WPAC: Tropical Depression (91W)

[senorpepr]

Reactivating this topic as it's the subject of another JMA tropical depression.

WWJP25 RJTD 040000
WARNING AND SUMMARY 040000.
WARNING VALID 050000.
WARNING IS UPDATED EVERY 6 HOURS.
WARNING.
DENSE FOG OBSERVED LOCALLY OVER SEA OF OKHOTSK SEA OF JAPAN BOHAI
YELLOW SEA EAST CHINA SEA.
WARNING.
DENSE FOG OBSERVED LOCALLY OVER WATERS BOUNDED BY 35N 140E 42N 141E
47N 152E 50N 155E 60N 164E 60N 180E 35N 180E 27N 157E 29N 140E 33N
136E 35N 140E.
SUMMARY.
LOW 994 HPA AT 56N 153E SE 10 KT.
LOW 994 HPA AT 49N 164E NNE 15 KT.
TROPICAL DEPRESSION 1012 HPA AT 16N 135E WNW 10 KT.
HIGH 1008 HPA AT 43N 127E ALMOST STATIONARY.
HIGH 1018 HPA AT 25N 145E ALMOST STATIONARY.
HIGH 1006 HPA AT 44N 146E SOUTH 10 KT.
STATIONARY FRONT FROM 35N 122E TO 36N 125E 37N 130E 38N 135E 38N 138E
38N 140E 38N 144E 36N 151E.
REMARKS.
SEVERE TROPICAL STORM 1703 NANMADOL (1703) 990 HPA AT 32.8N 130.4E :
SEE TROPICAL CYCLONE WARNING.

JAPAN METEOROLOGICAL AGENCY.=

[doomhaMwx]

So this new TD by JMA came from 90W eh...

The system is now also tagged Invest 91W by the Navy...

[senorpepr]

Considering that it's now tagged as 91W, I've split the former topic back into the archive.

[doomhaMwx]

Looks like it will be following a track towards Taiwan - Southern Ryukyu area, similar to Nanmadol earlier in its life...

[senorpepr]

JMA has deepened the depression by 2 hPa:

WWJP25 RJTD 040600
WARNING AND SUMMARY 040600.
WARNING VALID 050600.
WARNING IS UPDATED EVERY 6 HOURS.
WARNING.
DENSE FOG OBSERVED LOCALLY OVER SEA OF OKHOTSK SEA OF JAPAN BOHAI
YELLOW SEA EAST CHINA SEA.
WARNING.
DENSE FOG OBSERVED LOCALLY OVER WATERS BOUNDED BY 35N 140E 41N 142E
46N 150E 53N 160E 60N 164E 60N 180E 35N 180E 30N 160E 30N 140E 35N
140E.
SUMMARY.
LOW 994 HPA AT 57N 154E ALMOST STATIONARY.
LOW 994 HPA AT 51N 164E NORTH 15 KT.
TROPICAL DEPRESSION 1010 HPA AT 17N 133E NW 15 KT.
HIGH 1006 HPA AT 43N 148E ESE 10 KT.
HIGH 1016 HPA AT 26N 148E ALMOST STATIONARY.
STATIONARY FRONT FROM 35N 122E TO 36N 124E 37N 131E 39N 140E 37N 146E
37N 151E.
REMARKS.
SEVERE TROPICAL STORM 1703 NANMADOL (1703) 992 HPA AT 33.6N 134.2E :
SEE TROPICAL CYCLONE WARNING.

JAPAN METEOROLOGICAL AGENCY.=

[euro6208]

91W INVEST 170704 0600 16.0N 134.4E WPAC 15 NA

[euro6208]

[euro6208]

91W INVEST 170704 1200 18.4N 131.4E WPAC 15 1010

[euro6208]

[senorpepr]

JMA maintains this as a tropical depression. No discussion from JTWC or PAGASA.

WWJP25 RJTD 041800
WARNING AND SUMMARY 041800.
WARNING VALID 051800.
WARNING IS UPDATED EVERY 6 HOURS.
WARNING.
DENSE FOG OBSERVED LOCALLY OVER SEA OF OKHOTSK SEA OF JAPAN BOHAI
YELLOW SEA EAST CHINA SEA.
WARNING.
DENSE FOG OBSERVED LOCALLY OVER WATERS BOUNDED BY 35N 140E 42N 142E
46N 150E 53N 160E 60N 167E 60N 180E 35N 180E 30N 150E 30N 140E 35N
140E.
SUMMARY.
LOW 992 HPA AT 52N 156E ALMOST STATIONARY.
LOW 992 HPA AT 53N 165E NNE 10 KT.
TROPICAL DEPRESSION 1012 HPA AT 19N 131E NW 15 KT.
HIGH 1010 HPA AT 42N 128E ALMOST STATIONARY.
HIGH 1004 HPA AT 55N 142E SOUTH 10 KT.
HIGH 1018 HPA AT 25N 149E ALMOST STATIONARY.
HIGH 1008 HPA AT 41N 150E ALMOST STATIONARY.
STATIONARY FRONT FROM 35N 115E TO 37N 122E 36N 129E 35N 136E 38N 144E
36N 152E.
REMARKS.
SEVERE TROPICAL STORM 1703 NANMADOL (1703) 992 HPA AT 35.5N 142.6E :
SEE TROPICAL CYCLONE WARNING.

JAPAN METEOROLOGICAL AGENCY.=

[euro6208]

TXPQ29 KNES 050901
TCSWNP

A. TROPICAL DISTURBANCE (91W)

B. 05/0830Z

C. 19.7N

D. 127.5E

E. THREE/HIMAWARI-8

F. T1.0/1.0/D1.0/24HRS

G. IR/EIR/VIS

H. REMARKS...GREATER THAN .2 CURVED BANDING YIELDS A DT OF 1.0. MET=1.0
AND PT=1.0. FT IS BASED ON DT.

I. ADDL POSITIONS

NIL


...KIM

[euro6208]

AN AREA OF CONVECTION (INVEST 91W) HAS PERSISTED NEAR
19.7N 128E, APPROXIMATELY 480 NM SOUTHEAST OF TAIPEI, TAIWAN.
ANIMATED MULTISPECTRAL SATELLITE IMAGERY SHOWS AN ELONGATED
CIRCULATION WITH FLARING CONVECTION LOCATED ON THE PERIPHERY OF THE
DISTURBANCE. A 050627Z AMSU-B 89GHZ MICROWAVE IMAGE SHOWS MINIMAL
CONVECTION WITH A POORLY DEFINED ELONGATED CIRCULATION. THE
DISTURBANCE IS CURRENTLY LOCATED IN A FAVORABLE ENVIRONMENT WITH
GOOD DIVERGENCE ALOFT, LOW VERTICAL WIND SHEAR (5-10 KTS), AND VERY
HIGH SEA SURFACE TEMPERATURES (30-31 C). GLOBAL MODELS ARE CURRENTLY
NOT INITIALIZING WITH A CIRCULATION IN THE AREA OR DEVELOPING THE
SYSTEM HOWEVER, THE DISTURBANCE HAS BEEN TRACKING TO THE WEST-
NORTHWEST OVER THE PAST FEW DAYS. MAXIMUM SUSTAINED SURFACE WINDS
ARE ESTIMATED AT 10 TO 15 KNOTS. MINIMUM SEA LEVEL PRESSURE IS
ESTIMATED TO BE NEAR 1010 MB. THE POTENTIAL FOR THE DEVELOPMENT OF A
SIGNIFICANT TROPICAL CYCLONE WITHIN THE NEXT 24 HOURS IS LOW.

[euro6208]

WTPN21 PGTW 051900
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE FORMATION ALERT//
RMKS/
1. FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE WITHIN
160 NM EITHER SIDE OF A LINE FROM 21.2N 126.2E TO 25.4N 123.4E
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
IMAGERY AT 051800Z INDICATES THAT A CIRCULATION CENTER IS LOCATED
NEAR 21.5N 125.9E. THE SYSTEM IS MOVING NORTHWESTWARD AT 12
KNOTS.
2. REMARKS: THE AREA OF CONVECTION PREVIOUSLY LOCATED NEAR 20.0N
126.4E IS NOW LOCATED NEAR 21.5N 125.9E, APPROXIMATELY 310 NM SOUTH-
SOUTHWEST OF KADENA, AB. ANIMATED ENHANCED INFRARED SATELLITE
IMAGERY SHOWS A COMPACT LOW-LEVEL CIRCULATION WITH SHALLOW
ASSOCIATED CONVECTION BEING DISPLACED TO THE SOUTHERN PERIPHERY OF
THE DISTURBANCE. A 051318Z METOP-B ASCAT IMAGE SHOWS A TROPICAL
SURFACE WAVE WITH 20 KTS PROPAGATING ACROSS THE REGION. HOWEVER,
ANALYSIS OF THE ASCAT AMBIGUITY DATA COMPARED WITH SATELLITE IMAGERY
SUGGESTS A CLOSED CIRCULATION EXISTS AT THE SURFACE. THE
DISTURBANCE IS CURRENTLY LOCATED IN A FAVORABLE ENVIRONMENT WITH
FAIR DIVERGENCE ALOFT, LOW TO MODERATE VERTICAL WIND SHEAR (10-15
KTS), AND VERY HIGH SEA SURFACE TEMPERATURES (30-31 C). GLOBAL
MODELS ARE NOT CURRENTLY HANDLING THE MICROSCALE CIRCULATION IN THE
AREA OR DEVELOPING THE SYSTEM DESPITE THE FAVORABLE ENVIRONMENT WITH
AN EVIDENCED SURFACE CIRCULATION. MAXIMUM SUSTAINED SURFACE WINDS
ARE ESTIMATED AT 18 TO 23 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 HIGH.
3. THIS ALERT WILL BE REISSUED, UPGRADED TO WARNING OR CANCELLED BY
061900Z.
//
NNNN

[doomhaMwx]

The system has a well-defined and partially exposed circulation center, with most of the convection found to the south of it, due to moderate northerly shear... An ASCAT pass @ around 1:45am UTC today showed TD-threshold winds up to 30kts in the system's eastern semicircle...
This appears be close to a TD now, if it's not yet one, based on the satellite and ASCAT data... Model guidance indicates that the system will be short-lived as they show dissipation shortly after it moves past the southern Ryukyu islands...

[doomhaMwx]

After moving through the southern Ryukyus, the LLCC has become increasingly separated from the mass of convection as it enters an area of stronger northerly shear...Likely nearing dissipation...

[euro6208]

THE AREA OF CONVECTION (INVEST 91W) PREVIOUSLY LOCATED
NEAR 21.5N 125.9E IS NOW LOCATED NEAR 24.2N 124.6E, APPROXIMATELY
205 NM SOUTHWEST OF OKINAWA, JAPAN. ANIMATED MULTISPECTRAL SATELLITE
IMAGERY SHOWS A WELL DEFINED, EXPOSED LOW-LEVEL CIRCULATION CENTER
(LLCC) WITH LIMITED DEEP CONVECTIVE BANDING OVER THE SOUTHERN SEMI-
CIRCLE OF THE LLCC. A 060144Z METOP-B 89GHZ IMAGE DEPICTS SHALLOW
BANDING WRAPPING INTO A DEFINED CENTER WITH WEAK BANDING OVER THE
SOUTH QUADRANT. ANIMATED RADAR IMAGERY SHOWS A DEFINED CENTER WITH
FRAGMENTED BANDING, HOWEVER THE CONVECTIVE STRUCTURE HAS WEAKENED
OVER THE LAST 3 HOURS AS THE SYSTEM TRACKS OVER THE ISLAND CHAIN.
UPPER LEVEL ANALYSIS INDICATES A MARGINAL ENVIRONMENT WITH MODERATE
(20 KNOTS) NORTHERLY VERTICAL WIND SHEAR AND WEAK EQUATORWARD
OUTFLOW. SURFACE OBSERVATIONS FROM ISHIGAKI-JIMA AND NAKASUJI,
APPROXIMATELY 17NM WEST OF THE CENTER, INDICATE ONLY 10-15 KNOT
WINDS WITH SLP NEAR 1010 MB. GLOBAL MODELS INDICATE A RAPID
NORTHWARD TRACK WITH NO SIGNIFICANT DEVELOPMENT. MAXIMUM SUSTAINED
SURFACE WINDS ARE ESTIMATED AT 15 TO 20 KNOTS. MINIMUM SEA LEVEL
PRESSURE IS ESTIMATED TO BE NEAR 1008 MB. THE POTENTIAL FOR THE
DEVELOPMENT OF A SIGNIFICANT TROPICAL CYCLONE WITHIN THE NEXT 24
HOURS REMAINS HIGH.

[euro6208]

WTPN21 PGTW 061900
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE FORMATION ALERT CANCELLATION//
REF/A/MSG/JOINT TYPHOON WRNCEN PEARL HARBOR HI/051851ZJUL2017//
AMPN/REF A IS A TROPICAL CYCLONE FORMATION ALERT//
RMKS/
1. REMARKS: THIS CANCELS REF A (WTPN21 PGTW 051900). THE AREA OF
CONVECTION PREVIOUSLY LOCATED NEAR 20.0N 126.4E IS NOW LOCATED NEAR
28.5N 124.1E, APPROXIMATELY 235 NM WEST-NORTHWEST OF KADENA, AB.
ANIMATED ENHANCED INFRARED SATELLITE IMAGERY SHOWS A FULLY EXPOSED
COMPACT LOW-LEVEL CIRCULATION CENTER (LLCC) DEVOID OF ANY
CONVECTION. A 060146Z METOP-B ASCAT IMAGE SHOWS THE LLCC WITH HIGHER
WINDS CONCENTRATED ON THE EASTERN PERIPHERY AND RECENT SURFACE
OBSERVATIONS INDICATE THE SYSTEM HAS NOT INTENSIFIED SUFFICIENTLY TO
JUSTIFY WARNING STATUS. UPPER-LEVEL CONDITIONS ARE ALSO
DETERIORATING AS THE SYSTEM TRACKS NORTHWARD INTO A HOSTILE SHEAR
ENVIRONMENT. GLOBAL MODELS ARE STILL NOT HANDLING THE SYSTEM WELL OR
SHOWING ANY SIGNS OF DEVELOPMENT. MAXIMUM SUSTAINED SURFACE WINDS
ARE ESTIMATED AT 15 TO 20 KNOTS. MINIMUM SEA LEVEL PRESSURE IS
ESTIMATED TO BE NEAR 1008 MB. IN VIEW OF THE UNFAVORABLE
ENVIRONMENTAL CONDITIONS FOR THIS SYSTEM, THE POTENTIAL FOR THE
DEVELOPMENT OF A SIGNIFICANT TROPICAL CYCLONE WITHIN THE NEXT 24
HOURS IS DOWNGRADED TO MEDIUM.//
NNNN

[1900hurricane]

Heh, it reminds me a bit of 03W from last year.

[doomhaMwx]

[euro6208]

THE AREA OF CONVECTION PREVIOUSLY LOCATED NEAR 28.5N
124.1E HAS DISSIPATED AND IS NO LONGER SUSPECT FOR THE DEVELOPMENT
OF A SIGNIFICANT TROPICAL CYCLONE IN THE NEXT 24 HOURS.