WPAC: KAJIKI - Post-Tropical

[doomhaMwx]

At this time, all met agencies seem to agree that Kajiki and Invest / TD 94W will interact with each other, with Kajiki turning back towards northeast and emerging into the South China Sea (except for the JTWC which has Kajiki dissipating before reaching the South China Sea).





There is still rather low confidence in the forecast at this time. Model guidance have been suggesting the idea of Kajiki and 94W merging into one system and consolidate, but uncertainty has increased further on which of the two systems will become dominant. It is even possible that 94W will remain a separate system.

[doomhaMwx]

I find it funny though that JTWC said there was high confidence in the forecast when they issued their first TC warning, but suddenly low confidence in the second warning.
I mean, the models were already indicating an erratic movement followed by a NE turn, even before they upgraded it into a TD.

... GLOBAL MODELS ARE IN GENERAL AGREEMENT THAT
THE SYSTEM WILL TRACK TO THE SOUTHWEST AS IT DISSIPATES. THE JTWC
TRACK FORECAST IS PLACED NEAR THE MULTI-MODEL THE CONSENSUS WITH
HIGH CONFIDENCE.

... THE WEAKENED AND DECOUPLED NATURE OF THE SYSTEM IS
CAUSING MANY OF THE GLOBAL MODEL TRACKERS TO PRODUCE ERRATIC TRACK
SOLUTIONS AFTER TAUS 6-12 (MODEL DEPENDENT) CAUSING A HIGH DEGREE OF
UNCERTAINTY IN THE MODEL GUIDANCE. THE JTWC TRACK FORECAST IS PLACED
NEAR THE MULTI-MODEL THE CONSENSUS WITH OVERALL LOW CONFIDENCE DUE
TO THE MODEL UNCERTAINTY.

[euro6208]

WDPN33 PGTW 030300
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL DEPRESSION 16W (KAJIKI)
WARNING NR 02//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
TROPICAL DEPRESSION 16W (KAJIKI), LOCATED APPROXIMATELY
58 NM WEST OF DA NANG, VIETNAM, HAS TRACKED SOUTHWESTWARD AT 08
KNOTS OVER THE PAST SIX HOURS. ANIMATED ENHANCED INFRARED (EIR)
SATELLITE IMAGERY SHOWS CONVECTIVE BANDING WRAPPING INTO AN
ELONGATED LOW LEVEL CIRCULATION CENTER (LLCC). THE INITIAL POSITION
IS BASED ON THE ANIMATED EIR LOOP WITH LOW OVERALL CONFIDENCE DUE TO
THE ELONGATED NATURE OF THE CIRCULATION. THE INITIAL INTENSITY OF 30
KNOTS IS BASED ON 26-27 KNOT SURFACE OBSERVATIONS TO THE NORTH OF
THE SYSTEM AND IS SUPPORTED BY MINIMAL DEGRADATION IN SYSTEM
STRUCTURE SINCE LANDFALL. ENVIRONMENTAL ANALYSIS REVEALS THAT THE
SYSTEM IS IN AN AREA OF MODERATE (15-20 KT) VERTICAL WIND SHEAR
(VWS) AND HAS GOOD EQUATORWARD AND POLEWARD OUTFLOW. THE SYSTEM IS
CURRENTLY OVERLAND AND BEGINNING TO INTERACT WITH THE RUGGED
MOUNTAIN TERRAIN OF VIETNAM AND LAOS. TD 16W IS TRACKING SOUTHWEST
ALONG THE SOUTHEASTERN PERIPHERY OF A SUBTROPICAL RIDGE (STR)
CENTERED OVER THE BAY OF BENGAL.
3. FORECAST REASONING.
A. THE FORECAST PHILOSOPHY HAS CHANGED TO INCLUDE THE SYSTEM
RECURVING TO THE NORTHEAST AS IT DISSIPATES OF EASTERN INDOCHINA.
B. TD 16W IS FORECAST TO CONTINUE TO TRACK SOUTHWEST FOR THE NEXT
6 HOURS BEFORE BEGINNING A TURN BACK TO THE NORTHEAST. AS THE SYSTEM
IS WEAKENED BY THE MOUNTAINOUS TERRAIN OF INDOCHINA AND IMPACTED BY
INCREASING VERTICAL WIND SHEAR, IT WILL BEGIN TO DE-COUPLE. THE LLCC
IS EXPECTED TO RECURVE BACK TO THE NORTHEAST TOWARDS THE SOUTH CHINA
SEA. HOWEVER, THE UNFAVORABLE ENVIRONMENT WILL CAUSE THE SYSTEM TO
WEAKEN AND DISSIPATE AROUND TAU 36 PRIOR TO REACHING THE SOUTH CHINA
SEA. GLOBAL MODELS ARE IN GENERAL AGREEMENT THAT THE SYSTEM WILL
TRACK TO THE SOUTHWEST FOR A BRIEF PERIOD BEFORE TURNING BACK TO THE
NORTHEAST. THE WEAKENED AND DECOUPLED NATURE OF THE SYSTEM IS
CAUSING MANY OF THE GLOBAL MODEL TRACKERS TO PRODUCE ERRATIC TRACK
SOLUTIONS AFTER TAUS 6-12 (MODEL DEPENDENT) CAUSING A HIGH DEGREE OF
UNCERTAINTY IN THE MODEL GUIDANCE. THE JTWC TRACK FORECAST IS PLACED
NEAR THE MULTI-MODEL THE CONSENSUS WITH OVERALL LOW CONFIDENCE DUE
TO THE MODEL UNCERTAINTY.//
NNNN

[doomhaMwx]

Kajiki has emerged back over the South China Sea according to JTWC and JMA.
Most of the associated convection is located over the Indochina Peninsula, however.

[euro6208]

WDPN33 PGTW 030900
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 16W (SIXTEEN) WARNING
NR 03//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
TROPICAL DEPRESSION 16W (KAJIKI), LOCATED APPROXIMATELY
21 NM NORTH-NORTHWEST OF DA NANG, VIETNAM, HAS TRACKED EAST-
NORTHEASTWARD AT 09 KNOTS OVER THE PAST SIX HOURS.ANIMATED
MULTISPECTRAL SATELLITE IMAGERY (MSI) SHOWS THE BULK OF CONVECTION
IS SHEARED TO THE SOUTHWEST OF AN ELONGATED, PARTIALLY EXPOSED LOW
LEVEL CIRCULATION CENTER (LLCC). THE INIITAL POSITION IS BASED ON
THE ANIMATED MSI LOOP AND A 030612Z AMSR-2 89GHZ IMAGE SHOWING
BANDING WRAPPING INTO A SMALL FLARE OF CONVECTION NEAR THE LLCC WITH
LOW OVERALL CONFIDENCE DUE TO THE ELONGATED NATURE OF THE
CIRCULATION. THE INITIAL INTENSITY OF 30 KNOTS IS BASED ON 25-30 KT
WINDS IN A PARTIAL 030303Z PARTIAL METOP-B ASCAT PASS TO THE NORTH,
AND SURFACE OBSERVATIONS OF 998MB. ENVIRONMENTAL ANALYSIS REVEALS
THAT THE SYSTEM IS IN AND AREA OF HIGH (25-30 KT) VERTICAL WIND
SHEAR (VWS) AND HAS GOOD EQUATORWARD OUTFLOW, BUT THE NORTHEASTERLY
VWS IS PUSHING THE CONVECTION TO THE SOUTHEST OF THE LLCC. THE
SYSTEM HAS RECURVED FASTER THAN EXPECTED TO THE NORTHEAST AND IS RE-
EMERGING INTO THE SOUTH CHINA SEA. TS 14W IS TRACKING ALONG THE
NORTHERN PERIPHERY OF A NEAR-EQUATORIAL RIDGE TO THE SOUTHEAST.
3. FORECAST REASONING.
A. THE FORECAST PHILOSOPHY HAS CHANGED TO REFLECT THE FASTER THAN
EXPECTED TURN TO THE NORTHEAST, AND TO REFLECT THE SYSTEM
MAINTAINING INTENSITY AS IT MOVES BACK OVER WATER.
B. TD 16W IS FORECAST TO CONTINUE TRACKING TOWARDS THE NORTHEAST
AND MANTAIN INTENSITY. WHILE THE HIGH VWS IS UNFAVORABLE, GOOD
EQUATORWARD OUTFLOW AND TRACKING BACK OVER WARM (30-32 DEGREES
CELSIUS) WATER SHOULD ENABLE 16W TO MAINTAIN INTENSITY. GLOBAL
MODELS ARE IN GENERAL AGREEMENT THAT THE SYSTEM WILL TRACK TO THE
NORTHEAST, ALTHOUGH ECMWF IS SIGNIFICANTLY SLOWER THAN THE GFS,
UKMET, GALWEM, AND JAPANESE MODEL SOLUTIONS FOR TRACK MOTION. THE
OBSERVED TRACK MOTION OVER THE PAST 6 HOURS SUGGESTS THAT THE ALONG-
TRACK MOTION MAY BE FASTER THAN THE MODELS DEPICT. ADDITIONALLY, THE
PRESENCE OF INVEST 94W APPROXIMATELY 200 NM TO THE NORTHEAST MAY
IMPACT THE STEERING AND UPPER LEVEL ENVIRONMENT FOR TD 16W, CAUSING
A FUJIWHARA EFFECT AND EVENTUAL CONSOLIDATION. DUE TO THE BROAD
NATURE OF THE CIRCULATION, THE PRESENCE OF INVEST 94W, AND THE
SPREAD IN ALONG-TRACK MOTION, JTWC TRACK FORECAST IS PLACED CLOSE TO
THE MULTI-MODEL CONSENSUS WITH LOW CONFIDENCE.//
NNNN

[Hayabusa]

Dead

TD
Issued at 13:10 UTC, 3 September 2019

<Analysis at 12 UTC, 3 September>
Scale -
Intensity -
TD
Center position N17°00' (17.0°)
E109°00' (109.0°)
Direction and speed of movement NNE 20 km/h (10 kt)
Central pressure 998 hPa

[euro6208]

WTPN33 PGTW 032100
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL DEPRESSION 16W (KAJIKI) WARNING NR 005//
RMKS/
1. TROPICAL DEPRESSION 16W (KAJIKI) WARNING NR 005
03 ACTIVE TROPICAL CYCLONES IN NORTHWESTPAC
MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
WIND RADII VALID OVER OPEN WATER ONLY
---
WARNING POSITION:
031800Z --- NEAR 17.0N 107.4E
MOVEMENT PAST SIX HOURS - 360 DEGREES AT 07 KTS
POSITION ACCURATE TO WITHIN 060 NM
POSITION BASED ON CENTER LOCATED BY SATELLITE
PRESENT WIND DISTRIBUTION:
MAX SUSTAINED WINDS - 025 KT, GUSTS 035 KT
WIND RADII VALID OVER OPEN WATER ONLY
DISSIPATING AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER
REPEAT POSIT: 17.0N 107.4E
---
FORECASTS:
12 HRS, VALID AT:
040600Z --- 17.6N 107.8E
MAX SUSTAINED WINDS - 020 KT, GUSTS 030 KT
WIND RADII VALID OVER OPEN WATER ONLY
DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER
VECTOR TO 24 HR POSIT: 060 DEG/ 04 KTS
---
24 HRS, VALID AT:
041800Z --- 18.0N 108.6E
MAX SUSTAINED WINDS - 020 KT, GUSTS 030 KT
WIND RADII VALID OVER OPEN WATER ONLY
DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER
---
REMARKS:
032100Z POSITION NEAR 17.2N 107.5E.
03SEP19. TROPICAL DEPRESSION 16W (KAJIKI), LOCATED APPROXIMATELY
79 NM NORTHWEST OF DA NANG, VIETNAM, HAS TRACKED NORTHWARD AT 07
KNOTS OVER THE PAST SIX HOURS. 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 031800Z IS 10 FEET. REFER TO TROPICAL STORM 14W
(FOURTEEN) WARNINGS (WTPN31 PGTW) FOR SIX-HOURLY UPDATES. REFER TO
TYPHOON 15W (LINGLING) WARNINGS (WTPN32 PGTW) FOR SIX-HOURLY
UPDATES.//
NNNN

[doomhaMwx]

Lol what a mess...
Kajiki appears to have already merged with Invest/TD 94W. Model guidance are maintaining the circulation of Kajiki and show it tracking ENE over the
northern South China Sea towards Taiwan during the next few days, but remaining very weak. I guess it's still worth watching though.

[euro6208]

16W KAJIKI
As of 06:00 UTC Sep 05, 2019:

Location: 18.2°N 111.4°E
Maximum Winds: 15 kt
Minimum Central Pressure: 1000 mb

[Nancy Smar]

16W KAJIKI 190907 0000 19.3N 114.3E WPAC 15 1000

[Kingarabian]

Everytime I see Kajiki, I become in the mood for some raw Marlin.

[doomhaMwx]

A burst of convection occurred this morning. Back to a "minor" TD by JMA.

TROPICAL DEPRESSION 1000 HPA AT 20N 115E ENE 10 KT.

[1900hurricane]

Not sure I would have noticed it if you didn't say something.

[euro6208]

16W KAJIKI
As of 06:00 UTC Sep 07, 2019:

Location: 19.5°N 114.8°E
Maximum Winds: 15 kt
Minimum Central Pressure: 1001 mb