WPAC: BEBINCA - Post-Tropical

[mrbagyo]

[euro6208]

40 knots

WDPN33 PGTW 132100
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 20W (BEBINCA)
WARNING NR 06//
RMKS//
TROPICAL STORM (TS) 20W (BEBINCA), LOCATED APPROXIMATELY 117 NM
SOUTH-SOUTHWEST OF HONG KONG, HAS TRACKED EASTWARD-SOUTHEASTWARD AT
02 KNOTS OVER THE PAST SIX HOURS. ANIMATED ENHANCED INFRARED
SATELLITE IMAGERY DEPICTS FLARING DEEP CONVECTION WHICH IS OBSCURING
THE LLCC. UNFORTUNATELY, THERE HAVE BEEN NO RECENT MICROWAVE PASSES
TO ASSIST WITH PLACING THE LLCC, WITH THE MOST RECENT AVAILABLE
BEING A 131356Z AMSU 89 GHZ IMAGE, WHICH DEPICTED A POORLY DEFINED
LLCC JUST WEST OF THE DEEPEST CONVECTION ALONG THE EASTERN EDGE OF
THE SYSTEM. THE INITIAL INTENSITY IS ASSESSED AT 40 KNOTS BASED ON
DVORAK INTENSITY ESTIMATES OF T2.5 (35 KNOTS) FROM KNES AND PGTW,
HEDGED SLIGHTLY HIGHER IN LIGHT OF A 43 KNOT AUTOMATED DVORAK
ESTIMATE AND A SATCON OF 37 KNOTS. ENVIRONMENTAL ANALYSIS INDICATES
THAT THE SYSTEM LIES IN AN AREA OF MODERATE TO STRONG (25 TO 35
KNOTS) EASTERLY VWS, AND MODERATELY STRONG EQUATORWARD OUTFLOW,
WHICH IS OFFSETTING THE STRONG VWS. TS 20W IS SLOWLY DRIFTING IN A
WEAK STEERING ENVIRONMENT DUE TO THE PRESENCE OF A LARGE LOW
PRESSURE AREA ASSOCIATED WITH TS 20W, THE REMNANTS OF TROPICAL
DEPRESSION 18W AND INVEST 98W.
3. FORECAST REASONING.
A. THERE IS NO CHANGE TO THE FORECAST PHILOSOPHY FROM THE PREVIOUS
PROGNOSTIC REASONING MESSAGE.
B. TS 20W IS FORECASTED TO REMAIN QUASI-STATIONARY OVER THE NEXT
24 HOURS, UNDER THE AFOREMENTIONED WEAK STEERING ENVIRONMENT. AFTER
TAU 24, THE STR OVER EASTERN CHINA IS EXPECTED TO STRENGTHEN, AND
PUSH TS 20W ONTO AN ACCELERATING WESTWARD TRACK THROUGH TAU 72. TS
20W WILL REMAIN WITHIN A MARGINAL UPPER-LEVEL ENVIRONMENT WITH
MODERATE TO STRONG VWS, OFFSET BY MODERATE EQUATORWARD OUTFLOW
PROVIDED BY THE VIGOROUS NORTHEASTERLY FLOW, ALLOWING THE SYSTEM TO
MAINTAIN A STEADY INTENSITY THROUGH TAU 24. BETWEEN TAU 36 AND TAU
48, THE SYSTEM WILL WEAKEN SLIGHTLY DUE TO INCREASED LAND
INTERACTION AS IT NEARS THE CHINESE COAST, AND SLIGHTLY DECREASED
OUTFLOW. A SHORT PERIOD OF REINTENSIFCATION IS FORECAST AS THE
SYSTEM CROSSES THE LEIZHOU PENINSULA JUST SOUTH OF ZHANJIANG AND
EMERGES INTO THE GULF OF TONKIN BY AROUND TAU 60.
C. TS 20W WILL REACH ITS PEAK INTENSITY IN THE GULF OF TONKIN BY
TAU 72 AS THE RELATIVE VWS VALUES ARE DECREASED AS THE STORM PICKS
UP SPEED IN PHASE WITH THE SHEAR VECTOR. VERY WARM SSTS AND HIGH
OHC, WILL CONTRIBUTE TO THE INTENSIFICATION. THE SYSTEM WILL
ACCELERATE WESTWARD AND WILL MAKE A SECOND LANDFALL BETWEEN TAU 72
AND TAU 96 ALONG THE NORTHEAST COAST OF VIETNAM WITH DISSIPATION
EXPECTED BY TAU 120. DUE TO THE WEAK STEERING FLOW IN THE EARLY PART
OF THE FORECAST, AND THE ACCOMPANYING UNCERTAINTY IN THE AVAILABLE
MODEL GUIDANCE, THERE IS LOW CONFIDENCE IN THE JTWC FORECAST TRACK.//
NNNN

[euro6208]

Remains 40 knots.

WDPN33 PGTW 140300
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 20W (BEBINCA) WARNING NR
07//
RMKS//
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
TROPICAL STORM (TS) 20W (BEBINCA), LOCATED APPROXIMATELY 87 NM
SOUTH-SOUTHWEST OF HONG KONG, HAS TRACKED NORTH-NORTHEASTWARD AT
04 KNOTS OVER THE PAST SIX HOURS. ANIMATED MULTI-SPECTRAL SATELLITE
IMAGERY (MSI) DEPICTS A PARTIALLY EXPOSED LOW LEVEL CIRCULATION
CENTER (LLCC) WITH DEEP CONVECTION SHEARED TO THE WEST. A 132240Z
SSMIS 91 GHZ PASS IS CONSISTENT WITH THE MSI. THE INITIAL POSITION
IS BASED ON THE PGTW FIX AND NOTED SSMIS CENTER. THE INITIAL
INTENSITY IS ASSESSED AT 40 KNOTS BASED ON DVORAK INTENSITY
ESTIMATES OF T2.5 (35 KNOTS) FROM PGTW, AND HEDGED SLIGHTLY HIGHER
BASED ON RECENT SCATTEROMETRY INDICATING 40 KNOTS. ENVIRONMENTAL
ANALYSIS INDICATES THAT THE SYSTEM LIES IN AN AREA OF STRONG (30 TO
35 KNOTS) EASTERLY VWS, WITH MARGINAL OUTFLOW. THE STEERING FLOW IS
STARTING TO BECOME MORE DEFINED AS A STEERING RIDGE (STR) TO THE
NORTH BUILDS.
3. FORECAST REASONING.
A. THERE IS NO CHANGE TO THE FORECAST PHILOSOPHY FROM THE PREVIOUS
PROGNOSTIC REASONING MESSAGE, HOWEVER, THE TRACK HAS BEEN SHIFTED
NORTHWARD BASED ON THE LATEST ANALYSIS OF CURRENT TRACK MOTION.
B. TS 20W IS FORECAST TO SLOWLY TRACK NORTHWARD TOWARD HONG KONG
AND TURN BACK TO THE WEST AFTER TAU 12 UNDER THE STEERING FLOW OF THE
STR. THE INTENSITY SHOULD REMAIN FAIRLY CONSTANT UNTIL LANDFALL
OCCURS, AFTER WHICH A GRADUAL WEAKENING TREND WILL BEGIN. AFTER TAU
48, THE BUILDING STR MAY DEFLECT THE TRACK SOUTHWARD BACK OVER THE
SOUTH CHINA SEA, ALLOWING FOR SLIGHT INTENSIFICATION BEFORE MAKING
ANOTHER LANDFALL OVER VIETNAM.
C. BEYOND TAU 72, BEBINCA WILL MOVE INLAND INTO VIETNAM AND
DISSIPATE BY TAU 96. DUE TO THE WEAK STEERING FLOW IN THE EARLY PART
OF THE FORECAST, AND THE LARGE SPREAD IN MODEL TRACK SPEEDS, THERE IS
LOW CONFIDENCE IN THE JTWC FORECAST TRACK.//
NNNN

[doomhaMwx]

Bebinca has been impacted by strong northeasterly shear, but VIS satellite imagery in the last few hours shows deep convection redeveloping over the exposed circulation center. It remains to be seen if it can sustain this, however.

[euro6208]

WDPN33 PGTW 140900
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 20W (BEBINCA) WARNING
NR 08//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
TROPICAL STORM (TS) 20W (BEBINCA), LOCATED APPROXIMATELY 83 NM
SOUTH-SOUTHWEST OF HONG KONG, HAS TRACKED WEST-NORTHWESTWARD AT 02
KNOTS OVER THE PAST SIX HOURS. THE INITIAL POSITION IS PLACED WITH
FAIR CONFIDENCE BASED ON ANIMATED MULTI-SPECTRAL SATELLITE IMAGERY
(MSI) AND A 140646Z SSMI 85 GHZ IMAGE WHICH DEPICT A PARTIALLY
EXPOSED LOW LEVEL CIRCULATION CENTER (LLCC) WITH DEEP CONVECTION
SHEARED TO THE WEST. THE INITIAL INTENSITY OF 40 KNOTS IS HEDGED
SLIGHTLY ABOVE THE PGTW DVORAK CURRENT INTENSITY ESTIMATE OF T2.5
(35 KNOTS) BASED ON A 140226Z METOP-B ASCAT IMAGE WITH A FAIRLY
LARGE AREA OF 35 KNOTS SOUTHWEST OF THE LLCC. ENVIRONMENTAL
ANALYSIS INDICATES THAT THE SYSTEM LIES IN AN AREA OF STRONG (25 TO
35 KNOTS) VERTICAL WIND SHEAR AND MARGINAL OUTFLOW. TS 20W IS
DRIFTING SLOWLY IN THE ABSENCE OF A STRONG STEERING INFLUENCE AT
THIS TIME.
3. FORECAST REASONING.
A. THERE IS NO CHANGE TO THE FORECAST PHILOSOPHY FROM THE
PREVIOUS PROGNOSTIC REASONING MESSAGE.
B. TS 20W IS FORECAST TO BEGIN TRACKING WESTWARD AS A
SUBTROPICAL RIDGE (STR) BUILDS TO THE NORTH. THE INTENSITY SHOULD
REMAIN FAIRLY CONSTANT, WEAKENING SLIGHTLY AS IT SKIRTS THE COAST
OF CHINA BEFORE RE-EMERGING OVER WATER BETWEEN TAU 36 AND 48. AFTER
TAU 48, THE STR SHOULD DEFLECT THE TRACK SLIGHTLY SOUTHWARD OVER
THE SOUTH CHINA SEA AND SOME REINTENSIFICATION SHOULD OCCUR BEFORE
MAKING LANDFALL OVER VIETNAM JUST PRIOR TO TAU 72.
C. BEYOND TAU 72, TS 20W WILL MOVE INLAND AND SHOULD DISSIPATE
BY TAU 96. ALTHOUGH, WITH THE EXCEPTION OF HWRF, THE MODEL GUIDANCE
SHOWS A SIMILAR TRACK, THE SPREAD AMONG THE MEMBERS IS FAIRLY LARGE
AND, AS A RESULT, THERE IS LOW CONFIDENCE IN THE JTWC FORECAST
TRACK.//
NNNN

[euro6208]

[euro6208]

[mrbagyo]

I think Bebinca is making a run at typhoon status and I believe it's still possible. Look at that radar and microwave.

[Yellow Evan]

Too sheared to be a typhoon.

14/2030 UTC 21.3N 112.7E T3.0/3.5 BEBINCA

[mrbagyo]

[mrbagyo]

Too sheared to be a typhoon.

14/2030 UTC 21.3N 112.7E T3.0/3.5 BEBINCA

No longer badly sheared. 35 knots is too low.

[mrbagyo]

[euro6208]

WDPN33 PGTW 150300
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 20W (BEBINCA) WARNING
NR 11//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
TROPICAL STORM 20W (BEBINCA), LOCATED APPROXIMATELY 143 NM
SOUTHWEST OF HONG KONG, HAS TRACKED WEST-SOUTHWESTWARD AT 09 KNOTS
OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY
DEPICTS PERSISTENT FLARING CONVECTION WRAPPING INTO A COVERED LOW
LEVEL CIRCULATION CENTER. THE INITIAL POSITION IS PLACED WITH FAIR
CONFIDENCE BASED ON THE MSI LOOP AND A 142258Z SSMIS 91GHZ MICROWAVE
IMAGE, WHICH SHOWS DEEP CONVECTION COVERING THE CENTER AND EXTENDING
TO THE WEST. THE INITIAL INTENSITY OF 35 KNOTS IS CONSISTENT WITH A
PGTW DVORAK CURRENT INTENSITY ESTIMATE OF T2.5 (35 KNOTS) AND
SLIGHTLY ABOVE THE RJTD ESTIMATE OF T2.0 (30 KTS). OBSERVATIONS FROM
SITES 60-70 NM TO THE NORTH READ 16-20 KTS, WITH PRESSURES AROUND
994-995 MB. WARM SEA SURFACE TEMPERATURES (28-29 CELSIUS) AND STRONG
EQUATORWARD OUTFLOW ARE SUPPORTING CONVECTION DESPITE STRONG (25-30
KNOTS) VERTICAL WIND SHEAR. TS 20W IS MOVING WEST ALONG THE SOUTHERN
PERIPHERY OF THE STR TO THE NORTH.
3. FORECAST REASONING.
A. THERE IS NO CHANGE TO THE FORECAST PHILOSOPHY FROM THE
PREVIOUS PROGNOSTIC REASONING MESSAGE.
B. TS 20W IS FORECAST TO CONTINUE MOVING WESTWARD TO WEST-
SOUTHWESTWARD AS THE SUBTROPICAL RIDGE (STR) BUILDS TO THE NORTH.
RECENT MESOSCALE MODELS INDICATE A SLIGHT STRENGTHENING TREND AS THE
SYSTEM TRACKS OVER WATER, REACHING A PEAK OF 40 KTS BY TAU 12 AND
MAINTAINING THIS INTENSITY WHILE IT TRACKS OVER THE WARM WATERS OF
THE GULF OF TONKIN. CONTINUED HIGH VWS WILL LIMIT FURTHER
INTENSIFICATION.
C. AFTER TAU 48, THE SYSTEM WILL MAKE LANDFALL AND BEGIN TO
WEAKEN. ALONG-TRACK STORM MOTION VARIES BETWEEN MODELS AND THERE IS
SOME NORTH-SOUTH SPREAD, ALTHOUGH ALL SHOW WESTWARD MOTION.
THEREFORE, CONFIDENCE IN THE JTWC FORECAST TRACK IS LOW.//
NNNN

[mrbagyo]

JTWC is lowballing Bebinca. This is clearly more than 35 knots.

[euro6208]

TXPQ22 KNES 150333
TCSWNP

A. 20W (BEBINCA)

B. 15/0230Z

C. 21.2N

D. 111.9E

E. THREE/HIMAWARI-8

F. T3.5/3.5/D0.5/24HRS

G. IR/EIR/VIS

H. REMARKS...THIS INTENSITY ESTIMATE WAS DERIVED USING 4 KM IR DATA. DT
OF 3.5 IS BASED ON 0.9 TIGHT CURVED BANDING AS CONFIRMED BY THE 0204Z
AMSU MICROWAVE PASS. MET AND PT ARE 3.5. FT IS BASED ON DT.

I. ADDL POSITIONS

NIL


...RAMIREZ

[mrbagyo]

TS 1816 (Bebinca)
Issued at 07:05 UTC, 15 August 2018
<Analysis at 06 UTC, 15 August>
Scale -
Intensity -
Center position N21°00' (21.0°)
E111°25' (111.4°)
Direction and speed of movement WNW 10 km/h (6 kt)
Central pressure 990 hPa
Maximum wind speed near center 20 m/s (40 kt)
Maximum wind gust speed 30 m/s (60 kt)
≥ 30 kt wind area S 220 km (120 NM)
N 110 km (60 NM)

[doomhaMwx]

Effects of strong northeasterly shear apparent on 05Z microwave image and latest radar images.

[doomhaMwx]

Could be another big rainfall threat to Northern Vietnam.

[euro6208]

WDPN33 PGTW 150900
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 20W (BEBINCA) WARNING
NR 12//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
TROPICAL STORM 20W (BEBINCA), LOCATED APPROXIMATELY 170 NM WEST-
SOUTHWEST OF HONG KONG, HAS TRACKED WEST-NORTHWESTWARD AT 06 KNOTS
OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY
DEPICTS PERSISTENT CONVECTION NEAR THE LOW LEVEL CIRCULATION CENTER
(LLCC). THE INITIAL POSITION IS PLACED WITH FAIR CONFIDENCE BASED ON
A 150515Z ATMS 88 GHZ MICROWAVE IMAGE WHICH INDICATES THE LLCC IS
JUST EAST OF THE DEEP CONVECTION. THE INITIAL INTENSITY OF 35 KNOTS
IS CONSISTENT WITH PGTW AND RJTD DVORAK CURRENT INTENSITY ESTIMATES
OF T2.5 (35 KNOTS). OBSERVATIONS LOCATED 60-80 NM TO THE NORTHEAST
OF THE LLCC REPORTED 12-16 KTS. THE ENVIRONMENT IS MARGINALLY
FAVORABLE FOR INTENSIFICATION WITH GOOD EQUATORWARD OUTFLOW BEING
OFFSET BY MODERATE VERTICAL WIND SHEAR (VWS) OF 20-25 KTS. SEA
SURFACE TEMPERATURES (28-29 CELSIUS) SUPPORT INTENSIFICATION. TS 20W
IS MOVING WEST ALONG THE SOUTHERN PERIPHERY OF A SUBTROPICAL RIDGE
(STR) TO THE NORTH.
3. FORECAST REASONING.
A. THERE IS NO CHANGE TO THE FORECAST PHILOSOPHY FROM THE
PREVIOUS PROGNOSTIC REASONING MESSAGE.
B. TS 20W IS FORECAST TO CONTINUE TO BE STEERED WESTWARD TO WEST-
SOUTHWESTWARD BY THE STR TO THE NORTH. RECENT MESOSCALE MODELS
INDICATE SOME INTENSIFICATION IS POSSIBLE UNDER MARGINALLY FAVORABLE
CONDITIONS. VWS WILL REMAIN MODERATE TO HIGH THROUGHOUT THE
FORECAST, LIMITING THE POSSIBILITY OF SIGNIFICANT INTENSIFICATION.
AFTER TAU 48, THE SYSTEM WILL MAKE LANDFALL OVER VIETNAM AND BEGIN
TO WEAKEN UNTIL TAU 72 WHEN IT FALLS TO 25 KNOTS. WITH THE EXCEPTION
OF HWRF AND JGSM (BOTH CURL THE CYCLONE TO THE NORTH), DYNAMIC MODEL
GUIDANCE MOSTLY AGREES WITH THE JTWC FORECAST TRACK. THE SPREAD
AMONG THE MODEL GUIDANCE THAT DEPICTS A WESTWARD TRACK INTO VIETNAM
IS ABOUT 350 NM BY TAU 72, PRIMARILY DUE TO VARIATION IN THE ALONG-
TRACK SPEED AMONG THE MEMBERS. BASED ON THE SPREAD AMONG THE MODEL
GUIDANCE, CONFIDENCE IN THE JTWC FORECAST TRACK IS LOW.//
NNNN

[euro6208]

TPPN12 PGTW 150917

A. TROPICAL STORM 20W (BEBINCA)

B. 15/0900Z

C. 21.02N

D. 110.82E

E. FIVE/HMWRI8

F. T2.5/2.5/S0.0/24HRS STT: S0.0/03HRS

G. IR/EIR/VIS/MSI

H. REMARKS: 40A/PBO SBC/ANMTN. .50 WRAP ON LOG10 SPIRAL YIELDS
2.5 DT. MET/PT 2.5. DBO DT.

I. ADDITIONAL POSITIONS: NONE


DAVIS