WPAC: Ampil - Low

[euro6208]

Remains 45 knots 12Z.

12W AMPIL 180720 1200 24.1N 130.1E WPAC 45 987

[mrbagyo]

No 45knot barb

[euro6208]

[euro6208]

Looks poor.

[euro6208]

No 45knot barb

Here is the latest.

[NotoSans]

Suface observations from Okinawa supported JMA's intensity estimate.

[euro6208]

WDPN32 PGTW 202100
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 12W (AMPIL)
WARNING NR 13//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
TROPICAL STORM 12W (AMPIL), LOCATED APPROXIMATELY 104 NM SOUTHEAST
OF KADENA AB, HAS TRACKED NORTH-NORTHWESTWARD AT 12 KNOTS OVER THE
PAST SIX HOURS. ANIMATED ENHANCED INFRARED SATELLITE IMAGERY DEPICTS
A PARTIALLY EXPOSED LOW LEVEL CIRCULATION CENTER (LLCC) WITH A SMALL
AREA OF DEEP CONVECTION TO THE EAST OF THE LLCC. A 201729Z ATMS 89
GHZ IMAGE SUPPORTS THE INITIAL POSITION WITH FAIR CONFIDENCE. UPPER
LEVEL ANALYSIS CONTINUES TO INDICATE A MARGINALLY FAVORABLE
ENVIRONMENT WITH A SMALL TUTT CELL OVER THE LLCC PROVIDING LOW
VERTICAL WIND SHEAR (VWS) AND CONVERGENCE ALOFT. SST VALUES (27-28C)
REMAIN FAVORABLE, AND LIMITED OCEAN HEAT CONTENT IS LESS SIGNIFICANT
DUE TO FORWARD MOTION ACCELERATING TO 12 KNOTS. THE INITIAL
INTENSITY IS ASSESSED AT 45 KNOTS, SUPPORTED BY PGTW/RJTD DVORAK
CURRENT INTENSITY ESTIMATES OF T3.0 (45 KNOTS). TS 12W IS LOCATED ON
THE SOUTHERN PERIPHERY OF A STRONG EAST-WEST ORIENTED SUBTROPICAL
RIDGE (STR) TO THE NORTH.
3. FORECAST REASONING.
A. THERE IS NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE
PREVIOUS PROGNOSTIC REASONING MESSAGE.
B. TS 12W IS FORECAST TO CONTINUE NORTHWESTWARD UNDER THE
STEERING INFLUENCE OF THE AFOREMENTIONED STR. DUE TO THE MARGINALLY
FAVORABLE UPPER LEVEL ENVIRONMENT, WHICH IS EXPECTED TO PERSIST, TS
AMPIL IS FORECASTED TO INTENSIFY SLIGHTLY THROUGH TAU 24, PEAKING AT
AROUND 50 KNOTS. THE NUMERICAL MODEL GUIDANCE IS IN TIGHT AGREEMENT
IN INDICATING A TRACK OVER OKINAWA. AFTER TAU 24, TS 12W IS
FORECASTED TO CONTINUE TRACKING NORTHWESTWARD AND BEGIN TO WEAKEN
GRADUALLY BEFORE MAKING LANDFALL AT TAU 36, JUST SOUTH OF SHANGHAI.
SURFACE WINDS ARE FORECAST TO REMAIN EXTENSIVE AND ROBUST OVER THE
NORTHERN SEMICIRCLE DUE TO THE STRONG GRADIENT ASSOCIATED WITH THE
SYSTEM AND ADJACENT SURFACE HIGH. THE SYSTEM WILL TRACK INLAND AND
WEAKEN RAPIDLY, WITH DISSIPATION BY TAU 72. OVERALL, THERE IS
HIGH CONFIDENCE IN THE JTWC FORECAST TRACK, WHICH IS POSITIONED
CLOSE TO THE MULTI-MODEL CONSENSUS.//
NNNN

[Twisted-core]

STS 1810 (Ampil)
Issued at 00:45 UTC, 21 July 2018

<Analysis at 00 UTC, 21 July>
Scale -
Intensity -
Center position N26°40' (26.7°)
E127°55' (127.9°)
Direction and speed of movement NW 25 km/h (14 kt)
Central pressure 985 hPa
Maximum sustained wind speed 25 m/s (50 kt)
Maximum wind gust speed 35 m/s (70 kt)
≥ 30 kt wind area NE 500 km (270 NM)
SW 330 km (180 NM)

<Estimate for 01 UTC, 21 July>
Scale -
Intensity -
Center position N26°55' (26.9°)
E127°40' (127.7°)
Direction and speed of movement NW 25 km/h (14 kt)
Central pressure 985 hPa
Maximum sustained wind speed 25 m/s (50 kt)
Maximum wind gust speed 35 m/s (70 kt)
≥ 30 kt wind area NE 500 km (270 NM)
SW 330 km (180 NM)

<Forecast for 12 UTC, 21 July>
Intensity -
Center position of probability circle N28°30' (28.5°)
E125°25' (125.4°)
Direction and speed of movement NW 25 km/h (14 kt)
Central pressure 985 hPa
Maximum sustained wind speed 25 m/s (50 kt)
Maximum wind gust speed 35 m/s (70 kt)
Radius of probability circle 70 km (40 NM)

<Forecast for 00 UTC, 22 July>
Intensity -
Center position of probability circle N30°10' (30.2°)
E122°35' (122.6°)
Direction and speed of movement NW 30 km/h (15 kt)
Central pressure 980 hPa
Maximum sustained wind speed 30 m/s (55 kt)
Maximum wind gust speed 40 m/s (80 kt)
Radius of probability circle 110 km (60 NM)
Storm warning area NE 220 km (120 NM)
SW 150 km (80 NM)

<Forecast for 00 UTC, 23 July>
Intensity -
Center position of probability circle N33°35' (33.6°)
E118°25' (118.4°)
Direction and speed of movement NW 20 km/h (12 kt)
Central pressure 990 hPa
Maximum sustained wind speed 18 m/s (35 kt)
Maximum wind gust speed 25 m/s (50 kt)
Radius of probability circle 200 km (110 NM)

<Forecast for 00 UTC, 24 July>
Intensity -
TD
Center position of probability circle N36°50' (36.8°)
E116°30' (116.5°)
Direction and speed of movement NNW 20 km/h (10 kt)
Central pressure 992 hPa
Radius of probability



Previous reasoning 20th
[Div][WTPQ31 RJTD 201800
RSMC TROPICAL CYCLONE PROGNOSTIC REASONING
REASONING NO.14 FOR STS 1810 AMPIL (1810)
1.GENERAL COMMENTS
STS AMPIL IS LOCATED AT 25.6N, 129.0E. INFORMATION ON THE CURRENT
POSITION IS BASED ON SURFACE OBSERVATIONS AND ANIMATED MSI.
POSITIONAL ACCURACY IS GOOD. THE SYSTEM IS IN A NEUTRAL
ENVIRONMENT FOR DEVELOPMENT UNDER THE INFLUENCE OF HIGH TCHP, WEAK
VWS AND DRY AIR. THIS HAS CAUSED THE SYSTEM TO MAINTAIN ITS
INTENSITY OVER THE LAST SIX HOURS. INFORMATION ON CURRENT
INTENSITY IS BASED ON DVORAK INTENSITY ANALYSES AND SURFACE WINDS
DATA ESTIMATED FROM SATELLITE SCATTEROMETERS.
2.SYNOPTIC SITUATION
THE SYSTEM IS MOVING NORTH-NORTHWESTWARD ALONG THE SOUTHWESTERN
PERIPHERY OF A MID-LEVEL SUB-TROPICAL HIGH. ANIMATED MSI SHOWS CB
CLUSTERS ARE SCATTERED AROUND THE CSC.
3.TRACK FORECAST
THE SYSTEM WILL MOVE NORTHWESTWARD ALONG THE PERIPHERY OF A
MID-LEVEL SUB-TROPICAL HIGH UNTIL FT72. THE SYSTEM WILL HIT THE
CHINESE MAINLAND BY FT48. 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 GRADUALLY DEVELOP UNTIL FT12 DUE TO THE INFLUENCE
OF INTERACTION WITH HIGH TCHP AND WEAK VWS. THE SYSTEM WILL THEN
GRADUALLY WEAKEN UNTIL FT36 DUE TO THE INFLUENCE OF INTERACTION
WITH REDUCED TCHP AND INCREASED VWS. THE SYSTEM WILL THEN WEAKEN
RAPIDLY UNTIL FT72 DUE TO ITS LANDFALL. THE SYSTEM WILL WEAKEN TO
TD INTENSITY BY FT72. THE JMA INTENSITY FORECAST IS BASED ON
GUIDANCE DATA

[Twisted-core]

recovered at: 2018-07-21 0115Z

WTPQ21 RJTD 210000
RSMC TROPICAL CYCLONE ADVISORY
NAME STS 1810 AMPIL (1810)
ANALYSIS
PSTN 210000UTC 26.7N 127.9E GOOD
MOVE NW 14KT
PRES 985HPA
MXWD 050KT
GUST 070KT
30KT 270NM NORTHEAST 180NM SOUTHWEST
FORECAST
24HF 220000UTC 30.2N 122.6E 60NM 70%
MOVE NW 15KT
PRES 980HPA
MXWD 055KT
GUST 080KT
48HF 230000UTC 33.6N 118.4E 110NM 70%
MOVE NW 12KT
PRES 990HPA
MXWD 035KT
GUST 050KT
72HF 240000UTC 36.8N 116.5E 130NM 70% TROPICAL DEPRESSION =

, recovered at: 2018-07-21 0145Z

WTPQ31 RJTD 210000
RSMC TROPICAL CYCLONE PROGNOSTIC REASONING
REASONING NO.15 FOR STS 1810 AMPIL (1810)
1.GENERAL COMMENTS
STS AMPIL IS LOCATED AT 26.7N, 127.9E. INFORMATION ON THE CURRENT
POSITION IS BASED ON SURFACE OBSERVATIONS AND RADAR IMAGERY.
POSITIONAL ACCURACY IS GOOD. THE SYSTEM IS IN A NEUTRAL
ENVIRONMENT FOR DEVELOPMENT UNDER THE INFLUENCE OF LOWER SSTS,
REDUCED TCHP AND INCREASED VWS. THIS HAS CAUSED THE SYSTEM TO
MAINTAIN ITS INTENSITY OVER THE LAST SIX HOURS. INFORMATION ON
CURRENT INTENSITY IS BASED ON SURFACE OBSERVATIONS.
2.SYNOPTIC SITUATION
THE SYSTEM IS MOVING NORTHWESTWARD ALONG THE SOUTHERN PERIPHERY OF
A MID-LEVEL SUB-TROPICAL HIGH. ANIMATED MSI SHOWS CB CLUSTERS ARE
SCATTERED AROUND THE CSC.
3.TRACK FORECAST
THE SYSTEM WILL MOVE NORTHWESTWARD ALONG THE PERIPHERY OF A
MID-LEVEL SUB-TROPICAL HIGH UNTIL FT48. THE SYSTEM WILL THEN MOVE
NORTH-NORTHWESTWARD ALONG THE PERIPHERY OF A MID-LEVEL
SUB-TROPICAL HIGH UNTIL FT72. THE SYSTEM WILL HIT THE CHINESE
MAINLAND BY FT48. 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 GRADUALLY DEVELOP UNTIL FT24 DUE TO THE INFLUENCE
OF INTERACTION WITH HIGH SSTS, HIGH TCHP AND WEAK VWS. THE SYSTEM
WILL THEN WEAKEN UNTIL FT72 DUE TO ITS LANDFALL. THE SYSTEM WILL
WEAKEN TO TD INTENSITY BY FT72. THE JMA INTENSITY FORECAST IS
BASED ON GUIDANCE DATA.
=

............................................................................................................................................

KMA

2018-07-21 0115Z

WTKO20 RKSL 210000
KMA TROPICAL CYCLONE ADVISORY NO. 11
NAME 1810 AMPIL
ANALYSIS
POSITION 210000UTC 26.8N 128.1E
MOVEMENT NW 17KT
PRES/VMAX 985HPA 52KT
FORECAST
24HR
POSITION 220000UTC 30.0N 122.2E WITHIN 60NM
PRES/VMAX 990HPA 47KT
48HR
POSITION 230000UTC 32.9N 117.7E WITHIN 0NM
PRES/VMAX 998HPA 27KT
KOREA METEOROLOGICAL ADMINISTRATION.

[euro6208]

WDPN32 PGTW 210300
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 12W (AMPIL) WARNING NR
14//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
TROPICAL STORM 12W (AMPIL), LOCATED APPROXIMATELY 21 NM NORTH-
NORTHEAST OF KADENA AB, HAS TRACKED NORTHWESTWARD AT 18 KNOTS OVER
THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY, A
202124 SSMIS 37 GHZ IMAGE, AND KADENA RADAR IMAGERY DEPICT DEEP
CONVECTION TO THE NORTHEAST OF THE LOW LEVEL CIRCULATION CENTER
(LLCC). BASED ON THE MULTIPLE DATA SOURCES, THE INITIAL POSITION IS
PLACED WITH FAIR CONFIDENCE. THE INITIAL INTENSITY OF 45 KNOTS IS
BASED ON A 210000Z RJTD DVORAK CURRENT INTENSITY OF T3.0 (45 KNOTS)
AND 210040Z PARTIAL ASCAT PASS SHOWING A REGION OF 45 KNOTS TO THE
NORTHEAST OF THE LLCC. UPPER LEVEL ANALYSIS INDICATES A MARGINALLY
FAVORABLE ENVIRONMENT WITH A TUTT CELL WEST OF THE LLCC PROVIDING
LOW VERTICAL WIND SHEAR (VWS) AND LIMITED POLEWARD OUTFLOW, HOWEVER
THE ASSOCIATED CONVERGENCE ALOFT IS SUPPRESSING CONVECTION TO THE
WEST. SST VALUES (28-29C) REMAIN FAVORABLE. TS 12W IS LOCATED ON THE
SOUTHERN PERIPHERY OF A STRONG EAST-WEST ORIENTED SUBTROPICAL RIDGE
(STR) TO THE NORTH.
3. FORECAST REASONING.
A. THERE IS NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE
PREVIOUS PROGNOSTIC REASONING MESSAGE.
B. TS 12W IS FORECAST TO CONTINUE TRACKING NORTHWESTWARD UNDER
THE STEERING INFLUENCE OF THE STR. THE MARGINALLY FAVORABLE UPPER
LEVEL ENVIRONMENT IS EXPECTED TO PERSIST UNTIL MAKING LANDFALL JUST
NORTH OF SHANGHAI AFTER TAU 36. AFTER MAKING LANDFALL, TS 12W WILL
BEGIN DISSIPATING THROUGH TAU 72 WHEN THE INTENSITY FALLS BELOW 25
KNOTS. THE JTWC FORECAST TRACK IS POSITIONED CLOSE TO THE CONSENSUS
OF THE TIGHTLY GROUPED NUMERICAL MODEL GUIDANCE, LENDING HIGH
CONFIDENCE TO THE JTWC FORECAST TRACK.//
NNNN

[euro6208]

WDPN32 PGTW 210900
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 12W (AMPIL) WARNING NR
15//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
TROPICAL STORM (TS) 12W (AMPIL), LOCATED APPROXIMATELY 130 NM
NORTHWEST OF KADENA AB, OKINAWA, JAPAN, HAS TRACKED NORTHWESTWARD AT
21 KNOTS OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE
IMAGERY SHOWS A VERY BROAD AND PARTIALLY EXPOSED LOW LEVEL
CIRCULATION WITH THE DEEPEST CONVECTION IN THE NORTHEAST QUADRANT.
THE INITIAL POSITION IS BASED ON A 210540Z HIMAWARI VISIBLE SATELLITE
IMAGE WHICH SHOWS THE BROAD CIRCULATION. THE INITIAL INTENSITY OF 45
KNOTS IS BASED ON A PGTW DVORAK INTENSITY ESTIMATE OF T3.0 (45
KNOTS). ENVIRONMENTAL ANALYSIS SHOWS TS 12W HAS MODERATE POLEWARD
OUTFLOW BUT LIMITED EQUATORWARD OUTFLOW. VERTICAL WIND SHEAR REMAINS
FAVORABLE, BETWEEN 5 AND 10 KNOTS. SEA SURFACE TEMPERATURES ALSO
REMAIN FAVORABLE, BETWEEN 28 AND 29 DEGREES CELSIUS. TS 12W IS
TRACKING NORTHWESTWARD ALONG THE SOUTHWESTERN EDGE OF THE SUBTROPICAL
RIDGE (STR) LOCATED TO THE NORTHEAST.
3. FORECAST REASONING.
A. THERE IS NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE
PREVIOUS PROGNOSTIC REASONING MESSAGE.
B. TS 12W WILL CONTINUE ON A NORTHWESTERLY TRACK FOR THE REMAINDER
OF THE FORECAST. THE AFOREMENTIONED STR WILL REMAIN IN PLACE AND TS
12W WILL CONTINUE TO TRACK ALONG ITS SOUTHWESTERN EDGE. TS 12 WILL
MAINTAIN AN INTENSITY OF 45 KNOTS THROUGH TAU 12. AFTER TAU 12, TS
12W WILL STEADILY DECREASE IN INTENSITY. LANDFALL WILL OCCUR SHORTLY
BEFORE TAU 24, NEAR SHANGHAI, CHINA. OVERALL, DYNAMIC MODEL GUIDANCE
IS IN GOOD AGREEMENT, THEREFORE, THERE IS HIGH CONFIDENCE IN THE JTWC
FORECAST TRACK.//
NNNN

[euro6208]

[euro6208]

TPPN13 PGTW 211223

A. TROPICAL STORM 12W (AMPIL)

B. 21/1200Z

C. 29.20N

D. 125.19E

E. FIVE/HMWRI8

F. T3.0/3.0/D0.5/24HRS STT: S0.0/03HRS

G. IR/EIR

H. REMARKS: 38A/PBO SBC/ANMTN. CNVCTN WRAPS .50 ON LOG10 SPIRAL
YIELDING A DT OF 2.5. MET YIELDS A 3.5 WHILE PT YIELDS A 3.0.
DBO PT.

I. ADDITIONAL POSITIONS:
21/0658Z 27.82N 126.52E SSMS
21/0703Z 27.73N 126.40E MMHS
21/0842Z 28.25N 126.02E SSMS
21/0940Z 28.22N 126.08E WIND
21/1013Z 28.55N 126.33E SSMS


LEMBKE

TXPQ23 KNES 210925
TCSWNP

A. 12W (AMPIL)

B. 21/0830Z

C. 27.7N

D. 126.4E

E. THREE/HIMAWARI-8

F. T3.0/3.0/D0.5/24HRS

G. IR/EIR/VIS

H. REMARKS...THIS INTENSITY ESTIMATE WAS DERIVED USING 4 KM IR
DATA. DT=3.0 BASED ON 0.7 CURVED BANDING. MET AND PT AGREE. FT IS BASED
ON DT.

I. ADDL POSITIONS

NIL


...KIM

[euro6208]

[Twisted-core]

https://imgur.com/qmPrbjH

[euro6208]

WDPN32 PGTW 220300
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 12W (AMPIL) WARNING NR
18//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
TROPICAL STORM 12W (AMPIL), LOCATED APPROXIMATELY 338 NM NORTH-
NORTHEAST OF TAIPEI, TAIWAN, HAS TRACKED WEST-NORTHWESTWARD AT 12
KNOTS OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE
IMAGERY SHOWS SIGNIFICANT CONVECTION WRAPPING AROUND THE NORTHERN
HALF OF THE LOW LEVEL CIRCULATION CENTER (LLCC) AND MUCH LESS
CONVECTION SOUTH OF THE LLCC. THE INITIAL POSITION IS PLACED WITH
GOOD CONFIDENCE BASED ON A 202240Z SSMIS 91 GHZ IMAGE CLEARLY
SHOWING THE CONVECTION WRAPPING AROUND THE LLCC. THE INITIAL
INTENSITY OF 45 KNOTS IS BASED ON MULTI-AGENCY DVORAK CURRENT
INTENSITY ESTIMATES OF T3.0 (45 KNOTS). ENVIRONMENTAL ANALYSIS SHOWS
GOOD POLEWARD OUTFLOW, LOW VERTICAL WIND SHEAR (5-10 KNOTS) AND WARM
SEA SURFACE TEMPERATURES (28-29C) BEING COUNTERED BY DRIER AIR
ENTRAINING IN FROM THE SOUTH. TS 12W IS TRACKING NORTHWESTWARD ALONG
THE WESTERN EDGE OF THE SUBTROPICAL RIDGE (STR) LOCATED TO THE EAST.
3. FORECAST REASONING.
A. THERE IS NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE
PREVIOUS PROGNOSTIC REASONING MESSAGE.
B. TS 12W WILL CONTINUE ON A NORTHWESTERLY TRACK ALONG THE
WESTERN PERIPHERY OF THE STR FOR THE REMAINDER OF THE FORECAST. TS
12W WILL BEGIN SLOWLY WEAKENING AS IT MOVES OVER LAND JUST NORTH OF
SHANGHAI, CHINA IN THE NEXT 6 HOURS. THAT WEAKENING TREND WILL
CONTINUE UNTIL TS 12W FULLY DISSIPATES BY TAU 48. THE NUMERICAL
MODEL GUIDANCE HAS CONSISTENTLY SHIFTED EASTWARD IN THE LATER TAUS
(TAU 48 AND BEYOND) AS THE CYCLONE BEGINS TO INTERACT WITH THE MID-
LATITUDE WESTERLIES AND THE TRACK BECOMES NORTHEASTWARD. THE
FORECAST CALLS FOR TS 12W TO FALL BELOW 25 KNOTS PRIOR TO GOING
EXTRATROPICAL DUE TO LAND INTERACTION BUT THE CIRCULATION MAY
PERSIST BEYOND TAU 48. DESPITE THE UNCERTAINTY BEYOND TAU 48, THERE
IS HIGH CONFIDENCE IN THE JTWC FORECAST TRACK.//
NNNN

[Twisted-core]

https://imgur.com/4eAH0T8
Was clearly stronger than 45kts on approach. May have been a borderline typhoon.

[euro6208]

WDPN32 PGTW 220900
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 12W (AMPIL) WARNING NR
19//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
TROPICAL STORM (TS) 12W (AMPIL), LOCATED APPROXIMATELY 328 NM
SOUTHWEST OF KUNSAN AB, SOUTH KOREA, HAS TRACKED NORTH-NORTHWESTWARD
AT 14 KNOTS OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE
IMAGERY SHOWS A SYMMETRIC LOW LEVEL CLOUD FIELD WITH THE REMAINING
DEEP CONVECTION LOCATED TO THE NORTH AND WEST OF THE LOW LEVEL
CIRCULATION CENTER (LLCC). THE INITIAL POSITION IS PLACED WITH HIGH
CONFIDENCE BASED ON A 220611Z 85GHZ SSMI MICROWAVE IMAGE WHICH SHOWS
GOOD BANDING WITH AFOREMENTIONED DEEP CONVECTION TO THE NORTH AND
WEST OF THE LLCC. THE INITIAL INTENSITY OF 45 KNOTS IS BASED ON A
DVORAK INTENSITY ESTIMATE OF T3.0 (45 KNOTS) FROM PGTW. ENVIRONMENTAL
ANALYSIS SHOWS TS 12W HAS WEAK TO MODERATE RADIAL OUTFLOW ALONG WITH
FAVORABLE VERTICAL WIND SHEAR (10 TO 15 KNOTS). SEA SURFACE
TEMPERATURES ARE NOW COOLER BUT REMAIN FAVORABLE, RANGING BETWEEN 27
TO 28 DEGREES CELSIUS. TS 12W IS TRACKING NORTH-NORTHWESTWARD ALONG
THE SOUTHWESTERN EDGE OF THE SUBTROPICAL RIDGE (STR) WHICH REMAINS
LOCATED TO THE NORTHEAST.
3. FORECAST REASONING.
A. THERE IS NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE
PREVIOUS PROGNOSTIC REASONING MESSAGE.
B. TS 12W WILL CONTINUE TO TRACK NORTH-NORTHWESTWARD AROUND THE
SOUTHWESTERN PERIPHERY OF THE AFOREMENTIONED STR. LAND INTERACTION
WILL CAUSE TS 12W TO STEADILY DECREASE IN INTENSITY, REACHING 40
KNOTS BY TAU 12. TS 12W WILL TRACK ALONG THE COAST OF EASTERN CHINA
THROUGH TAU 24. AFTER TAU 24, TS 12W WILL TRACK FARTHER INLAND, THEN
CROSS OVER BOHAI BAY AS IT TRACKS NORTHWARD, AND EVENTUALLY DISSIPATE
OVER LAND WITH AN INTENSITY OF 20 KNOTS BY TAU 48. OVERALL, DYNAMIC
MODEL GUIDANCE IS IN GOOD AGREEMENT, THEREFORE, THERE IS HIGH
CONFIDENCE IN THE JTWC FORECAST TRACK.//
NNNN

[NotoSans]

https://imgur.com/4eAH0T8
Was clearly stronger than 45kts on approach. May have been a borderline typhoon.

ASCAT data are prone to land contamination. Surface observations from China suggested that landfall pressure is near 980 mb, which, combined with surface observations from Okinawa, clearly suggested that it was NOT a typhoon.

[euro6208]

WDPN32 PGTW 222100
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 12W (AMPIL) WARNING NR
21//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
TROPICAL STORM 12W (AMPIL), LOCATED APPROXIMATELY 351 NM WEST-
SOUTHWEST OF KUNSAN AB, HAS TRACKED NORTHWESTWARD AT 11 KNOTS OVER
THE PAST SIX HOURS. ANIMATED ENHANCED INFRARED (EIR) SATELLITE
IMAGERY SHOWS THAT TS 12W REMAINS SYMMETRIC BUT IS LACKING DEEP
CONVECTION, PARTICULARLY IN THE SOUTHWEST QUADRANT AND HAS A FULLY
EXPOSED LOW LEVEL CIRCULATION CENTER (LLCC) LOCATED OVER LAND. THE
INITIAL POSITION IS PLACED WITH HIGH CONFIDENCE BASED ON THE EIR
IMAGERY. THE INITIAL INTENSITY OF 35 KNOTS IS BASED ON THE 221200Z
DVORAK CURRENT INTENSITY (CI) ESTIMATE OF T2.5 (35 KNOTS) AND
REFLECTS A SLIGHT WEAKENING FROM THE PREVIOUS FORECAST.
ENVIRONMENTAL ANALYSIS SHOWS TS 12W STILL HAS WEAK TO MODERATE
POLEWARD OUTFLOW AND MODERATE VERTICAL WIND SHEAR (15 TO 20 KNOTS).
TS 12W IS TRACKING NORTHWESTWARD ALONG THE WESTERN EDGE OF A
SUBTROPICAL RIDGE (STR) LOCATED TO THE NORTHEAST.
3. FORECAST REASONING.
A. THERE IS NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE
PREVIOUS PROGNOSTIC REASONING MESSAGE. THE TRACK HAS MOVED SLIGHTLY
WEST OF THE PREVIOUS FORECAST, BRINGING TS 12W FURTHER INLAND.
B. TS 12W WILL CONTINUE TO TRACK NORTHWESTWARD ALONG THE
PERIPHERY OF THE STR BEFORE ROUNDING THE RIDGE AXIS AND GRADUALLY
TURNING NORTHEASTWARD BETWEEN TAU 12 AND TAU 48. ALTHOUGH TS 12W
WILL BRIEFLY PASS OVER THE BOHAI SEA BETWEEN TAU 24 AND 36, LAND
INTERACTION WILL CONTINUE TO AFFECT THE CYCLONE AND IT WILL WEAKEN
TO 20 KNOTS BY TAU 48. OVERALL, DYNAMIC MODEL GUIDANCE IS IN GOOD
AGREEMENT, THEREFORE, THERE IS HIGH CONFIDENCE IN THE JTWC FORECAST
TRACK.//
NNNN