WPAC: RUMBIA - Post-Tropical

[Twisted-core]

WTPQ33 RJTD 160600
RSMC TROPICAL CYCLONE PROGNOSTIC REASONING
REASONING NO. 6 FOR TS 1818 RUMBIA (1818)
1.GENERAL COMMENTS
TS RUMBIA IS LOCATED AT 29.9N, 124.4E. INFORMATION ON THE CURRENT
POSITION IS BASED ON ANIMATED MSI. POSITIONAL ACCURACY IS FAIR.
THE SYSTEM IS IN A NEUTRAL ENVIRONMENT FOR DEVELOPMENT UNDER THE
INFLUENCE OF HIGH SSTS, WEAK VWS AND DRY AIR. THIS HAS CAUSED THE
SYSTEM TO MAINTAIN ITS INTENSITY OVER THE LAST SIX HOURS.
INFORMATION ON CURRENT INTENSITY IS BASED ON DVORAK INTENSITY
ANALYSES AND SURFACE OBSERVATIONS.
2.SYNOPTIC SITUATION
THE SYSTEM IS MOVING WEST-NORTHWESTWARD ALONG THE SOUTHWESTERN
PERIPHERY OF A MID-LEVEL SUB-TROPICAL HIGH. ANIMATED MSI SHOWS CB
CLUSTERS GATHERING AROUND THE CSC. ANIMATED MSI SHOWS GOOD CLOUD
CHARACTERISTICS OF ANTICYCLONIC OUTFLOW. WATER VAPOR IMAGERY SHOWS
DRY AIR AROUND THE SYSTEM. GCOM-W/AMSR2 89 GHZ MICROWAVE IMAGERY
SHOWS THE SYSTEM HAS ACTIVE CONVECTIVE CLOUD CLUSTERS AROUND THE
CSC.
3.TRACK FORECAST
THE SYSTEM WILL MOVE WEST-NORTHWESTWARD ALONG THE PERIPHERY OF A
MID-LEVEL SUB-TROPICAL HIGH UNTIL FT48. THE SYSTEM WILL HIT THE
CHINESE MAINLAND BY FT18. THE JMA TRACK FORECAST IS BASED ON GSM
PREDICTIONS, AND REFERENCE TO OTHER NWP MODELS. JMA TRACK FORECAST
CONFIDENCE IS FAIR BECAUSE ALL NUMERICAL MODELS ARE IN CLOSE
AGREEMENT.
4.INTENSITY FORECAST
THE SYSTEM WILL MAINTAIN ITS INTENSITY UNTIL FT24 DUE TO THE
INFLUENCE OF INTERACTION WITH HIGH SSTS AND WEAK VWS. THE SYSTEM
WILL THEN WEAKEN UNTIL FT48 DUE TO ITS CONTINUED PRESENCE OVER
LAND. THE SYSTEM WILL WEAKEN TO TD INTENSITY BY FT48. THE JMA
INTENSITY FORECAST IS BASED ON A CONSENSUS OF GUIDANCE DATA
INCLUDING GSM.
=

[euro6208]

WDPN32 PGTW 160900
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 21W (RUMBIA) WARNING NR
06//
RMKS//
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
TROPICAL STORM 21W (RUMBIA), LOCATED APPROXIMATELY 145 NM EAST-
SOUTHEAST OF SHANGHAI, CHINA, HAS TRACKED WEST-NORTHWESTWARD AT
06 KNOTS OVER THE PAST SIX HOURS. THE CURRENT POSITION IS SITUATED
WITHIN A LOW-LEVEL CIRCULATION CENTER FEATURE EVIDENT IN 160519Z
AMSR2 MICROWAVE SATELLITE IMAGERY. THE INTENSITY OF 40 KNOTS IS SET
SLIGHTLY ABOVE SUBJECTIVE DVORAK CURRENT INTENSITY ESTIMATES RANGING
FROM T2.0 TO T2.5, BASED ON 35-40 KNOT PERIPHERAL WINDS EVIDENT IN A
160040Z ASCAT PASS. TS 21W HAS INTENSIFIED SLIGHTLY OVER THE PAST
SIX HOURS AS UPPER-LEVEL RIDGING HAS DEVELOPED OVER THE SYSTEM IN
THE WAKE OF A TROUGH THAT HAD PREVIOUSLY SUPPRESSED CONVECTIVE
DEVELOPMENT OVER THE WESTERN PORTION OF THE CIRCULATION. DEEP
CONVECTION REMAINS FRAGMENTED AND FOCUSED TO THE EAST AND NORTH OF
THE CIRCULATION CENTER, ALTHOUGH IT HAS BECOME MORE WIDESPREAD
RECENTLY. TS 21W IS TRACKING WEST-NORTHWESTWARD UNDER THE INFLUENCE
OF A DEEP-LAYER STEERING RIDGE TO THE NORTH.
3. FORECAST REASONING.
A. THERE IS NO SIGNIFICANT CHANGE TO THE FORECAST PHILOSOPHY FROM
THE PREVIOUS PROGNOSTIC REASONING MESSAGE.
B. TS RUMBIA WILL CONTINUE TRACKING WEST-NORTHWESTWARD UNDER THE
INFLUENCE OF THE STEERING RIDGE TO THE NORTH THROUGHOUT THE FORECAST
PERIOD. THE SYSTEM IS EXPECTED TO MAKE LANDFALL JUST SOUTH OF
SHANGHAI AROUND TAU 12 AND DISSIPATE INLAND BY TAU 36. MINIMAL TO NO
INTENSIFICATION IS ANTICIPATED PRIOR TO LANDFALL, AS ALONG-TRACK SEA
SURFACE TEMPERATURES DECREASE AND AS THE BROAD CIRCULATION RUNS
SHORT ON TIME TO CONSOLIDATE BEFORE EXPERIENCING THE NEGATIVE IMPACT
OF LAND INTERACTION. NUMERICAL MODELS REMAIN IN GOOD AGREEMENT,
RESULTING IN HIGH CONFIDENCE IN THE TRACK FORECAST.//
NNNN

[mrbagyo]

[euro6208]

WDPN34 PGTW 162100
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 21W (RUMBIA) WARNING NR
08//
RMKS//
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
TROPICAL STORM 21W (RUMBIA), LOCATED APPROXIMATELY 56 NM SOUTH-
SOUTHEAST OF SHANGHAI, CHINA, HAS TRACKED WESTWARD AT 12 KNOTS
OVER THE PAST SIX HOURS. ANIMATED ENHANCED INFRARED SATELLITE
IMAGERY INDICATED A BRIEF PERIOD OF INTENSIFICATION, WITH INCREASED
CONVECTIVE SYMMETRY AND A BRIEF APPEARANCE OF A REGION OF WARMER
CLOUD-TOP BRIGHTNESS TEMPERATURES SURROUNDED BY DEEP CONVECTION. A
161813Z ATMS 18GHZ MICROWAVE IMAGE INDICATES DEEP CONVECTION
WRAPPING AROUND A LOW-LEVEL CIRCULATION CENTER, WHICH WAS PLACED
WITH GOOD CONFIDENCE. THE INTENSITY WAS RAISED TO 50 KNOTS BASED ON
A BLEND OF DVORAK INTENSITY ESTIMATES OF T3.5 (PGTW) AND T2.5
(RJTD), ALONG WITH A SHIP OBSERVATION AT THE MOUTH OF HANGZHOU BAY
AT 161800Z REPORTING WINDS OF 42 KNOTS WITH PRESSURE FALLING THROUGH
986 MB AND ASSOCIATED WIND SHIFT. TS 21W HAS GRADUALLY INTENSIFIED
AS IT MOVES THROUGH HANGZHOU BAY, WITH GOOD OUTFLOW AND LOW VERTICAL
WIND SHEAR OF LESS THAN 5 KNOTS. IT CONTINUES TO TRACK WESTWARD
UNDER THE INFLUENCE OF A DEEP-LAYER STEERING RIDGE TO THE NORTH.
3. FORECAST REASONING.
A. THERE IS NO SIGNIFICANT CHANGE TO THE FORECAST PHILOSOPHY FROM
THE PREVIOUS PROGNOSTIC REASONING MESSAGE.
B. TS RUMBIA WILL CONTINUE TRACKING WEST-NORTHWESTWARD UNDER THE
INFLUENCE OF THE STEERING RIDGE TO THE NORTH THROUGHOUT THE FORECAST
PERIOD. THE SYSTEM IS EXPECTED TO MAKE LANDFALL WITHIN THE NEXT 6 TO
12 HOURS AND DISSIPATE INLAND BY TAU 36. GRADUAL WEAKENING IS
FORECAST TO COMMENCE AS THE SYSTEM MOVES DEEPER INTO HANGZOU BAY AND
THE IMPACTS OF LAND INTERACTION INCREASE. NUMERICAL MODELS REMAIN IN
GOOD AGREEMENT, RESULTING IN HIGH CONFIDENCE IN THE JTWC TRACK
FORECAST.//
NNNN

[NotoSans]

Landfall pressure appears to be 985 mb.

[euro6208]

Amazing rapid strengthening before landfall...

[euro6208]

2nd largest city in the world escapes yet again.

WTPN34 PGTW 170300
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE WARNING//
RMKS/
1. TROPICAL STORM 21W (RUMBIA) WARNING NR 009
03 ACTIVE TROPICAL CYCLONES IN NORTHWESTPAC
MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
WIND RADII VALID OVER OPEN WATER ONLY
---
WARNING POSITION:
170000Z --- NEAR 31.3N 120.7E
MOVEMENT PAST SIX HOURS - 305 DEGREES AT 12 KTS
POSITION ACCURATE TO WITHIN 060 NM
POSITION BASED ON CENTER LOCATED BY SATELLITE
PRESENT WIND DISTRIBUTION:
MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT
WIND RADII VALID OVER OPEN WATER ONLY
DISSIPATING AS A SIGNIFICANT TROPICAL CYCLONE OVER LAND
RADIUS OF 034 KT WINDS - 185 NM NORTHEAST QUADRANT
120 NM SOUTHEAST QUADRANT
070 NM SOUTHWEST QUADRANT
150 NM NORTHWEST QUADRANT
REPEAT POSIT: 31.3N 120.7E
---
FORECASTS:
12 HRS, VALID AT:
171200Z --- 31.9N 117.9E
MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT
WIND RADII VALID OVER OPEN WATER ONLY
DISSIPATING AS A SIGNIFICANT TROPICAL CYCLONE OVER LAND
VECTOR TO 24 HR POSIT: 300 DEG/ 11 KTS
---
24 HRS, VALID AT:
180000Z --- 32.9N 115.6E
MAX SUSTAINED WINDS - 025 KT, GUSTS 035 KT
WIND RADII VALID OVER OPEN WATER ONLY
DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER LAND
---
REMARKS:
170300Z POSITION NEAR 31.5N 120.0E.
TROPICAL STORM 21W (RUMBIA), LOCATED APPROXIMATELY 41 NM WEST OF
SHANGHAI, CHINA, HAS TRACKED NORTHWESTWARD AT 12 KNOTS OVER THE
PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI)
INDICATES THAT TS 21W HAS MADE LANDFALL SOUTHWEST OF SHANGHAI. THE
INITIAL POSITION IS PLACED WITH GOOD CONFIDENCE USING MSI AND RADAR
IMAGERY. THE CURRENT INTENSITY IS LOWERED TO 45 KNOTS AS LAND-
INDUCED FRICTIONAL DISSIPATION COMMENCES. THE SYSTEM IS FORECAST TO
CONTINUE MOVING TOWARD THE WEST-NORTHWEST AS IT IS STEERED FURTHER
INLAND INTO CHINA BY A SUBTROPICAL RIDGE, WITH DISSIPATION EXPECTED
BY TAU 24. DYNAMICAL MODELS ARE IN GOOD AGREEMENT, AND THERE IS
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.
REFER TO TROPICAL STORM 20W (BEBINCA) WARNINGS (WTPN33 PGTW)
FOR SIX-HOURLY UPDATES. REFER TO TYPHOON 22W (SOULIK) WARNINGS
(WTPN35 PGTW) FOR SIX-HOURLY UPDATES.
//
NNNN

[NotoSans]

The JTWC is inaccurate for the landfall position. According to the CMA, RUMBIA made landfall directly over Shanghai at 2005Z. This is also the first time that three typhoons have made landfall over Shanghai in a single year.

[euro6208]

Really organize despite being overland...