WPAC: LAN - Post-Tropical

[Sciencerocks]

 https://twitter.com/zoom_earth/status/1690492178773016576

[cycloneye]

WDPN31 PGTW 130900
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TYPHOON 07W (LAN) WARNING NR 023//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
INITIAL POSITION: 30.2N 138.9E
INITIAL INTENSITY: 70 KTS
GEOGRAPHIC REFERENCE: 255 NM NORTHWEST OF CHICHI JIMA
MOVEMENT PAST 6 HOURS: NORTHWESTWARD AT 07 KTS
SIGNIFICANT WAVE HEIGHT: 30 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) DEPICTS A LARGE
TYPHOON STRENGTH CIRCULATION, WITH A ROUGHLY 76NM QUASI-EYE FEATURE
IN THE CENTER WHERE THE CORE CONVECTION HAS COLLAPSED. A RECENT
130556Z SSMIS 89GHZ COLOR COMPOSITE MICROWAVE IMAGE SHOWS A THIN
FRAMEWORK OF DEEP CONVECTION COMPRISING THE EYE WALL AND FRAIL
BANDING FEATURES. THE INITIAL POSITION IS PLACED WITH HIGH
CONFIDENCE BASED ON MSI AND SSMIS IMAGERY. THE INITIAL INTENSITY OF
70 KTS IS ASSESSED WITH MEDIUM CONFIDENCE BASED ON AGENCY DVORAK
AND AUTOMATED FIXES GENERALLY INDICATING 70-75 KTS WITH A FEW
OUTLIERS TOWARDS 80KTS SUCH AS CIMSS SATCON AND ADT.

INITIAL WIND RADII BASIS: PERSISTENCE

CURRENT STEERING MECHANISM: SUBTROPICAL RIDGE TO THE NORTHEAST

AGENCY DVORAK AND AUTOMATED FIXES:
PGTW: T4.0 - 65 KTS
RJTD: T4.5 - 77 KTS
RCTP: T4.5 - 77 KTS
KNES: T4.5 - 77 KTS
CIMSS SATCON: 80 KTS AT 130034Z
CIMSS ADT: 84 KTS AT 130540Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: MARGINALLY FAVORABLE
VWS: 0-5 KTS
SST: 28-29 CELSIUS
OUTFLOW: MODERATE RADIAL

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

3. FORECAST REASONING.

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

FORECAST DISCUSSION: TYPHOON 07W (LAN) IS FORECAST TO CONTINUE
TRACKING GENERALLY NORTHWESTWARD OVER THE NEXT 36 HOURS. DURING
THAT TIME, IMPROVING OCEAN HEAT CONTENT AND LOW VERTICAL WIND SHEAR
MAY FUEL MARGINAL INTENSIFICATION AS THE SYSTEM APPROACHES JAPAN.
JUST AFTER TAU 36 AND THROUGH TAU 48, 07W WILL CROSS THE ISLAND OF
HONSHU AND QUICKLY EXIT INTO THE SEA OF JAPAN. AS THE SYSTEM ROUNDS
THE STR AXIS, TRACK SPEEDS WILL GREATLY INCREASE AS THE SYSTEM IS
DIRECTED NORTHEASTWARD. BY TAU 72, THE SYSTEM WILL BEGIN TO
INTERACT WITH AN UPPER-LEVEL TROUGH OVER NORTHEASTERN CHINA AND A
COOLER AIR MASS, WHICH IS EXPECTED TO INITIATE EXTRATROPICAL
TRANSITION (ETT). THIS ETT IS ANTICIPATED TO COMPLETE BY TAU 120 AS
THE LAST ELEMENTS OF A WARM CORE TROPICAL CYCLONE ARE LOST.

MODEL DISCUSSION: NUMERICAL MODELS ARE IN GOOD AGREEMENT THROUGH
TAU 72 WITH MINIMAL CROSS TRACK SPREADING. AS THE TIMING AND EXTENT
OF THE NORTHEASTWARD TURN VARIES AMONGST THE MEMBERS, THE CONSENSUS
BEYOND TAU 72 IS NOT AS TIGHT. FOR THIS REASON THE JTWC TRACK
FORECAST IS PLACED INITIALLY WITH HIGH CONFIDENCE AND WITH MEDIUM
CONFIDENCE THEREAFTER. RELIABLE MODEL INTENSITY GUIDANCE IS IN FAIR
AGREEMENT WITH ALL MEMBERS GENERALLY FOLLOWING THE MULTI-MODEL
CONSENSUS THROUGH THE FORECAST PERIOD. FOR THIS REASON THE JTWC
INTENSITY FORECAST IS PLACED WITH OVERALL MEDIUM CONFIDENCE.

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

[cycloneye]

WDPN31 PGTW 131500
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TYPHOON 07W (LAN) WARNING NR 024//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
INITIAL POSITION: 30.7N 138.5E
INITIAL INTENSITY: 75 KTS
GEOGRAPHIC REFERENCE: 283 NM SOUTH-SOUTHWEST OF YOKOSUKA, JAPAN
MOVEMENT PAST 6 HOURS: NORTHWESTWARD AT 06 KTS
SIGNIFICANT WAVE HEIGHT: 35 FEET

SATELLITE ANALYSIS, INITIAL POSITION, AND INTENSITY DISCUSSION:
ANIMATED ENHANCED INFRARED SATELLITE IMAGERY (GOES H-8 PROXY VIS)
SHOWS A MEDIUM-SIZED SYMMETRICAL CYCLONE THAT HAS MOSTLY MAINTAINED
ITS OVERALL CONVECTIVE AND WRAP STRUCTURE WITH A LARGE 60X40-NM
BANDING EYE, EXPOSING A RAGGED BUT DEFINED LOW LEVEL CIRCULATION
CENTER (LLCC). THE INITIAL POSITION IS PLACED WITH HIGH CONFIDENCE
BASED ON THE EXPOSED LLCC FEATURE. THE INITIAL INTENSITY OF 75KTS
IS ALSO PLACED WITH HIGH CONFIDENCE BASED ON A 130851Z SAR PASS,
SUPPORTED BY AGENCY DVORAK ESTIMATES, AND REFLECTS THE MOSTLY
SUSTAINED STRUCTURE. ANALYSIS INDICATES A MARGINALLY FAVORABLE
ENVIRONMENT WITH LOW VWS AND MODERATE OUTFLOW OFFSET BY LOCALIZED
LOW SST AND OHC VALUES DUE TO OCEANIC UPWELLING AND DRY AIR
INTRUSION.

INITIAL WIND RADII BASIS: SAR DATA.

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


AGENCY DVORAK AND AUTOMATED FIXES:
PGTW: T4.0 - 65 KTS
RJTD: T4.5 - 77 KTS
RCTP: T4.0 - 65 KTS
KNES: T4.5 - 77 KTS
CIMSS SATCON: 81 KTS AT 131149Z
CIMSS ADT: 90 KTS AT 131140Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: MARGINALLY FAVORABLE
VWS: 0-5 KTS
SST: 28-29 CELSIUS
OUTFLOW: MODERATE EQUATORWARD

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: TYPHOON LAN WILL CONTINUE ON ITS CURRENT TRACK
TOWARD CENTRAL HONSHU, JAPAN, MAKING LANDFALL JUST BEFORE TAU 36
NEAR WAKAYAMA PREFECTURE. AFTERWARD, IT WILL TRACK MORE NORTHWARD
AS THE STR RECEDES IN RESPONSE TO A MID-LATITUDE TROUGH APPROACHING
FROM THE NORTHWEST, EXIT INTO THE SEA OF JAPAN (SOJ), CREST THE STR
AXIS BY TAU 60, THEN ACCELERATE NORTHEASTWARD ON THE POLEWARD SIDE
OF THE STR, CLIPPING THE NORTHERN TIP OF HOKKAIDO JUST BEFORE TAU
120. THE MARGINALLY FAVORABLE ENVIRONMENT WILL PROMOTE A MODEST
INTENSIFICATION TO A PEAK OF 80KTS AT TAUS 12-24; AFTERWARD,
INCREASING VWS, DRY AIR INTRUSION, THEN LAND INTERACTION WILL REDUCE
IT TO 50KTS BY TAU 48. DESPITE THE RELATIVELY WARM SST IN THE SOJ,
INCREASING VWS, THEN INTERACTION WITH THE BAROCLINIC ZONE AS TY 07W
BEGINS EXTRA-TROPICAL TRANSITION AROUND TAU 72 WILL GRADUALLY ERODE IT
TO A 45-KT COLD CORE LOW BY TAU 120.

MODEL DISCUSSION: NUMERICAL MODELS ARE IN VERY GOOD AGREEMENT WITH
A GRADUAL AND EVEN SPREAD TO JUST 140NM BY TAU 72, LENDING HIGH
CONFIDENCE TO THIS PORTION OF THE JTWC TRACK FORECAST. AFTERWARD,
THE MODELS REMAIN FAIRLY TIGHT BUT DUE TO THE UNCERTAINTIES INHERENT
WITH EXTRA-TROPICAL TRANSITION THERE IS ONLY MEDIUM CONFIDENCE IN
THE EXTENDED PORTION OF THE TRACK FORECAST. THERE IS MEDIUM
CONFIDENCE IN THE JTWC INTENSITY FORECAST UP TO TAU 72 THEN LOW
AFTERWARD FOR THE SAME REASON.

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]

WDPN31 PGTW 132100
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TYPHOON 07W (LAN) WARNING NR 025//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
INITIAL POSITION: 31.2N 138.1E
INITIAL INTENSITY: 80 KTS
GEOGRAPHIC REFERENCE: 283 NM SOUTH-SOUTHWEST OF YOKOSUKA, JAPAN
MOVEMENT PAST 6 HOURS: NORTHWESTWARD AT 06 KTS
SIGNIFICANT WAVE HEIGHT: 36 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED ENHANCED INFRARED SATELLITE IMAGERY (HM9 CIRA PROXY VIS)
SHOWS AN ENVIRONMENTALLY CONSTRAINED TROPICAL CYCLONE WITH FAIRLY
SYMMETRICAL NARROW BANDING WRAPPING INTO A RAGGED, ELLIPTICAL EYE
(SEMI MAJOR AXIS OF APPROX 55NM). THE CIRRUS CANOPY HAS EXPANDED
GREATLY OVER THE PAST 6 HOURS, INCREASING FROM APPROX 265NM TO 365NM.
DEEP FLARING CONVECTION IS MOST CONCENTRATED IN THE FRONT RIGHT
QUADRANT BUT IS PRESENT AROUND THE ENTIRE CIRCULATION. SSTS (27-29
DEGREES CELSIUS) AND OCEAN HEAT CONTENT REMAIN MARGINAL. THE INITIAL
POSITION IS PLACED WITH HIGH CONFIDENCE BASED ON A 131800Z HM9 IR BD
IMAGE. THE INITIAL INTENSITY OF 80KTS IS PLACED WITH MEDIUM
CONFIDENCE BASED ON GROWTH OF THE CIRRUS CANOPY AND IS SUPPORTED BY
AGENCY DVORAK ESTIMATES (AVG 4.5). ANALYSIS INDICATES A MARGINALLY
FAVORABLE ENVIRONMENT WITH LOW VWS AND MODERATE OUTFLOW OFFSET BY
LOCALIZED LOW SST AND OHC VALUES DUE TO UPWELLING ASSOCIATED WITH THE
SLOWER STORM SPEED AS WELL AS DRY AIR WRAPPING INTO THE CIRCULATION
FROM THE OUTERMOST WESTERN PERIPHERY.

INITIAL WIND RADII BASIS: PERSISTENCE

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

AGENCY DVORAK AND AUTOMATED FIXES:
PGTW: T4.0 - 65 KTS
RJTD: T4.5 - 77 KTS
RCTP: T4.5 - 77 KTS
KNES: T4.5 - 77 KTS
CIMSS ADT: 92 KTS AT 131430Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: MARGINALLY FAVORABLE
VWS: 0-5 KTS
SST: 27-29 CELSIUS
OUTFLOW: MODERATE POLEWARD

ANALYSIS CONFIDENCE:
INITIAL POSITION: HIGH
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: TYPHOON LAN WILL CONTINUE ON ITS CURRENT TRACK
TOWARD CENTRAL HONSHU, JAPAN, MAKING LANDFALL BETWEEN TAU 24 AND
TAU 36. DURING THIS PERIOD, SLIGHT INTENSIFICATION MAY OCCUR AS THE
SYSTEM BEGINS TO PICK UP SPEED, MOVING AWAY FROM UPWELLED SEAS AND
ROUNDING THE AXIS OF THE STR POSITIONED TO THE NORTHEAST. A WEAKENING
PHASE IS EXPECTED AS THE SYSTEM TRACKS OVER CENTRAL JAPAN AND THE
KYOTO REGION AND UNDERGOES THE EFFECTS OF LAND INTERACTION THROUGH
TAU 48, AFTER WHICH THE SYSTEM IS FORECAST TO RETURNS OVER WATER IN
THE SEA OF JAPAN AT TROPICAL STORM INTENSITY. AFTER TAU 48, THE
SYSTEM WILL CONTINUE TO TRACK NORTHEASTWARD AROUND THE RIDGING TO THE
EAST AND DRAMATICALLY ACCELERATE TOWARD THE NORTHEAST DUE TO A DEEP,
SHARP MIDLATITUDE TROUGH THAT IS EXPECTED TO DIG TO THE WEST. THE
SYSTEM IS ANTICIPATED TO COMPLETE EXTRATROPICAL TRANSITION BETWEEN
TAU 96 AND TAU 120, STARTING THE TRANSITION AS EARLY AS TAU 72.

MODEL DISCUSSION: WITH THE EXCEPTION OF NAVGEM, NUMERICAL MODELS
ARE IN VERY GOOD AGREEMENT WITH CROSS-TRACK ERROR OF 24NM AT
LANDFALL AND 113NM AT TAU 72, LENDING HIGH CONFIDENCE TO THIS
PORTION OF THE JTWC TRACK FORECAST. DUE TO THE UNCERTAINTIES
INHERENT WITH EXTRATROPICAL TRANSITION AND MID-LATTIUDE TROUGH
VARIABILITY TO THE WEST, THERE IS MEDIUM CONFIDENCE IN THE EXTENDED
PORTION OF THE TRACK FORECAST.

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

[Sciencerocks]

 https://twitter.com/zoom_earth/status/1690806274642890752

[Sciencerocks]

 https://twitter.com/VortixWx/status/1690891035788926976

[Sciencerocks]

[cycloneye]

DPN31 PGTW 140300
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TYPHOON 07W (LAN) WARNING NR 026//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
INITIAL POSITION: 31.8N 137.5E
INITIAL INTENSITY: 85 KTS
GEOGRAPHIC REFERENCE: 237 NM SOUTH-SOUTHWEST OF YOKOSUKA, JAPAN
MOVEMENT PAST 6 HOURS: NORTHWESTWARD AT 08 KTS
SIGNIFICANT WAVE HEIGHT: 37 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED ENHANCED INFRARED SATELLITE IMAGERY (HM9 CIRA PROXY VIS)
SHOWS TYPHOON (TY) LAN'S RAGGED EYE TIGHTENING OVER TIME, CONTRACTING
FROM A 55NM DIAMETER TO 35NM IN JUST SIX HOURS. THE CONVECTIVE
CANOPY APPEARS TO HAVE INCREASED IN DEPTH (COOLER CLOUD TOPS ON HM9
IR-BD IMAGERY) AND EXPANDED RADIALLY FROM THE CORE, OBSCURING THE
PREVIOUSLY OBSERVED FLARING CONVECTIVE CELLS. STRONG POLEWARD OUTFLOW
IS EVIDENT IN THE CIRRUS LAYER, WITH OUTFLOW RESTRICTED ELSEWHERE.
GOES-H9 ANIMATED WATER VAPOR IMAGERY DEPICTS DRY AIR ALONG THE ENTIRE
WESTERN PERIPHERY OF THE CIRCULATION, WHICH IS CORROBORATED BY
SUBSTANTIAL CLEARING ON PROXYVIS TO THE WEST AND SOUTH OF THE STORM.
THE SYSTEM REMAINS SYMMETRIC IN APPEARANCE WITH NARROW BANDING
WRAPPING INTO THE LLCC OBSCURED BY THE DEEP CONVECTIVE TOPS. SSTS ARE
ASSESSED TO BE 28-29 DEGREES CELSIUS. THE INITIAL POSITION IS PLACED
WITH HIGH CONFIDENCE BASED ON A 140000Z RJTD RADAR FIX AND
EXTRAPOLATION OF A 132204Z SSMS 37GHZ IMAGE. THE INITIAL INTENSITY OF
85KTS IS ASSESSED WITH MEDIUM CONFIDENCE BASED ON GROWTH OF THE
CONVECTIVE CANOPY AND IS SUPPORTED BY AGENCY DVORAK ESTIMATES (ALL
T4.5). ANALYSIS INDICATES A MARGINALLY FAVORABLE ENVIRONMENT WITH LOW
VWS AND STRONG POLEWARD OUTFLOW OFFSET BY MODERATE TO LOW SST AND OHC
VALUES.

INITIAL WIND RADII BASIS: PERSISTENCE AND SAR DATA

CURRENT STEERING MECHANISM: DEEP-LAYER SUBTROPICAL RIDGE (STR) TO
THE NORTHEAST

AGENCY DVORAK AND AUTOMATED FIXES:
PGTW: T4.5 - 77 KTS
RJTD: T4.5 - 77 KTS
RCTP: T4.5 - 77 KTS
KNES: T4.5 - 77 KTS
CIMSS ADT: 97 KTS AT 132330Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: MARGINALLY FAVORABLE
VWS: 0-5 KTS
SST: 28-29 CELSIUS
OUTFLOW: STRONG POLEWARD

ANALYSIS CONFIDENCE:
INITIAL POSITION: HIGH
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: TYPHOON LAN WILL CONTINUE ON ITS CURRENT TRACK
TOWARD CENTRAL HONSHU, JAPAN, MAKING LANDFALL NEAR TAU 24. DURING
THIS PERIOD, SOME FURTHER SLIGHT INTENSIFICATION MAY OCCUR AS THE
SYSTEM BEGINS TO PICK UP SPEED, MOVING AWAY FROM UPWELLED SEAS AND
ROUNDING THE AXIS OF THE STR POSITIONED TO THE NORTHEAST. A WEAKENING
PHASE IS EXPECTED AS THE SYSTEM TRACKS OVER CENTRAL JAPAN AND THE
KYOTO REGION AND UNDERGOES THE EFFECTS OF LAND INTERACTION THROUGH
TAU 36, AFTER WHICH THE SYSTEM IS FORECAST TO RETURN OVER WATER IN
THE SEA OF JAPAN AT TROPICAL STORM INTENSITY. AFTER TAU 36, THE
SYSTEM WILL CONTINUE TO TRACK NORTHEASTWARD AROUND THE RIDGING TO THE
EAST AND DRAMATICALLY ACCELERATE TOWARD THE NORTHEAST DUE TO A DEEP,
SHARP MIDLATITUDE TROUGH THAT IS EXPECTED TO DIG TO THE WEST. THE
SYSTEM IS ANTICIPATED TO COMPLETE EXTRATROPICAL TRANSITION BETWEEN
TAU 96 AND TAU 120, STARTING THE TRANSITION AS EARLY AS TAU 72.

MODEL DISCUSSION: NUMERICAL MODELS ARE IN GOOD AGREEMENT WITH
CROSS-TRACK ERROR OF 40NM AT LANDFALL AND 167NM AT TAU 72, LENDING
HIGH CONFIDENCE TO THIS PORTION OF THE JTWC TRACK FORECAST. DUE TO
THE UNCERTAINTIES INHERENT WITH EXTRATROPICAL TRANSITION AND MID-
LATITUDE TROUGH INTERACTION TO THE WEST, THERE IS MEDIUM CONFIDENCE
IN THE EXTENDED PORTION OF THE TRACK FORECAST.

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

[cycloneye]

WDPN31 PGTW 140900
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TYPHOON 07W (LAN) WARNING NR 027//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
INITIAL POSITION: 32.3N 136.9E
INITIAL INTENSITY: 85 KTS
GEOGRAPHIC REFERENCE: 228 NM SOUTHWEST OF YOKOSUKA, JAPAN
MOVEMENT PAST 6 HOURS: NORTHWESTWARD AT 07 KTS
SIGNIFICANT WAVE HEIGHT: 40 FEET

SATELLITE ANALYSIS, INITIAL POSITION, AND INTENSITY DISCUSSION:
ANIMATED MULTISPECTRAL SATELLITE IMAGERY (GOES H-8 PROXY VIS) SHOWS
A MEDIUM-SIZED SYMMETRICAL CYCLONE THAT HAS MAINTAINED ITS OVERALL
CONVECTIVE AND WRAP STRUCTURE WITH A LARGE 30X40-NM BANDING EYE,
EXPOSING A RAGGED AND IRREGULAR BUT DEFINED LOW LEVEL CIRCULATION
CENTER (LLCC). THE INITIAL POSITION IS PLACED WITH HIGH CONFIDENCE
BASED ON THE EXPOSED LLCC FEATURE. THE INITIAL INTENSITY OF 85KTS
IS ALSO PLACED WITH HIGH CONFIDENCE BASED ON A 140340Z AMSR2
WINDSPEED GRAPHIC, SUPPORTED BY AUTOMATED DVORAK ESTIMATES, AND
REFLECTS THE SUSTAINED STRUCTURE. ANALYSIS INDICATES A MARGINAL
ENVIRONMENT WITH LOW VWS AND MODERATE OUTFLOW OFFSET BY LOCALIZED
LOW SST AND OHC VALUES DUE TO OCEANIC UPWELLING AND DRY AIR
INTRUSION.

INITIAL WIND RADII BASIS: AMSR2 WINDSPEED GRAPHIC.

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


AGENCY DVORAK AND AUTOMATED FIXES:
PGTW: T4.5 - 77 KTS
RJTD: T4.0 - 65 KTS
KNES: T4.5 - 77 KTS
CIMSS SATCON: 86 KTS AT 140400Z
CIMSS ADT: 92 KTS AT 140640Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: MARGINAL
VWS: 5-10 KTS
SST: 28-29 CELSIUS
OUTFLOW: MODERATE EQUATORWARD
OTHER FACTORS: DRY AIR INTRUSION WRAPPING IN FROM THE NORTHWEST.

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: TYPHOON LAN WILL CONTINUE ON ITS CURRENT
NORTHWESTWARD TRACK AND MAKE LANDFALL JUST BEFORE TAU 12 OVER
WAKAYAMA PREFECTURE THEN INLAND JUST TO THE WEST OF KYOTO BY TAU
24. AFTERWARD, IT WILL TRACK MORE NORTHWARD
AS THE STR RECEDES IN RESPONSE TO A MID-LATITUDE TROUGH
APPROACHING
FROM THE NORTHWEST, EXIT INTO THE SEA OF JAPAN (SOJ), CREST THE
STR
AXIS BY TAU 36, THEN ACCELERATE NORTHEASTWARD ON THE POLEWARD SIDE
OF THE STR, CLIPPING THE NORTHERN TIP OF HOKKAIDO JUST AFTER TAU
72 AND BACK INTO THE PACIFIC OCEAN BY TAU 96. THE MARGINAL
ENVIRONMENT WILL BECOME UNFAVORABLE WITH DRY AIR INTRUSION,
INCREASING VWS, THEN LAND INTERACTION REDUCING IT TO 65KTS BY TAU
24. DESPITE THE RELATIVELY WARM SST IN THE SOJ, INCREASING VWS,
THEN INTERACTION WITH THE BAROCLINIC ZONE AS TY 07W BEGINS
EXTRA-TROPICAL TRANSITION BY TAU 72, IT WILL GRADUALLY ERODE TO A
45-KT COLD CORE LOW BY TAU 96.


MODEL DISCUSSION: NUMERICAL MODELS ARE IN VERY GOOD AGREEMENT WITH
A GRADUAL AND EVEN SPREAD TO JUST 116NM BY TAU 72, LENDING HIGH
CONFIDENCE TO THIS PORTION OF THE JTWC TRACK FORECAST. AFTERWARD,
THE MODELS SPREAD OUT TO 388NM BY TAU 96. THIS PLUS THE
UNCERTAINTIES INHERENT WITH EXTRA-TROPICAL TRANSITION LENDS ONLY
MEDIUM CONFIDENCE IN THE EXTENDED PORTION OF THE TRACK FORECAST.
THERE IS MEDIUM CONFIDENCE IN THE JTWC INTENSITY FORECAST UP TO TAU
72 THEN LOW AFTERWARD FOR THE SAME REASON.

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

[cycloneye]

WDPN31 PGTW 141500
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TYPHOON 07W (LAN) WARNING NR 028//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
INITIAL POSITION: 32.7N 136.6E
INITIAL INTENSITY: 85 KTS
GEOGRAPHIC REFERENCE: 219 NM SOUTHWEST OF YOKOSUKA, JAPAN
MOVEMENT PAST 6 HOURS: NORTH-NORTHWESTWARD AT 05 KTS
SIGNIFICANT WAVE HEIGHT: 40 FEET

SATELLITE ANALYSIS, INITIAL POSITION, AND INTENSITY DISCUSSION:
ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY (GOES H-8 PROXY
VIS) SHOWS A MEDIUM-SIZED SYMMETRICAL CYCLONE THAT HAS MAINTAINED
ITS OVERALL CONVECTIVE AND WRAP STRUCTURE WITH A LARGE 40-NM
BANDING EYE, EXPOSING A RAGGED AND IRREGULAR BUT DEFINED LOW LEVEL
CIRCULATION CENTER (LLCC). THE INITIAL POSITION IS PLACED WITH HIGH
CONFIDENCE BASED ON THE EXPOSED LLCC FEATURE, CONCENTRIC WITH AN
EQUALLY LARGE LLCC IN A COMPOSITE RADAR LOOP FROM JMA AND LINED UP
WITH A DEFINED LLCC FEATURE IN THE 140920Z SSMIS. THE INITIAL
INTENSITY OF 85KTS IS ALSO PLACED WITH HIGH CONFIDENCE BASED ON THE
140859Z SAR PASS INDICATING 85KT WINDS CIRCLING TWO-THIRDS OF THE
EYEWALL AND REFLECTS THE SUSTAINED 6-HR STRUCTURE. THE INITIAL
INTENSITY IS ALSO SUPPORTED BY THE HIGH END OF AGENCY AND AUTOMATED
DVORAK ESTIMATES. ANALYSIS INDICATES A MARGINAL ENVIRONMENT WITH LOW
VWS AND MODERATE OUTFLOW OFFSET BY LOCALIZED LOW SST AND OHC VALUES
DUE TO OCEANIC UPWELLING AND DRY AIR INTRUSION.

INITIAL WIND RADII BASIS: SAR DATA.

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


AGENCY DVORAK AND AUTOMATED FIXES:
PGTW: T4.5 - 77 KTS
RJTD: T3.5 - 55 KTS
RCTP: T4.0 - 65 KTS
KNES: T4.5 - 77 KTS
CIMSS SATCON: 80 KTS AT 141210Z
CIMSS ADT: 79 KTS AT 141120Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: MARGINAL
VWS: 0-5 KTS
SST: 28-29 CELSIUS
OUTFLOW: MODERATE EQUATORWARD
OTHER FACTORS: DRY AIR INTRUSION WRAPPING IN FROM THE NORTHWEST.

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: TYPHOON LAN WILL CONTINUE ON ITS CURRENT
NORTHWESTWARD TRACK AND MAKE LANDFALL BEFORE TAU 12 OVER WAKAYAMA
PREFECTURE THEN INLAND JUST TO THE WEST OF KYOTO, EXIT INTO THE SEA
OF JAPAN (SOJ) BY TAU 12. AFTERWARD, IT WILL TRACK MORE NORTHWARD,
CREST THE STR AXIS BEFORE TAU 24 THEN ACCELERATE NORTHEASTWARD AS
THE STR RECEDES IN RESPONSE TO A MID-LATITUDE TROUGH APPROACHING
FROM THE NORTHWEST, AND CLIPPING THE NORTHERN TIP OF HOKKAIDO JUST
BEFORE TAU 72. THE MARGINAL ENVIRONMENT WILL BECOME UNFAVORABLE
WITH DRY AIR INTRUSION, INCREASING VWS, THEN LAND INTERACTION
REDUCING IT TO 60KTS BY TAU 24. DESPITE THE RELATIVELY WARM SST IN
THE SOJ, INCREASING VWS THEN INTERACTION WITH THE BAROCLINIC ZONE
AS TY 07W BEGINS EXTRA-TROPICAL TRANSITION BY TAU 48 WILL GRADUALLY
ERODE IT TO A 40-KT COLD CORE LOW BY TAU 72.

MODEL DISCUSSION: NUMERICAL MODELS ARE IN VERY GOOD AGREEMENT WITH
A GRADUAL AND EVEN SPREAD TO JUST 129NM BY TAU 72, LENDING HIGH
CONFIDENCE TO THE JTWC TRACK FORECAST. THERE IS ONLY MEDIUM
CONFIDENCE IN THE JTWC INTENSITY FORECAST DUE TO UNCERTAINTIES
INHERENT WITH EXTRA-TROPICAL TRANSITION, I.E., EXPANDING WIND FIELD
AND ABSORPTION INTO THE BAROCLINIC ZONE.

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

[Sciencerocks]

 https://twitter.com/CIRA_CSU/status/1691094229278425088

[Sciencerocks]

 https://twitter.com/zoom_earth/status/1691144571361570826

[cycloneye]

 https://twitter.com/iCyclone/status/1691164664955039744

[cycloneye]

 https://twitter.com/EarthUncutTV/status/1691113681852260352

[cycloneye]

WDPN31 PGTW 142100
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TYPHOON 07W (LAN) WARNING NR 029//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
INITIAL POSITION: 33.4N 136.1E
INITIAL INTENSITY: 80 KTS
GEOGRAPHIC REFERENCE: 212 NM WEST-SOUTHWEST OF YOKOSUKA, JAPAN
MOVEMENT PAST 6 HOURS: NORTHWESTWARD AT 07 KTS
SIGNIFICANT WAVE HEIGHT: 33 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY DEPICTS A LARGE,
CLOUD-FILLED, 45NM WIDE EYE FEATURE IN THE CENTER OF WEAK AND
FRAGMENTED CONVECTIVE BANDS. ANIMATED RADAR DATA FROM JMA INDICATE
THE SYSTEM IS IN THE PROCESS OF MAKING LANDFALL ALONG THE COAST OF
CAPE SHINONO, NEAR THE TOWN OF SHINGU. A 141700Z GPM 37GHZ MICROWAVE
IMAGE SHOWED THICK, WELL-DEFINED LOW-LEVEL RAIN BANDS SURROUNDING A
30NM WIDE MICROWAVE EYE FEATURE, WHILE THE 89GHZ IMAGE SHOWED MUCH
WEAKER FRAGMENTED CONVECTIVE BANDS AROUND A MUCH LARGER, 70NM WIDE
EYE IN THE UPPER-LEVELS. THE INITIAL POSITION IS ASSESSED WITH HIGH
CONFIDENCE BASED ON THE RADAR FIX DATA AS WELL AS AN EXTRAPOLATION
OF THE GPM 37GHZ EYE FEATURE. THE INITIAL INTENSITY IS ASSESSED
WITH MEDIUM CONFIDENCE, HEDGED HIGHER THAN THE BULK OF SUBJECTIVE
AND OBJECTIVE INTENSITY ESTIMATES IN LIGHT OF AN EARLIER 140859Z
RCM-1 SAR PASS, WHICH INDICATED WINDS BETWEEN 85-89 KNOTS
SURROUNDING TWO-THIRDS OF THE CIRCULATION CENTER. WIND SPEEDS ALONG
THE COAST HAVE BEEN RELATIVELY LOW COMPARED TO THE OVERWATER
INTENSITIES, BUT WINDS ARE ALREADY ABOVE 40 KNOTS AT KANSAI
AIRPORT, EXPOSED IN OSAKA BAY. WINDS WILL INCREASE AS THE SYSTEM
TRACKS CLOSE BY THE AIRPORT IN THE NEXT FEW HOURS. THE INITIAL
CENTRAL PRESSURE HAS BEEN ADJUSTED TO 970MB BASED ON AN
EXTRAPOLATION OF A 975MB MEAN SEA LEVEL PRESSURE (MSLP) READING
FROM CAPE SHINONO ON THE OUTER PERIPHERY OF THE EYE AS IT PASSED.
THE WIND RADII HAVE ALSO BEEN ADJUSTED SIGNIFICANTLY SMALLER BASED
ON THE PREVIOUSLY MENTIONED SAR DATA AND A 141217Z ASCAT-B PASS.
ENVIRONMENTAL CONDITIONS ARE MARGINALLY FAVORABLE, WITH ROBUST
POLEWARD OUTFLOW AND LOW SHEAR OFFSET BY TERRAIN INFLUENCES WHICH
WILL TEAR UP THE LOW-LEVEL CORE.

INITIAL WIND RADII BASIS: SCATTEROMETER AND SAR DATA.

CURRENT STEERING MECHANISM: WESTERN PERIPHERY OF A SUBTROPICAL
RIDGE (STR) TO THE EAST.

AGENCY DVORAK AND AUTOMATED FIXES:
PGTW: T4.0 - 65 KTS
RJTD: T3.5 - 55 KTS
RCTP: T3.5 - 55 KTS
KNES: T4.0 - 65 KTS
CIMSS ADT: 61 KTS AT 141750Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: MARGINALLY FAVORABLE
VWS: 0-5 KTS
SST: 28-29 CELSIUS
OUTFLOW: STRONG POLEWARD

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

3. FORECAST REASONING.

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

FORECAST DISCUSSION: NOW MAKING LANDFALL, TYPHOON (TY) 07W (LAN) IS
FORECAST TO CONTINUE TRACKING NORTHWESTWARD, INTO OSAKA BAY AND
THEN TURN MORE NORTHWARD AND EMERGE INTO THE SOUTHWESTERN SEA OF
JAPAN BY TAU 24. TRACK SPEEDS SHOULD SLOW DOWN AS IT TRANSITS
ACROSS THE RUGGED TERRAIN DUE TO FRICTIONAL EFFECTS, BUT THEN JUMP
UP ONCE THE REMAINING LLCC MOVES BACK OVER OPEN WATERS. THE SYSTEM
WILL GRADUALLY TURN NORTH-NORTHEASTWARD AFTER TAU 24 AS THE
STEERING RIDGE TO THE EAST IS ERODED BY THE APPROACH OF A
MID-LATITUDE TROUGH MOVING EAST OVER SOUTHEASTERN RUSSIA. WHILE THE
BULK OF THE MODEL GUIDANCE SUPPORTS THE FORECAST TRACK TO THE
NORTHEAST, INCREASING NUMBERS OF ENSEMBLE MEMBERS FROM BOTH THE
GEFS AND ECENS ARE BEGINNING TO BRING THE SYSTEM INTO SOUTHERN
RUSSIA, TO THE EAST OF VLADIVOSTOK WITHIN THE FIRST 48 HOURS OF THE
FORECAST. THERE IS SOME SUPPORT FOR THIS SCENARIO IN THE GFS
DEEP-LAYER MEAN STEERING PATTERN, WHICH SHOWS AN EXTENSION OF THE
STEERING RIDGE BUILDING IN TOWARDS THE WEST ACROSS THE NORTHERN SEA
OF JAPAN, AND HOLDING THE SYSTEM ON A TRACK FURTHER TOWARDS
THE WEST. THE CURRENT FORECAST TRENDS TOWARDS THE WEST BUT HOLDS TO
THE RECURVE SCENARIO FOR NOW, BUT THE ALTERNATE SCENARIO BEARS
WATCHING. ON THE CURRENT FORECAST TRACK, IF THE CORE OF THE SYSTEM
CAN MAKE IT ACROSS HONSHU IT WILL HAVE A SHORT PERIOD OF TIME TO
MAINTAIN INTENSITY AS IT MOVES ACROSS VERY WARM WATERS (28C), AND
TAPS INTO STRONG POLEWARD OUTFLOW INTO THE BASE OF THE TROUGH
PASSING TO THE NORTH. AFTER TAU 36 HOWEVER, SHEAR WILL COME TO
DOMINATE OVER THE OUTFLOW AND TEAR THE SYSTEM APART, LEADING TO
RAPID WEAKENING. THE SYSTEM WILL COMMENCE EXTRATROPICAL TRANSITION
(ETT) AROUND TAU 48, COMPLETING TRANSITION TO A GALE-FORCE
EXTRATROPICAL LOW OVER SAKHALIN ISLAND BY TAU 72.

MODEL DISCUSSION: DETERMINISTIC TRACK GUIDANCE IS IN GOOD AGREEMENT
ON THE RECURVE SCENARIO, WITH ALL MEMBERS OF THE TRACK CONSENSUS
CONTAINED WITHIN AN ENVELOPE THAT GRADUALLY EXPANDS TO 160NM BY TAU
72. AS MENTIONED ABOVE, THE MAJORITY OF THE ENSEMBLE MEMBERS ALSO
SUPPORT THE RECURVE SCENARIO BUT INCREASING NUMBERS OF MEMBERS ARE
STARTING TO PULL THE SYSTEM ONTO A DUE NORTH TRACK INTO SOUTHERN
RUSSIA. THE JTWC FORECAST REMAINS CONSISTENT WITH THE PREVIOUS
FORECAST BUT DOES SHIFT THE TRACK ABOUT 30NM TO THE WEST AFTER TAU
24. CONFIDENCE REMAINS MEDIUM DUE TO THE INCREASING UNCERTAINTY IN
THE ENSEMBLE GUIDANCE. INTENSITY GUIDANCE IS IN RELATIVELY GOOD
AGREEMENT, WITH ALL CONSENSUS MEMBERS SHOWING WEAKENING THROUGH THE
FORECAST, WHILE THE HWRF AND HAFS-A INDICATE A SHORT PERIOD OF
ARRESTED WEAKENING IN THE SEA OF JAPAN THROUGH TAU 36. THE JTWC
FORECAST LIES VERY CLOSE TO THE HAFS-A SOLUTION, THOUGH AS WITH THE
TRACK FORECAST, UNCERTAINTY AS TO THE EXACT TRACK AFTER TAU 24
INTRODUCES UNCERTAINTY INTO THE INTENSITY FORECAST AS WELL, LEADING
TO OVERALL MEDIUM CONFIDENCE.

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

[cycloneye]

 https://twitter.com/VortixWx/status/1691201053960585216

[Sciencerocks]

[cycloneye]

WDPN31 PGTW 150900
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 07W (LAN) WARNING NR
031//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
INITIAL POSITION: 35.4N 134.9E
INITIAL INTENSITY: 50 KTS
GEOGRAPHIC REFERENCE: 153 NM EAST-NORTHEAST OF IWAKUNI, JAPAN
MOVEMENT PAST 6 HOURS: NORTH-NORTHWESTWARD AT 12 KTS
SIGNIFICANT WAVE HEIGHT: 28 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) DEPICTS THAT TS 07W
(LAN) IS QUICKLY MARCHING OVER THE ISLAND OF HONSHU, ON ROUTE TO
THE SEA OF JAPAN. SURFACE OBSERVATION FROM TAJIMA AND TOTTORI
AIRPORT COMBINED WITH ANIMATED RADAR IMAGERY HAVE AIDED
TREMENDOUSLY IN LOCALIZING THE SYSTEM AS IT APPROACHES OPEN OCEAN
ONCE MORE. A 150425Z AMSR2 89GHZ MICROWAVE IMAGE REVEALS A
PARTIALLY EXPOSED LLCC WITH DEEP CONVECTION FLARING OVER THE WARM
WATERS OUT AHEAD OF TRACK MOTION. THE INITIAL POSITION IS PLACED
WITH MEDIUM CONFIDENCE BASED ON MSI, AMSR2 AND RADAR IMAGERY. THE
INITIAL INTENSITY OF 50 KTS IS ASSESSED WITH MEDIUM CONFIDENCE
BASED ON AVAILABLE DVORAK INTENSITY ESTIMATES GENERALLY MATCHING
CIMSS DPRINT OF 50KTS, WHICH IS ONE OF THE FEW AUTOMATED INTENSITY
ESTIMATES THAT REPORTS OVER LAND.

INITIAL WIND RADII BASIS: PERSISTENCE

CURRENT STEERING MECHANISM: WESTERN PERIPHERY OF A DEEP-LAYER
SUBTROPICAL RIDGE (STR) CENTERED FAR TO THE EAST.

AGENCY DVORAK AND AUTOMATED FIXES:
PGTW: T3.0 - 45 KTS
RJTD: T3.0 - 45 KTS
RCTP: T3.0 - 45 KTS

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: MARGINAL
VWS: 10-15 KTS
SST: 28-29 CELSIUS
OUTFLOW: MODERATE POLEWARD

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

3. FORECAST REASONING.

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

FORECAST DISCUSSION: AS WE SPEAK, TS 07W (LAN) IS ONCE AGAIN MOVING
BACK OVER OPEN OCEAN AND IS FORECAST TO PROCEED GENERALLY POLEWARD.
AFTER ENTERING THE SEA OF JAPAN, WARM WATERS AND STEADILY IMPROVING
OUTFLOW ALOFT WILL FIGHT TO OVERCOME GRADUALLY INCREASING VERTICAL
WIND SHEAR VALUES. THE RESULT OF THE BATTLE WILL ALMOST CERTAINLY
BE ANTICLIMACTIC, AS 07W STRUGGLES TO REORGANIZE AS IT IS QUICKLY
MOVED POLEWARD. AS THE GRADUAL WESTWARD SHIFT IN TRACK FORECAST
OVER THE LAST FEW DAYS WOULD INDICATE, THERE IS A CHANCE 07W MAKES
LANDFALL OVER EASTERN RUSSIA AND DISSIPATES BY TAU 72. THE CURRENT
JTWC FORECAST PHILOSOPHY HOWEVER IS ONE OF GRADUAL DECLINE THROUGH
TAU 48 DUE TO THE INCREASING SHEAR VALUES. NEAR THE 44TH PARALLEL,
THE SYSTEM WILL BEGIN TO INTERACT WITH A STRONG BAROCLINIC ZONE AS
IT FURTHER INCREASES ITS POLEWARD TRACK SPEED, THEREBY INITIATING
EXTRA-TROPICAL TRANSITION (ETT). BY TAU 120, NOW WELL INTO THE SEA
OF OKHOTSK, 07W WILL LOSE ITS LAST REMAINING TROPICAL
CHARACTERISTICS AND COMPLETE ETT.

MODEL DISCUSSION: NUMERICAL MODELS ARE IN GOOD AGREEMENT, WITH ALL
MEMBERS FOLLOWING THE JTWC TRACK FORECAST AND MULTI-MODEL CONSENSUS
WITH MINIMAL VARIABILITY THROUGH TAU 72. FOR THIS REASON THE JTWC
TRACK FORECAST IS PLACED WITH OVERALL MEDIUM CONFIDENCE. RELIABLE
MODEL INTENSITY GUIDANCE IS IN GOOD AGREEMENT WITH ALL MEMBERS
SHOWING GRADUAL DECLINE THROUGH TAU 24 AND AFTER THAT SHARPER
DECLINE THROUGH THE FORECAST PERIOD. FOR THIS REASON THE JTWC
INTENSITY FORECAST IS PLACED WITH OVERALL MEDIUM CONFIDENCE AS
WELL.

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

[cycloneye]

WDPN31 PGTW 151500
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 07W (LAN) WARNING NR
032//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
INITIAL POSITION: 36.2N 134.8E
INITIAL INTENSITY: 45 KTS
GEOGRAPHIC REFERENCE: 175 NM NORTHEAST OF IWAKUNI, JAPAN
MOVEMENT PAST 6 HOURS: NORTHWARD AT 10 KTS
SIGNIFICANT WAVE HEIGHT: 15 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY DEPICTS A
DETERIORATING AND ASYMMETRIC WEB OF CONVECTIVE BANDS WITH
THE A LOW LEVEL CIRCULATION CENTER THAT IS DECOUPLED FROM THE UPPER
LEVEL CIRCULATION CENTER. WITHOUT THE LUXURY OF NEW MICROWAVE
IMAGERY, ANIMATED RADAR IMAGERY WAS THE PRIMARY LOCALIZING TOOL. A
LARGE DONUT-LIKE STRUCTURE IS STILL EVIDENT AS THE CIRCULATION
EMERGES BACK OVER OPEN WATER. A 150848Z PARTIAL SOIL MOISTURE ACTIVE
PASSIVE (SMAP) PASS REVEALED THE LEADING EDGE OF THE CIRCULATION HAS
WEAKENED TO AROUND 45 KTS WITH A MAJORITY OF THE PRIMARY WIND FIELD
AT 35-40 KTS. THE INITIAL POSITION IS PLACED WITH LOW CONFIDENCE
BASED ON THE LACK OF MICROWAVE DATA AND THE AMORPHOUS, BROAD
STRUCTURE EVIDENT IN RADAR IMAGERY. THE INITIAL INTENSITY OF 45 KTS
IS ASSESSED WITH MEDIUM CONFIDENCE BASED ON THE MAJORITY OF INTENSITY
ESTIMATES SUCH AS PGTW DVORAK ESTIMATE, CIMSS, AIDT AND DPRINT
SUPPORTING 45KTS.

INITIAL WIND RADII BASIS: PERSISTENCE

CURRENT STEERING MECHANISM: WESTERN PERIPHERY OF A DEEP-LAYER
SUBTROPICAL RIDGE (STR) CENTERED FAR TO THE EAST.

AGENCY DVORAK AND AUTOMATED FIXES:
PGTW: T3.0 - 45 KTS
RJTD: T2.5 - 35 KTS
RCTP: T2.5 - 35 KTS
CIMSS ADT: 33 KTS AT 151130Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: MARGINAL
VWS: 15-20 KTS
SST: 28-29 CELSIUS
OUTFLOW: MODERATE POLEWARD

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

3. FORECAST REASONING.

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

FORECAST DISCUSSION: HAVING RECENTLY ENTERED THE WARM WATERS OF THE
SEA OF JAPAN, TS 07W (LAN) IS FORECAST TO PROCEED GENERALLY
POLEWARD. AS 07W TRACKS NORTHWARD, STEADILY IMPROVING OUTFLOW ALOFT
WILL FIGHT TO OVERCOME GRADUALLY INCREASING VERTICAL WIND SHEAR
VALUES. THE RESULT OF THIS BATTLE WILL ALMOST CERTAINLY BE
ANTICLIMACTIC, 07W WILL LIKELY ONLY MAINTAIN MOST OF ITS INTENSITY
THROUGH TAU 24. THE CURRENT JTWC FORECAST PHILOSOPHY IS ONE OF
GRADUAL DECLINE DUE TO THE INCREASING SHEAR VALUES BEYOND TAU 36. AS
THE SYSTEM PASSES THE 44TH PARALLEL, 07W WILL BEGIN TO INTERACT WITH
A STRONG BAROCLINIC ZONE AS IT FURTHER INCREASES ITS POLEWARD TRACK
SPEED, THEREBY INITIATING EXTRA-TROPICAL TRANSITION (ETT). BY TAU
120, NOW WELL INTO THE SEA OF OKHOTSK, 07W WILL LOSE ITS LAST
REMAINING TROPICAL CHARACTERISTICS AND COMPLETE ETT JUST BEFORE ITS
EVENTUAL DISSIPATION.

MODEL DISCUSSION: NUMERICAL MODELS ARE IN GOOD AGREEMENT, WITH ALL
MEMBERS FOLLOWING THE JTWC TRACK FORECAST AND MULTI-MODEL CONSENSUS
WITH MINIMAL VARIABILITY THROUGH TAU 72. FOR THIS REASON THE JTWC
TRACK FORECAST IS PLACED WITH OVERALL MEDIUM CONFIDENCE. RELIABLE
MODEL INTENSITY GUIDANCE IS IN GOOD AGREEMENT WITH ALL MEMBERS
SHOWING GRADUAL DECLINE THROUGH TAU 24 AND AFTER THAT SHARPER
DECLINE THROUGH THE FORECAST PERIOD. FOR THIS REASON THE JTWC
INTENSITY FORECAST IS PLACED WITH OVERALL MEDIUM CONFIDENCE AS
WELL.

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