WPAC: 96W - Post Tropical

[Nancy Smar]

TROPICAL DEPRESSION 1014 HPA AT 26N 148E ALMOST STATIONARY.

[Hayabusa]

I thought my eyes were deceiving me when I was looking the westpac satellite image earlier and I thought this looks like a TD, and yes it got classified

[doomhaMwx]

Looks like something that deserves a TCFA from JTWC.

[mrbagyo]

I was browsing the other system on windy app when I saw this dude that looks kinda spinning in the middle of WPAC. Upon closer look, oh yeah, it's really spinning haha.

Based on that above pass, this deserves a TCFA

[Nancy Smar]

96W INVEST 200809 0600 26.0N 148.0E WPAC 15 0
96W INVEST 200809 0600 26.0N 148.3E WPAC 20 1004

[Ed_2001]

Looks like something that deserves a TCFA from JTWC.

WTPN22 PGTW 090830
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE FORMATION ALERT (INVEST 96W)//
REF/A/JOINT TYPHOON WRNCEN PEARL HARBOR HI/090821ZAUG20//
AMPN/REF A IS TROPICAL CYCLONE FORMATION ALERT //
RMKS/
1. FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE WITHIN
160 NM EITHER SIDE OF A LINE FROM 26.1N 148.7E TO 26.0N 142.4E
WITHIN THE NEXT 12 TO 24 HOURS. AVAILABLE DATA DOES NOT JUSTIFY
ISSUANCE OF NUMBERED TROPICAL CYCLONE WARNINGS AT THIS TIME.
WINDS IN THE AREA ARE ESTIMATED TO BE 15 TO 20 KNOTS. METSAT
IMAGERY AT 090600Z INDICATES THAT A CIRCULATION CENTER IS LOCATED
NEAR 26.0N 148.3E. THE SYSTEM IS MOVING WESTWARD AT 04 KNOTS.
2. REMARKS: AN AREA OF CONVECTION (INVEST 96W) HAS PERSISTED
NEAR 26.0N 148.3E, APPROXIMATELY 805 NM NORTH OF GUAM. ANIMATED
MULTISPECTRAL SATELLITE IMAGERY AND 090647Z SSMIS IMAGE DEPICT A
CONSOLIDATING LOW LEVEL CIRCULATION (LLC) WITH FLARING CONVECTION
OVERHEAD. 96W IS CURRENTLY IN A FAVORABLE ENVIRONMENT FOR
DEVELOPMENT WITH GOOD POLEWARD OUTFLOW, LOW (<15 KNOTS) VERTICAL
WIND SHEAR, AND WARM (27 TO 28 DEGREES CELSIUS) SEA SURFACE
TEMPERATURES. GLOBAL MODELS ARE CURRENTLY SHOWING LITTLE
DEVELOPMENT, IF ANY, WITH A STEADY WESTWARD TRACK. MAXIMUM SUSTAINED
SURFACE WINDS ARE ESTIMATED AT 15 TO 20 KNOTS. MINIMUM SEA LEVEL
PRESSURE IS ESTIMATED TO BE NEAR 1007 MB. THE POTENTIAL FOR THE
DEVELOPMENT OF A SIGNIFICANT TROPICAL CYCLONE
WITHIN THE NEXT 24 HOURS IS HIGH.

[euro6208]

Upgraded straight to a TS.

[euro6208]

Solid. ASCAT showing TS winds.

[euro6208]

TPPN12 PGTW 091514

A. TROPICAL STORM 06W (N OF GUAM)

B. 09/1430Z

C. 25.83N

D. 147.05E

E. FIVE/HMWRI8

F. T2.5/2.5 STT: D1.0/03HRS

G. IR/EIR

H. REMARKS: 38A/PBO SBC/ANMTN. CNVCTN WRAPS .40 ON LOG10 SPIRAL
YIELDING A DT OF 2.5. MET IS 1.5. PT IS 2.0. DBO DT.
CONSTRAINTS BKN.

I. ADDITIONAL POSITIONS:
09/1136Z 26.03N 147.67E MMHS


MARTIN

[1900hurricane]

Really fortunate to have such a good ASCAT pass.

[euro6208]

WDPN31 PGTW 091500
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 06W (SIX)
WARNING NR 1//
RMKS//
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
TROPICAL STORM 06W (SIX), LOCATED APPROXIMATELY 350 NM
EAST-NORTHEAST OF IWO TO, HAS TRACKED WESTWARD AT 07 KNOTS OVER
THE PAST SIX HOURS. ANIMATED ENHANCED INFRARED (EIR) SATELLITE
IMAGERY DEPICTS A COMPACT, SYMMETRIC SYSTEM OF DEEP CONVECTION
OBSCURING A LOW LEVEL CIRCULATION CENTER (LLCC). THE INITIAL
POSITION IS PLACED WITH HIGH CONFIDENCE BASED ON THE LOW LEVEL
CIRCULATION (LLC) FEATURE PRESENT IN A 091136Z AMSU COMPOSITE
IMAGE. THE INITIAL INTENSITY OF 35KTS IS PLACED WITH HIGH
CONFIDENCE BASED ON A PARTIAL 091137Z ASCAT-B IMAGE DEPICTING
35 KTS WINDS ALONG THE EASTERN PERIPHERY OF THE LLC AND HEDGED
ABOVE A PGTW DVORAK CURRENT INTENSITY ESTIMATE OF T1.5 (25 KTS)
BASED ON THE SCATTEROMETRY DATA. TS 06W IS TRACKING ALONG THE
SOUTHERN PERIPHERY OF A SUBTROPICAL RIDGE (STR) AND THROUGH AN
UNFAVORABLE ENVIRONMENT FOR CONTINUED DEVELOPMENT WITH MODERATE
(15-20) KTS) VERTICAL WIND SHEAR (VWS) AND WEAK UPPER LEVEL
OUTFLOW OFFSET BY WARM (29-30 CELSIUS) SEA SURFACE TEMPERATURES.
3. FORECAST REASONING.
A. THIS IS THE FIRST PROGNOSTIC REASONING MESSAGE AND SETS
THE FORECAST PHILOSOPHY.
B. TS 06W IS FORECAST TO CONTINUE TRACKING WESTWARD ALONG
THE SOUTHERN EDGE OF THE STR. THE ENVIRONMENT WILL BECOME
INCREASINGLY UNFAVORABLE DUE TO THE ROBUST EASTERLY FLOW ALOFT,
LEADING TO A RISE IN VWS TO 25 KTS BY TAU 12 AND 30 KTS BY TAU
48. DESPITE THE CONTINUED WARM (29-30 CELSIUS) SSTS DURING THIS
TIME, THE SYSTEM IS FORECAST TO WEAKEN TO 30 KTS BY TAU 12 AND
25 KTS BY TAU 24. CONTINUED HIGH (25-30 KTS) VWS AT TAU 36 WILL
CAUSE THE SYSTEM TO BEGIN DISSIPATION OVER WATER AND LEAD TO
DISSIPATION OVER WATER BY TAU 72 AFTER WEAKENING TO 20 KTS.
NUMERICAL MODEL SOLUTIONS ARE IN TIGHT AGREEMENT LENDING HIGH
CONFIDENCE TO THE OVERALL JTWC FORECAST TRACK.//
NNNN

[doomhaMwx]

Already up to 45kts from JTWC @ 18Z and JMA still not showing signs of naming it. Ironic how JMA noticed this first but now they're way behind.

[euro6208]

WDPN31 PGTW 092100
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 06W (SIX)
WARNING NR 002//
RMKS//
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
TROPICAL STORM 06W (SIX), LOCATED APPROXIMATELY 264 NM EAST-
SOUTHEAST OF CHICHI JIMA, HAS TRACKED WESTWARD AT 05 KNOTS OVER THE
PAST SIX HOURS. THE CURRENT POSITION IS BASED ON RECENT MICROWAVE
SATELLITE IMAGERY, INCLUDING A 091813Z SSMIS 91 GHZ IMAGE, AND A
091750Z PGTW SATELLITE FIX. THE INTENSITY OF 45 KNOTS IS CONSISTENT
WITH A BYU HIGH RESOLUTION ANALYSIS OF A 091133Z ASCAT PASS, AND
FURTHER SUPPORTED BY CURRENT LOW-LEVEL BANDING STRUCTURE EVIDENT IN
RECENT MICROWAVE SATELLITE IMAGERY INCLUDING THE AFOREMENTIONED
SSMIS IMAGE. TS 06W IS TRACKING WESTWARD ALONG THE SOUTHERN
PERIPHERY OF A SUBTROPICAL STEERING RIDGE (STR) TO THE NORTH. THE
SYSTEM IS PASSING OVER WARM WATER (29-30C) IN AN AREA OF MODERATE
VERTICAL WIND SHEAR (15-20 KTS). UPPER LEVEL OUTFLOW TOWARD TROPICAL
UPPER TROPOSPHERIC TROUGH (TUTT) CELLS TO THE WEST AND SOUTHEAST IS
SUPPORTING SYSTEM DEVELOPMENT.
3. FORECAST REASONING.
A. FORECAST INTENSITIES HAVE INCREASED FROM THE PREVIOUS WARNING
AND THE FORECAST PERIOD HAS BEEN EXTENDED TO 96 HOURS.
B. TS 06W WILL CONTINUE TRACKING WESTWARD ALONG THE SOUTHERN EDGE
OF THE STR. THE ENVIRONMENT WILL BECOME UNFAVORABLE AS STRONG
EASTERLY FLOW ALOFT DEVELOPS OVER THE CIRCULATION, INCREASING
VERTICAL WIND SHEAR, OVER THE NEXT 24 TO 36 HOURS. DESPITE THE
INCREASING SHEAR, PASSAGE OVER WARM WATER AND A FAVORABLE OUTFLOW
PATTERN IN THE NEAR-TERM SHOULD ALLOW THE SYSTEM TO REMAIN INTACT AS
A WEAK TROPICAL STORM OR TROPICAL DEPRESSION THROUGH TAU 72.
C. TS 06W IS EXPECTED TO FINALLY SUCCUMB TO INCREASING VWS AND
DISSIPATE BY TAU 96, TURNING SOUTHWESTWARD WITH LOWER-LEVEL FLOW.
NUMERICAL MODEL SOLUTIONS ARE IN TIGHT AGREEMENT, LENDING HIGH
CONFIDENCE TO THE OVERALL JTWC FORECAST TRACK.//
NNNN

[Hayabusa]

TC warning hehe and TS forecast

TD
Issued at 01:30 UTC, 10 August 2020

<Analysis at 00 UTC, 10 August>
Scale -
Intensity -
TD
Center position N26°10' (26.2°)
E146°10' (146.2°)
Direction and speed of movement NW 10 km/h (6 kt)
Central pressure 1012 hPa
Maximum sustained wind speed 15 m/s (30 kt)
Maximum wind gust speed 23 m/s (45 kt)

<Forecast for 12 UTC, 10 August>
Intensity -
TD
Center position of probability circle N26°25' (26.4°)
E144°10' (144.2°)
Direction and speed of movement W 15 km/h (9 kt)
Central pressure 1008 hPa
Maximum sustained wind speed 15 m/s (30 kt)
Maximum wind gust speed 23 m/s (45 kt)
Radius of probability circle 110 km (60 NM)

<Forecast for 00 UTC, 11 August>
Intensity -
Center position of probability circle N26°50' (26.8°)
E141°30' (141.5°)
Direction and speed of movement W 20 km/h (12 kt)
Central pressure 1004 hPa
Maximum wind speed near center 18 m/s (35 kt)
Maximum wind gust speed 25 m/s (50 kt)
Radius of probability circle 150 km (80 NM)

[euro6208]

WDPN31 PGTW 100900
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 06W (SIX)
WARNING NR 004//
RMKS//
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
TROPICAL STORM (TS) 06W (SIX), LOCATED APPROXIMATELY 232
NM EAST-NORTHEAST OF IWO TO, HAS TRACKED WESTWARD AT 09 KNOTS OVER
THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI)
DEPICTS A FULLY EXPOSED LOW LEVEL CIRCULATION CENTER (LLCC) WITH
ASSOCIATED CONVECTION SHEARED OVER THE WESTERN SEMICIRCLE. THE
INITIAL POSITION IS PLACED WITH HIGH CONFIDENCE BASED ON THE EXPOSED
LLCC IN THE MSI AND THE LOW LEVEL CIRCULATION FEATURE PRESENT IN A
100634Z SSMIS 91GHZ IMAGE. THE INITIAL INTENSITY IS PLACED WITH HIGH
CONFIDENCE BASED ON MULTIAGENCY DVORAK CURRENT INTENSITY ESTIMATES
OF T1.5 (25 KTS, RJTD) AND T2.0 (30 KTS, PGTW), A 100610Z ADVANCED
DVORAK TECHNIQUE CURRENT INTENSITY ESTIMATE OF T2.5 (35 KTS) AND A
100540Z SATCON INTENSITY ESTIMATE OF 39 KTS. TS 06W IS TRACKING
WESTWARD THROUGH A MARGINAL ENVIRONMENT FOR DEVELOPMENT WITH
MODERATE TO STRONG (20-25 KTS) VERTICAL WIND SHEAR (VWS) OFFSET BY
VERY WARM (30-31 CELSIUS) SEA SURFACE TEMPERATURES (SST). INCREASING
EASTERLY VWS HAS SHEARED THE ASSOCIATED CONVECTION TO THE WEST AND
LEFT THE LLCC FULLY EXPOSED. UPPER LEVEL SUPPORT ASSOCIATED WITH A
NARROW TROPICAL UPPER TROPOSPHERIC TROUGH (TUTT) TO THE WEST,
HOWEVER, IS HELPING TO SUSTAIN THE SYSTEM IN THE PRESENCE OF THE
INCREASING VWS.
3. FORECAST REASONING.
A. NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE PREVIOUS
PROGNOSTIC REASONING MESSAGE.
B. TS 06W WILL CONTINUE TRACKING GENERALLY WESTWARD ALONG THE
SOUTHERN EDGE OF THE STR THROUGHOUT THE 96 HOUR FORECAST. THE
ENVIRONMENT WILL BECOME INCREASINGLY UNFAVORABLE AS VERTICAL WIND
SHEAR INDUCED BY STRONG EASTERLY FLOW ALOFT PERSISTS. DESPITE THE
PERSISTENT SHEAR, PASSAGE OVER WARM WATER AND A FAVORABLE OUTFLOW
PATTERN IN THE NEAR-TERM SHOULD ALLOW THE SYSTEM TO REMAIN INTACT
AS A WEAK TROPICAL STORM OR TROPICAL DEPRESSION THROUGH TAU 48 AND
BY TAU 72 WILL BEGIN TO DISSIPATE OVER WATER.
C. TS 06W IS EXPECTED TO WEAKEN TO 20 KTS BY TAU 96 DUE TO THE
HOSTILE SHEAR ENVIRONMENT AND DISSIPATE OVER WATER AT THAT TIME.
NUMERICAL MODEL SOLUTIONS REMAIN IN TIGHT AGREEMENT WITH MINIMAL
SPREAD IN SOLUTIONS THROUGH THE ENTIRE FORECAST PERIOD. THE TIGHT
AGREEMENT OF MODEL SOLUTIONS LENDS HIGH CONFIDENCE TO THE OVERALL
96 HOUR JTWC FORECAST TRACK.//
NNNN

[euro6208]

Clear TS but the *official* agency says otherwise despite all the data.

Give it a name.

It's ok if you don't do.

[euro6208]

06W SIX 200810 1200 26.3N 144.1E WPAC 30 1008

[doomhaMwx]

Another excellent pass.

[euro6208]

Expected to remain a TD for 4 days.


WDPN32 PGTW 1100300
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 06W (SIX)
WARNING NR 007//
RMKS//
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
TROPICAL DEPRESSION 06W (SIX), LOCATED APPROXIMATELY 109 NM NORTH
OF IWO TO, HAS TRACKED WESTWARD AT 12 KNOTS OVER THE PAST SIX HOURS.
ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) DEPICTS A FULLY
EXPOSED LOW LEVEL CIRCULATION CENTER (LLCC) WITH FLARING CONVECTION
SHEARED TO THE EAST OF THE LLCC. THE INITIAL POSITION IS PLACED WITH
HIGH CONFIDENCE BASED ON THE EXPOSED LLCC IN THE VISIBLE SATELLITE
IMAGERY. THE INITIAL INTENSITY OF 25 KNOTS IS ASSESSED WITH HIGH
CONFIDENCE BASED ON DVORAK CURRENT INTENSITY ESTIMATES OF T1.5 (25
KNOTS) FROM BOTH PGTW AND RJTD, AND A RAW ADT ESTIMATE OF 1.5. TD 06W
REMAINS IN A VERY MARGINAL ENVIRONMENT WITH MODERATE TO STRONG (20-25
KNOTS) VWS, HIGH SSTS NEAR 30 DEG C AND WEAKLY DIVERGENT UPPER-LEVEL
OUTFLOW. TD 06W CONTINUES TO TRACK WESTWARD ALONG THE SOUTHERN
PERIPHERY OF A DEEP-LAYER STR LOCATED TO JUST SOUTHEAST OF TOKYO.
3. FORECAST REASONING.
A. NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE PREVIOUS
PROGNOSTIC REASONING MESSAGE.
B. TD 06W WILL CONTINUE TRACKING WESTWARD ALONG THE SOUTHERN
PERIPHERY OF THE STR THROUGH TAU 24 BEFORE TURNING MORE WEST-
SOUTHWEST AS THE SYSTEM WEAKENS, COMING UNDER THE INFLUENCE OF THE
LOWER LEVEL FLOW PATTERN. BY TAU 72, THE SYSTEM WILL LIE BETWEEN
OKINAWA AND MINAMI DAITO JIMA, HAVING SLOWED SIGNIFICANTLY AS IT
APPROACHES A WEAK STEERING ENVIRONMENT INDUCED BETWEEN SUBTROPICAL
RIDGES TO THE NORTHEAST AND NORTHWEST. INTENSITY IS FORECAST TO
REMAIN FLAT THROUGH TAU 48 UNDER THE COMPETING INFLUENCES OF HIGH
SSTS AND MODERATE WESTWARD OUTFLOW OFFSET BY MODERATE TO STRONG VWS.
THERE LIKELY WILL BE SHORT DURATION FLUCTUATIONS ABOVE AND BELOW 25
KNOTS AS CONVECTION FLARES AND DISSIPATES, BUT OVERALL INTENSITY WILL
REMAIN STEADY THROUGH TAU 48. AFTER THIS POINT AND THROUGH TAU 72,
THE SYSTEM WILL BEGIN DISSIPATING AS VWS BECOMES DOMINANT OVER THE
OUTFLOW.
C. BY TAU 96, TD 06W IS FORECAST TO SLOW, BECOMING NEARLY QUASI-
STATIONARY SOUTH OF OKINAWA UNDER THE INFLUENCE OF A WEAK LOW-LEVEL
STEERING PATTERN. AT THE SAME TIME, TD 06W IS EXPECTED TO CONTINUE
WEAKENING AS A TROPICAL CYCLONE BY TAU 96 AS INCREASING VWS AND LACK
OF UPPER-LEVEL OUTFLOW WILL COMBINE TO DISSIPATE THE SYSTEM BY TAU
96 JUST SOUTH OF OKINAWA NUMERICAL MODEL GUIDANCE ALL AGREE ON THE
GENERAL FORECAST, BUT DIFFER IN THE EXACT TRACK, WITH A 100 NM SPREAD
AT TAU 48, WITH SPREAD ABOUT 150 NM BY TAU 96. THE OFFICIAL JTWC
FORECAST LIES TO THE NORTH OF THE MULTI-MODEL CONSENSUS, CLOSER TO
THE GROUPING OF JGSM, ECMWF AND UKMO MODEL TRACKERS. DUE TO THE
MODERATE SPREAD IN THE MODEL SOLUTIONS, THERE IS FAIR CONFIDENCE IN
THE JTWC FORECAST TRACK.//
NNNN

[doomhaMwx]

This poor thing's not just being blasted by shear and dry air, it's also "inhaling" a lot of ash/dust (or whatever that is) from Japan's volcanic islands