WPAC: DOLPHIN - Post-Tropical

[Nancy Smar]

93W.INVEST

[Hayabusa]

The 12th named storm in 2010 formed on September 22, and if the 12th still don't form before or by then, 2020 would overtake that record. 1998 still leads on late formation though, at this time 1998 was still at its 8th named storm.

[euro6208]

AN AREA OF CONVECTION (INVEST 93W) HAS PERSISTED NEAR
21.5N 135.3E, APPROXIMATELY 505 NM EAST-SOUTHEAST OF KADENA AB,
OKINAWA. ANIMATED ENHANCED INFRARED SATELLITE IMAGERY AND A 191227Z
MHS METOP-B 89GHZ MICROWAVE IMAGE DEPICT A BROAD LOW LEVEL
CIRCULATION (LLC) OBSCURED BY FLARING CONVECTION. A 190917Z SSMIS
IMAGE DEPICTS LOW LEVEL BANDING ASSOCIATED WITH A POORLY-ORGANIZED
AREA OF CYCLONIC TURNING. UPPER-LEVEL ANALYSIS DEPICTS A FAVORABLE
ENVIRONMENT WITH WEAK EQUATORWARD OUTFLOW IN AN AREA OF LOW (5-10
KTS) VERTICAL WIND SHEAR. ADDITIONALLY, WARM (29-30 CELSIUS) SEA
SURFACE TEMPERATURES ARE CONDUCIVE FOR TROPICAL TRANSITION. MAXIMUM
SUSTAINED SURFACE WINDS ARE ESTIMATED AT 15 TO 20 KNOTS. MINIMUM SEA
LEVEL PRESSURE IS ESTIMATED TO BE NEAR 1008 MB. THE POTENTIAL FOR
THE DEVELOPMENT OF A SIGNIFICANT TROPICAL CYCLONE WITHIN THE NEXT 24
HOURS IS UPGRADED TO LOW.

[Hayabusa]

WWJP27 RJTD 191800
WARNING AND SUMMARY 191800.
WARNING VALID 201800.
WARNING IS UPDATED EVERY 6 HOURS.
TROPICAL DEPRESSION 1008 HPA AT 22N 135E NNW SLOWLY.

[euro6208]

THE AREA OF CONVECTION (INVEST 93W) PREVIOUSLY LOCATED
NEAR 21.5N 135.3E IS NOW LOCATED NEAR 24.0N 134.0E, APPROXIMATELY
367 NM EAST-SOUTHEAST OF KADENA, OKINAWA. ANIMATED MULTISPECTRAL
SATELLITE IMAGERY AND A 200353Z AMSR2 89GHZ MICROWAVE IMAGE DEPICT
A BROAD LOW LEVEL CIRCULATION (LLC) INDICATED BY LOW LEVEL BANDING
OBSCURED BY FLARING CONVECTION IN THE NORTHEAST PERIPHERY. UPPER-
LEVEL ANALYSIS DEPICTS A FAVORABLE ENVIRONMENT WITH ROBUST POLEWARD
OUTFLOW IN AN AREA OF LOW (10-15 KTS) VERTICAL WIND SHEAR.
ADDITIONALLY, WARM (29-30 CELSIUS) SEA SURFACE TEMPERATURES ARE
CONDUCIVE FOR TROPICAL TRANSITION. GLOBAL MODELS ARE IN AGREEMENT
THAT THIS SYSTEM WILL BECOME SUB-TROPICAL WITHIN 24-48 HOURS AS IT
BECOMES EMBEDDED IN THE FRONTAL BOUNDARY EAST OF HONSHU. MAXIMUM
SUSTAINED SURFACE WINDS ARE ESTIMATED AT 17 TO 23 KNOTS. MINIMUM
SEA LEVEL PRESSURE IS ESTIMATED TO BE NEAR 1005 MB. THE POTENTIAL
FOR THE DEVELOPMENT OF A SIGNIFICANT TROPICAL CYCLONE WITHIN THE
NEXT 24 HOURS IS UPGRADED TO MEDIUM.

[euro6208]

TXPQ22 KNES 200901
TCSWNP

A. TROPICAL DISTURBANCE (93W)

B. 20/0830Z

C. 24.0N

D. 134.1E

E. FIVE/HIMAWARI-8

F. T2.0/2.0

G. IR/EIR/VIS

H. REMARKS...THIS INTENSITY ESTIMATE WAS DERIVED USING 4 KM IR
DATA. 3/10 W BANDING WAS OBSERVED AROUND THE LLCC WHICH MAKES THE DT
EQUAL TO 2.0. THE MET IS EQUAL TO 1.0 AND THE PT IS EQUAL TO 1.5. THE
FT IS BASED ON THE DT.

I. ADDL POSITIONS

NIL


...SAMBUCCI

[Hayabusa]

Straight to warning, it's unofficially a TS but I kept it as TD because JMA still sees it as TD

14W FOURTEEN 200920 1200 23.9N 133.9E WPAC 35 1003

[euro6208]

What a surprise.

Saw this a few hours ago and was hoping it won't be another missed ts.

[euro6208]

[euro6208]

Interesting...

WDPN31 PGTW 200900
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 14W (FOURTEEN)
WARNING NR 001//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
TROPICAL STORM (TS) 14W (FOURTEEN), LOCATED APPROXIMATELY
366NM EAST-SOUTHEAST OF KADENA AB, HAS TRACKED NORTH-NORTHWESTWARD
AT 03 KNOTS OVER THE PAST SIX HOURS. ANIMATED ENHANCED INFRARED
(EIR) SATELLITE IMAGERY DEPICTS SYMMETRIC, CENTRAL CONVECTION
OBSCURING A LOW LEVEL CIRCULATION CENTER (LLCC). THE INITIAL
POSITION IS PLACED WITH HIGH CONFIDENCE BASED ON THE LOW LEVEL
CIRCULATION (LLC) EVIDENT IN WIND FIELD DATA FROM A TIMELY 201053Z
ASCAT-A PASS. THE INITIAL INTENSITY OF 35 KTS IS ALSO PLACED WITH
HIGH CONFIDENCE BASED ON THE 35 KTS WINDS PRESENT ALONG THE EASTERN
PERIPHERY OF THE LLC IN THE ASCAT-A DATA AND IS HEDGED SLIGHTLY
HIGHER THAN MULTI-AGENCY DVORAK CURRENT INTENSITY ESTIMATES OF T2.0
(30 KTS, PGTW AND KNES). THE SYSTEM HAS SUBTROPICAL CHARACTERISTICS.
THE INTENSITY OF THE WIND FIELD, FOR EXAMPLE, IS HIGHLY ASYMMETRIC
WITH HIGH (30+ KTS) WINDS ALONG THE EASTERN PERIPHERY AND WEAKER
(15 KTS) WINDS ALONG THE WESTERN PERIPHERY. FURTHERMORE, THE OUTFLOW
FROM THE SYSTEM HAS ALREADY TAPPED INTO THE DEEP WESTERLY FLOW
ASSOCIATED WITH THE JET OVER HONSHU, JAPAN. DESPITE THIS, ANALYSIS
OF THE WIND FIELD AND THERMAL PROFILE REVEALS THAT THE SYSTEM
MAINTAINS MOSTLY TROPICAL CHARACTERISTICS. ENVIRONMENTAL ANALYSIS
FURTHER REVEALS AN ENVIRONMENT THAT IS FAVORABLE FOR DEVELOPMENT WITH
LOW (10-15 KTS) VERTICAL WIND SHEAR, WARM (30-31 CELSIUS) SEA SURFACE
TEMPERATURES (SST) AND WELL ESTABLISHED POLEWARD AND EQUATORWARD
OUTFLOW ALOFT. THE SYSTEM IS NEARLY QUASISTATIONARY AND IS TRACKING
THROUGH A WEAK STEERING ENVIRONMENT DUE TO ITS PLACEMENT INSIDE A
COL REGION THAT IS INDUCED BY A SUBTROPICAL RIDGE (STR) POSITIONED
TO THE EAST AND A SECOND STR POSITIONED TO THE WEST-SOUTHWEST.
3. FORECAST REASONING.
A. THIS IS THE INITIAL PROGNOSTIC REASONING MESSAGE FOR THIS
SYSTEM AND SETS THE FORECAST PHILOSOPHY.
B. TS 14W WILL CONTINUE TRACKING GENERALLY NORTHWARD UNDER THE
INFLUENCE OF THE TWO AFOREMENTIONED STEERING RIDGES. THE SYSTEM WILL
POSSIBLY TAKE ON ADDITIONAL SUBTROPICAL CHARACTERISTICS DURING THIS
TIME, HOWEVER THE FAVORABLE CONDITIONS WILL ALLOW IT TO INTENSIFY TO
55 KTS BY 24. INCREASING VWS AFTER TAU 24 WILL STIFLE FURTHER
INTENSIFICATION, HOWEVER THE ENVIRONMENT WILL REMAIN OVERALL FAVORABLE
THROUGH TAU 36 AND ALLOW THE SYSTEM TO MAINTAIN 55 KTS INTENSITY.
BY TAU 48 INCREASING (20+ KTS) VWS WILL LEAD TO A GRADUAL WEAKENING
TREND TO 50 KTS. ADDITIONALLY, THE SYSTEM WILL BEGIN TO ROUND THE STR
TO THE EAST WHICH WILL THEREAFTER BE THE PRIMARY STEERING MECHANISM.
AFTER TAU 48 THE SYSTEM WILL INTERACT FURTHER WITH THE AFOREMENTIONED
WESTERLY FLOW ALOFT AND WILL BEGIN EXTRATROPICAL TRANSITION (ETT).
AS IT CONTINUES TO TRACK GENERALLY NORTHEASTWARD AFTER THIS TIME, IT
WILL BECOME FURTHER EMBEDDED IN THE WESTERLY FLOW AND CONTINUE ETT.
NUMERICAL MODEL GUIDANCE IS IN POOR OVERALL AGREEMENT WITH A 550 NM
SPREAD IN ACROSS TRACK SOLUTIONS BY TAU 72. THE SPREAD IN MODEL
SOLUTIONS IS LIKELY DUE TO UNCERTAINTY IN THE TIMING OF AN INCOMING
SHORTWAVE TROUGH PROPAGATING FROM THE NORTHWEST THAT TEMPORARILY
ERODES THE STEERING RIDGES. THIS SPREAD IN MODEL SOLUTIONS LENDS
OVERALL POOR CONFIDENCE IN THE INITIAL PORTION OF THE JTWC FORECAST
TRACK.
C. AFTER TAU 72 THE SYSTEM WILL CONTINUE TO TRACK ALONG THE WEST-
NORTHWESTERN PERIPHERY OF THE STR POSITIONED TO THE EAST. BY TAU 96
IT WILL BECOME FULLY EMBEDDED IN THE BAROCLINIC ZONE AND COMPLETE ETT.
THE INTENSITY IS FORECAST TO WEAKEN TO 40 KTS BY THIS TIME. NUMERICAL
MODEL SOLUTIONS CONTINUE TO DIVERGE FURTHER WITH A SPREAD OF 630 NM BY
TAU 96. THIS CONTINUED HIGH DEGREE OF SPREAD IN SOLUTIONS LENDS POOR
CONFIDENCE IN THE OVERALL JTWC FORECAST TRACK. //
NNNN

[euro6208]

UW - CIMSS
ADVANCED DVORAK TECHNIQUE
ADT-Version 9.0
Tropical Cyclone Intensity Algorithm

----- Current Analysis -----
Date : 20 SEP 2020 Time : 151000 UTC
Lat : 24:06:37 N Lon : 133:53:57 E


CI# /Pressure/ Vmax
2.6 /1000.5mb/ 37.0kt


Final T# Adj T# Raw T#
2.6 2.7 3.3

Center Temp : -56.9C Cloud Region Temp : -56.3C

Scene Type : IRREGULAR CDO

Subtropical Adjustment : OFF

Extratropical Adjustment : OFF

Positioning Method : FORECAST INTERPOLATION

Ocean Basin : WEST PACIFIC
Dvorak CI > MSLP Conversion Used : CKZ Method

Tno/CI Rules : Constraint Limits : 0.2T/hour
Weakening Flag : OFF
Rapid Dissipation Flag : OFF

C/K/Z MSLP Estimate Inputs :
- Average 34 knot radii : 30nmi
- Environmental MSLP : 1010mb

Satellite Name : HIM-8
Satellite Viewing Angle : 29.2 degrees

****************************************************

[NotoSans]

Latest METOP-A reveals several 45kt wind barbs. JMA finally expects this to become a TS within 24 hours (if it isn't one already).

[euro6208]

Up to 45 knots.

14W FOURTEEN 200921 0000 24.7N 133.9E WPAC 45 993

[euro6208]

TPPN11 PGTW 210000

A. TROPICAL STORM 14W (SE OF OKINAWA)

B. 20/2340Z

C. 24.72N

D. 134.07E

E. FIVE/HMWRI8

F. ST3.0/3.0

G. IR/EIR/VIS/MSI

H. REMARKS: 40A/PBO SBC/ANMTN. ST3.0/3.0

I. ADDITIONAL POSITIONS: NONE


RHOADES

[1900hurricane]

Can we cut it with the subtropical Dvorak fixes Rhoades?

[1900hurricane]

Looks like a bit of a dry push into the TC below anvil layer. Convection already appears to be waining as a result.

[euro6208]

Impressive.

[1900hurricane]

Hmm, a bit of conflicting signals, because the MW is really good.

[euro6208]

Transition underway.

WDPN31 PGTW 210300
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 14W (FOURTEEN)
WARNING NR 003//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
TROPICAL STORM (TS) 14W (FOURTEEN), LOCATED 347NM EAST-SOUTHEAST
OF KADENA AB, OKINAWA, JAPAN HAS TRACKED NORTHWARD AT 06 KNOTS OVER
THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY SHOWS
THE MAIN CONVECTION REMAINS ELONGATED AND OFFSET TO THE NORTH AND
EAST OF A PARTLY OBSCURED LOW LEVEL CIRCULATION (LLC) AS THE SYSTEM
BEGUN TO INTERACT WITH THE STATIONARY FRONT TO THE NORTHWEST, AS
EVIDENCED BY LOW LEVEL COLD-AIR STRATOCUMULUS LINES WRAPPING IN FROM
THE NORTHWEST. THE INITIAL POSITION IS PLACED WITH FAIR CONFIDENCE
BASED ON A RAGGED BUT DEFINED LLC IN THE 202033Z SSMIS 91GHZ PASS
WHICH ALSO DEPICTS THE LLC BEING DISPLACED FROM THE ASSOCIATED
CONVECTION. THE INITIAL INTENSITY OF 45 KTS IS BASED ON THE DVORAK
INTENSITY ESTIMATE OF T3.0/45KTS FROM PGTW. ANALYSIS INDICATES THE
SYSTEM HAS BEGUN EXTRA-TROPICAL TRANSITION AS IT APPROACHES THE
BAROCLINIC ZONE ASSOCIATED WITH THE STATIONARY FRONT. POLEWARD
OUTFLOW REMAINS ROBUST AND CONTINUE TO VENTILATE THE OFFSET
CONVECTION. SEA SURFACE TEMPERATURES (SST), FOR NOW, REMAIN WARM AND
CONDUCIVE AT 30-31C. MODERATE (15-20KT) VERTICAL WIND SHEAR VALUES
HAVE ALSO INCREASED TO 20-25KTS. THIS AND SUBSIDENCE ALONG THE
NORTHWEST PERIPHERIES ASSOCIATED WITH THE SHORTWAVE TROUGH ARE
OFFSETTING THE OUTFLOW AND SST, RESULTING IN A MARGINALLY FAVORABLE
ENVIRONMENT. THE CYCLONE HAS MOVED OUT OF THE COL BETWEEN THE
SUBTROPICAL RIDGE (STR) TO THE WEST AND THE STR TO THE EAST THAT HAS
BECOME THE PRIMARY STEERING MECHANISM.
3. FORECAST REASONING.
A. THERE IS NO SIGNIFICANT CHANGE TO THE FORECAST PHILOSOPHY
FROM THE PREVIOUS PROGNOSTIC REASONING MESSAGE.
B. TS 14W WILL CONTINUE TO TRACK NORTHWARD THROUGHOUT THE
FORECAST PERIOD UNDER THE INFLUENCE OF THE STEERING STR TO THE EAST.
THE AFOREMENTIONED MARGINALLY FAVORABLE CONDITIONS WILL FUEL SLIGHT
INTENSIFICATION TO 55 KTS BY TAU 36. ALSO, BY TAU 24, IT WILL BECOME
FULLY EXTRA-TROPICAL AS IT GETS ABSORBED INTO THE STATIONARY FRONT.
NUMERICAL MODELS ARE IN TIGHT AGREEMENT, LENDING HIGH CONFIDENCE IN
THE JTWC FORECAST TRACK.//
NNNN

[1900hurricane]

Uhhh...

TPPN11 PGTW 210250

A. TROPICAL STORM 14W (SE OF OKINAWA)

B. 21/0230Z

C. 24.86N

D. 134.43E

E. FIVE/HMWRI8

F. XT2.5/2.5

G. IR/EIR/VIS/MSI

H. REMARKS: 40A/PBO SBC/ANMTN. WELL ORGANIZED LLCC EXTENDING TO
MID-LEVELS WITH CONVECTION AND FORWARD SPEED OF 7 KTS YIELDS XT
2.5.

I. ADDITIONAL POSITIONS: NONE


RHOADES

Are we legit looking at the same system right now?