WPAC: INVEST 91W (FAIR) - discussion

[Chacor]

AN AREA OF CONVECTION HAS PERSISTED NEAR 7.1N 112.2E,
APPROXIMATELY 210 NM NORTHWEST OF BRUNEI. RECENT ANIMATED INFRARED
SATELLITE IMAGERY AND A 011427Z AMSU-B PASS INDICATE A WEAK CYCLONIC
CIRCULATION WITH CONVECTIVE BANDING MOSTLY ON THE NORTHERN FLANK.
UPPER LEVEL ANALYSIS SHOWS THE AREA IS SOUTH OF THE SUBTROPICAL
RIDGE AXIS WHICH IS ENHANCING POLEWARD OUTFLOW ALBEIT WITH MODERATE
TO HIGH VERTICAL WIND SHEAR. MAXIMUM SUSTAINED SURFACE WINDS ARE
ESTIMATED AT 10-15 KNOTS VALIDATED BY A 011427Z ASCAT PASS. MINIMUM
SEA LEVEL PRESSURE IS ESTIMATED TO BE NEAR 1008 MB BASED ON A SHIP
REPORT AT 011800Z JUST TO THE NORTH OF THE CENTER. THE POTENTIAL FOR
THE DEVELOPMENT OF A SIGNIFICANT TROPICAL CYCLONE WITHIN THE NEXT
24 HOURS IS POOR.

JMA:
LOW PRESSURE AREA 1008 HPA NEAR 07N 113E WEST SLOWLY.

[HURAKAN]

Floater: http://www.ssd.noaa.gov/PS/TROP/mtsatfloat1.html

[HURAKAN]

02/0230 UTC 7.5N 112.4E T1.5/1.5 91W -- West Pacific

[RattleMan]

WTPN21 PGTW 020230
MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC//
SUBJ/TROPICAL CYCLONE FORMATION ALERT//
RMKS/
1. FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE WITHIN
150 NM EITHER SIDE OF A LINE FROM 7.5N 113.1E TO 5.3N 108.4E
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 22 KNOTS. METSAT IM-
AGERY AND SYNOPTIC DATA AT 020130Z INDICATE THAT A CIRCULATION
CENTER IS LOCATED NEAR 7.5N 112.5E. THE SYSTEM IS MOVING SOUTH-
WESTWARD AT 04 KNOTS.
2. REMARKS: AN AREA OF CONVECTION NEAR 7.6N 112.6E, APPROXIMATELY
210 NM NORTHWEST OF BRUNEI, HAS INTENSIFIED OVER THE PAST 24
HOURS. RECENT ANIMATED MULTISPECTRAL IMAGERY AND A 012357Z SSMIS
PASS INDICATE A CYCLONIC CIRCULATION WITH CONVECTIVE BANDING
WRAPPING INTO THE CENTER. UPPER LEVEL ANALYSIS INDICATES THE AREA
IS SOUTH OF THE SUBTROPICAL RIDGE AXIS AND SOUTHEAST OF A MIDLAT-
ITUDE SHORT-WAVE TROUGH THAT ARE ENHANCING POLEWARD OUTFLOW AL-
BEIT WITH MODERATE VERTICAL WIND SHEAR. SYNOPTIC 24-HOUR OBSERVA-
TION TREND FROM TRUONG SA, APPROXIMATELY 75 NM TO THE NORTH-
NORTHWEST, INDICATES A 24-HOUR SLP DECREASE OF -1.2 MB. MAXI-
MUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT 15-22 KNOTS AND
THE MINIMUM SEA LEVEL PRESSURE AT 1005 MB. BASED ON A MORE SYM-
METRIC AND A RAPIDLY CONSOLIDATING CENTER WITH IMPROVED CONVEC-
TIVE BANDING, THE POTENTIAL FOR THE DEVELOPMENT OF A SIGNIFICANT
TROPICAL CYCLONE WITHIN THE NEXT 24 HOURS IS GOOD.
3. THIS ALERT WILL BE REISSUED, UPGRADED TO WARNING OR CANCELLED
BY 030230Z.//
NNNN

[Chacor]

TROPICAL DEPRESSION 1008 HPA AT 08N 113E ALMOST STATIONARY.

[RattleMan]

WTPN21 PGTW 030230
MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC//
SUBJ/TROPICAL CYCLONE FORMATION ALERT CANCELLATION //
REF/A/NAVMARFCSTCEN PEARL HARBOR HI/020221Z DEC 08//
AMPN/REF IS TROPICAL CYCLONE FORMATION ALERT (WTPN21 PGTW 020230)//
RMKS/
1. REMARKS: THIS CANCELS REF A. THE AREA OF CONVECTION PREVIOUSLY
LOCATED NEAR 7.6N 112.6E IS NOW LOCATED NEAR 6.5N 110.7E, APPROXI-
MATELY 355 NM SOUTHEAST OF HO CHI MINH, VIETNAM. ANIMATED MULTI-
SPECTRAL SATELLITE IMAGERY AND A 021826 AMSR-E IMAGE INDICATE A
WEAKENING LOW-LEVEL CIRCULATION CENTER (LLCC) DISPLACED SOUTHEAST
OF PERSISTENT, INCREASINGLY DISORGANIZED DEEP CONVECTION. RECENT
SCATTEROMETER DATA DEPICTS A SHEAR LINE WITH CONVERGENT FLOW
NORTH AND NORTHWEST OF THE LLCC, WHICH IS CONTINUING TO PRODUCE
DEEP CONVECTIVE BURSTS, WITH A DEFINED 10-15 KNOT LLCC SOUTH. THE
LLCC APPEARS TO BE TRACKING WEST-SOUTHWESTWARD WHILE CONVECTION IS
SHEARING WESTWARD TO NORTHWESTWARD UNDER STRONG DIFFLUENT UPPER-
LEVEL FLOW. THE SYSTEM HAS NOT CONSOLIDATED AS MUCH AS PREVIOUSLY
ANTICIPATED WITH AN INCREASINGLY DISORGANIZED SIGNATURE. MAXIMUM
SUSTAINED SURFACE WINDS ARE ESTIMATED AT 12-18 KNOTS. MINIMUM
SEA LEVEL PRESSURE IS ESTIMATED TO BE NEAR 1006 MB. BASED ON THE
LACK OF A SIGNIFICANT LLCC SIGNATURE ON SATELLITE IMAGERY AS WELL
AS THE DISPLACED CENTER, THE POTENTIAL FOR THE DEVELOPMENT OF A
SIGNIFICANT TROPICAL CYCLONE WITHIN THE NEXT 24 HOURS IS DOWNGRADED
TO POOR. HOWEVER, DEEP CONVECTION IS STILL EXPECTED TO FORM
ALONG THE SHEAR LINE DUE TO STRONG LINEAR CONVERGENCE AND GOOD
DIFFLUENCE ALOFT.//

[Chacor]

THE AREA OF CONVECTION PREVIOUSLY LOCATED NEAR 7.6N 112.6E
IS NOW LOCATED NEAR 6.5N 110.7E, APPROXIMATELY 355 NM SOUTHEAST OF
HO CHI MINH, VIETNAM. ANIMATED MULTISPECTRAL SATELLITE IMAGERY AND A
021826 AMSR-E IMAGE INDICATE A WEAKENING LOW-LEVEL CIRCULATION
CENTER (LLCC) DISPLACED SOUTHEAST OF PERSISTENT, INCREASINGLY
DISORGANIZED DEEP CONVECTION. RECENT SCATTEROMETER DATA DEPICTS A
SHEARLINE WITH CONVERGENT FLOW NORTH AND NORTHWEST OF THE LLCC,
WHICH IS CONTINUING TO PRODUCE DEEP CONVECTIVE BURSTS, WITH A
DEFINED 10-15 KNOT LLCC SOUTH. THE LLCC APPEARS TO BE TRACKING WEST-
SOUTHWESTWARD WHILE CONVECTION IS SHEARING WESTWARD TO NORTHWESTWARD
UNDER STRONG DIFFLUENT UPPER-LEVEL FLOW. THE SYSTEM HAS NOT
CONSOLIDATED AS MUCH AS PREVIOUSLY ANTICIPATED WITH AN INCREASINGLY
DISORGANIZED SIGNATURE. HOWEVER, DEEP CONVECTION IS STILL EXPECTED
TO FORM ALONG THE SHEAR LINE DUE TO STRONG LINEAR CONVERGENCE AND
GOOD DIFFLUENCE ALOFT. MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED
AT 12-18 KNOTS. MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE NEAR
1006 MB. BASED ON THE LACK OF A SIGNIFICANT LLCC SIGNATURE ON
SATELLITE IMAGERY AS WELL AS THE DISPLACED CENTER, THE POTENTIAL
FOR THE DEVELOPMENT OF A SIGNIFICANT TROPICAL CYCLONE WITHIN THE
NEXT 24 HOURS REMAINS POOR.

[Chacor]

THE AREA OF CONVECTION PREVIOUSLY LOCATED NEAR 6.5N
110.7E, IS NOW LOCATED NEAR 5.9N 109.7E, APPROXIMATELY 340 NM SOUTH-
SOUTHEAST OF HO CHI MINH, VIETNAM. ANIMATED MULTISPECTRAL SATELLITE
IMAGERY AND A 040221Z AMSU-B IMAGE INDICATES A DEVELOPING LOW LEVEL
CIRCULATION CENTER (LLCC) HAS BEGUN TO RECONSOLIDATE WITH INCREASING
DEEP CONVECTION IN THE NORTHWEST QUADRANT OF THE LLCC. RECENT
SCATTEROMETER DATA DEPICTS STRONG NORTHEASTERLY FLOW BEGINNING TO
WRAP INTO THE LLCC WITH CONVERGENT FLOW NORTH AND NORTHWEST OF THE
LLCC, WHICH IS CONTINUING TO PRODUCE DEEP CONVECTIVE BURSTS, WITH A
WELL DEFINED 15-20 KNOT LLCC. THE LLCC APPEARS TO BE TRACKING
WESTSOUTHWESTWARD WHILE CONVECTION IS SHEARING WESTWARD TO
NORTHWESTWARD UNDER STRONG DIFFLUENT UPPER-LEVEL FLOW. THE SYSTEM
HAS BEEN ABLE TO MAINTAIN A WELL CONSOLIDATED LLCC WITH CYCLIC DEEP
CONVECTION. MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT 15 TO
20 KNOTS. MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE NEAR 1004
MB. THE POTENTIAL FOR THE DEVELOPMENT OF A SIGNIFICANT TROPICAL
CYCLONE WITHIN THE NEXT 24 HOURS IS UPGRADED TO FAIR.

[Chacor]

THE AREA OF CONVECTION PREVIOUSLY LOCATED NEAR 5.9N
109.7E, IS NOW LOCATED NEAR 6.1N 108.6E, APPROXIMATELY 300 NM SOUTH-
SOUTHEAST OF HO CHI MINH, VIETNAM. ANIMATED MULTISPECTRAL SATELLITE
IMAGERY AND A 050238Z AMSU-B IMAGE INDICATES THAT THE LOW LEVEL
CIRCULATION CENTER (LLCC) AND CORRESPONDING DEEP CONVECTION HAS
WEAKENED OVER THE PAST 12 HOURS. RECENT SCATTEROMETER DATA DEPICTS
STRONG NORTHEASTERLY FLOW TO THE WEST OF THE CIRCULATION, WITH ONLY
10-15 KNOTS NEAR THE LLCC. THE LLCC APPEARS TO BE TRACKING SLOWLY
WESTWARD AND CONVECTION CONTINUES TO BE SHEARED TO THE WEST UNDER
THE INFLUENCE OF MODERATE VERTICAL WIND SHEAR. MAXIMUM SUSTAINED
SURFACE WINDS ARE ESTIMATED AT 10 TO 15 KNOTS. MINIMUM SEA LEVEL
PRESSURE IS ESTIMATED TO BE NEAR 1006 MB. THE POTENTIAL FOR THE
DEVELOPMENT OF A SIGNIFICANT TROPICAL CYCLONE WITHIN THE NEXT
24 HOURS IS DOWNGRADED TO POOR.