WPAC: LIONROCK - Post-Tropical

[euro6208]

Will EURO verify?

Latest makes this the strongest of the trough systems. 973mb through Amami Ōshima, 945mb northwest of Okinawa.

[euro6208]

GFS weaker but does a full 360 degrees...Brings it right back to the NMI...

[1900hurricane]

JMA is classifying it as a Tropical Depression, not something extratropical. They're even stating max sustained winds of 30 kt despite ASCAT data indicating a stronger system. Maybe it's their turn to not look at the data?

WWJP25 RJTD 180600
WARNING AND SUMMARY 180600.
WARNING VALID 190600.
WARNING IS UPDATED EVERY 6 HOURS.
STORM WARNING.
DEVELOPED LOW 980 HPA
AT 54N 147E SEA OF OKHOTSK MOVING NORTHNORTHEAST 35 KNOTS.
OCCLUDED FRONT FROM 55N 146E TO 58N 150E 58N 154E.
WARM FRONT FROM 58N 154E TO 56N 160E 52N 165E.
COLD FRONT FROM 58N 154E TO 53N 155E 49N 153E.
STATIONARY FRONT FROM 49N 153E TO 46N 150E 43N 144E 40N 143E 36N
139E.
WINDS 30 TO 50 KNOTS WITHIN 400 MILES OF LOW SOUTHEAST SEMICIRCLE AND
200 MILES ELSEWHERE.
FORECAST POSITION FOR 181800UTC AT 60N 151E WITH UNCERTAINTY OF 85
MILES RADIUS.
FORECAST POSITION FOR 190600UTC AT 66N 160E WITH UNCERTAINTY OF 130
MILES RADIUS.
GALE WARNING.
EASTERLY TO SOUTHEASTERLY WINDS 30 TO 35 KNOTS PREVAILING OVER WATERS
BOUNDED BY 33N 148E 37N 151E 34N 160E 27N 162E 24N 155E 30N 154E 33N
148E.
WARNING.
TROPICAL DEPRESSION 996 HPA
AT 29.9N 149.5E SEA AROUND OF MINAMITORISIMA MOVING WEST 18 KNOTS.
POSITION FAIR.
MAX WINDS 30 KNOTS NEAR CENTER.
WARNING.
TROPICAL DEPRESSION 996 HPA
AT 15.5N 142.8E MARIANAS MOVING EASTNORTHEAST 09 KNOTS.
POSITION POOR.
MAX WINDS 30 KNOTS NEAR CENTER.
WARNING.
DENSE FOG OBSERVED LOCALLY OVER SEA OF OKHOTSK NORTHERN PART OF SEA
OF JAPAN.
WARNING.
DENSE FOG OBSERVED LOCALLY OVER WATERS BOUNDED BY 39N 142E 42N 141E
42N 143E 47N 152E 55N 162E 60N 164E 60N 180E 40N 180E 38N 170E 40N
160E 37N 145E 39N 142E.
SUMMARY.
HIGH 1026 HPA AT 43N 166E ALMOST STATIONARY.
HIGH 1022 HPA AT 52N 178E ALMOST STATIONARY.
REMARKS.
TROPICAL STORM 1608 DIANMU (1608) 985 HPA AT 20.8N 110.3E : SEE
TROPICAL CYCLONE WARNING.

JAPAN METEOROLOGICAL AGENCY.=

[euro6208]

JMA is classifying it as a Tropical Depression, not something extratropical. They're even stating max sustained winds of 30 kt despite ASCAT data indicating a stronger system. Maybe it's their turn to not look at the data?

Oh comes on! Don't start now...JTWC is not the official agency but it's still the most popular and recognized with all the bashing. Bash JMA and you're gone RSMC. It's the rules...Cricket...

[1900hurricane]

I'm not trying to bash JMA, but their handling of 12W is odd so far. Usually, JMA is more liberal than JTWC when it comes to classifying these lower convective storms in the subtropics.

[euro6208]

I'm not trying to bash JMA, but their handling of 12W is odd so far. Usually, JMA is more liberal than JTWC when it comes to classifying these lower convective storms in the subtropics.

JTWC does well with stronger systems and JMA with weaker...I wonder if we will see these same criticizing when a cat 4 or 5 comes out...

[NotoSans]

I'm not trying to bash JMA, but their handling of 12W is odd so far. Usually, JMA is more liberal than JTWC when it comes to classifying these lower convective storms in the subtropics.

Just want to point out that they issue gale warning for the area northeast of 12W. Technically they're not neglecting the gale force winds, but they don't consider these winds to be associated with 12W.
I also find their handling to be odd though. They used to be much more lenient on this type of systems. It should be named IMO.

[1900hurricane]

Whew, the 12Z ECMWF solution for 12W is quite something to look at. This is a week or more out, and the system may not even survive that long, but if it can linger and loop around south of Japan long enough, it may actually find some favorable conditions. That's a long way out though, and it is a little bit on an island compared to other members of guidance, but it's definitely the interesting solution.

It's hard to fathom that such a journey could be in store for something that currently looks so innocuous.

[euro6208]

WDPN34 PGTW 181500
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 12W (TWELVE) WARNING NR
03//
RMKS//
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
TROPICAL STORM (TS) 12W (TWELVE), LOCATED APPROXIMATELY 522 NM
EAST-SOUTHEAST OF YOKOSUKA, JAPAN, HAS TRACKED NORTHWESTWARD AT 14
KNOTS OVER THE PAST SIX HOURS. ANIMATED ENHANCED INFRARED SATELLITE
IMAGERY REVEALS A BROAD LOW-LEVEL CIRCULATION CENTER (LLCC) WITH THE
BULK OF THE DEEP CONVECTION PERSISTING OVER THE NORTHERN SEMI-CIRCLE
OF THE LLCC. A 181126Z METOP-A 89GHZ IMAGE DEPICTS A SYMMETRIC LLCC
WITH SHALLOW BANDING WRAPPING INTO THE CENTER WITH LIMITED DEEP
CONVECTION OVER THE NORTHERN QUADRANT. A 181041Z ASCAT IMAGE,
HOWEVER, SHOWS A WELL-DEFINED CENTER WITH GALE-FORCE WINDS (35 TO 40
KNOTS) OVER THE NORTHEAST QUADRANT. THIS IMAGE SUPPORTS THE CURRENT
POSITION WITH GOOD CONFIDENCE AS WELL AS THE CURRENT INTENSITY OF 40
KNOTS. UPPER-LEVEL ANALYSIS INDICATES THAT THE SYSTEM IS LOCATED
ALONG THE NORTHERN PERIPHERY OF THE UPPER LOW, WHICH IS CENTERED TO
THE SOUTH AT APPROXIMATELY 27N 149E, WITH STRONG DIFFLUENCE AND LOW
VERTICAL WIND SHEAR AIDING IN SUSTAINING THE DEEP CONVECTION. TS 12W
IS TRACKING ALONG THE ENHANCED GRADIENT BETWEEN THE MONSOON GYRE AND
THE SUBTROPICAL RIDGE (STR) TO THE NORTHEAST.
3. FORECAST REASONING.
A. NO CHANGE IN THE FORECAST PHILOSOPHY SINCE THE PREVIOUS
PROGNOSTIC REASONING MESSAGE. 34-KNOT WIND RADII HAVE BEEN ADJUSTED
BASED ON THE RECENT ASCAT IMAGE.
B. TS 12W IS EXPECTED TO CONTINUE MOVING WEST-NORTHWESTWARD TO
NORTHWESTWARD AND MAINTAIN INTENSITY OVER THE NEXT 24 HOURS DUE TO
THE MARGINAL ENVIRONMENTAL CONDITIONS DUE TO THE UPPER-LEVEL LOW.
BEYOND TAU 24, THE SYSTEM WILL TURN WEST-SOUTHWESTWARD AND THEN
SOUTHWESTWARD AS THE DOMINANT STEERING MECHANISM TRANSITIONS TO THE
WESTERN SUBTROPICAL RIDGE EXTENDING FROM CHINA INTO WESTERN JAPAN.
THE UPPER-LEVEL LOW IS FORECAST TO GRADUALLY FILL AND MOVE AHEAD OF
THE TROPICAL STORM WHICH, COMBINED WILL INCREASING SEA SURFACE
TEMPERATURES, WILL ALLOW FOR A MODEST INTENSIFICATION. DYNAMIC MODEL
GUIDANCE IS IN GOOD AGREEMENT DURING THIS PORTION OF THE FORECAST;
HOWEVER, THE INTENSITY FORECAST IS CHALLENGING DUE TO THE COMPLEX
UPPER LEVEL ENVIRONMENT AND POTENTIAL DIRECT CYCLONE INTERACTION
WITH TD 10W.
C. IN THE EXTENDED PERIOD, TS 12W WILL SLOW SIGNIFICANTLY WHILE
TRACKING WESTWARD AS THE WESTERN STR RETREATS DUE TO A DEEPENING
SHORTWAVE TROUGH PASSING TO THE NORTH. AS ASSESSED IN THE MODEL
FIELDS, THIS SHORTWAVE TROUGH IS CHARACTERIZED BY NEUTRAL VORTICITY
ADVECTION AND WEAK BAROCLINICITY (WEAK DYNAMICS) AND IS UNLIKELY TO
INDUCE A RE-CURVE TRACK, HENCE, THE MORE LIKELY WESTWARD TRACK. THE
SYSTEM WILL INTENSIFY TO A PEAK OF 65 KNOTS DUE TO INCREASING SST
AND IMPROVED POLEWARD VENTING. ADDITIONALLY, THERE IS AN ALTERNATE
SCENARIO WHERE THE CYCLONE COULD CLOSE WITHIN 500NM OF TD 10W. IF
THIS OCCURS THEN THE TRACK WILL TURN MORE SOUTHWARD AND WEAKEN.
DYNAMIC MODEL GUIDANCE IS IN FAIR AGREEMENT IN THIS PORTION OF THE
FORECAST; HOWEVER, DUE TO THE COMPLEXITY OF THE STEERING ENVIRONMENT
AND THE POTENTIAL DIRECT CYCLONE INTERACTION, THERE IS LOW
CONFIDENCE IN THE JTWC FORECAST.//
NNNN

[euro6208]

12Z even stronger...911mb east of Okinawa after completing a 360 loop south of the island...

[NotoSans]

JMA has also issued gale warning on this system, and expects this to become a TS within 12 hours.

TD
Issued at 01:15 UTC, 19 August 2016

<Analysis at 00 UTC, 19 August>
Scale -
Intensity -
TD
Center position N32°50' (32.8°)
E144°40' (144.7°)
Direction and speed of movement WNW 35 km/h (19 kt)
Central pressure 996 hPa
Maximum wind speed near center 15 m/s (30 kt)
Maximum wind gust speed 23 m/s (45 kt)

<Forecast for 12 UTC, 19 August>
Intensity -
Center position of probability circle N32°10' (32.2°)
E141°20' (141.3°)
Direction and speed of movement W 30 km/h (15 kt)
Central pressure 994 hPa
Maximum wind speed near center 18 m/s (35 kt)
Maximum wind gust speed 25 m/s (50 kt)
Radius of probability circle 110 km (60 NM)

<Forecast for 00 UTC, 20 August>
Intensity -
Center position of probability circle N31°05' (31.1°)
E138°35' (138.6°)
Direction and speed of movement WSW 25 km/h (13 kt)
Central pressure 994 hPa
Maximum wind speed near center 18 m/s (35 kt)
Maximum wind gust speed 25 m/s (50 kt)
Radius of probability circle 200 km (110 NM)

[euro6208]

WDPN34 PGTW 190300
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 12W (TWELVE) WARNING NR
05//
RMKS//
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
TROPICAL STORM (TS) 12W (TWELVE), LOCATED APPROXIMATELY 299 NM
EAST-SOUTHEAST OF YOKOSUKA, JAPAN, HAS TRACKED WEST-NORTHWESTWARD AT
17 KNOTS OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE
IMAGERY SHOWS SHALLOW CONVECTION WRAPPING INTO A PARTIALLY EXPOSED
LOW LEVEL CIRCULATION CENTER (LLCC) THAT SUPPORTS THE CURRENT
POSITION WITH HIGH CONFIDENCE. A 190043Z ASCAT BULLSEYE SHOWS A WELL
DEFINED LLCC WITH A SWATH OF 35 KNOT WINDS ALONG THE NORTHERN
PERIPHERY. THIS DATA SUPPORTS THE CURRENT INTENSITY OF 35 KNOTS.
ENVIRONMENTAL CONDITIONS CONTINUE TO IMPROVE WITH INCREASED POLEWARD
OUTFLOW PROVIDING EXHAUST FOR THE DEVELOPING SHALLOW CONVECTION;
HOWEVER, THE UPPER LEVEL LOW CONTINUES TO ENTRAIN DRY AIR INTO THE
SYSTEM. TS 12W IS TRACKING ALONG THE ENHANCED GRADIENT BETWEEN THE
MONSOON GYRE AND THE SUBTROPICAL RIDGE (STR) TO THE NORTHEAST.
3. FORECAST REASONING.
A. NO CHANGE IN THE FORECAST PHILOSOPHY SINCE THE PREVIOUS
PROGNOSTIC REASONING MESSAGE.
B. TS 12W IS EXPECTED TO TURN WESTWARD AND MAINTAIN INTENSITY
OVER THE NEXT 12 HOURS DUE TO THE MARGINAL ENVIRONMENTAL CONDITIONS.
BEYOND TAU 12, THE SYSTEM WILL TURN WEST-SOUTHWESTWARD AND THEN
SOUTHWESTWARD AS THE DOMINANT STEERING MECHANISM TRANSITIONS TO THE
WESTERN SUBTROPICAL RIDGE EXTENDING FROM CHINA INTO WESTERN JAPAN.
THE UPPER LEVEL LOW IS FORECAST TO GRADUALLY FILL AND MOVE SOUTH OF
THE TROPICAL STORM WHICH, COMBINED WILL INCREASING SEA SURFACE
TEMPERATURES (SSTS), WILL ALLOW FOR A SLIGHT INTENSIFICATION AS IT
TRACKS TOWARD THE RYUKYU ISLANDS. DYNAMIC MODEL GUIDANCE HAS COME
INTO BETTER AGREEMENT DURING THIS PORTION OF THE FORECAST; HOWEVER,
THE INTENSITY FORECAST IS CHALLENGING DUE TO THE COMPLEX UPPER LEVEL
ENVIRONMENT.
C. IN THE EXTENDED PERIOD, TS 12W WILL CONTINUE TRACKING
SOUTHWESTWARD ALONG THE EASTERN PERIPHERY OF THE WESTERN STR. THE
SYSTEM WILL INTENSIFY TO A PEAK OF 55 KNOTS DUE TO INCREASING SSTS
AND IMPROVED DIVERGENT OUTFLOW. DYNAMIC MODEL GUIDANCE IS IN FAIR
AGREEMENT IN THIS PORTION OF THE FORECAST WITH ONLY NOTED
DIFFERENCES IN FORWARD SPEED OF THE CYCLONE; HOWEVER, LONG RANGE
MODELS ARE SHOWING THE POTENTIAL FOR THE SYSTEM TO TURN
SOUTHEASTWARD AROUND THE SOUTHERN FLANK OF THE MONSOON GYRE. DUE TO
CONTINUED COMPLEXITY WITH THE OVERALL SYNOPTIC PATTERN AND
UNCERTAINTY IN THE MODEL GUIDANCE, THERE IS LOW CONFIDENCE IN THE
JTWC FORECAST.//
NNNN

[euro6208]

00Z EURO continues with the massive intensification as this stalls over the Ryukyu Islands. Slightly weaker at 916mb...

GFS probrably confuse with the outbreak. Doesn't do much with this at all as it dissipates south of Japan...

HWRF very similiar to EURO...

[NotoSans]

Finally we have TS Lionrock.

TS 1610 (Lionrock)
Issued at 13:15 UTC, 19 August 2016

<Analysis at 12 UTC, 19 August>
Scale -
Intensity -
Center position N33°05' (33.1°)
E141°25' (141.4°)
Direction and speed of movement W 20 km/h (11 kt)
Central pressure 994 hPa
Maximum wind speed near center 18 m/s (35 kt)
Maximum wind gust speed 25 m/s (50 kt)
30 kt wind area N 220 km (120 NM)
S 170 km (90 NM)

<Forecast for 00 UTC, 20 August>
Intensity -
Center position of probability circle N31°35' (31.6°)
E138°50' (138.8°)
Direction and speed of movement WSW 25 km/h (13 kt)
Central pressure 994 hPa
Maximum wind speed near center 18 m/s (35 kt)
Maximum wind gust speed 25 m/s (50 kt)
Radius of probability circle 70 km (40 NM)

<Forecast for 12 UTC, 20 August>
Intensity -
Center position of probability circle N30°05' (30.1°)
E136°40' (136.7°)
Direction and speed of movement SW 20 km/h (12 kt)
Central pressure 994 hPa
Maximum wind speed near center 18 m/s (35 kt)
Maximum wind gust speed 25 m/s (50 kt)
Radius of probability circle 150 km (80 NM)

<Forecast for 12 UTC, 21 August>
Intensity -
Center position of probability circle N28°50' (28.8°)
E133°20' (133.3°)
Direction and speed of movement WSW 15 km/h (8 kt)
Central pressure 990 hPa
Maximum wind speed near center 20 m/s (40 kt)
Maximum wind gust speed 30 m/s (60 kt)
Radius of probability circle 200 km (110 NM)

<Forecast for 12 UTC, 22 August>
Intensity -
Center position of probability circle N28°25' (28.4°)
E132°30' (132.5°)
Direction and speed of movement Almost stationary
Central pressure 980 hPa
Maximum wind speed near center 25 m/s (50 kt)
Maximum wind gust speed 35 m/s (70 kt)
Radius of probability circle 310 km (170 NM)

[euro6208]

907mb...

[1900hurricane]

These ECMWF solutions are some weird looking things, but it has been remarkably consistent. It's a little hard to believe that it blows up something that currently looks relatively innocuous, but that's tropical meteorology for you.

[euro6208]

12W LIONROCK 160820 0000 32.0N 138.4E WPAC 35 996

[euro6208]

[euro6208]

The best it's looked it's entire life...

[shah83]

Man, what the Euro keeps wanting to do with Lionrock is so scary...