WPAC: Ex Tropical Depression 03W

[euro6208]

The main weather feature for the week is the disturbance in
eastern Micronesia. Both GFS and ECMWF show either a surface
trough or a weak circulation moving west with clouds and
precipitation increasing across the Marianas around midweek. Have
added scattered showers for Wednesday night and Thursday, but
exact timing may need to be fine-tuned as the system nears.

[euro6208]

AN AREA OF CONVECTION HAS PERSISTED NEAR 9.8N 155.5E,
APPROXIMATELY 255 NM NORTHEAST OF CHUUK. ANIMATED MULTISPECTRAL
SATELLITE IMAGERY, A 100404Z METOP-B IMAGE, AND SCATTEROMETER DATA
INDICATE A LOW-LEVEL WAVE WITH A SLOWLY IMPROVING CONVECTIVE
SIGNATURE. THE UPPER-LEVEL ENVIRONMENT INDICATES AN AREA OF
FAVORABLE DIVERGENCE ALOFT WITH WEAK (05 TO 10 KNOT) VERTICAL WIND
SHEAR. SEA SURFACE TEMPERATURES BETWEEN 28 AND 30 CELSIUS ARE ALSO
FAVORABLE FOR DEVELOPMENT. CURRENT MODEL GUIDANCE SUGGESTS ONLY WEAK
DEVELOPMENT OVER THE NEXT FEW DAYS. MAXIMUM SUSTAINED SURFACE WINDS
ARE ESTIMATED AT 10 TO 15 KNOTS. MINIMUM SEA LEVEL PRESSURE IS
ESTIMATED TO BE NEAR 1010 MB. BASED ON THE WEAK LOW-LEVEL SIGNATURE
OF THIS DISTURBANCE AND LIMITED MODEL DEVELOPMENT, THE POTENTIAL FOR
THE DEVELOPMENT OF A SIGNIFICANT TROPICAL CYCLONE WITHIN THE NEXT 24
HOURS IS LOW.

[1900hurricane]

What invest?

[dexterlabio]

JTWC must have been bored mentioning this area. Although if there's something that deserves a mention, it is the one west of Guam IMO.

[euro6208]

THE AREA OF CONVECTION PREVIOUSLY LOCATED NEAR 9.8N
155.5E, HAS DISSIPATED AND IS NO LONGER SUSPECT FOR THE DEVELOPMENT
OF A SIGNIFICANT TROPICAL CYCLONE IN THE NEXT 24 HOURS.

[euro6208]

91W INVEST 160713 1200 13.9N 147.0E WPAC 15 1009

[1900hurricane]

Heh, a few models are actually developing a weak system out of this. If it does end up developing in some fashion, it'll be score one for persistence. Vorticity certainly doesn't look horrible right now.

[euro6208]

THE AREA OF CONVECTION PREVIOUSLY LOCATED NEAR 14.9N
141.3E, IS NOW LOCATED NEAR 15.3N 140.7E, APPROXIMATELY 286 NM WEST-
NORTHWEST OF GUAM. ANIMATED MULTISPECTRAL SATELLITE IMAGERY DEPICTS
A BROAD, DISORGANIZED LOW-LEVEL CIRCULATION CENTER WITH FLARING
CONVECTION ALONG THE SOUTHERN SEMICIRCLE. A 150018Z AMSU 89 GHZ
IMAGE REVEALS CURVED SHALLOW CONVECTION WITH WEAK INFLOW FROM THE
NORTH. UPPER-LEVEL ANALYSIS SHOWS A MARGINAL ENVIRONMENT FOR
DEVELOPMENT WITH LOW (5 TO 10 KNOTS) VERTICAL WIND SHEAR, OFFSET BY
WEAK OUTFLOW AND DRY AIR OVER THE PHILIPPINE SEA. GLOBAL MODEL
GUIDANCE DOES NOT SHOW SIGNIFICANT DEVELOPMENT AT THIS TIME AS THE
DISTURBANCE TRACKS WESTWARD. MAXIMUM SUSTAINED SURFACE WINDS ARE
ESTIMATED AT 10 TO 15 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 LOW.

[euro6208]

AN AREA OF CONVECTION HAS PERSISTED NEAR 18.3N 131.8E,
APPROXIMATELY 535 NM SOUTH-SOUTHEAST OF KADENA AIR BASE, OKINAWA.
RECENT ANIMATED INFRARED SATELLITE IMAGERY SHOWS DEEP CONVECTION
FLARING OVER THE WESTERN PERIPHERY OF A LOW LEVEL CIRCULATION CENTER
(LLCC) EVIDENT IN A 161158Z ASCAT PASS. THIS DISTURBANCE LIES IN AN
AREA OF MODERATE EASTERLY VERTICAL WIND SHEAR AND WESTWARD
DIFFLUENCE ALOFT. SEA SURFACE TEMPERATURES IN EXCESS OF 30 DEGREES
CELSIUS ARE FAVORABLE FOR FURTHER DEVELOPMENT. ALTHOUGH VERTICAL
WIND SHEAR IS EXPECTED TO INCREASE AS THE LLCC TRACKS POLEWARD OVER
THE NEXT DAY OR TWO, INCREASING ORGANIZATION DRIVEN BY CYCLICAL
CONVECTIVE DEVELOPMENT MAY BE SUFFICIENT TO INCREASE SURFACE WIND
SPEEDS TO THE WARNING THRESHOLD OF 25 KNOTS. MAXIMUM SUSTAINED
SURFACE WINDS ARE ESTIMATED AT 15 TO 20 KNOTS. MINIMUM SEA LEVEL
PRESSURE IS ESTIMATED TO BE NEAR 1009 MB. BASED AN IMPROVING LOW
LEVEL SIGNATURE AND RECENT CONVECTIVE DEVELOPMENT, THE POTENTIAL FOR
FORMATION FOR A SIGNIFICANT TROPICAL CYCLONE WITHIN THE NEXT 24
HOURS IS MEDIUM.

[euro6208]

TXPQ29 KNES 162115
TCSWNP

A. TROPICAL DISTURBANCE (91W)

B. 16/2030Z

C. 18.7N

D. 130.3E

E. FIVE/HIMAWARI-8

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

G. IR/EIR/SWIR

H. REMARKS...DIFFICULT TO DETERMINE WHERE LOW LEVEL CENTER IS LOCATED
AND NOT MUCH HELP FROM MICROWAVE IMAGERY. SHEAR MATRIX USED WITH LOOSELY
DEFINED CLOUD LINES LESS THAN 1.25 DEGREE FROM GREATER THAN 1.5 DEGREE
DG RESULTS IN A DT OF 1.5. MET AND PT = 1.0. FT IS BASED ON MET.

I. ADDL POSITIONS

NIL


...KIBLER

[euro6208]

[euro6208]

TXPQ29 KNES 170258
TCSWNP

A. TROPICAL DISTURBANCE (91W)

B. 17/0230Z

C. 19.3N

D. 129.8E

E. FIVE/HIMAWARI-8

F. T1.5/1.5/D1.0/24HRS

G. IR/EIR/VIS

H. REMARKS...3/10 BANDING FOR DT=1.5. MET AND PT AGREE. FT IS BASED
ON DT.

I. ADDL POSITIONS

NIL


...SALEMI

[1900hurricane]

Hey hey, a Tropical Cyclone Formation Alert!

WTPN21 PGTW 170400
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE FORMATION ALERT//
RMKS/
1. FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE WITHIN
120 NM EITHER SIDE OF A LINE FROM 19.1N 130.3E TO 23.5N 127.3E
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 20 TO 25 KNOTS. METSAT
IMAGERY AT 170000Z INDICATES THAT A CIRCULATION CENTER IS LOCATED
NEAR 19.4N 130.0E. THE SYSTEM IS MOVING NORTHWESTWARD AT 10
KNOTS.
2. REMARKS: THE AREA OF CONVECTION PREVIOUSLY LOCATED NEAR 18.3N
131.8E IS NOW LOCATED NEAR 19.4N 130.0E, APPROXIMATELY 435 NM SOUTH-
SOUTHEAST OF KADENA AIR BASE, OKINAWA. RECENT ANIMATED MULTISPECTRAL
SATELLITE IMAGERY SHOWS DEEP CONVECTION PERSISTING OVER THE WESTERN
PORTION OF A CONSOLIDATING, PARTIALLY-EXPOSED LOW LEVEL CIRCULATION
CENTER (LLCC). A 170030Z METOP-B ASCAT IMAGE INDICATES 20 KNOT WINDS
ON THE SOUTHERN AND EASTERN PERIPHERIES OF THE CIRCULATION WRAPPING
INTO THE CENTER. THE UPPER-LEVEL ENVIRONMENT IS MARGINAL, WITH GOOD
WESTWARD DIFFLUENCE AND MODERATE EASTERLY VERTICAL WIND SHEAR THAT
IS EXPECTED TO INCREASE OVER THE NEXT DAY OR TWO. GIVEN INCREASING
ORGANIZATION DURING THE PAST 12 HOURS, IT IS LIKELY THE DISTURBANCE
WILL REACH THE MINIMUM WARNING THRESHOLD INTENSITY OF 25 KNOTS AND
REMAIN A WEAK TROPICAL DEPRESSION FOR A SHORT PERIOD BEFORE
INCREASING VERTICAL SHEAR ULTIMATELY RESULTS IN DISSIPATION. MAXIMUM
SUSTAINED SURFACE WINDS ARE ESTIMATED AT 20 TO 25 KNOTS. MINIMUM SEA
LEVEL PRESSURE IS ESTIMATED TO BE NEAR 1007 MB. BASED ON THE
CONSOLIDATING LOW LEVEL SIGNATURE AND PERSISTENT CONVECTIVE
SIGNATURE, THE POTENTIAL FOR FORMATION FOR A SIGNIFICANT TROPICAL
CYCLONE WITHIN THE NEXT 24 HOURS IS HIGH.
3. THIS ALERT WILL BE REISSUED, UPGRADED TO WARNING OR CANCELLED BY
180400Z.//
NNNN

[1900hurricane]

I can't say with 100% certainty that the western side of the circulation is closed, but it does look like it might be nearly a depression.

[1900hurricane]

91W is a JMA TD now.



I don't think 91W will have enough of a favorable environment or enough time to be classified as a TS by either agency, bat at the same time, I wouldn't be too terribly surprised if it was one briefly.

[euro6208]

Hey hey, a Tropical Cyclone Formation Alert!

Just like Nepartak, seems like the systems are popping out of nowhere...sneaky...

[euro6208]

TPPN10 PGTW 170252

A. TROPICAL DISTURBANCE 91W (E OF PHILIPPINES)

B. 17/0230Z

C. 19.67N

D. 129.63E

E. FIVE/HMWRI8

F. T1.0/1.0 STT: S0.0/03HRS

G. IR/EIR/VIS/MSI

H. REMARKS: 40A/PBO SBC/ANMTN. .25 WRAP YIELDS A DT OF 1.0. PT
AND MET ARE CURRENTLY UNAVAILABLE. DBO DT.

I. ADDITIONAL POSITIONS:
16/2205Z 19.23N 129.80E MMHS
16/2212Z 19.24N 129.83E SSMS


MARTINEZ

[euro6208]

SST over the area is 30C and shear has dropped by 20 to 30 knots but still moderate plus easterly shear is still quite favorable for TCs.

[euro6208]

03W THREE 160717 0600 20.2N 129.7E WPAC 25 1004

We now have 03W!

[euro6208]

WDPN31 PGTW 170900
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL DEPRESSION 03W (THREE)
WARNING NR 01//
RMKS//
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
TROPICAL DEPRESSION 03W (THREE), LOCATED APPROXIMATELY 392 NM
SOUTH-SOUTHEAST OF KADENA AB, HAS TRACKED NORTH-NORTHWESTWARD AT
08 KNOTS OVER THE PAST SIX HOURS. THE CURRENT POSITION IS BASED,
WITH HIGH CONFIDENCE, ON MULTIPLE AGENCY SATELLITE FIXES ON A
PARTIALLY-EXPOSED LOW-LEVEL CIRCULATION CENTER (LLCC). THE INTENSITY
OF 25 KNOTS IS CONSISTENT WITH SUBJECTIVE DVORAK SATELLITE INTENSITY
ESTIMATES FROM RJTD, KNES, AND PGTW AND ASCAT SCATTEROMETER PASSES
FROM 170030Z AND 170117Z. TD 03W HAS CONSOLIDATED INTO A TROPICAL
DEPRESSION DURING THE PAST SIX HOURS, WITH STRONG WESTWARD
DIFFLUENCE ALOFT CONTRIBUTING TO CONVECTIVE DEVELOPMENT AND
CONSEQUENT INTENSIFICATION OF THE LLCC. HOWEVER, INCREASING EASTERLY
VERTICAL WIND SHEAR IS IMPACTING THE SYSTEM AND LIMITING THE
POTENTIAL FOR FURTHER DEVELOPMENT. TD 03W IS TRACKING POLEWARD
FOLLOWING THE LOW TO MID-LEVEL FLOW ASSOCIATED WITH A SUBTROPICAL
STEERING RIDGE TO THE EAST.
3. FORECAST REASONING.
A. THIS IS THE INITIAL PROGNOSTIC REASONING AND SETS THE FORECAST
PHILOSOPHY.
B. TD 03W IS EXPECTED TO TRACK POLEWAARD FOLLOWING THE LOW TO MID-
LEVEL FLOW ASSOCIATED WITH THE SUBTROPICAL STEERING RIDGE OVER THE
NEXT 24 HOURS. PERSISTENT UPPER-LEVEL EASTERLY FLOW WILL IMPACT THE
SYSTEM AS IT TRACKS POLEWARD, RESULTING IN STEADY DISSIPATION OVER
THE NEXT 24 HOURS. THE CURRENT FORECAST LIES SLIGHTLY TO THE WEST OF
THE NUMERICAL MODEL CONSENSUS NEAR THE ECMWF MODEL SOLUTION WITH
HIGH CONFIDENCE.//
NNNN