UNDER EVEN THE MOST
MUNDANE PATTERNS. WITH THREE DIFFERENT STEERING FORCES AND OVER
900 MILES TO THE RYUKUS SOME VARIATION IN THE CPAS IS TO BE
EXPECTED. OPERATORS ARE REMINDED TO USE THE CAC-ENABLED DECISION
SUPPORT PORTAL TO SEE WIND FIELD PROBABILITIES AND ONSET TIMES.

MODEL DISCUSSION: TRACK GUIDANCE SPREAD A LITTLE DURING THE MOST
RECENT CYCLE BUT STILL SHOWS EXCELLENT AGREEMENT AROUND A PASSAGE
NEAR OR JUST SOUTH OF OKINAWA. INTENSITY GUIDANCE SHOWS A LINEAR
INTENSIFICATION TREND AND MESOSCALE MODELS ARE SHOWING SIGNIFICANT
PROBABILITIES OF RAPID INTENSIFIATION IN THE 48 THROUGH 96 HOUR
PERIOD. THE JTWC TRACK FORECAST STAYS NEAR THE CONSENSUS WHILE THE
INTENSITY FORECAST RIDES THE HIGH SIDE OF THE GUIDANCE ENVELOPE,
FAVORING THE MESOSCALE GUIDANCE SUCH AS COAMPS-TC.

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

[Sciencerocks]

[Hayabusa]

Two large tropical cyclones at the same time

T2306(Khanun)
Issued at 2023/07/28 07:05 UTC
Analysis at 07/28 06 UTC
Grade TS
Scale Large
Intensity -
Center position N13°40′ (13.7°)
E136°10′ (136.2°)
Direction and speed of movement NW 15 km/h (8 kt)
Central pressure 998 hPa
Maximum sustained wind speed near center 18 m/s (35 kt)
Maximum wind gust speed 25 m/s (50 kt)
Radius of 30-kt wind area S650 km (350 NM)
N440 km (240 NM)

T2305(Doksuri)
Issued at 2023/07/28 06:45 UTC
Analysis at 07/28 06 UTC
Grade TY
Scale Large
Intensity -
Center position N25°10′ (25.2°)
E118°35′ (118.6°)
Direction and speed of movement N 30 km/h (15 kt)
Central pressure 975 hPa
Maximum sustained wind speed near center 35 m/s (65 kt)
Maximum wind gust speed 50 m/s (95 kt)
Radius of 50-kt wind area 110 km (60 NM)
Radius of 30-kt wind area NE650 km (350 NM)
SW500 km (270 NM)

[cycloneye]

WDPN32 PGTW 280900
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 06W (KHANUN) WARNING NR
005//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
INITIAL POSITION: 13.4N 135.9E
INITIAL INTENSITY: 35 KTS
GEOGRAPHIC REFERENCE: 908 NM SOUTH-SOUTHEAST OF KADENA AB
MOVEMENT PAST 6 HOURS: NORTHWARD AT 09 KTS
SIGNIFICANT WAVE HEIGHT: 16 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
TROPICAL STORM (TS) 06W (KHANON) REMAINS BROAD, WITH MULTIPLE
LOW-LEVEL VORTICES EVIDENT IN THE ANIMATED MULTISPECTRAL SATELLITE
IMAGERY (MSI). A 280020Z ASCAT-B PASS SHOWED THE BROAD LOW LEVEL
CIRCULATION CENTER (LLCC) DRIFTED SOUTH THE PRECEDING SIX HOURS,
AND THEN SUBSEQUENTLY HAS PERFORMED A COUNTER-CLOCKWISE LOOP AND IS
NOW TRACKING TOWARDS THE NORTH. A 280432Z AMSR2 36GHZ MICROWAVE
IMAGE SHOWED WELL-DEFINED BANDING FEATURES ARCING ACROSS THE
SOUTHERN PERIPHERY OF THE CIRCULATION, BEGINNING TO WRAP UP THE
EASTERN SIDE, WITH FRAGMENTED SHALLOW BANDING ACROSS THE NORTHERN
HEMISPHERE. THE HIGH-RESOLUTION MICROWAVE ALSO SHOWED A BROAD LOW
EMISSIVITY REGION WITH POCKETS OF ENHANCED ROTATION, PROVIDING
INCREASED CONFIDENCE IN THE ASSESSMENT OF MULTIPLE VORTICES WITHIN
THE BROAD CENTER OF ROTATION. THE PRESENCE OF THE MULTIPLE VORTICES
AND THE USAGE OF THE CENTROID METHOD PRECLUDES PLACEMENT OF THE
INITIAL POSITION WITH ANYTHING MORE THAN LOW CONFIDENCE. THE
INITIAL INTENSITY IS INCREASED TO 35 KNOTS WITH MEDIUM CONFIDENCE,
HEDGED 5 KNOTS HIGHER THAN THE AGREED UPON T2.0 DVORAK CURRENT
INTENSITY ESTIMATES FROM ALL AGENCIES, IN LIGHT OF THE OBJECTIVE FIX
INTENSITIES (ADT, AIDT, DPRINT, DMINT AND SATCON) RANGING FROM
32-42 KNOTS. THE ENVIRONMENT REMAINS MARGINALLY FAVORABLE, WITH LOW
TO MODERATE (15-20 KNOTS) NORTHERLY SHEAR AND THE DISORGANIZED
NATURE OF THE VORTEX OFFSETTING THE STRONG EQUATORWARD OUTFLOW AND
WARM SSTS.

INITIAL WIND RADII BASIS: SCATTEROMETER AND AMSR2 WINDSPEED DATA

CURRENT STEERING MECHANISM: WESTERN PERIPHERY OF A DEEP-LAYER
NEAR-EQUATORIAL RIDGE (NER) CENTERED EAST OF THE MARIANAS.

AGENCY DVORAK AND AUTOMATED FIXES:
PGTW: T2.0 - 30 KTS
RJTD: T2.0 - 30 KTS
RCTP: T2.0 - 30 KTS
KNES: T2.0 - 30 KTS
CIMSS SATCON: 42 KTS AT 280422Z
CIMSS ADT: 35 KTS AT 280530Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: MARGINALLY FAVORABLE
VWS: 15-20 KTS
SST: 29-30 CELSIUS
OUTFLOW: STRONG EQUATORWARD

ANALYSIS CONFIDENCE:
INITIAL POSITION: LOW
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 EXPECTED TO CONTINUE ON ITS SLOW AND
STEADY CONSOLIDATION TREND OVER THE NEXT 24 TO 36 HOURS AS IT
WOBBLES GENERALLY TOWARDS THE NORTH-NORTHWEST ALONG THE WEST SIDE
OF THE NER TO THE EAST. GIVEN THE UNCERTAINTIES IN THE INITIAL
POSITION, THE EXACT TRACK IS LIKELY TO SHIFT CONSIDERABLY LEFT AND
RIGHT OF THE MEAN THROUGH THE FIRST 24 TO 36 HOURS OF THE FORECAST.
UPPER-LEVEL CONDITIONS ARE MARGINALLY SUPPORTIVE AT BEST, WITH
NORTHERLY FLOW USHERING IN MODERATE SHEAR AND SOME MID-LEVEL DRY
AIR, INHIBITING AND SLOWING DEVELOPMENT OF A ROBUST CORE ON THE
NORTHERN SIDE. A WEAK TUTT-CELL IS CURRENTLY ANALYZED NEAR 24N
138E, MOVING TO THE WEST, AND HELPING TO CREATE A DEFORMATION ZONE
JUST NORTH OF TS 06W. THIS DEFORMATION ZONE IS EXPECTED TO
STRENGTHEN IN THE NEXT 24 HOURS OR SO, WHICH WILL LESSEN THE SHEAR
A BIT OVER TOP OF TS 06W. HIGH-RESOLUTION HAFS-A AND HWRF MODELS
SUGGEST THE MULTIPLE VORTICES WILL ULTIMATELY MERGE INTO ONE ROBUST
LLCC AROUND TAU 36 AND IN THE MEANTIME, THE SYSTEM WILL ONLY SLOWLY
INTENSIFY AT ROUGHLY THE CLIMATOLOGICAL RATE OF ONE T-NUMBER PER
DAY. BY TAU 36, THE TUTT-CELL WILL MOVE INTO A MORE FAVORABLE
POSITION, TO THE NORTHWEST OF TS 06W, ALLOWING FOR A DRAMATIC
INCREASE IN POLEWARD OUTFLOW, WHICH WILL SUPPORT A BURST OF RAPID
INTENSIFICATION BETWEEN TAU 48 AND TAU 72. AFTER TAU 72, THE
DEVELOPMENT OF AN ANTICYCLONE ALOFT SOUTH OF KYUSHU WILL INTRODUCE
EASTERLY SHEAR OVER TS 06W, BUT BY THIS POINT THE SYSTEM WILL
LIKELY BE STRONG ENOUGH TO COCOON ITSELF FROM THE EASTERLY SHEAR
AND IS FORECAST TO CONTINUE TO INTENSIFY A BIT PRIOR TO MAKING
LANDFALL IN THE VICINITY OF SHANGHAI BY TAU 120.

MODEL DISCUSSION: DETERMINISTIC TRACK GUIDANCE IS IN GOOD AGREEMENT
THROUGH TAU 72, THOUGH CROSS-TRACK SPREAD HAS INCREASED TO 230NM AS
THE NAVGEM HAS STARTED TO PULL AWAY FROM THE PACK TO THE EAST AND
THE ECMWF AND ECENS ENSEMBLE HAVE BEGUN TO TRACK FURTHER SOUTH AND
WEST. THE REMAINDER OF THE GUIDANCE IN TIGHTLY PACKED ABOUT THE
CONSENSUS MEAN, LENDING HIGH CONFIDENCE TO THE JTWC FORECAST TRACK
THROUGH TAU 72. AFTER TAU 72, THE GUIDANCE PACKAGE BEGINS TO
RESEMBLE A BIFURCATION, WITH THE ECMWF AND ECENS KEEPING THE STR IN
PLACE TO THE NORTH AND TRACKING THE SYSTEM INTO EASTERN CHINA
AROUND 27N. MEANWHILE THE NAVGEM, HWRF AND COAMPS-TC (NAVGEM) SHOW
THE RIDGING ERODING FROM THE WEST AHEAD OF A DEEP UPPER-LEVEL
TROUGH AND TURNING THE SYSTEM POLEWARD INTO THE EAST CHINA SEA
AROUND THE 125E LONGITUDE, GENERATING A 410NM SPREAD BY TAU 120. IN
THE LONGER TERM, BEYOND THE FORECAST, THE GFS, GEFS, EGRR AND UKMET
ENSEMBLE ALSO SHOW THE RIDGE BREAKING DOWN, ALLOWING THE SYSTEM TO
RECURVE, AND EARLY HINTS OF THIS SCENARIO ARE SHOWN IN THIS
FORECAST WITH THE TAU 120 POSITION PULLING SLIGHTLY MORE NORTH AND
EAST THAN THE PREVIOUS FORECAST. THE SUPER ENSEMBLE MEAN IS ALSO
BEGINNING TO PICK UP ON THIS SCENARIO, LENDING INCREASED CONFIDENCE
TO THE LONG-RANGE FORECAST. HOWEVER, DUE TO THE LARGE SPREAD IN THE
DETERMINISTIC TRACKERS AND THE INDIVIDUAL ENSEMBLE MEMBERS, THERE
IS MEDIUM CONFIDENCE IN THE LATER PORTION OF THE JTWC FORECAST
TRACK. INTENSITY GUIDANCE REMAINS IN GOOD AGREEMENT ON THE
INTENSIFICATION TREND, AND SIMILAR TO PREVIOUS FORECASTS, THE JTWC
FORECAST IS BELOW THE CONSENSUS THROUGH TAU 36, THEN DEVIATES FAR
ABOVE THE MEAN, BUT IS CONSISTENT WITH THE HWRF AND COAMPS-TC
ENSEMBLE PEAK, THROUGH TAU 96. CONFIDENCE IS MEDIUM DUE TO
UNCERTAINTY IN THE TIMING OF CONSOLIDATION AND THE JUMP OFF POINT
OF THE RI.

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

[cycloneye]

06W KHANUN 230728 1200 14.8N 135.4E WPAC 35 996

[cycloneye]

WDPN32 PGTW 281500
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 06W (KHANUN) WARNING NR
006//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
INITIAL POSITION: 14.8N 135.4E
INITIAL INTENSITY: 35 KTS
GEOGRAPHIC REFERENCE: 821 NM SOUTH-SOUTHEAST OF KADENA AB
MOVEMENT PAST 6 HOURS: NORTH-NORTHWESTWARD AT 13 KTS
SIGNIFICANT WAVE HEIGHT: 17 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY SHOWS THAT
TROPICAL STORM (TS) 06W (KHANUN) IS HAVING A HARD TIME
CONSOLIDATING IN THE FACE OF PERSISTENT NORTHERLY SHEAR AND MID TO
UPPER-LEVEL DRY AIR PRESSING DOWN FROM THE NORTH AND WEST. ANIMATED
SHORTWAVE INFRARED IMAGERY SHOWS THE PRIMARY LOW LEVEL VORTEX IS
NOW EXPOSED IN THE MIDDLE OF AN AREA OF DISORGANIZED CONVECTION
FLARING AROUND THE PERIPHERY OF THE BROADER CIRCULATION. A TIMELY
281116Z GPM 36GHZ MICROWAVE IMAGE PROVIDED HIGH CONFIDENCE IN THE
ASSESSMENT OF THE INITIAL POSITION AND THAT THIS VORTEX IS THE
PRIMARY ONE. THE INITIAL INTENSITY REMAINS SET AT 35 KNOTS, AT THE
HIGHER END OF THE AGENCY DVORAK INTENSITY ESTIMATES AND IN LINE
WITH THE OBJECTIVE ESTIMATES RANGING FROM 32-41 KNOTS. THE LATEST
CIMSS TOTAL PRECIPITABLE WATER (TPW) DATA SUGGESTS THE SYSTEM IS
COCOONED IN A VERY MOIST ENVIRONMENT, BUT THE HIGH-RESOLUTION
HAFS-A AND HWRF AS WELL AS THE GFS AND ECMWF GLOBAL MODEL FIELDS
PLUS THE CIMSS UPPER-LEVEL ANALYSIS, REVEAL A WEDGE OF VERY DRY,
CONVERGENT AIR IN THE MID TO UPPER-LEVELS TO THE NORTHWEST OF THE
SYSTEM. THIS, ALONG WITH THE CONTINUED NORTHERLY PRESSURE IS
OFFSETTING THE STRONG EQUATORWARD OUTFLOW AND SUPPORTIVE SSTS AND
PRECLUDING HINDERING THE LOW-LEVEL CONSOLIDATION AND
INTENSIFICATION.

INITIAL WIND RADII BASIS: PERSISTENCE

CURRENT STEERING MECHANISM: WESTERN PERIPHERY OF A DEEP-LAYER NEAR
EQUATORIAL RIDGE (NER) CENTERED EAST OF GUAM.

AGENCY DVORAK AND AUTOMATED FIXES:
PGTW: T2.5 - 35 KTS
RJTD: T2.0 - 30 KTS
RCTP: T2.5 - 35 KTS
KNES: T2.0 - 30 KTS
CIMSS ADT: 32 KTS AT 281130Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: MARGINALLY FAVORABLE
VWS: 15-20 KTS
SST: 29-30 CELSIUS
OUTFLOW: STRONG EQUATORWARD
OTHER FACTORS: MID TO UPPER-LEVEL DRY AIR IN THE NORTH-NORTHWEST
QUADRANT OF THE CIRCULATION.

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: THROUGH THE FIRST 36 HOURS OF THE FORECAST, TS
06W IS EXPECTED TO TRACK GENERALLY TOWARDS THE NORTH-NORTHWEST
ALONG THE PERIPHERY OF THE NER TO THE EAST. SHORT-TERM WOBBLES AND
EXCURSIONS LEFT AND RIGHT OF THE FORECAST TRACK ARE TO BE
ANTICIPATED AS THE VORTEX STRUCTURE CONTINUES TO CONSOLIDATE BUT
THE OVERALL TRACK MADE GOOD WILL BE TOWARDS THE NORTH-NORTHWEST. BY
TAU 36 THE STEERING PATTERN WILL BEGIN TO SHIFT, AS THE NER SLIDES
TOWARDS THE SOUTHWEST, HANDING THE BATON TO THE STRONG SUBTROPICAL
RIDGE (STR) LYING ON AN EAST-WEST AXIS FROM TOKYO TO SEOUL AND INTO
NORTHERN CHINA. BY TAU 72, THE STR BECOMES THE PRIMARY STEERING
INFLUENCE AND TS 06W WILL TURN ONTO A MORE WEST-NORTHWEST TRACK
THROUGH THE REMAINDER OF THE FORECAST. TRACK SPEEDS ARE EXPECTED TO
SLOW AS THE SYSTEM PASSES OKINAWA AS THE RIDGE TO THE NORTH WEAKENS
AND THE SYSTEM MOVES INTO A WEAKER STEERING ENVIRONMENT. A VERY
CLOSE PASSAGE TO OKINAWA IS EXPECTED BY TAU 72 WITH A LANDFALL IN
THE VICINITY OF SHANGHAI FORECAST BY TAU 120. IN TERMS OF
INTENSITY, THE SLOW PACE OF INTENSIFICATION IS EXPECTED TO CONTINUE
FOR THE NEXT 36 TO 48 HOURS, AS THE WEDGE OF DRY MID AND
UPPER-LEVEL AIR IS FORECAST TO PENETRATE FURTHER INTO THE
CIRCULATION ON THE WESTERN SIDE, OFFSETTING IMPROVED POLEWARD
OUTFLOW INTO A TUTT-CELL WHICH KICKS OFF AROUND TAU 18. ALL GLOBAL
AND MESOSCALE MODELS AGREE THAT BY TAU 48 THE DRY AIR IS PUSHED
ASIDE, AND COINCIDES WITH BOTH THE CONSOLIDATION OF THE LOW-LEVEL
CORE AND THE PEAK IN THE POLEWARD OUTFLOW. THIS CONGRUENCE OF
IMPROVED ENVIRONMENTAL PARAMETERS WILL ALLOW FOR A BURST OF RAPID
INTENSIFICATION BETWEEN TAU 48 AND TAU 72, WITH THE INTENSITY
FORECAST TO INCREASE FROM 60 TO 100 KNOTS WITHIN THIS 24 HOUR
PERIOD. BY TAU 72, THE DEVELOPMENT OF AN UPPER-LEVEL ANTICYCLONE
JUST NORTH OF THE SYSTEM WILL INTRODUCE EASTERLY CONVERGENT FLOW
AROUND THE SYSTEM, BUT THE SYSTEM IS EXPECTED TO BE STRONG ENOUGH
BY THAT TIME TO PUT UP A GOOD FIGHT AGAINST THIS MALIGN INFLUENCE,
AND IS FORECAST TO CONTINUE TO STRENGTHEN SLIGHTLY PRIOR TO
LANDFALL IN EASTERN CHINA. AFTER SLOWLY MOVING ASHORE SOUTH OF
SHANGHAI, THE SYSTEM WILL RAPIDLY WEAKEN DUE TO TERRAIN EFFECTS AND
INCREASED SHEAR.

MODEL DISCUSSION: DETERMINISTIC TRACK GUIDANCE IS IN VERY TIGHT
AGREEMENT, WITH THE CONSENSUS MEMBERS CONSTRAINED TO A 150NM
ENVELOPE AT TAU 72. THE ECMWF, WHILE STILL DEPICTED A FLATTER
TRAJECTORY PATH, HAS SHIFTED POLEWARD WITH THIS RUN AND HAS CLOSED
THE GAP BETWEEN IT AND THE CONSENSUS MEAN A CONSIDERABLE AMOUNT.
THE REMAINDER OF THE GUIDANCE PACKAGE IS CONTAINED IN A VERY TIGHT
ENVELOPE CENTERED ON OKINAWA. SPREAD GRADUALLY INCREASES TO 245NM
BY TAU 120, WITH ALL BUT THE ECMWF BEGINNING TO TURN POLEWARD BY
THIS POINT. ENSEMBLE MEANS HAVE ALSO CONGEALED, AND NOW ARE TIGHTLY
CLUSTERED AROUND THE CONSENSUS MEAN. IN LIGHT OF THIS, CONFIDENCE
IS HIGH IN THE TRACK FORECAST THROUGH TAU 72, DECREASING TO MEDIUM
IN THE LONG-TERM FORECAST. INTENSITY GUIDANCE IS MIXED, WITH THE
GLOBAL MODEL-BASED GUIDANCE SUCH AS SHIPS INDICATING A STEADILY AND
RATHER QUICKLY INTENSIFYING SYSTEM THAT PEAKS AT TAU 72 AT JUST
75-80 KNOTS. MEANWHILE THE COAMPS-TC BASED CTR1 AID, ALONG WITH THE
COAMPS-TC (GFS VERSION), ALONG WITH SEVERAL RI AIDS, INDICATE RI
STARTING NOW, CONTINUING THROUGH TAU 48 TO TAU 60, WITH A PEAK OF
105 KNOTS. THE JTWC IS A BLEND OF THESE TWO EXTREMES, INTENSIFYING
THE SYSTEM AT A SLOWER PACE THAN THE CONSENSUS THROUGH TAU 48, THEN
JUMPING UP TO MEET THE RI AIDS AT THE PEAK AT TAU 72. IN LIGHT OF
THE HIGH UNCERTAINTY IN THE GUIDANCE, CONFIDENCE IN THE INTENSITY
FORECAST IS MEDIUM TO TAU 72, AND LOW THEREAFTER.

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

[Sciencerocks]

[cycloneye]

WDPN32 PGTW 282100
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 06W (KHANUN) WARNING NR
007//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
INITIAL POSITION: 15.6N 134.6E
INITIAL INTENSITY: 35 KTS
GEOGRAPHIC REFERENCE: 756 NM SOUTH-SOUTHEAST OF KADENA AB,
OKINAWA, JAPAN
MOVEMENT PAST 6 HOURS: NORTHWESTWARD AT 11 KTS
SIGNIFICANT WAVE HEIGHT: 15 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY SHOWS A POORLY
ORGANIZED MEDIUM-SIZED SYSTEM WITH CONVECTION CONCENTRATED
SOUTHWARD OF A BROAD AND PARTIALLY EXPOSED LOW LEVEL CIRCULATION
(LLC). THE INITIAL POSITION IS PLACED WITH MEDIUM CONFIDENCE BASED
ON THE PARTLY EXPOSED LLC. THE INITIAL INTENSITY OF 35 KTS IS BASED
ON THE UNANIMOUS DVORAK ESTIMATES FROM PGTW, KNES, AND RJTD, AND
REFLECTS THE 6-HR SUSTAINED EIR STRUCTURE. ANALYSIS INDICATES A
MARGINALLY FAVORABLE ENVIRONMENT WITH WARM SSTS IN THE PHILIPPINE
SEA AND STRONG POLEWARD OUTFLOW ALOFT OFFSET BY MODERATE VWS AND
SUBSIDENCE ALONG THE NORTHWEST QUADRANT DUE TO PRESSURE FROM THE
SUBTROPICAL HIGH TO THE NORTHWEST.

INITIAL WIND RADII BASIS: PERSISTENCE.

CURRENT STEERING MECHANISM: WESTERN PERIPHERY OF A DEEP-LAYER NEAR
EQUATORIAL RIDGE (NER) CENTERED EAST OF GUAM.

AGENCY DVORAK AND AUTOMATED FIXES:
PGTW: T2.5 - 35 KTS
RCTP: T2.5 - 35 KTS
KNES: T2.5 - 35 KTS
CIMSS D-PRINT: 36 KTS AT 281700Z
CIMSS D-MINT: 35 KTS AT 281646Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: MARGINALLY FAVORABLE
VWS: 15-20 KTS
SST: 29-30 CELSIUS
OUTFLOW: STRONG EQUATORWARD
OTHER FACTORS: SUBSIDENCE ALONG THE NORTHWEST QUADRANT.


ANALYSIS CONFIDENCE:
INITIAL POSITION: MEDIUM
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 KHANUN WILL CONTINUE ON A
NORTH-NORTHWESTWARD TRACK UNDER THE STEERING INFLUENCE OF THE NER
EAST OF GUAM. AFTER TAU 48, A SUBTROPICAL RIDGE (STR) TO THE
NORTHEAST WILL ASSUME STEERING AND DRIVE THE SYSTEM ON A MORE
NORTHWESTWARD TRAJECTORY TOWARD OKINAWA, PASSING JUST WEST OF THE
ISLAND BEFORE TAU 72 PRIOR TO DRIFTING INTO THE EAST CHINA SEA AND
MAKING LANDFALL SOUTH OF SHANGHAI AROUND TAU 108. THE MARGINALLY
FAVORABLE ENVIRONMENT WILL FUEL A SLOW INTENSIFICATION TO 60KTS BY
TAU 36. AFTERWARD, INCREASING POLEWARD OUTFLOW AS THE STEERING
MECHANISM SWITCHES TO THE STR WILL PROMOTE SIGNIFICANT
INTENSIFICATION TO A PEAK OF 90KTS BY TAU 72. AFTER TAU 72, A
BUILDING STR TO THE NORTH WILL ONCE AGAIN PROMOTE SUBSIDENCE
LEADING TO GRADUAL DISSIPATION TO 80 KTS PRIOR TO LANDFALL. AFTER
LANDFALL, INTERACTION WITH THE RUGGED CHINESE INTERIOR WILL MOSTLY
BE RESPONSIBLE FOR THE RAPID EROSION, AND BY TAU 120, TC 06W WILL
BE REDUCED TO 55KTS, POSSIBLY WEAKER, AS IT TRACKS FURTHER INLAND.

MODEL DISCUSSION: NUMERICAL MODELS ARE IN VERY GOOD AGREEMENT WITH
A GRADUAL SPREAD TO A MERE 185NM BY TAU 72 THEN TO 516 NM BY TAU
120 WITH UKMET THE NOTABLE LEFT-OF-TRACK OUTLIER. IN VIEW OF THIS,
THERE IS HIGH CONFIDENCE IN THE JTWC FORECAST TRACK UP TO TAU 72
THEN MEDIUM CONFIDENCE AFTERWARD.

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

[cycloneye]

06W KHANUN 230729 0000 16.8N 133.7E WPAC 40 996

[cycloneye]

WDPN32 PGTW 290300
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 06W (KHANUN) WARNING NR
008//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
INITIAL POSITION: 16.8N 133.7E
INITIAL INTENSITY: 40 KTS
GEOGRAPHIC REFERENCE: 668 NM SOUTH-SOUTHEAST OF KADENA AB,
OKINAWA, JAPAN
MOVEMENT PAST 6 HOURS: NORTHWESTWARD AT 15 KTS
SIGNIFICANT WAVE HEIGHT: 16 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) SHOWS A POORLY
ORGANIZED MEDIUM-SIZED SYSTEM WITH CONVECTION CONCENTRATED
SOUTHWARD OF A BROAD AND PARTIALLY EXPOSED LOW LEVEL CIRCULATION
(LLC). THE NORTHWEST QUADRANT IS VOID OF ANY DEEP CONVECTION AND
THE MSI LOOP SHOWS COLD DRY AIR STRATOCUMULUS LINES FEEDING INTO
THE LLC. THE INITIAL POSITION IS PLACED WITH MEDIUM CONFIDENCE
BASED ON THE PARTLY EXPOSED LLC AND LINED UP WITH A MICROWAVE LLC
IN THE 282240Z GPM 37GHZ AND 89GHZ IMAGE. THE INITIAL INTENSITY OF 40
KTS IS ALSO PLACED AT WITH MEDIUM CONFIDENCE BASED ON THE
ASSESSMENT OF THE 282117Z SMAP DATA AND SUPPORTED BY CIMSS SATCON
DVORAK ESTIMATE OF 42KTS AND REFLECTS THE SLIGHT 6-HR IMPROVEMENT.
ANALYSIS INDICATES A MARGINALLY FAVORABLE ENVIRONMENT WITH WARM SST
IN THE PHILIPPINE SEA, LOW VWS, AND STRONG POLEWARD OUTFLOW ALOFT
OFFSET BY UPPER LEVEL SUBSIDENCE ALONG THE NORTHWEST QUADRANT DUE
TO PRESSURE FROM THE SUBTROPICAL HIGH TO THE NORTHWEST AND THE
INFLUX OF COLD DRY AIR AT THE LOW LEVELS.

INITIAL WIND RADII BASIS: SMAP DATA.

CURRENT STEERING MECHANISM: WESTERN PERIPHERY OF A DEEP-LAYER NEAR
EQUATORIAL RIDGE (NER) CENTERED EAST OF GUAM.

AGENCY DVORAK AND AUTOMATED FIXES:
PGTW: T2.5 - 35 KTS
RJTD: T2.0 - 30 KTS
RCTP: T2.5 - 35 KTS
KNES: T2.5 - 35 KTS
CIMSS SATCON: 42 KTS AT 282214Z
CIMSS ADT: 33 KTS AT 282330Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: MARGINALLY FAVORABLE
VWS: 10-15 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 KHANUN WILL CONTINUE ON A
NORTH-NORTHWESTWARD TRACK UNDER THE STEERING INFLUENCE OF THE NER
EAST OF GUAM. AFTER TAU 36, A SUBTROPICAL RIDGE (STR) TO THE
NORTHEAST WILL ASSUME STEERING AND DRIVE THE SYSTEM ON A MORE
NORTHWESTWARD TRAJECTORY TOWARD OKINAWA, PASSING JUST WEST OF THE
ISLAND AROUND TAU 60 PRIOR TO DRIFTING INTO THE EAST CHINA SEA AND

MAKING LANDFALL SOUTH OF SHANGHAI AROUND TAU 96. THE MARGINALLY
FAVORABLE ENVIRONMENT WILL FUEL A SLOW INTENSIFICATION TO 65KTS BY

TAU 36. AFTERWARD, INCREASING POLEWARD OUTFLOW AS THE STEERING
MECHANISM SWITCHES TO THE STR WILL PROMOTE SIGNIFICANT A MORE
GRADUAL TO A PEAK OF 85KTS BY TAU 72. AFTER TAU 72, A BUILDING STR
TO THE NORTH WILL ONCE AGAIN PROMOTE SUBSIDENCE LEADING TO GRADUAL
WEAKENING TO 70 KTS AT LANDFALL. AFTER LANDFALL, INTERACTION WITH
THE RUGGED CHINESE INTERIOR WILL MOSTLY BE RESPONSIBLE FOR THE
RAPID EROSION, AND BY TAU 120, TC 06W WILL BE REDUCED TO 45KTS,
POSSIBLY WEAKER, AS IT TRACKS FURTHER INLAND.

MODEL DISCUSSION: NUMERICAL MODELS ARE IN VERY GOOD AGREEMENT WITH
A GRADUAL SPREAD TO A MERE 190NM BY TAU 72 THEN TO 486 NM BY TAU
120 WITH UKMET THE NOTABLE LEFT-OF-TRACK OUTLIER. IN VIEW OF THIS,
THERE IS HIGH CONFIDENCE IN THE JTWC FORECAST TRACK THAT IS LAID
JUST TO THE RIGHT OF THE MODEL CONSENSUS TO OFFSET UKMET UP TO TAU
72 THEN MEDIUM CONFIDENCE AFTERWARD.

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

[ElectricStorm]

Really struggling right now. Forecasted peak down to 85kts. Was 115kts on the first few advisories

[dexterlabio]

^might be too early to say especially when it's currently building convection at the center

[Sciencerocks]