WPAC: CHAN-HOM - Post-Tropical

[euro6208]

[euro6208]

60 knots

WDPN31 PGTW 070300
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 16W (CHAN-HOM) WARNING
NR 010//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
TROPICAL STORM (TS) 16W (CHAN-HOM), LOCATED APPROXIMATELY 456 NM
EAST OF KADENA AB, OKINAWA, HAS TRACKED WEST-NORTHWESTWARD AT 07
KNOTS (KTS) OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL
SATELLITE IMAGERY (MSI) REVEALS CONVECTIVE BANDING WRAPPING INTO THE
LOW LEVEL CIRCULATION CENTER (LLCC), OBSCURED BY FLARING CONVECTION
OVERHEAD. THERE IS GOOD CONFIDENCE IN THE INITIAL POSITION, BASED ON
AN EXTRAPOLATION OF A 062123Z SSMIS 37 GHZ MICROWAVE IMAGE DEPICTING
A WELL-DEFINED MICROWAVE EYE FEATURE AND PLACED NEAR THE PGTW AND
RJTD FIXES. THE INITIAL INTENSITY IS SET AT 60 KTS, HEDGED SLIGHTLY
ABOVE MULTI-AGENCY DVORAK CURRENT INTENSITY ESTIMATES OF T3.5 (55
KTS) AND JUST UNDER A 062052Z SMAP WIND SPEED IMAGE DEPICTING 57 KTS
(10-MINUTE AVERAGE)/63 KTS (1-MINUTE AVERAGE) WINDS. CURRENT 34-KT
AND 50-KT WIND RADII HAVE BEEN UPDATED WITH RECENT ASCAT DATA.
ENVIRONMENTAL CONDITIONS REMAIN FAVORABLE AS TS 16W IS POSITIONED
UNDER AN UPPER LEVEL POINT SOURCE CONTRIBUTING TO ENHANCED POLEWARD
OUTFLOW AND GOOD EQUATORWARD OUTFLOW. ADDITIONALLY, LOW (5-10 KT)
VERTICAL WIND SHEAR (VWS) AND WARM (29-30 CELSIUS) SEA SURFACE
TEMPERATURES (SST) ARE CONDUCIVE FOR CONTINUED DEVELOPMENT. TS 16W
IS TRACKING ALONG THE SOUTHWESTERN PERIPHERY OF A SUBTROPICAL RIDGE
(STR) POSITIONED TO THE NORTHEAST.
3. FORECAST REASONING.
A. NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE PREVIOUS
PROGNOSTIC REASONING MESSAGE.
B. TS 16W IS FORECAST TO TRACK GENERALLY NORTHWESTWARD ALONG THE
SOUTHWESTERN PERIPHERY OF THE STEERING STR THROUGH TAU 48,
INTENSIFYING TO A PEAK OF 80 KTS BY TAU 36. TS 16W IS EXPECTED TO
SLOW SIGNIFICANTLY AS IT APPROACHES THE RYUKYU ISLANDS AND BEGINS TO
RECURVE AROUND THE STEERING STR. THE SPREAD IN THE NUMERICAL MODEL
GUIDANCE NEAR THE RECURVE POINT REACHES 192 NM NEAR TAU 48 DUE TO
THE PRESENCE OF A LARGE BREAK IN THE WESTERN AND EASTERN SUBTROPICAL
RIDGES, ALONG WITH THE LACK OF A DYNAMIC MIDLATITUDE SHORTWAVE
TROUGH, WHICH WOULD TYPICALLY ACCELERATE THE SYSTEM POLEWARD. AFTER
TAU 48, THE SYSTEM WILL BEGIN TO CREST THE STR AXIS AND TURN TO A
GENERALLY NORTH-NORTHEASTWARD TRACK THROUGH TAU 72. THE GLOBAL
MODELS CURRENTLY DEPICT A ZONAL PATTERN WITH A SHORTWAVE RIDGE
PROPAGATING OVER THE KOREAN PENINSULA NEAR TAU 60. AS THE SYSTEM
TURNS TO THE NORTH-NORTHEASTWARD TRACK, IT WILL INTERACT WITH THIS
ZONAL FLOW. BASED ON THE COMPLEX STEERING PATTERN AND MODERATE
SPREAD IN SOLUTIONS, THERE IS LOW CONFIDENCE IN THIS PORTION OF THE
JTWC FORECAST TRACK.
C. IN THE EXTENDED RANGE, TS 16W WILL TRACK NORTHEASTWARD ALONG
THE SOUTHERN COAST OF JAPAN. DUE TO HIGH (>30 KTS) VWS ONSET
BEGINNING AT TAU 72, TS 16W IS EXPECTED TO GRADUALLY WEAKEN FOR THE
REMAINDER OF THE FORECAST PERIOD TO AN INTENSITY OF 50 KTS BY TAU
120. DURING THIS TIME, TS 16W WILL BEGIN TO INTERACT WITH THE
BAROCLINIC ZONE AND COMMENCE EXTRATROPICAL TRANSITION (ETT) BY TAU
72. ETT COMPLETION IS EXPECTED BY TAU 120 AS THE SYSTEM GAINS
FRONTAL CHARACTERISTICS AND BECOMES EMBEDDED IN THE WESTERLY FLOW.
IN THE EXTENDED RANGE, THERE ARE LARGE VARIATIONS IN THE TRACK
SPEEDS WITH GFS, GALWEM, AND GFS ENSEMBLE DISPLAYING SIGNIFICANTLY
FASTER TRACK SPEEDS WHILE THE REMAINDER OF THE GUIDANCE INDICATES
SLOWER TRACK SPEEDS. THE JTWC FORECAST TRACK HAS REMAINED FAIRLY
CONSISTENT AND IS POSITIONED NEAR THE ECMWF AND ECMWF ENSEMBLE MEAN
SOLUTIONS, IN LINE WITH THE MAJORITY OF THE MODEL SOLUTIONS. THE
LATEST MODEL RUN REVEALED NAVGEM AS A SIGNIFICANT OUTLIER TO THE
EAST THAT RECURVES SIGNIFICANTLY FASTER THAN THE MAJORITY OF THE
MODEL SOLUTIONS. DUE TO THESE MODEL DIFFERENCES, THERE IS OVERALL
LOW CONFIDENCE (HIGH UNCERTAINTY) IN THE JTWC FORECAST TRACK.//
NNNN

[ElectricStorm]

After the absolute onslaught of typhoons impacting Japan the last couple years, they have enjoyed a much-needed break this year besides the far western areas affected by Haishen. Chan-hom looks to become one of the only Japan landfalls this year. I would think we should be getting to the point in the year where storms don't make it too far north to reach Japan, so hopefully Chan-hom will be there last one of the season.

[Hayabusa]

TY 2014 (Chan-hom)
Issued at 06:50 UTC, 7 October 2020

<Analysis at 06 UTC, 7 October>
Scale -
Intensity -
Center position N25°40' (25.7°)
E135°00' (135.0°)
Direction and speed of movement WNW 20 km/h (10 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 95 km (50 NM)
≥ 30 kt wind area ALL 440 km (240 NM)

[mrbagyo]

[euro6208]

8th typhoon of the season


WDPN31 PGTW 070900
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TYPHOON 16W (CHAN-HOM) WARNING NR 011//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
TYPHOON (TY) 16W (CHAN-HOM), LOCATED APPROXIMATELY 378 NM EAST OF
KADENA AB, OKINAWA, HAS TRACKED NORTHWESTWARD AT 11 KNOTS OVER THE
PAST SIX HOURS. ANIMATED ENHANCED INFRARED SATELLITE IMAGERY DEPICTS
A CONSOLIDATING SYSTEM WITH A RAGGED EYE, WHICH SUPPORTS THE INITIAL
POSITION AND RECENT TRACK MOTION WITH GOOD CONFIDENCE. A 070435Z
AMSR2 36GHZ MICROWAVE IMAGE INDICATES IMPROVED CONVECTIVE BANDING
WRAPPING TIGHTLY INTO A MICROWAVE EYE FEATURE. THE INITIAL
INTENSITY IS ASSESSED AT 65 KNOTS BASED ON PGTW/KNES DVORAK
INTENSITY ESTIMATES OF T4.0 (65 KNOTS). ENVIRONMENTAL CONDITIONS
REMAIN FAVORABLE WITH ENHANCED POLEWARD OUTFLOW, GOOD EQUATORWARD
OUTFLOW, LOW (5-10 KT) VERTICAL WIND SHEAR (VWS), AND WARM (28-29
CELSIUS) SEA SURFACE TEMPERATURES. THE SYSTEM IS TRACKING ALONG THE
SOUTHWESTERN PERIPHERY OF A SUBTROPICAL RIDGE (STR) POSITIONED TO
THE NORTHEAST.
3. FORECAST REASONING.
A. NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE PREVIOUS
PROGNOSTIC REASONING MESSAGE. IMPORTANT NOTE: TY 16W HAS MAINTAINED
EXTENSIVE GALE-FORCE WINDS AS LARGE AS 180NM RADIUS. TO FURTHER
COMPLICATE THIS SCENARIO, THE SYSTEM IS TRACKING INTO A STRONG
BAROCLINIC ZONE WITH ITS OWN TIGHT GRADIENT AS EVIDENCED BY 25 TO 35
KNOT SURFACE WIND REPORTS ACROSS WESTERN JAPAN AND THE RYUKYU
ISLANDS. THUS GALE-FORCE WINDS ARE POSSIBLE ALONG AND OUTSIDE THE
PERIPHERY OF THE SYSTEM AS IT TRACKS CLOSER TO JAPAN.
B. TY 16W IS FORECAST TO TRACK NORTHWESTWARD TO NORTHWARD THROUGH
TAU 48 AS IT RECURVES. NUMERICAL MODEL GUIDANCE IS IN BETTER
AGREEMENT BUT STILL INDICATES SIGNIFICANT UNCERTAINTY IN THE TIMING
AND POINT OF THE RECURVE WITH A 130NM SPREAD IN SOLUTIONS AT TAU 48.
AFTER TAU 48, THE SYSTEM WILL ACCELERATE NORTHEASTWARD AS IT BEGINS
TO INTERACT WITH THE MIDLATITUDE WESTERLIES. THE UNCERTAINTY IN THE
NUMERICAL MODEL SOLUTIONS IS DUE TO THE PRESENCE OF A LARGE BREAK IN
THE WESTERN AND EASTERN SUBTROPICAL RIDGES AND THE LACK OF A DYNAMIC
MIDLATITUDE SHORTWAVE TROUGH, WHICH WOULD TYPICALLY ACCELERATE THE
SYSTEM POLEWARD. IN FACT, THE GLOBAL MODELS DEPICT A ZONAL PATTERN
WITH A SHORTWAVE RIDGE PROPAGATING OVER THE KOREAN PENINSULA NEAR
TAU 36-48. TY 16W IS FORECAST TO INTENSIFY TO A PEAK INTENSITY OF 80
KNOTS BY TAU 24-36 UNDER FAVORABLE CONDITIONS. BASED ON THE COMPLEX
STEERING PATTERN AND SPREAD IN SOLUTIONS, THERE IS FAIR CONFIDENCE
IN THIS PORTION OF THE JTWC FORECAST TRACK.
C. AFTER TAU 72, THE SYSTEM WILL ROUND THE STR AXIS AND TURN TO A
GENERALLY EAST-NORTHEASTWARD TRACK ALONG THE SOUTHERN COAST OF
JAPAN. DUE TO HIGH (>35 KTS) VWS, TY 16W IS EXPECTED TO WEAKEN
STEADILY FOR THE REMAINDER OF THE FORECAST PERIOD TO AN INTENSITY OF
45 KTS BY TAU 120. TY 16W WILL BEGIN EXTRATROPICAL TRANSITION (ETT)
BY TAU 72 AND WILL COMPLETE ETT BETWEEN TAU 96 AND TAU 120 AS IT
GAINS FRONTAL CHARACTERISTICS. THE JTWC FORECAST TRACK IS POSITIONED
ON THE SOUTHERN EDGE OF THE AIDS ENVELOPE CLOSE TO THE ECMWF
SOLUTION AND THE OFFICIAL JMA FORECAST TRACK. DUE TO UNCERTAINTY IN
THE TRACK AS THE SYSTEM UNDERGOES ETT, THERE IS FAIR CONFIDENCE
(MODERATE UNCERTAINTY) IN THE JTWC FORECAST TRACK.//
NNNN

[euro6208]

80 knots?


CURRENT ESTIMATE
Date (mmddhhmm): 10070424
SATCON: MSLP = 964 hPa MSW = 78 knots
SATCON Member Consensus: 77.0 knots
Pressure -> Wind Using SATCON MSLP: 79 knots
Distance to Outer Closed Isobar Used is 215 nm
Eye Size Correction Used is -1.9 knots Source: IR

Member Estimates

ADT: 973 hPa 72 knots Scene: CDO Date: OCT070640
CIMSS AMSU: 975 hPa 68 knots Bias Corr: 0 (MW) Date: 10070056
ATMS: 960.5 hPa 80.0 knots Date: 10070424
SSMIS: 960.5 hPa 80.0 knots Date: 10070424
CIRA ATMS: 1001 hPa 32 knots Date: 10041608

[euro6208]

TXPQ24 KNES 070859
TCSWNP

A. 16W (CHAN-HOM)

B. 07/0830Z

C. 26.3N

D. 134.1E

E. ONE/HIMAWARI-8

F. T4.5/4.5

G. IR/EIR/SWIR

H. REMARKS...THIS INTENSITY ESTIMATE WAS DERIVED USING 4 KM IR DATA. AN
OFF WHITE EYE THAT IS SURROUNDED BY MEDIUM GREY AND EMBEDDED IN DARK GREY
MAKES THE DT EQUAL TO 4.5 WITH NO EYE ADJUSTMENT MADE TO THE DT VALUE. THE
MET AND PT AGREE AND ARE ALSO EQUAL TO 4.5 BASED ON A DEVELOPMENT TREND
OVER THE PAST 24 HOURS. THE FT IS BASED ON THE DT.

I. ADDL POSITIONS

NIL


...SAMBUCCI

[euro6208]

CI# /Pressure/ Vmax
4.9 / 960.9mb/ 87.4kt


Final T# Adj T# Raw T#
4.9 5.5 5.5

[euro6208]

Anticyclone right over the system.

[euro6208]

[euro6208]

TPPN10 PGTW 071238

A. TYPHOON 16W (CHAN-HOM)

B. 07/1200Z

C. 26.44N

D. 133.69E

E. THREE/HMWRI8

F. T4.5/4.5/D1.0/24HRS STT: D0.5/03HRS

G. IR/EIR

H. REMARKS: 09A/PBO RAGGED EYE/ANMTN. OW EYE SURROUNDED BY DG
YIELDS AN E# AND DT (NO EYE ADJUSTMENT) OF 4.5. MET/PT AGREE.
DBO DT.

I. ADDITIONAL POSITIONS:
07/0750Z 25.97N 134.23E SSMS
07/1005Z 26.25N 133.80E GPMI


MARTIN

[euro6208]

When is this beauty contest going to end?

Recon?

[euro6208]

CI# /Pressure/ Vmax
5.1 / 954.8mb/ 92.4kt


Final T# Adj T# Raw T#
5.0 5.0 5.0



Amazing what recon would find. An eye like that would be stronger right?

Nope...

[mrbagyo]

[euro6208]

[Ed_2001]

Amazing what recon would find. An eye like that would be stronger right?

Nope...

We all agree that WPAC without recon is a shame but it’s redundant when you complain about the same thing on every single WPAC typhoon thread...

[euro6208]

WDPN31 PGTW 080300
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TYPHOON 16W (CHAN-HOM) WARNING NR 014//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
TYPHOON 16W (CHAN-HOM), LOCATED APPROXIMATELY 280 NM
EAST-NORTHEAST OF KADENA AB, HAS TRACKED NORTH-NORTHWESTWARD AT
07 KNOTS OVER THE PAST SIX HOURS. ANIMATED ENHANCED INFRARED
SATELLITE IMAGERY DEPICTS FLARING CONVECTION WRAPPING AROUND A LARGE
AND RAGGED 50NM DIAMETER EYE. THE INITIAL POSITION WAS PLACED WITH
GOOD CONFIDENCE USING MULTISPECTRAL SATELLITE AND A 072325Z GMI
37GHZ MICROWAVE IMAGE. THE INITIAL INTENSITY REMAINS ASSESSED AT 70
KNOTS BASED ON AN AVERAGE OF PGTW/RJTD DVORAK INTENSITY ESTIMATES OF
T4.0 (65 KNOTS) AND A KNES ESTIMATE OF T4.5 (77 KNOTS). VERTICAL
WIND SHEAR IS GRADUALLY INCREASING (10-15 KNOTS), BUT OVERALL
ENVIRONMENTAL CONDITIONS REMAIN FAVORABLE WITH ENHANCED POLEWARD
OUTFLOW, GOOD EQUATORWARD OUTFLOW, AND WARM (28-29 CELSIUS)
SEA SURFACE TEMPERATURES. THE SYSTEM IS TRACKING ALONG THE
SOUTHWESTERN PERIPHERY OF A SUBTROPICAL RIDGE (STR) POSITIONED TO
THE NORTHEAST.
3. FORECAST REASONING.
A. NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE PREVIOUS
PROGNOSTIC REASONING MESSAGE.
B. TY 16W CONTINUES TO TURN POLEWARD AND IS FORECAST TO TRACK
TOWARD THE NORTH AND THEN NORTHEASTWARD BY TAU 24 TO 36. NUMERICAL
MODEL GUIDANCE IS NOW SPLIT INTO SOMEWHAT OF A BIFURCATION SCENARIO,
WITH THE GFS AND UKMET GLOBAL DETERMINISTIC AND ENSEMBLE MODELS
SUGGESTING A SHARPER TURN TOWARD THE EAST-NORTHEAST AND THE OTHER
MODELS INDICATING A TRACK CLOSER TO THE COAST OF JAPAN. THE JTWC
FORECAST TRACK LIES CLOSER TO THE COAST OF JAPAN AND FALLS TO THE
LEFT OF THE MULTI-MODEL CONSENSUS. AFTER TAU 36, THE SYSTEM WILL
ACCELERATE NORTHEASTWARD AS IT INTERACTS WITH THE ZONAL MIDLATITUDE
FLOW. AS VERTICAL SHEAR INCREASES, THE WINDOW OF OPPORTUNITY FOR TY
16W TO INTENSIFY IS GRADUALLY CLOSING, SO THE PEAK INTENSITY
FORECAST HAS BEEN SLIGHTLY LOWERED TO 75 KNOTS BY TAU 12. BASED ON
THE ZONAL STEERING PATTERN AND SPREAD IN SOLUTIONS, THERE IS FAIR
CONFIDENCE IN THIS PORTION OF THE JTWC FORECAST TRACK.
C. AFTER TAU 72, THE SYSTEM WILL CONTINUE TO ACCELERATE EAST-
NORTHEASTWARD AS IT MOVES AWAY FROM JAPAN. DUE TO HIGH VERTICAL
WIND SHEAR, TY 16W IS EXPECTED TO WEAKEN STEADILY FOR THE
REMAINDER OF THE FORECAST PERIOD TO AN INTENSITY OF 45 KTS BY TAU
96. TY 16W WILL COMPLETE EXTRATROPICAL TRANSITION (ETT) BY TAU 96 AS
IT GETS ABSORBED INTO THE BAROCLINIC ZONE. THE JTWC FORECAST
TRACK LIES SLIGHTLY POLEWARD OF THE MULTI-MODEL CONSENSUS. DUE TO
UNCERTAINTY IN THE TRACK AS THE SYSTEM UNDERGOES ETT, THERE IS FAIR
CONFIDENCE IN THE JTWC FORECAST TRACK. ALL INTERESTS IN THE KANTO
PLAIN REGION OF JAPAN SHOULD PAY CLOSE ATTENTION TO THE TIMING OF
THE NORTHEASTWARD TURN AND EVOLUTION OF THE WIND FIELD, GIVEN THE
AMBIENT NORTHEASTERLY ENVIRONMENTAL FLOW. THE POSSIBILITY EXISTS FOR
A MINOR FORECAST TRACK SHIFT TOWARD THE WEST THAT WOULD BRING THE
CORE OF TY 16W ASHORE.//
NNNN

[doomhaMwx]

 https://twitter.com/sayakasofiamori/status/1314070128892366848

[euro6208]

At peak


WDPN31 PGTW 080900
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TYPHOON 16W (CHAN-HOM)
WARNING NR 015//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
TYPHOON 16W (CHAN-HOM), LOCATED APPROXIMATELY 524 NM
SOUTHWEST OF YOKOSUKA, JAPAN, HAS TRACKED NORTHWARD AT 09 KNOTS
OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY
(MSI) DEPICTS SPIRAL BANDS OF DEEP CONVECTION WRAPPING INTO A
RAGGED, 30 NM DIAMETER EYE. THE INITIAL POSITION IS PLACED WITH
HIGH CONFIDENCE BASED ON THE EYE FEATURE IN THE MSI LOOP. THE
INITIAL INTENSITY OF 80 KTS IS PLACED WITH HIGH CONFIDENCE AND IS
HEDGED ABOVE MULTI-AGENCY DVORAK CURRENT INTENSITY ESTIMATES OF
T4.0 (65 KTS, RJTD) AND T4.5 (77 KTS, PGTW AND KNES) BASED ON A
TIMELY 080119Z CIMSS SATCON INTENSITY ESTIMATE OF 86 KTS. TY 16W
IS TRACKING ALONG THE WESTERN PERIPHERY OF A SUBTROPICAL RIDGE
(STR) POSITIONED TO THE EAST AND THROUGH AN ENVIRONMENT THAT HAS
REMAINED FAVORABLE FOR DEVELOPMENT OVER THE PAST 6 HOURS WITH
LOW (10-15 KTS) VERTICAL WIND SHEAR (VWS), WARM (27-28 CELSIUS)
SEA SURFACE TEMPERATURE (SST) AND ROBUST POLEWARD AND EQUATORWARD
OUTFLOW ALOFT. THE POLEWARD OUTFLOW CONTINUES TO BE ENHANCED BY
THE WESTERLY FLOW OF THE JET POSITIONED TO THE NORTH OVER JAPAN.
3. FORECAST REASONING.
A. NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE PREVIOUS
PROGNOSTIC REASONING MESSAGE.
B. TY CHAN-HOM WILL CONTINUE TO TRACK GENERALLY NORTHWARD
AS IT ROUNDS THE STR AXIS THROUGH TAU 24. THE SYSTEM WILL BEGIN
TO GRADUALLY WEAKEN TO 70 KTS BY TAU 24 DUE TO INCREASING VWS
ASSOCIATED WITH THE AFOREMENTIONED WESTERLY FLOW ALOFT. AFTER
ROUNDING THE STR THE SYSTEM WILL BEGIN TO INTERACT WITH THE
BAROCLINIC ZONE AND TRACK GENERALLY NORTHEASTWARD. THIS
INTERACTION WILL CAUSE THE SYSTEM TO BEGIN EXTRATROPICAL TRANSITION
(ETT) BY TAU 36. TY CHAN-HOM WILL CONTINUE TO WEAKEN TO 50 KTS BY
TAU 72 AS VWS INCREASES AND SST DECREASES TO 25-26 CELSIUS. BY THIS
TIME, THE SYSTEM WILL BECOME FULLY EMBEDDED IN THE BAROCLINIC ZONE
AND COMPLETE ETT. NUMERICAL MODEL TRACK GUIDANCE IS IN ONLY FAIR
AGREEMENT WITH A MAXIMUM 370 NM ACROSS TRACK SPREAD IN SOLUTIONS BY
TAU 72. ALL INTERESTS IN THE KANTO PLAIN REGION OF JAPAN SHOULD PAY
CLOSE ATTENTION TO THE TIMING OF THE NORTHEASTWARD TURN AND
EVOLUTION OF THE WIND FIELD, GIVEN THE EXTENSIVE AMBIENT
NORTHEASTERLY FLOW. OVERALL, THE SPREAD IN MODEL SOLUTIONS LENDS
ONLY FAIR CONFIDENCE IN THIS INITIAL PORTION OF THE JTWC FORECAST
TRACK.
C. AFTER TAU 72, THE SYSTEM WILL CONTINUE TO ACCELERATE EAST-
NORTHEASTWARD AS IT MOVES AWAY FROM JAPAN AS A COLD CORE LOW. WINDS
WILL REMAIN SIGNIFICANT DUE TO THE FRONTAL NATURE OF THE SYSTEM,
HOWEVER HIGH (50+ KTS) VWS WILL FURTHER WEAKEN THE SYSTEM TO 45 KTS
BY THIS TIME. THE SPREAD IN NUMERICAL MODEL SOLUTIONS INCREASES
DURING THIS PORTION OF THE FORECAST TO 960 NM AND THEREFORE LENDS
OVERALL POOR CONFIDENCE IN THE REMAINDER OF THE JTWC FORECAST TRACK.
//
NNNN