WPAC: NARI - Post-Tropical

[Nancy Smar]

91W INVEST 190723 0600 24.8N 135.2E WPAC 15 1005

[Nancy Smar]

ABPW10 PGTW 230600
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/SIGNIFICANT TROPICAL WEATHER ADVISORY FOR THE WESTERN AND
/SOUTH PACIFIC OCEANS/230600Z-240600ZJUL2019//
RMKS/
1. WESTERN NORTH PACIFIC AREA (180 TO MALAY PENINSULA):
A. TROPICAL CYCLONE SUMMARY: NONE.
B. TROPICAL DISTURBANCE SUMMARY:
(1) AN AREA OF CONVECTION (INVEST 91W) HAS PERSISTED NEAR
24.8N 135.2E, APPROXIMATELY 670 NM SOUTH-SOUTHWEST OF YOKOSUKA,
JAPAN. THIS SYSTEM IS CLASSIFIED AS A WEAK SUBTROPICAL CYCLONE.
ANIMATED MULTISPECTRAL SATELLITE IMAGERY DEPICTS A BROAD, ILL-
DEFINED LOW-LEVEL CIRCULATION CENTER (LLCC) WITH FLARING DEEP
CONVECTION DISPLACED TO THE EAST AND SOUTHEAST. A 230012Z ASCAT-C
IMAGE SHOWS AN ASYMMETRIC WIND FIELD WITH WEAK (10-20 KNOTS) CORE
WINDS AND A SMALL AREA OF 25-30 KNOT SOUTHERLY WINDS DISPLACED ABOUT
180NM EAST-SOUTHEAST OF THE CENTER, TYPICAL OF A SUBTROPICAL TYPE
SYSTEM. THIS SYSTEM IS LOCATED UNDER A SHARP 500MB SHORTWAVE TROUGH,
WHICH IS POSITIONED WITHIN A BREAK IN THE SUBTROPICAL RIDGE. THE
UPPER-LEVEL ENVIRONMENT IS MARGINALLY FAVORABLE WITH LOW TO MODERATE
VERTICAL WIND SHEAR, AND CONVERGENCE ALOFT BUT VENTING EAST OF THE
LLCC WHICH IS FUELING THE DISORGANIZED DEEP CONVECTION. SST VALUES
OF 28-30C ARE CONDUCIVE FOR FURTHER DEVELOPMENT. DYNAMIC MODEL
GUIDANCE INDICATES THAT 91W WILL CONSOLIDATE INTO A WARM-CORE
TROPICAL SYSTEM WITHIN THE NEXT 2-3 DAYS AS IT TRACKS POLEWARD
TOWARD MAINLAND JAPAN. MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED
AT 15 TO 20 KNOTS. MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE
NEAR 1005 MB. THE POTENTIAL FOR THE DEVELOPMENT OF A SIGNIFICANT
TROPICAL CYCLONE WITHIN THE NEXT 24 HOURS IS LOW.
(2) 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.//
NNNN

[Nancy Smar]

91W INVEST 190723 0600 25.2N 135.4E WPAC 20 1005

[Hayabusa]

So why this is not 92W?

[Nancy Smar]

So why this is not 92W?

Maybe JTWC is facing some technical issues.

[Hayabusa]

JMA issued TD warning

TD
Issued at 01:00 UTC, 24 July 2019

<Analysis at 00 UTC, 24 July>
Scale -
Intensity -
TD
Center position N23°10' (23.2°)
E136°30' (136.5°)
Direction and speed of movement NE Slow
Central pressure 1008 hPa
Maximum wind speed near center 15 m/s (30 kt)
Maximum wind gust speed 23 m/s (45 kt)

[Hayabusa]

Up to medium

ABPW10 PGTW 240200
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/SIGNIFICANT TROPICAL WEATHER ADVISORY FOR THE WESTERN AND
/SOUTH PACIFIC OCEANS/REISSUED/240200Z-240600ZJUL2019//
RMKS/
1. WESTERN NORTH PACIFIC AREA (180 TO MALAY PENINSULA):
A. TROPICAL CYCLONE SUMMARY: NONE.
B. TROPICAL DISTURBANCE SUMMARY:
(1) AN AREA OF CONVECTION (INVEST 91W) PREVIOUSLY LOCATED NEAR
24.8N 135.2E, IS NOW LOCATED NEAR 23.9N 136.2E APPROXIMATELY 705 NM
SOUTH-SOUTHWEST OF YOKOSUKA, JAPAN. THIS SYSTEM IS CLASSIFIED AS A
WEAK SUBTROPICAL CYCLONE. ANIMATED INFRARED SATELLITE IMAGERY
DEPICTS A BROAD, LOW-LEVEL CIRCULATION CENTER WITH FLARING DEEP
CONVECTION DISPLACED TO THE EAST AND SOUTHEAST. THE UPPER-LEVEL
ENVIRONMENT IS MARGINALLY FAVORABLE WITH LOW TO MODERATE VERTICAL
WIND SHEAR AND GOOD POLEWARD OUTFLOW. SST VALUES OF 27-28C ARE
CONDUCIVE FOR FURTHER DEVELOPMENT. DYNAMIC MODEL GUIDANCE INDICATES
THAT 91W WILL CONSOLIDATE INTO A WARM-CORE TROPICAL SYSTEM AS IT
TRACKS POLEWARD TOWARD MAINLAND JAPAN. 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
MEDIUM.

[Hayabusa]

[euro6208]

Looks good. If this was the atlantic it should be a named system by now.

[Nancy Smar]

WTPN21 PGTW 240800
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE FORMATION ALERT//
RMKS/
1. FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE WITHIN
080 NM EITHER SIDE OF A LINE FROM 24.1N 136.4E TO 29.1N 137.9E
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 240600Z INDICATES THAT A CIRCULATION CENTER IS LOCATED
NEAR 24.7N 136.8E. THE SYSTEM IS MOVING NORTH-NORTHEASTWARD AT 07
KNOTS.
2. REMARKS: THE AREA OF CONVECTION (INVEST 91W) PREVIOUSLY LOCATED
NEAR 24.8N 135.2E, IS NOW LOCATED NEAR 24.7N 136.8E, APPROXIMATELY
650 NM SOUTH-SOUTHWEST OF YOKOSUKA, JAPAN. THIS SYSTEM PREVIOUSLY
DISPLAYED TRAITS OF A WEAK SUBTROPICAL CYCLONE, BUT HAS RECENTLY
DEVELOPED DEFINED TROPICAL CHARACTERISTICS. ANIMATED INFRARED
SATELLITE IMAGERY DEPICTS A CONSOLIDATING LOW-LEVEL CIRCULATION
CENTER WITH DEEP CONVECTION BUILDING OVER AND TO THE EAST OF THE
CENTER. THE UPPER-LEVEL ENVIRONMENT IS MARGINALLY FAVORABLE WITH LOW
TO MODERATE VERTICAL WIND SHEAR (15-20 KNOTS) AND GOOD POLEWARD
OUTFLOW. SST VALUES OF 28-29C ARE CONDUCIVE FOR FURTHER DEVELOPMENT.
DYNAMIC MODEL GUIDANCE INDICATES THAT 91W WILL CONSOLIDATE AS A
WARM-CORE TROPICAL SYSTEM AS IT TRACKS NORTHEAST TOWARD MAINLAND
JAPAN OVER THE NEXT FEW DAYS. MAXIMUM SUSTAINED SURFACE WINDS ARE
ESTIMATED AT 18 TO 23 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 HIGH.
3. THIS ALERT WILL BE REISSUED, UPGRADED TO WARNING OR CANCELLED BY
250800Z.//
NNNN

TCFA

[NewbieAboutcyclones]

Waaaaay better than td 3 in Atl.

[1900hurricane]

It isn't the nicest thing I've ever laid eyes on, but probably worthy of classification.

[Yellow Evan]

TXPQ23 KNES 242128
TCSWNP

A. TROPICAL DISTURBANCE (91W)

B. 24/2030Z

C. 25.9N

D. 138.0E

E. THREE/HIMAWARI-8

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

G. IR/EIR/SWIR

H. REMARKS...THIS INTENSITY ESTIMATE WAS DERIVED USING 4 KM IR DATA. >
2/10 BANDING RESULTS IN A DT OF 1.0. MET AND PT ARE 1.0. FT IS BASED
ON DT.

I. ADDL POSITIONS

NIL


...LEVINE

[Nancy Smar]

07W.INVEST.25kts.1003mb.26.3N.137.6E

[euro6208]

Big burst of convection near the center. Better upgrade this now or it will be another missed TS.

[euro6208]

WDPN31 PGTW 250300
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL DEPRESSION TROPICAL
DEPRESSION 07 (SEVEN) WARNING NR 001//
RMKS//
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
TROPICAL DEPRESSION 07W (SEVEN), LOCATED APPROXIMATELY 220 NM
WEST-NORTHWEST OF IWO TO, HAS TRACKED NORTHWARD AT 11 KNOTS OVER THE
PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI)
DEPICTS AN EXPOSED LOW LEVEL CIRCULATION CENTER (LLCC) WITH DEEP
CONVECTION DISPLACED TO THE EAST OF THE LLCC AND SHALLOW RAIN BANDS
STARTING TO WRAP IN FROM THE NORTH. THE INITIAL POSITION IS PLACED
WITH GOOD CONFIDENCE BASED ON THE LLCC SEEN IN THE MSI LOOP AND A
250005Z METOP-B ASCAT PASS. A 242141Z F-17 SSMIS 91 GHZ MICROWAVE
IMAGE SHOWS CONVECTIVE BANDING WITHIN THE EASTERN SEMI-CIRCLE WITH
LIMITED BANDING TO THE WEST. THE INITIAL INTENSITY OF 25 KTS IS
CONSISTENT WITH THE MULTI-AGENCY DVORAK INTENSITY OF T1.0-1.5 (25
KTS) AND THE AFOREMENTIONED ASCAT PASS WHICH SHOWED 25-30 KT WINDS
IN THE CONVECTION TO THE NORTH AND EAST OF THE LLCC WITH 10-20 KTS
IN THE SOUTHWEST QUADRANT. ENVIRONMENTAL CONDITIONS FOR TD 07W ARE
MARGINAL WITH GOOD POLEWARD OUTFLOW SLIGHTLY TO THE EAST OF THE LLCC
AND WARM SEA SURFACE TEMPERATURES (28-30 CELSIUS) BEING OFFSET BY
MODERATE TO STRONG VERTICAL WIND SHEAR (VWS) (20-25 KTS). TD 07W IS
TRACKING ALONG THE WESTERN PERIPHERY OF A SUBTROPICAL RIDGE (STR).
3. FORECAST REASONING.
A. THIS IS THE INITIAL PROGNOSTIC REASONING AND SETS THE FORECAST
PHILOSOPHY.
B. BY TAU 48, TD 07W SHOULD BE TRACKING NORTHEASTWARD AS IT ROUNDS
THE STR AXIS. THE JTWC TRACK FORECAST CLOSELY FOLLOWS THE CONSENSUS
TRACK WITH TRACK SPREAD LIMITED TO 50NM AT TAU 48. CONTINUED HIGH VWS
AND OFFSET UPPER LEVEL DIVERGENCE WILL PREVENT TD 07W FROM
INTENSIFYING SIGNIFICANTLY THROUGH TAU 48. AFTER TAU 48, LAND
INTERACTION AND COOL SEA SURFACE TEMPERATURES ARE EXPECTED TO
SIGNIFICANTLY HINDER ANY FURTHER DEVELOPMENT OF TD 07W. THE JTWC
INTENSITY FORECAST CLOSELY FOLLOWS THE INTENSITY GUIDANCE THROUGH TAU
72.
C. AFTER TAU 72, TD 07W IS EXPECTED TO CONTINUE TRACKING ALONG THE
NORTHERN PERIPHERY OF THE STR AS IT BRUSHES THE SOUTHERN COAST OF
JAPAN AND GRADUALLY DISSIPATES BELOW WARNING THRESHOLD OVER COOLER
SEAS (24-26 DEGREES CELSIUS). THE JTWC TRACK FORECAST CLOSELY
FOLLOWS THE CONSENSUS TRACK WITH TRACK SPREAD LIMITED TO UNDER 40NM
AT TAU 96. FOR THIS PORTION OF THE FORECAST, THERE IS HIGH CONFIDENCE
IN THE JTWC TRACK FORECAST DUE TO LOW UNCERTAINTY IN THE MODEL
GUIDANCE AND THE INITIAL POSITION OF THE SYSTEM.//
NNNN

[euro6208]

TS anyone? Recon?

[euro6208]

Upgraded to a TS based on ASCAT.

WDPN31 PGTW 251500
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 07 (SEVEN) WARNING
NR 003//
RMKS//
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
TROPICAL STORM 07W (SEVEN), LOCATED APPROXIMATELY 483 NM
SOUTH-SOUTHWEST OF YOKOSUKA, JAPAN, HAS TRACKED NORTHWARD AT 10 KNOTS
OVER THE PAST SIX HOURS. THE CURRENT POSITION IS BASED ON RECENT
AGENCY SATELLITE FIXES FROM VARIOUS REPORTING AGENCIES AND MICROWAVE
SATELLITE IMAGERY INCLUDING A 250858Z SSMIS PASS, WHICH SHOWS A
PARTIALLY-EXPOSED LOW LEVEL CIRCULATION. THE INTENSITY IS SET AT 35
KNOTS BASED ON A 251119Z PARTIAL ASCAT PASS INDICATING AN EXTENSIVE
AREA OF 30-35 KNOT WINDS TO THE EAST OF THE LOW LEVEL CIRCULATION
CENTER. TS 07W HAS ACCELERATED POLEWARD OVER THE PAST SIX HOURS ALONG
THE PERIPHERY OF A SUBTROPICAL RIDGE TO THE EAST. PERSISTENT,
MODERATE SOUTHWESTERLY VERTICAL WIND SHEAR (VWS) ASSOCIATED WITH THE
FLOW AROUND AN UPPER-LEVEL LOW TO THE WEST HAS KEPT DEEP CONVECTION
CONFINED TO THE EASTERN AND NORTHERN PORTIONS OF THE STORM
CIRCULATION. WARM SEA SURFACE TEMPERATURES (28-29C) AND STRONG
EASTWARD AND EQUATORWARD OUTFLOW ALOFT HAVE COUNTERED THE IMPACT OF
THE PERSISTENT VWS, ENABLING THE SYSTEM TO INTENSIFY SLIGHTLY OVER
THE PAST SEVERAL HOURS.
3. FORECAST REASONING.
A. THERE IS NO CHANGE TO THE FORECAST PHILOSOPHY FROM THE PREVIOUS
WARNING.
B. TS 07W WILL CONTINUE TRACKING POLEWARD THROUGH TAU 36, AND
SUBSEQUENTLY TURN EASTWARD AS IT ROUNDS THE SUBTROPICAL STEERING
RIDGE AXIS. PASSAGE OVER WARM WATER AND FAVORABLE OUTFLOW SHOULD
ALLOW THE SYSTEM TO MAINTAIN WEAK TROPICAL STORM INTENSITY FOR THE
NEXT 24 HOURS OR SO. AFTER TAU 24, INCREASING VWS AND PASSAGE OVER
LAND WILL INDUCE PRONOUNCED WEAKENING.
C. TS 07W WILL DISSIPATE BY TAU 96 DUE TO PASSAGE OVER LAND AND
COOL WATER, AS WELL AS INCREASING VWS. THE CIRCULATION IS EXPECTED TO
REMAIN SEPARATE FROM THE MID-LATITUDE FLOW PATTERN AS IT DISSIPATES,
SO EXTRATROPICAL TRANSITION IS NOT ANTICIPATED. NUMERICAL MODEL
GUIDANCE REMAINS IN GOOD AGREEMENT REGARDING THE STEERING SCENARIO,
LENDING HIGH CONFIDENCE TO THE CURRENT JTWC TRACK FORECAST.//
NNNN

[Nancy Smar]

WTPQ20 RJTD 260000
RSMC TROPICAL CYCLONE ADVISORY
NAME TS 1906 NARI (1906) UPGRADED FROM TD
ANALYSIS
PSTN 260000UTC 29.8N 137.1E GOOD
MOVE N 12KT
PRES 1000HPA
MXWD 035KT
GUST 050KT
30KT 240NM EAST 120NM WEST
FORECAST
24HF 270000UTC 33.5N 135.8E 50NM 70%
MOVE N 09KT
PRES 1004HPA
MXWD 035KT
GUST 050KT
48HF 280000UTC 35.8N 140.2E 90NM 70% TROPICAL DEPRESSION =

[euro6208]

WDPN31 PGTW 260300
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 07W (NARI) WARNING
NR 005//
RMKS//
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
TROPICAL STORM (TS) 07W (NARI), LOCATED APPROXIMATELY 311 NM
WEST-NORTHWEST OF CHICHI JIMA, HAS TRACKED NORTHWARD AT 12 KNOTS OVER
THE PAST SIX HOURS.
ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) SHOWS BANDING WRAPPING
INTO THE EXPOSED LOW LEVEL CIRCULATION CENTER (LLCC). THE INITIAL
POSITION IS BASED WITH HIGH CONFIDENCE FROM MSI, MULTIPLE AGENCY
DVORAK FIXES AND A 252126Z SSMIS 91 GHZ PASS. THE INTENSITY IS SET AT
35 KNOTS BASED ON MULTIPLE AGENCY DVORAK ESTIMATES OF T2.0-T2.5 AND A
260110Z ADT ESTIMATE OF 32 KNOTS.
TS 07W HAS CONTINUED POLEWARD OVER THE PAST SIX HOURS ALONG THE
PERIPHERY OF A SUBTROPICAL RIDGE TO THE EAST. PERSISTENT, MODERATE
SOUTHWESTERLY VERTICAL WIND SHEAR (VWS) ASSOCIATED WITH THE FLOW
AROUND AN UPPER-LEVEL LOW TO THE WEST HAS STIFLED DEEP CONVECTION.
WARM SEA SURFACE TEMPERATURES (28-29C) AND GOOD POLEWARD OUTFLOW
ALOFT HAVE COUNTERED THE IMPACT OF THE PERSISTENT VWS, ENABLING THE
SYSTEM TO MAINTAIN OVER THE PAST SEVERAL HOURS.
3. FORECAST REASONING.
A. THERE IS NO CHANGE TO THE FORECAST PHILOSOPHY FROM THE PREVIOUS
WARNING.
B. TS 07W WILL CONTINUE TRACKING POLEWARD THROUGH TAU 24, AND
SUBSEQUENTLY TURN EASTWARD AS IT ROUNDS THE SUBTROPICAL STEERING
RIDGE AXIS. PASSAGE OVER WARM WATER AND FAIR OUTFLOW SHOULD ALLOW THE
SYSTEM TO MAINTAIN WEAK TROPICAL STORM INTENSITY FOR THE NEXT 24
HOURS, DESPITE THE MODERATE TO STRONG SHEAR ALONG THE FORECAST TRACK.
AFTER TAU 24, PASSAGE OVER LAND WILL INDUCE PRONOUNCED WEAKENING.
C. TS 07W WILL DISSIPATE BY TAU 72 DUE TO PASSAGE OVER LAND AND
COOL WATER (24-26 DEGREES CELSIUS) AS IT EXITS OFF THE EAST COAST OF
JAPAN. THE CIRCULATION IS EXPECTED TO REMAIN SEPARATE FROM THE
MID-LATITUDE FLOW PATTERN AS IT DISSIPATES, SO EXTRATROPICAL
TRANSITION IS NOT ANTICIPATED. NUMERICAL MODEL GUIDANCE REMAINS IN
GOOD AGREEMENT REGARDING THE STEERING SCENARIO, LENDING HIGH
CONFIDENCE TO THE CURRENT JTWC TRACK FORECAST.//
NNNN