WPAC: DOLPHIN - Post-Tropical

[euro6208]

WDPN31 PGTW 230300
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 14W (DOLPHIN) WARNING NR
011//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
TROPICAL STORM (TS) 14W (DOLPHIN), LOCATED APPROXIMATELY 256 NM
SOUTH-SOUTHWEST OF YOKOSUKA, JAPAN, HAS TRACKED NORTHEASTWARD AT 20
KNOTS (KTS) OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE
IMAGERY (MSI) REVEALS AN OBSCURED LOW LEVEL CIRCULATION CENTER (LLCC)
WITH DEEP CONVECTION LOCATED OVERHEAD AND SHEARED OVER THE NORTHEAST
QUADRANT. A 230017Z ASCAT-A IMAGE DEPICTS HIGHER WINDS (50 KTS)
LOCATED TO THE NORTH OF AN ELONGATED LLCC. THE INITIAL INTENSITY IS
ASSESSED AT 50 KTS BASED ON DVORAK CURRENT INTENSITY ESTIMATES OF
T3.0-3.5 (45-55 KTS), A 232340Z ADVANCED DVORAK TECHNIQUE ESTIMATE OF
T3.1 (47KTS), AND A 232211Z SATCON ESTIMATE OF 48 KTS. ALL WIND RADII
HAVE BEEN UPDATED WITH RECENT ASCAT DATA. UPPER LEVEL ANALYSIS REVEALS
HIGH (25-30 KT) VERTICAL WIND SHEAR BEING OFFSET BY WARM SEA SURFACE
TEMPERATURES (SST) AND ROBUST POLEWARD OUTFLOW THAT IS BEING ENHANCED
BY THE WESTERLIES TO THE NORTH. OVERALL, THIS PRESENTS AN OVERALL
MARGINALLY FAVORABLE ENVIRONMENT FOR CONTINUED DEVELOPMENT AS HIGH
SHEAR IMPACTS THE SYSTEM. DUE TO THE ELONGATED NATURE OF THE LLCC,
WEAK TEMPERATURE GRADIENT, AND EXPANDING WIND FIELD, THIS SYSTEM IS
CURRENTLY ASSESSED AS SUBTROPICAL. TS 14W IS TRACKING NORTHEASTWARD
ALONG THE NORTHWESTERN PERIPHERY OF THE SUBTROPICAL RIDGE (STR).
3. FORECAST REASONING.
A. NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE PREVIOUS
PROGNOSTIC REASONING MESSAGE.
B. IN THE NEAR TERM, TS 14W SHOULD TRACK NORTHEASTWARD THROUGH TAU
36 UNDER THE INFLUENCE OF THE STR. AFTERWARDS, IT WILL SHIFT TO A
NORTH-NORTHEASTWARD TRACK AS THE SYSTEM BECOMES EMBEDDED IN THE JET
FLOW. AROUND TAU 24, TS 14W IS EXPECTED TO BEGIN EXTRATROPICAL
TRANSITION AS BAROCLINICITY INCREASES AND THE SYSTEM STARTS TO GAIN
FRONTAL CHARACTERISTICS AS IT APPROACHES A DEEPENING MIDLATITUDE
TROUGH. AROUND THIS TIME, INCREASING VERTICAL WIND SHEAR (>40 KTS)
WILL BE IMPACTING THE SYSTEM AS WELL. EXTRATROPICAL TRANSITIONS
COMPLETION IS EXPECTED BY TAU 36 AS THE 1000-500 MB THICKNESS FIELDS
SHOW A FRONTAL SYSTEM. AFTERWARDS, TS 14W SHOULD TRACK NORTH-
NORTHEASTWARD AS AN EXTRATROPICAL LOW. NUMERICAL MODEL GUIDANCE IS IN
TIGHT AGREEMENT THROUGH TAU 36 AND THEN SLOWLY DIVERGES TO 80 NM
SPREAD AT TAU 48 AND 150 NM BY TAU 72. THE 22/18Z ECMWF ENSEMBLE
SOLUTIONS REMAIN IN GOOD AGREEMENT AND DEPICT PASSAGE EAST OF HONSHU.
PLACED NEAR THE ECMWF SOLUTION AND THE MULTI-MODEL CONSENSUS, THERE IS
HIGH CONFIDENCE IN THE JTWC FORECAST TRACK.//
NNNN

[euro6208]

WDPN31 PGTW 230900
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 14W (DOLPHIN) WARNING
NR 012//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
TROPICAL STORM (TS) 14W (DOLPHIN), LOCATED APPROXIMATELY 205
NM SOUTH-SOUTHWEST OF YOKOSUKA, JAPAN, HAS TRACKED NORTHEASTWARD
AT 16 KNOTS OVER THE PAST SIX HOURS. DESPITE INCREASING VERTICAL
WIND SHEAR (VWS) OF 30 KNOTS, ANIMATED MULTISPECTRAL SATELLITE
IMAGERY DEPICTS A CONSOLIDATED SYSTEM WITH DEEP CONVECTIVE BANDING
WRAPPING INTO THE LOW-LEVEL CIRCULATION CENTER (LLCC). A 230726Z
SSMIS 91GHZ IMAGE REVEALS TIGHTLY-CURVED BANDING WRAPPING INTO THE
LLCC BUT ALSO SHOWS A WEAK FRONTAL STRUCTURE FORMING AND POSSIBLE
TILT. THE HYBRID (SUBTROPICAL) SYSTEM IS EMBEDDED WITHIN THE
SUBTROPICAL WESTERLIES BUT HAS MAINTAINED A STRONG POLEWARD OUTFLOW
CHANNEL AND WARM (29C) SST VALUES TO OFFSET THE STRONG VWS.
THEREFORE, THE SYSTEM'S CONVECTIVE STRUCTURE HAS STRENGTHENED OVER
THE PAST SIX HOURS AND NOW APPEARS TO BE MORE TROPICAL IN NATURE.
THE INITIAL INTENSITY REMAINS ASSESSED AT 50 KNOTS BASED ON A PGTW
SUBTROPICAL FIX OF ST3.0 (45-50 KNOTS) AND A RJTD DVORAK INTENSITY
ESTIMATE OF T3.5 (55 KNOTS). A RECENT ASCAT IMAGE SHOWED AN
EXPANSIVE REGION GALE-FORCE WINDS TO THE NORTH WITH AN ELONGATED
CENTER AND MAXIMUM WINDS OF 45-50 KNOTS. SURFACE OBSERVATIONS FROM
CHICHI-JIMA (33.1N 139.8E), ABOUT 96NM NORTHEAST, INDICATE EAST-
NORTHEASTERLY WINDS AT 26 TO 30 KNOTS. TS 14W IS TRACKING
NORTHEASTWARD ALONG THE NORTHERN PERIPHERY OF THE SUBTROPICAL RIDGE
(STR) WITHIN THE SUBTROPICAL WESTERLIES.
3. FORECAST REASONING.
A. NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE PREVIOUS
PROGNOSTIC REASONING MESSAGE.
B. TS 14W IS ACCELERATING WITHIN THE SUBTROPICAL WESTERLIES AND
IS FORECAST TO CONTINUE TRACKING NORTHEASTWARD TO NORTH-
NORTHEASTWARD THROUGH THE FORECAST PERIOD. NUMERICAL MODEL GUIDANCE
IS IN TIGHT AGREEMENT THROUGH TAU 24 WITH A 36NM SPREAD IN SOLUTIONS
AT TAU 24 BUT DIVERGES SIGNIFICANTLY AFTER TAU 24 WHEN THE SYSTEM
UNDERGOES EXTRA-TROPICAL TRANSITION (ETT) EAST OF NORTHERN HONSHU.
TS 14W SHOULD COMPLETE ETT BY TAU 36. AS MENTIONED PREVIOUSLY, THE
SYSTEM HAS RE-CONSOLIDATED DESPITE THE SUBTROPICAL AND BAROCLINIC
INFLUENCES ON THE SYSTEM. THERE IS SOME UNCERTAINTY IN THE PEAK
INTENSITY, AT LEAST OVER THE NEXT 12 HOURS, UNTIL VWS INCREASES TO
35-40 KNOTS. BY TAU 24, VWS WILL INCREASE TO 40-50 KNOTS, WHICH WILL
LEAD TO A WEAKENING TREND. BASED ON THE MODEL SPREAD AFTER TAU 24
AND POSITIONAL UNCERTAINTY, THERE IS NOW MODERATE CONFIDENCE IN THE
JTWC FORECAST TRACK.//
NNNN

[euro6208]

Too bad. Looks stronger than 50 knots.

[euro6208]

WDPN31 PGTW 231500
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 14W (DOLPHIN) WARNING
NR 013//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
TROPICAL STORM (TS) 14W (DOLPHIN), LOCATED APPROXIMATELY 174 NM
SOUTH-SOUTHEAST OF YOKOSUKA, JAPAN, HAS TRACKED EAST-NORTHEASTWARD
AT 17 KNOTS OVER THE PAST SIX HOURS. ANIMATED ENHANCED INFRARED
SATELLITE IMAGERY INDICATES ERODING DEEP CONVECTION SHEARING
EASTWARD DUE TO STRONG (35 KNOTS) WESTERLY VERTICAL WIND SHEAR (VWS).
A 231245Z GMI 37GHZ IMAGE REVEALS A LARGE AREA OF DEEP CONVECTION
OVER THE EASTERN SEMICIRCLE OF AN ELONGATED CENTER WITH A WEAK
FRONTAL STRUCTURE EVIDENT. THE HYBRID (SUBTROPICAL) SYSTEM IS
EMBEDDED WITHIN THE SUBTROPICAL WESTERLIES AND IS GRADUALLY BECOMING
MORE ASYMMETRIC WITH MODERATE BAROCLINICITY. HOWEVER, THE SYSTEM HAS
MAINTAINED GOOD POLEWARD OUTFLOW CHANNEL AND WARM (29C) SST VALUES
TO PARTIALLY OFFSET THE STRONG VWS. THE INITIAL INTENSITY IS
ASSESSED AT 55 KNOTS BASED ON A 231108Z ASCAT-B IMAGE SHOWING 50-55
KNOT WINDS. ADDITIONALLY, SURFACE OBSERVATIONS FROM CHICHI-JIMA
(33.1N 139.8E), AT 23/09Z ABOUT 50NM NORTH-NORTHWEST, INDICATE
MAXIMUM WINDS OF 35 KNOTS GUSTING TO 53 KNOTS. TS 14W IS TRACKING
NORTHEASTWARD ALONG THE NORTHERN PERIPHERY OF THE SUBTROPICAL RIDGE
(STR) WITHIN THE SUBTROPICAL WESTERLIES.
3. FORECAST REASONING.
A. NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE PREVIOUS
PROGNOSTIC REASONING MESSAGE.
B. TS 14W IS ACCELERATING WITHIN THE SUBTROPICAL WESTERLIES AND
IS FORECAST TO CONTINUE TRACKING NORTHEASTWARD TO NORTH-
NORTHEASTWARD THROUGH THE FORECAST PERIOD. NUMERICAL MODEL GUIDANCE
IS IN TIGHT AGREEMENT THROUGH THE FORECAST PERIOD, HOWEVER, THERE IS
MODERATE CONFIDENCE IN THE JTWC FORECAST TRACK DUE TO HIGH
UNCERTAINTY IN THE INITIAL POSITION, WHICH IS BROADENING. TS 14W IS
FORECAST TO BEGIN EXTRA-TROPICAL TRANSITION (ETT) NEAR TAU 12 AND
SHOULD COMPLETE ETT BY TAU 36 AS IT TRACKS UNDER THE JET AND GAINS
FRONTAL CHARACTERISTICS. THE SYSTEM SHOULD GRADUALLY WEAKEN AS VWS
INCREASES TO 40-50 KNOTS.//
NNNN

[1900hurricane]

 https://twitter.com/1900hurricane/status/1308778801577562115

[euro6208]

Final Warning



WTPN31 PGTW 240300
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL STORM 14W (DOLPHIN) WARNING NR 015//
RMKS/
1. TROPICAL STORM 14W (DOLPHIN) WARNING NR 015
01 ACTIVE TROPICAL CYCLONE IN NORTHWESTPAC
MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
WIND RADII VALID OVER OPEN WATER ONLY
---
WARNING POSITION:
240000Z --- NEAR 32.9N 141.7E
MOVEMENT PAST SIX HOURS - 180 DEGREES AT 01 KTS
POSITION ACCURATE TO WITHIN 015 NM
POSITION BASED ON CENTER LOCATED BY A COMBINATION OF
SATELLITE AND SYNOPTIC DATA
PRESENT WIND DISTRIBUTION:
MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT
WIND RADII VALID OVER OPEN WATER ONLY
EXTRATROPICAL
RADIUS OF 034 KT WINDS - 125 NM NORTHEAST QUADRANT
105 NM SOUTHEAST QUADRANT
135 NM SOUTHWEST QUADRANT
100 NM NORTHWEST QUADRANT
REPEAT POSIT: 32.9N 141.7E
---
FORECASTS:
12 HRS, VALID AT:
241200Z --- 33.7N 142.2E
MAX SUSTAINED WINDS - 030 KT, GUSTS 040 KT
WIND RADII VALID OVER OPEN WATER ONLY
EXTRATROPICAL
VECTOR TO 24 HR POSIT: 005 DEG/ 10 KTS
---
24 HRS, VALID AT:
250000Z --- 35.7N 142.5E
MAX SUSTAINED WINDS - 030 KT, GUSTS 040 KT
WIND RADII VALID OVER OPEN WATER ONLY
EXTRATROPICAL
---
REMARKS:
240300Z POSITION NEAR 33.1N 141.8E.
24SEP20. TROPICAL STORM 14W (DOLPHIN), LOCATED APPROXIMATELY 175 NM
SOUTHEAST OF YOKOSUKA, JAPAN, HAS TRACKED SOUTHWARD AT 01 KNOT OVER
THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY SHOWS
THE RAGGED LOW LEVEL CIRCULATION HAS BECOME QUASI-STATIONARY AND
FULLY EXPOSED AS THE RAPIDLY DECAYING CENTRAL CONVECTION SHEARED
140NM+ EAST-NORTHEASTWARD. THE INITIAL POSITION IS PLACED WITH HIGH
CONFIDENCE BASED ON THE ABOVE ANIMATION. ANALYSIS INDICATES THAT TS
14W IS NOW FULLY EMBEDDED IN THE BAROCLINIC ZONE AND HAS BECOME
EXTRA-TROPICAL. THE REMNANT STORM-FORCE COLD-CORE LOW WILL DRIFT
SLOWLY POLEWARD AND DEEPER INTO THE COLD POLAR AIR MASS. THERE IS
ALSO A DISTINCT POSSIBILITY THAT THE CYCLONE WILL REMAIN QUASI-
STATIONARY AND DISSIPATE. THIS IS THE FINAL WARNING ON THIS SYSTEM
BY THE JOINT TYPHOON WRNCEN PEARL HARBOR HI. THE SYSTEM WILL BE
CLOSELY MONITORED FOR SIGNS OF REGENERATION. MAXIMUM SIGNIFICANT
WAVE HEIGHT AT 240000Z IS 15 FEET.//
NNNN

[Hayabusa]

Dolphin is already long gone but Kujira got archived first.