WPAC: PRAPIROON - Post-Tropical

[1900hurricane]

JTWC is up to 65 kt.

09W PRAPIROON 180701 1800 26.2N 126.8E WPAC 65 976

[euro6208]

Just the 2nd typhoon so far this season.

WDPN31 PGTW 012100
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TYPHOON 09W (PRAPIROON)
WARNING NR 14//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
TYPHOON (TY) 09W (PRAPIROON), LOCATED APPROXIMATELY 57 NM WEST-
SOUTHWEST OF KADENA AB, OKINAWA, HAS TRACKED NORTHWARD AT 08
KNOTS OVER THE PAST SIX HOURS. ANIMATED ENHANCED INFRARED SATELLITE
IMAGERY INDICATES CONSOLIDATING CORE CONVECTION WITH TIGHTLY-CURVED
BANDING WRAPPING AROUND A WEAK, RAGGED EYE. RADAR IMAGERY FROM JAPAN
SHOWS SPIRAL BANDING WRAPPING INTO AN OBLONG EYE FEATURE, WHICH
SUPPORTS THE CURRENT POSITION WITH HIGH CONFIDENCE. THE CURRENT
INTENSITY IS ASSESSED AT 65 KNOTS BASED ON A DVORAK ESTIMATE OF T4.0
(65 KNOTS) FROM PGTW AND RECENT SURFACE OBSERVATIONS. FROM 01/18-
19Z, TY 09W TRACKED DIRECTLY OVER KUMEJIMA, WHICH REPORTED MAXIMUM
10-MINUTE SUSTAINED WINDS OF 56 KNOTS WITH MINIMUM SLP VALUE OF
971.2MB, WHICH GENERALLY SUPPORTS AN INTENSITY OF 65 TO 70 KNOTS.
KADENA AIR BASE REPORTED MAXIMUM 1-MINUTE SUSTAINED WINDS OF 41
KNOTS GUSTING AS HIGH AS 63 KNOTS (AT 01/1849Z). ADDITIONAL SURFACE
OBSERVATIONS FROM THE REGION SHOWED PERSISTENT 10-MINUTE WINDS
RANGING FROM 35 TO 50 KNOTS. OVER THE PAST 24 HOURS, POLEWARD
OUTFLOW HAS IMPROVED AS EVIDENT IN THE ANIMATED WATER VAPOR IMAGERY,
WHICH INDICATES ROBUST EQUATORWARD OUTFLOW AND A DISTINCT POLEWARD
OUTFLOW CHANNEL ENHANCED BY A SHARP MIDLATITUDE SHORTWAVE TROUGH
DIGGING OVER THE EAST CHINA SEA. HOWEVER, WATER VAPOR IMAGERY ALSO
SHOWS INCREASED PRESSURE OVER THE NORTHWEST PERIPHERY AS THE
AFOREMENTIONED TROUGH BEGINS TO IMPINGE ON OUTFLOW. TY 09W IS
TRACKING ALONG THE WESTERN PERIPHERY OF A DEEP-LAYERED SUBTROPICAL
RIDGE (STR) POSITIONED TO THE EAST.
3. FORECAST REASONING.
A. THERE IS NO CHANGE IN THE FORECAST PHILOSOPHY SINCE THE
PREVIOUS PROGNOSTIC REASONING MESSAGE. THE 64-KNOT AND 34-KNOT WIND
RADII HAVE BEEN ADJUSTED SLIGHTLY BASED ON THE ABUNDANT SURFACE
OBSERVATIONS IN THE AREA AND CONTINUE TO SHOW STRONGER, MORE
EXTENSIVE WINDS OVER THE EASTERN SEMICIRCLE.
B. TY 09W WILL CONTINUE TO TRACK POLEWARD ALONG THE WESTERN
PERIPHERY OF THE STR. WITH THE EXCEPTION OF THE LONE OUTLIER,
NAVGEM, THE BULK OF THE DYNAMIC MODEL GUIDANCE IS IN EXCEPTIONALLY
TIGHT AGREEMENT THROUGH TAU 36 WITH A 41-NM SPREAD IN SOLUTIONS
NEAR SASEBO, JAPAN. UPPER-LEVEL CONDITIONS ARE FORECAST TO REMAIN
FAVORABLE FOR SLIGHT INTENSIFICATION THROUGH TAU 12 WITH A PEAK
INTENSITY OF 70 KNOTS. BY TAU 24, NORTH OF 30N LATITUDE, VWS IS
FORECAST TO INCREASE SIGNIFICANTLY WITH COOLER SST (25C), WHICH WILL
SERVE TO WEAKEN TY 09W AS IT APPROACHES THE SOUTHERN COAST OF SOUTH
KOREA. AS TY PRAPIROON TRACKS OVER THE EAST SEA, SST VALUES ARE
FORECAST TO COOL SIGNIFICANTLY TO LESS THAN 22C, THEREFORE, THE
SYSTEM WILL WEAKEN RAPIDLY WHILE UNDERGOING EXTRA-TROPICAL
TRANSITION (ETT). TY 09W WILL COMPLETE ETT BY TAU 48 AS IT BECOMES
EMBEDDED WITHIN STRONG MIDLATITUDE WESTERLY FLOW NEAR THE JET. AFTER
TAU 72, THE EXTRA-TROPICAL LOW WILL ACCELERATE EASTWARD AND TRACK
OVER NORTHERN HONSHU. OVERALL, THERE IS HIGH CONFIDENCE IN THE JTWC
FORECAST TRACK.//
NNNN

TPPN10 PGTW 012106

A. TROPICAL STORM 09W (PRAPIROON)

B. 01/2030Z

C. 26.75N

D. 126.83E

E. ONE/HMWRI8

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

G. IR/EIR

H. REMARKS: 05A/PBO IRREG EYE/ANMTN. DG EYE SURROUNDED BY LG
YIELDS AN E# AND DT (NO EYE ADJUSTMENT) OF 5.0. MET YIELDS A
4.0 WITH PT ADJUSTMENT YIELDING A 4.5. DBO PT.

I. ADDITIONAL POSITIONS: NONE


RICHARDSON

TXPQ29 KNES 012109
TCSWNP

A. 09W (PRAPIROON)

B. 01/2030Z

C. 26.7N

D. 126.8E

E. ONE/HIMAWARI-8

F. T4.5/4.5/D1.5/24HRS

G. IR/EIR/SWIR

H. REMARKS...THIS INTENSITY ESTIMATE WAS DERIVED USING 4 KM IR DATA. DG
EYE EMBEDDED BY MG AND SURROUNDED BY B RESULTS IN DT=4.5. MET=4.5 AND
PT=4.5. FT IS BASED ON DT.

I. ADDL POSITIONS

NIL


...BOLL

[euro6208]

UW - CIMSS
ADVANCED DVORAK TECHNIQUE
ADT-Version 8.2.1
Tropical Cyclone Intensity Algorithm

----- Current Analysis -----
Date : 01 JUL 2018 Time : 203000 UTC
Lat : 26:42:07 N Lon : 126:47:50 E


CI# /Pressure/ Vmax
3.1 / 987.4mb/ 47.0kt


Final T# Adj T# Raw T#
3.1 3.5 5.0

Estimated radius of max. wind based on IR :N/A km

Center Temp : -30.1C Cloud Region Temp : -64.3C

Scene Type : EYE

Positioning Method : FORECAST INTERPOLATION

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

Tno/CI Rules : Constraint Limits : 0.5T/hour
Weakening Flag : OFF
Rapid Dissipation Flag : OFF

C/K/Z MSLP Estimate Inputs :
- Average 34 knot radii : 112km
- Environmental MSLP : 1005mb

Satellite Name : HIM-8
Satellite Viewing Angle : 34.8 degrees

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

[euro6208]

What a monster.

[euro6208]

[1900hurricane]

Not too bad.

[euro6208]

09W PRAPIROON 180702 0000 27.0N 126.9E WPAC 70 970

Up to 70 knots although this may be on the low side.

[CyclonicFury]

The best looking storm in the WPAC in a while. Definitely appears to be a typhoon now.

[cycloneye]

JMA upgrades to Typhoon.

TY 1807 (Prapiroon)
Issued at 00:50 UTC, 2 July 2018

<Analysis at 00 UTC, 2 July>
Scale -
Intensity Strong
Center position N27°10' (27.2°)
E127°00' (127.0°)
Direction and speed of movement N 20 km/h (11 kt)
Central pressure 965 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 90 km (50 NM)
≥ 30 kt wind area SE 500 km (270 NM)
NW 280 km (150 NM)

<Estimate for 01 UTC, 2 July>
Scale -
Intensity Strong
Center position N27°25' (27.4°)
E127°00' (127.0°)
Direction and speed of movement N 20 km/h (11 kt)
Central pressure 965 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 90 km (50 NM)
≥ 30 kt wind area SE 500 km (270 NM)
NW 280 km (150 NM)

<Forecast for 12 UTC, 2 July>
Intensity Strong
Center position of probability circle N29°50' (29.8°)
E127°30' (127.5°)
Direction and speed of movement N 25 km/h (13 kt)
Central pressure 965 hPa
Maximum wind speed near center 35 m/s (65 kt)
Maximum wind gust speed 50 m/s (95 kt)
Radius of probability circle 70 km (40 NM)
Storm warning area ALL 170 km (90 NM)

<Forecast for 00 UTC, 3 July>
Intensity -
Center position of probability circle N32°30' (32.5°)
E128°10' (128.2°)
Direction and speed of movement N 25 km/h (14 kt)
Central pressure 980 hPa
Maximum wind speed near center 30 m/s (55 kt)
Maximum wind gust speed 40 m/s (80 kt)
Radius of probability circle 150 km (80 NM)
Storm warning area ALL 240 km (130 NM)

<Forecast for 00 UTC, 4 July>
Intensity -
Center position of probability circle N38°00' (38.0°)
E133°00' (133.0°)
Direction and speed of movement NNE 30 km/h (17 kt)
Central pressure 990 hPa
Maximum wind speed near center 23 m/s (45 kt)
Maximum wind gust speed 35 m/s (65 kt)
Radius of probability circle 280 km (150 NM)

<Forecast for 00 UTC, 5 July>
Intensity -
LOW
Center position of probability circle N40°55' (40.9°)
E139°30' (139.5°)
Direction and speed of movement ENE 25 km/h (14 kt)
Central pressure 996 hPa
Maximum sustained wind speed 18 m/s (35 kt)
Maximum wind gust speed 25 m/s (50 kt)
Radius of probability circle 410 km (220 NM)

[euro6208]

CURRENT ESTIMATE
Date (mmddhhmm): 07012205
SATCON: MSLP = 973 hPa MSW = 68 knots
SATCON Member Consensus: 67.0 knots
Pressure -> Wind Using SATCON MSLP: 73 knots
Distance to Outer Closed Isobar Used is 220 nm
Eye Size Correction Used is 5.9 knots Source: IR

Member Estimates

ADT: 976 hPa 65 knots Scene: CDO Date: JUL012340
CIMSS AMSU: 960 hPa 77 knots Bias Corr: 0 (MW) Date: 07012001
ATMS: 968.3 hPa 75.1 knots Date: 07011734
SSMIS: 972.0 hPa 70.0 knots Date: 07012205
CIRA ATMS: 972 hPa 76 knots Date: 07011735

[euro6208]

UW - CIMSS
ADVANCED DVORAK TECHNIQUE
ADT-Version 8.2.1
Tropical Cyclone Intensity Algorithm

----- Current Analysis -----
Date : 02 JUL 2018 Time : 001000 UTC
Lat : 27:15:52 N Lon : 127:00:30 E


CI# /Pressure/ Vmax
4.2 / 972.9mb/ 69.8kt


Final T# Adj T# Raw T#
4.2 4.4 5.7

Estimated radius of max. wind based on IR : 16 km

Center Temp : +8.8C Cloud Region Temp : -63.0C

Scene Type : EYE

Positioning Method : RING/SPIRAL COMBINATION

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

Tno/CI Rules : Constraint Limits : 1.7T/6hr
Weakening Flag : OFF
Rapid Dissipation Flag : OFF

C/K/Z MSLP Estimate Inputs :
- Average 34 knot radii : 112km
- Environmental MSLP : 1005mb

Satellite Name : HIM-8
Satellite Viewing Angle : 35.2 degrees

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

[Alyono]

could see a fairly strong typhoon heading into large cities along the coast of South Korea

Also, the island of Tsushima is in the firing line for a destructive typhoon. Could see 85 kt sustained there

[cycloneye]

[NotoSans]

WTPQ30 RJTD 020000
RSMC TROPICAL CYCLONE PROGNOSTIC REASONING
REASONING NO.15 FOR TY 1807 PRAPIROON (1807)
1.GENERAL COMMENTS
TY PRAPIROON IS LOCATED AT 27.2N, 127.0E. INFORMATION ON THE
CURRENT POSITION IS BASED ON ANIMATED MSI AND RADAR IMAGERY.
POSITIONAL ACCURACY IS GOOD. THE SYSTEM IS IN A FAVORABLE
ENVIRONMENT FOR DEVELOPMENT UNDER THE INFLUENCE OF HIGH SSTS AND
GOOD UPPER-LEVEL OUTFLOW. THIS HAS CAUSED THE SYSTEM TO DEVELOP
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 NORTHWARD ALONG THE WESTERN PERIPHERY OF A
MID-LEVEL SUB-TROPICAL HIGH. ANIMATED MSI SHOWS A BAND SPIRALING
AROUND THE CSC BY AT LEAST 360 DEGREES. ANIMATED MSI SHOWS GOOD
CLOUD CHARACTERISTICS OF ANTICYCLONIC OUTFLOW. WATER VAPOR IMAGERY
SHOWS DRY AIR IN THE DIRECTION OF THE MOVEMENT. DMSP-F17/SSMIS 89
GHZ MICROWAVE IMAGERY SHOWS THE SYSTEM HAS A BAND WITH CURVATURE
INDICATING THE CSC.
3.TRACK FORECAST
THE SYSTEM WILL MOVE NORTHWARD ALONG THE PERIPHERY OF A MID-LEVEL
SUB-TROPICAL HIGH UNTIL FT24. THE SYSTEM WILL THEN MOVE
NORTH-NORTHEASTWARD ALONG THE PERIPHERY OF A MID-LEVEL
SUB-TROPICAL HIGH UNTIL FT48. THE SYSTEM WILL THEN MOVE
EAST-NORTHEASTWARD UNDER THE INFLUENCE OF MID-LATITUDE PREVAILING
WESTERLIES UNTIL FT72. 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 FT12 DUE TO THE
INFLUENCE OF INTERACTION WITH HIGH SSTS AND GOOD UPPER LEVEL
OUTFLOW. THE SYSTEM WILL THEN WEAKEN UNTIL FT48 DUE TO THE
INFLUENCE OF INTERACTION WITH LOWER SSTS AND LOW TCHP. THE SYSTEM
WILL THEN WEAKEN UNTIL FT72 IN A STATE OF EXTRATROPICAL
TRANSITION. THE SYSTEM WILL TRANSFORM INTO AN EXTRATROPICAL
CYCLONE BY FT72. THE JMA INTENSITY FORECAST IS BASED ON A
CONSENSUS OF GUIDANCE DATA INCLUDING GSM.
=

[euro6208]

WDPN31 PGTW 020300
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TYPHOON 09W (PRAPIROON)
WARNING NR 15//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
TYPHOON (TY) 09W (PRAPIROON), LOCATED APPROXIMATELY 64 NM
NORTHWEST OF KADENA AB, OKINAWA, HAS TRACKED AT 11 KNOTS OVER THE
PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY AND RADAR
IMAGERY DEPICT TIGHTLY-CURVED DEEP CONVECTIVE BANDING WRAPPING INTO
A COMPACT CORE WITH AN 8NM OBLONG EYE, THEREFORE, THERE IS GOOD
CONFIDENCE IN THE CURRENT POSITION. THE CURRENT INTENSITY IS
ASSESSED AT 75 KNOTS BASED ON DVORAK ESTIMATES OF T4.5 (77 KNOTS)
FROM PGTW AND KNES. ANIMATED WATER VAPOR IMAGERY INDICATES ROBUST
EQUATORWARD OUTFLOW AND A DISTINCT POLEWARD OUTFLOW CHANNEL ENHANCED
BY A SHARP MIDLATITUDE SHORTWAVE TROUGH DIGGING OVER THE EAST CHINA
SEA. HOWEVER, WATER VAPOR IMAGERY ALSO SHOWS INCREASED PRESSURE OVER
THE WESTERN PERIPHERY AS THE AFOREMENTIONED TROUGH BEGINS TO IMPINGE
ON OUTFLOW. TY 09W IS TRACKING ALONG THE WESTERN PERIPHERY OF A DEEP-
LAYERED SUBTROPICAL RIDGE (STR) POSITIONED TO THE EAST.
3. FORECAST REASONING.
A. THERE IS NO CHANGE IN THE FORECAST PHILOSOPHY SINCE THE
PREVIOUS PROGNOSTIC REASONING MESSAGE.
B. TY 09W WILL CONTINUE TO TRACK POLEWARD ALONG THE WESTERN
PERIPHERY OF THE STR. DYNAMIC MODEL GUIDANCE REMAINS IN GOOD
AGREEMENT THROUGH TAU 24 WITH AN 80NM SPREAD IN SOLUTIONS
NEAR SASEBO, JAPAN. UPPER-LEVEL CONDITIONS ARE FORECAST TO REMAIN
FAVORABLE FOR SLIGHT INTENSIFICATION THROUGH TAU 12 WITH A PEAK
INTENSITY OF 80 KNOTS. BY TAU 24, NORTH OF 30N LATITUDE, VWS IS
FORECAST TO INCREASE SIGNIFICANTLY WITH COOLER SST (25C), WHICH WILL
SERVE TO WEAKEN TY 09W AS IT RECURVES SOUTH OF THE KOREAN PENINSULA.
AS TY PRAPIROON TRACKS OVER THE EAST SEA, SST VALUES ARE FORECAST TO
COOL SIGNIFICANTLY TO LESS THAN 22C, THEREFORE, THE SYSTEM WILL
WEAKEN RAPIDLY WHILE UNDERGOING EXTRA-TROPICAL TRANSITION (ETT). TY
09W WILL COMPLETE ETT BY TAU 48 AS IT BECOMES EMBEDDED WITHIN STRONG
MIDLATITUDE WESTERLY FLOW NEAR THE JET. NEAR TAU 72, THE EXTRA-
TROPICAL LOW WILL ACCELERATE EAST-NORTHEASTWARD AND TRACK OVER
NORTHERN HONSHU. OVERALL, THERE IS HIGH CONFIDENCE IN THE JTWC
FORECAST TRACK.//
NNNN

[doomhaMwx]

Impressive...

[euro6208]

Just rolling along.

[cycloneye]

[euro6208]

WDPN31 PGTW 020900
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TYPHOON 09W (PRAPIROON)
WARNING NR 16//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
TYPHOON (TY) 09W (PRAPIROON), LOCATED APPROXIMATELY 105 NM
NORTH-NORTHWEST OF KADENA AB, OKINAWA, JAPAN, HAS TRACKED
NORTH-NORTHEASTWARD AT 09 KNOTS OVER THE PAST SIX HOURS. ANIMATED MSI
AND A COMPOSITE RADAR LOOP FROM JMA DEPICT TIGHTLY-CURVED DEEP
CONVECTIVE BANDING WRAPPING INTO A RAGGED 10 NM EYE, LENDING HIGH
CONFIDENCE IN THE INITIAL POSITION. THE INITIAL INTENSITY OF 75 KNOTS
IS BASED ON MULTI-AGENCY DVORAK ESTIMATES RANGING FROM T4.0 TO T4.5
(65-77 KNOTS) AND IS SUPPORTED BY SURFACE OBSERVATIONS FROM THE
NEARBY RYUKYU ISLANDS. UPPER LEVEL ANALYSIS INDICATES CONTINUED
STRONG POLEWARD OUTFLOW - ENHANCED BY THE MIDLATITUDE WESTERLIES -
THAT IS OFFSETTING THE MODERATE (15-20 KNOT) VWS. ADDITIONALLY,
ALONG-TRACK SSTS, FOR NOW, ARE CONDUCIVE AT 29 CELSIUS. TY 09W IS NOW
TRACKING ALONG THE NORTHWESTERN PERIPHERY OF A DEEP-LAYERED STR TO
THE EAST.
3. FORECAST REASONING.
A. THERE IS NO CHANGE IN THE FORECAST PHILOSOPHY SINCE THE
PREVIOUS PROGNOSTIC REASONING MESSAGE.
B. TY PRAPIROON WILL TRACK MORE NORTHEASTWARD AS IT ACCELERATES
ALONG THE POLEWARD SIDE OF THE STR IN RESPONSE TO A MID-LATITUDE
TROUGH DIGGING IN FROM THE NORTHWEST. THE OVERALL FAVORABLE
ENVIRONMENT MAY PERSIST FOR UP TO TAU 12 AND SUSTAIN THE CURRENT
INTENSITY. AFTERWARD, INCREASING VWS AND COOLING SSTS WILL GRADUALLY
THEN RAPIDLY ERODE THE SYSTEM AS THE CYCLONE CLIPS SASEBO, JAPAN AND
TRANSITS THROUGH THE KOREA STRAIT. BY TAU 36, 09W WILL ENTER THE COLD
WATERS OF THE SEA OF JAPAN (25 CELSIUS AND BELOW) AND BEGIN
EXTRA-TROPICAL TRANSITION. BY TAU 72, TY 09W WILL EXIT INTO THE
PACIFIC OCEAN JUST SOUTH OF HOKKAIDO AS A COLD CORE EXTRA-TROPICAL
LOW. AVAILABLE NUMERIC GUIDANCE REMAINS IN TIGHT AGREEMENT, LENDING
HIGH CONFIDENCE IN THE JTWC FORECAST TRACK.//
NNNN

[wxman57]

Looks like it's fading fast this morning, hit by increasing shear and merging with a frontal boundary. Transition to ET is beginning.