WPAC: INVEST 91W

[Iune]

TCFA Issued:
WTPN21 PGTW 251730
MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC//
SUBJ/TROPICAL CYCLONE FORMATION ALERT//
RMKS/
1. FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE WITHIN
100 NM EITHER SIDE OF A LINE FROM 12.0N 111.7E TO 15.8N 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 18 TO 23 KNOTS. METSAT IM-
AGERY AT 251200Z INDICATES THAT A CIRCULATION CENTER IS LOCATED
NEAR 12.2N 111.4E. THE SYSTEM IS MOVING WEST-NORTHWESTWARD AT 09
KNOTS.
2. REMARKS: THE AREA OF CONVECTION PREVIOUSLY LOCATED NEAR 11.7N
111.4E IS NOW LOCATED NEAR 12.2N 111.4E, APPROXIMATELY 290 NM EAST-
NORTHEAST OF HO CHI MINH, VIETNAM. ANIMATED INFRARED SATELLITE
IMAGERY SHOWS A BURST OF DEEP CONVECTION PERSISTING OVER THE WESTERN
SEMICIRCLE OF A LOW-LEVEL CIRCULATION CENTER (LLCC) EVIDENT IN A
251210Z SSMIS IMAGE. THE SSMIS IMAGE AND OTHER RECENT MICROWAVE
PASSES INDICATE A SLIGHT IMPROVEMENT IN LOW-LEVEL BANDING OVER THE
PAST TWELVE HOURS. THIS DISTURBANCE LIES EQUATORWARD OF AN UPPER-
LEVEL RIDGE AXIS IN AN AREA OF MODERATE VERTICAL WIND SHEAR,
APPROXIMATELY 20 KNOTS FROM THE EAST-NORTHEAST. RECENT SHIP REPORTS
NEAR THE LLCC INDICATE SUSTAINED WINDS AS HIGH AS 20 KNOTS AND
SURFACES PRESSURES RANGING FROM 1001 TO 1004 MB. ALTHOUGH THE
MAXIMUM SUSTAINED WIND SPEED ASSOCIATED WITH THIS DISTURBANCE IS
ESTIMATED TO BE NEAR THE WARNING THRESHOLD OF 25 KNOTS, CONTINUED
MODERATE VERTICAL WIND SHEAR AND POTENTIAL LAND INTERACTION COULD
STILL INHIBIT THIS LOW PRESSURE AREA FROM CONSOLIDATING INTO A
SIGNIFICANT TROPICAL DEPRESSION. MAXIMUM SUSTAINED SURFACE WINDS ARE
ESTIMATED AT 18 TO 23 KNOTS. MINIMUM SEA LEVEL PRESSURE IS ESTIMATED
TO BE NEAR 1001 MB. BASED ON IMPROVED LOW LEVEL ORGANIZATION
INDICATED IN BOTH MICROWAVE SATELLITE IMAGERY AND SURFACE
OBSERVATIONS AND THE RECENT INCREASE IN DEEP CONVECTION JUST WEST OF
THE LLCC, 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
261730Z.//
NNNN

[Iune]

[supercane]

Tropical Cyclone 91W

26 Jul 2010 0000Z
Location: 13.3 109.8
Winds: 20 knots
Central Pressure: 1007 hPa

[supercane]

running out of room

[supercane]

522
abpw10 pgtw 251830
msgid/genadmin/navmarfcstcen Pearl Harbor hi/jtwc//
subj/significant tropical weather advisory for the western and
/South Pacific oceans reissued/251830z-260600zjul2010//
ref/a/msg/navmarfcstcen Pearl Harbor hi/251721zjul10//
ampn/ref a is a tropical cyclone formation alert.//
Rmks/
1. Western North Pacific area (180 to Malay Peninsula):
a. Tropical cyclone summary: none.
B. Tropical disturbance summary:
(1) the area of convection previously located near 11.7n
111.4e is now located near 12.3n 110.6e, approximately 285 nm east-
northeast of Ho Chi Minh, Vietnam. Animated infrared satellite
imagery shows a burst of deep convection persisting over the western
semicircle of a low-level circulation center (LLCC) evident in a
251210z ssmis image. The ssmis image and other recent microwave
passes indicate a slight improvement in low-level banding over the
past twelve hours. This disturbance lies equatorward of an upper-
level ridge axis in an area of moderate vertical wind shear,
approximately 20 knots from the east-northeast. Recent ship reports
near the LLCC, but outside of a band of higher gradient-induced
winds to the south of the LLCC, indicate sustained winds as high as
20 knots and surfaces pressures ranging from 1001 to 1004 mb.
Although the maximum sustained wind speed associated with this
disturbance is estimated to be near the warning threshold of 25
knots, continued moderate vertical wind shear and potential land
interaction could still inhibit this low pressure area from
consolidating into a significant tropical depression. Maximum
sustained surface winds are estimated at 18 to 23 knots. Minimum sea
level pressure is estimated to be near 1001 mb. See ref a (wtpn21
pgtw 251730) for further details. Based on improved low level
organization indicated in both microwave satellite imagery and
surface observations and the recent increase in deep convection just
west of the LLCC, the potential for the development of a significant
tropical cyclone within the next 24 hours is upgraded to good.
(3) no other suspect areas.
2. South Pacific area (west coast of South America to 135 east):
a. Tropical cyclone summary: none.
B. Tropical disturbance summary: none.
3. Justification for reissue: upgraded area in para 1.B.(1) to
good.//

Anticipate cancellation of TCFA soon.

[supercane]

0Z SLP analysis from Digital Atmosphere:

[supercane]

WWJP25 RJTD 260000
WARNING AND SUMMARY 260000.
<snip>
LOW PRESSURE AREA 1004 HPA NEAR 13N 111E NW SLOWLY.
<snip>

No advisory written by JMA, meaning that they do not anticipate strengthening to TS. Also JMA position somewhat E of JTWC's.

[Typhoon10]

I dont think it will amount to much and just slowly head inland bringing a little wind and rain to Vietnam

[phwxenthusiast]

dissipated accdg to JTWC...

1. REMARKS: THIS CANCELS REF A. THE AREA OF CONVECTION PREVIOUSLY
LOCATED NEAR 12.2N 111.4E IS NOW LOCATED NEAR 13.8N 109.2E,
APPROXIMATELY 235 NM NORTHEAST OF HO CHI MINH, VIETNAM. ANIMATED
MULTISPECTRAL SATELLITE IMAGERY INDICATES THE LOW LEVEL CIRCULATION
CENTER DISSIPATED OVER EASTERN VIETNAM BETWEEN 0100Z AND 0300Z.
COINCIDENTALLY, ALL DEEP CONVECTION PREVIOUSLY ASSOCIATED WITH THE
SYSTEM HAS SUBSIDED AND BLOWN OFF TO THE SOUTHWEST DUE TO EAST-
NORTHEASTERLY VERTICAL WIND SHEAR OVER THE AREA. A 260224Z AMSU
MICRWOAVE IMAGE SHOWS DEGRADATION IN LOW-LEVEL BANDING DUE TO LAND
INTERACTION OVER THE PAST 06 HOURS. AS PREVIOUSLY STATED IN REF A,
CONTINUED MODERATE VERTICAL WIND SHEAR AND LAND INTERACTION HAVE
INHIBITED THIS LOW PRESSURE AREA FROM CONSOLIDATING INTO A
SIGNIFICANT TROPICAL CYCLONE. MAXIMUM SUSTAINED WINDS ARE ESTIMATED
AT 10 TO 15 KNOTS. MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE
NEAR 1005 MB. DUE TO LACK OF CONSOLIDATION AND LAND INTERACTION, THE
POTENTIAL FOR THE DEVELOPMENT OF A SIGNIFICANT TROPICAL CYCLONE
WITHIN THE NEXT 24 HOURS IS DOWNGRADED TO POOR.//

[HURAKAN]

done