WPAC: HAISHEN - Post-Tropical

[Hayabusa]

Why was this renamed to a Tropical Storm? JMA still has it as a TYPHOON

TY 2010 (Haishen)
Issued at 04:45 UTC, 7 September 2020

<Analysis at 04 UTC, 7 September>
Scale Large
Intensity -
Center position N37°25' (37.4°)
E129°25' (129.4°)
Direction and speed of movement N 50 km/h (26 kt)
Central pressure 970 hPa
Maximum wind speed near center 35 m/s (65 kt)
Maximum wind gust speed 50 m/s (95 kt)
≥ 50 kt wind area E 280 km (150 NM)
W 165 km (90 NM)
≥ 30 kt wind area E 700 km (375 NM)
W 440 km (240 NM)

[euro6208]

WDPN32 PGTW 070300 AMD
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 11W (HAISHEN)
WARNING NR 027A AMENDED//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
TROPICAL STORM 11W (HAISHEN), LOCATED APPROXIMATELY 26 NM NORTH-
NORTHWEST OF BUSAN, SOUTH KOREA, HAS TRACKED NORTHWARD AT 23 KNOTS
OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY
AND A COMPOSITE RADAR LOOP INDICATE THE SYSTEM HAS RAPIDLY ERODED AFTER
IT MADE LANDFALL AS EVIDENCED BY THE UNRAVELING AND COLLAPSING OF
CONVECTIVE BANDS. THE INITIAL POSITION IS PLACED WITH HIGH
CONFIDENCE BASED ON THE CIRCULATION FEATURE IN THE RADAR LOOP AND
TRIANGULATION OF NUMEROUS WIND OBSERVATIONS OVER LAND. THE INITIAL
INTENSITY OF 65 KTS IS EXTRAPOLATED FROM AGENCY DVORAK ESTIMATES PRIOR
TO LANDFALL, SURFACE WIND OBSERVATIONS, AND A TIMELY 070030 ASCAT-A
PASS. FURTHERMORE, 062240Z ADT ESTIMATE OF T4.4 (75 KTS). UPPER LEVEL
ANALYSIS INDICATES A ROBUST POLEWARD OUTFLOW THAT IS OFFSET BY STRONG
(30-KT+) VERTICAL WIND SHEAR. ALSO, THE RUGGED MOUNTAINOUS TERRAIN IS
GREATLY CONTRIBUTING TO THE RAPID EROSION OF THE SYSTEM FROM BELOW. THE
CYCLONE IS TRACKING ALONG THE WESTERN PERIPHERY OF THE SUBTROPICAL
RIDGE (STR) TO THE EAST.
3. FORECAST REASONING.
A. THERE IS NO SIGNIFICANT CHANGE TO THE FORECAST PHILOSOPHY FROM
THE LAST PROGNOSTIC REASONING MESSAGE.
B. TS HAISHEN WILL CONTINUE TO TRACK NORTHWARD THROUGHOUT THE
FORECAST PERIOD UNDER THE STR, MOMENTARILY EXIT INTO THE SEA OF
JAPAN SHORTLY AFTER TAU 06, THEN MAKE A SECONDARY AND FINAL LANDFALL
INTO NORTH KOREA BY TAU 12 BEFORE CROSSING INTO MANCHURIA. THE HOSTILE
ENVIRONMENT, WITH THE ADDITION OF FRICTIONAL EFFECTS OF THE RUGGED
MOUNTAIN RANGES OF THE KOREAN PENINSULA WILL RAPIDLY ERODE AND DISPERSE
THE CONVECTIVE BANDS. CONCURRENTLY, THE SYSTEM HAS ENTERED THE
BAROCLINIC ZONE AND BEGUN EXTRA-TROPICAL TRANSITION AND WILL TRANSFORM
INTO A 30-KNOT COLD-CORE LOW BY TAU 12. NUMERICAL MODELS REMAIN IN
TIGHT AGREEMENT WITH THE EXCEPTION OF AFUM WHICH CONTINUES TO BE AN
EXTREME RIGHT-OF-TRACK OUTLIER AND DRIVES THE VORTEX INTO THE STR.
THERE IS HIGH CONFIDENCE IN THE JTWC FORECAST TRACK THAT IS LAID LEFT
OF THE MODEL CONSENSUS TO OFFSET AFUM.
4. JUSTIFICATION FOR AMENDMENT: AMENDED CURRENT INTENSITY DUE TO
OBJECTIVE WIND SPEED DATA.//
NNNN

[mrbagyo]

Storm to Busan Part 1 : Maysak


Storm to Busan Part 2 : Haishen

[Hayabusa]

Threadly reminder that JMA is the official RSMC for the Northwestern Pacific. No disrespect to the mods especially the mod that renamed it to a TS just because JTWC said it. I'm just stating a fact.

TY 2010 (Haishen)
Issued at 06:45 UTC, 7 September 2020

<Analysis at 06 UTC, 7 September>
Scale Large
Intensity -
Center position N38°25' (38.4°)
E129°20' (129.3°)
Direction and speed of movement N 50 km/h (26 kt)
Central pressure 970 hPa
Maximum wind speed near center 35 m/s (65 kt)
Maximum wind gust speed 50 m/s (95 kt)
≥ 50 kt wind area ALL 165 km (90 NM)
≥ 30 kt wind area E 600 km (325 NM)
W 500 km (270 NM)

[doomhaMwx]

 https://twitter.com/NHKWORLD_News/status/1302857324860788736

[doomhaMwx]

Haishen seen from the ISS when it was near the Ryukyus.

 https://twitter.com/Astro_SEAL/status/1302694615397457920

[euro6208]

Final Warning



WTPN32 PGTW 071500
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE WARNING//
RMKS/
1. TROPICAL STORM 11W (HAISHEN) WARNING NR 029
01 ACTIVE TROPICAL CYCLONE IN NORTHWESTPAC
MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
WIND RADII VALID OVER OPEN WATER ONLY
---
WARNING POSITION:
071200Z --- NEAR 40.7N 128.9E
MOVEMENT PAST SIX HOURS - 360 DEGREES AT 24 KTS
POSITION ACCURATE TO WITHIN 030 NM
POSITION BASED ON CENTER LOCATED BY SATELLITE
PRESENT WIND DISTRIBUTION:
MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT
WIND RADII VALID OVER OPEN WATER ONLY
BECOMING EXTRATROPICAL
RADIUS OF 034 KT WINDS - 260 NM NORTHEAST QUADRANT
280 NM SOUTHEAST QUADRANT
210 NM SOUTHWEST QUADRANT
150 NM NORTHWEST QUADRANT
REPEAT POSIT: 40.7N 128.9E
---
FORECASTS:
12 HRS, VALID AT:
080000Z --- 44.0N 128.5E
MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT
WIND RADII VALID OVER OPEN WATER ONLY
EXTRATROPICAL
RADIUS OF 034 KT WINDS - 020 NM NORTHEAST QUADRANT
170 NM SOUTHEAST QUADRANT
050 NM SOUTHWEST QUADRANT
020 NM NORTHWEST QUADRANT
VECTOR TO 24 HR POSIT: 355 DEG/ 09 KTS
---
24 HRS, VALID AT:
081200Z --- 45.7N 128.3E
MAX SUSTAINED WINDS - 030 KT, GUSTS 040 KT
WIND RADII VALID OVER OPEN WATER ONLY
EXTRATROPICAL
---
REMARKS:
071500Z POSITION NEAR 41.5N 128.8E.
07SEP20. TROPICAL STORM (TS) 11W (HAISHEN), LOCATED
APPROXIMATELY 233 NM NORTH-NORTHEAST OF OSAN AB, SOUTH
KOREA HAS TRACKED NORTHWARD AT 24 KNOTS OVER THE PAST SIX
HOURS. ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY
REVEALS CONTINUED DECAYING CONVECTION THAT IS BECOMING
INCREASINGLY DECOUPLED FROM A BROADENING LOW LEVEL
CIRCULATION CENTER (LLCC) WHICH IS NOW TRACKING OVER LAND.
THE INITIAL POSITION IS PLACED WITH FAIR CONFIDENCE BASED
ON THE LOCATION OF THE LLCC IN THE EIR LOOP AS WELL AS VIA
EXTRAPOLATION THROUGH A LOW LEVEL CIRCULATION FEATURE IN
THE SCATTEROMETRY DATA FROM A TIMELY 071206Z ASCAT-A PASS.
THE INTENSITY IS PLACED WITH FAIR CONFIDENCE BASED ON THE
35 KTS WIND SPEEDS PRESENT IN THE AFOREMENTIONED ASCAT-A
DATA. TS HAISHEN WILL CONTINUE TO TRACK POLEWARD THROUGH
THE REMAINDER OF THE FORECAST PERIOD. BY TAU 12 THE SYSTEM
WILL BECOME FULLY EMBEDDED IN THE MID-LATITUDE FLOW AND
COMPLETE EXTRATROPICAL TRANSITION AS A COLD CORE LOW.
DYNAMIC GUIDANCE REMAINS IN TIGHT AGREEMENT LENDING HIGH
CONFIDENCE IN THE JTWC FORECAST TRACK. 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.
//
NNNN

[Hayabusa]

LOW
Issued at 18:50 UTC, 7 September 2020

<Analysis at 18 UTC, 7 September>
Scale -
Intensity -
LOW
Center position N42°00' (42.0°)
E129°00' (129.0°)
Direction and speed of movement N 35 km/h (20 kt)
Central pressure 988 hPa

[1900hurricane]

[NotoSans]

A buoy recorded a minimum pressure of 919.0mb inside the eye slightly before peak (at 07Z Sept 4). This observation seems quite consistent with microwave estimates (AMSU has 913mb at 12Z Sept 4).
 https://twitter.com/ben108472/status/1405796661180338176