WPAC: KAMMURI - Post-Tropical

[1900hurricane]

I'll take a degree or two of spread between operational members of guidance in the mid-range taus. Positions are within 100 nm or so of each other through tau 120 on the 00Z ECMWF/tau 108 on the 12Z GFS. That's rather tight agreement given the bifurcation scenarios we've been seeing previously. Of course, the rest of the 12Z suite hasn't come out yet, including the 12Z ECMWF, so we'll have to see if agreement is still rather tight.

[aspen]

12z Euro still shows a massive latitude jump from Kammuri eating 94Wb.

[aspen]

29W KAMMURI 191126 1800 11.5N 143.5E WPAC 50 990

[Hayabusa]

[Hayabusa]

It could be STS soon

TS 1928 (Kammuri)
Issued at 18:50 UTC, 26 November 2019

<Analysis at 18 UTC, 26 November>
Scale -
Intensity -
Center position N11°50' (11.8°)
E143°50' (143.8°)
Direction and speed of movement W 30 km/h (17 kt)
Central pressure 992 hPa
Maximum wind speed near center 23 m/s (45 kt)
Maximum wind gust speed 35 m/s (65 kt)
≥ 30 kt wind area N 560 km (300 NM)
S 330 km (180 NM)

[Hayabusa]

Almost cat 5

[Hayabusa]

15Z

WDPN31 PGTW 261500
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 29W (KAMMURI)
WARNING NR 004//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
TROPICAL STORM (TS) 29W (KAMMURI), LOCATED APPROXIMATELY 145 NM
SOUTH OF ANDERSEN AFB, GUAM, HAS TRACKED WESTWARD AT 21 KNOTS OVER
THE PAST SIX HOURS. ANIMATED ENHANCED INFRARED SATELLITE IMAGERY
DEPICTS A CONSOLIDATING SYSTEM WITH IMPROVED CONVECTIVE STRUCTURE
AND ROBUST POLEWARD OUTFLOW. A 261147Z AMSU 89GHZ IMAGE DEPICTS
SPIRAL BANDING WRAPPING INTO A DEFINED LOW LEVEL CIRCULATION CENTER.
THE INITIAL POSITION IS PLACED WITH HIGH CONFIDENCE BASED ON A
261036Z ASCAT-A IMAGE WHICH DEPICTS A DEFINED CIRCULATION AS WELL AS
A 261229Z PGTW RADAR FIX. THE INITIAL INTENSITY ESTIMATE OF 40KTS
REFLECTS THE GRADUAL DEVELOPMENT OF THE SYSTEM AND IS BASED ON THE
ASCAT-A IMAGERY DEPICTING 35KT WINDS IN THE NORTH QUADRANT, A CIMSS
SATCON ESTIMATE OF 43KTS AND A PGTW DVORAK INTENSITY ESTIMATE OF
T2.5 (35KTS). ENVIRONMENTAL ANALYSIS DEPICTS A FAVORABLE ENVIRONMENT
FOR DEVELOPMENT WITH LOW (10-15KTS) VERTICAL WIND SHEAR (VWS),
STRONG POLEWARD OUTFLOW ALOFT AND WARM (29-30C) SEA SURFACE
TEMPERATURES (SST). GUAM SOUNDINGS (26/06-12Z) INDICATE DEEP
EASTERLY FLOW WITH 45-55KT GRADIENT WINDS. CONSEQUENTLY, TS 29W IS
TRACKING QUICKLY WESTWARD ALONG THE SOUTHERN PERIPHERY OF THE
SUBTROPICAL RIDGE (STR).
3. FORECAST REASONING.
A. THERE IS NO SIGNIFICANT CHANGE TO THE FORECAST PHILOSOPHY FROM
THE PREVIOUS PROGNOSTIC REASONING MESSAGE. THE 34-KNOT WIND RADII
HAVE BEEN ADJUSTED SLIGHTLY OVER THE NORTHERN SEMICIRCLE TO REFLECT
THE EXTENSIVE GALE-FORCE WINDS OVER THE NORTHERN MARIANAS.
B. TS 29W WILL CONTINUE ITS CURRENT TRACK UNDER THE STR THROUGH
TAU 24, PASSING APPROXIMATELY 135 NM SOUTH OF ANDERSEN AFB, GUAM.
AFTERWARD, A SHORTWAVE TROUGH TO THE NORTHWEST WILL WEAKEN THE STR
AND CAUSE 29W TO TRACK NORTH-NORTHWESTWARD TO NORTHWARD. LOW VWS,
COUPLED WITH WARM SST WILL CONTINUE TO FUEL THE DEVELOPMENT OF THE
SYSTEM AS IT BEGINS THIS POLEWARD TRACK, EVENTUALLY INTENSIFYING TO
105KTS BY TAU 72. NUMERICAL MODELS ARE IN TIGHT AGREEMENT THROUGH
TAU 24, LENDING HIGH CONFIDENCE TO THE EARLY PORTION OF THE JTWC
FORECAST TRACK.
C. AFTER TAU 72, TS 29W WILL SLOW SIGNIFICANTLY AS IT BEGINS TO
TRACK WESTWARD ALONG A SECONDARY, BUILDING STR TO THE NORTHWEST.
CONTINUED FAVORABLE ENVIRONMENTAL CONDITIONS WILL ALLOW THE SYSTEM
TO CONTINUE INTENSIFICATION TO A PEAK INTENSITY OF 115KTS BY TAU 96.
NUMERICAL MODELS DIVERGE AFTER TAU 36 AS THE SYSTEM DRIVES POLEWARD.
THE LARGE SPREAD IN SOLUTIONS LENDS OVERALL LOW CONFIDENCE TO THE
JTWC FORECAST TRACK.//
NNNN

[Hayabusa]

'94Wb' already a TD by JMA

'94Wb'

[aspen]

Microwave pass from 1600z shows a tiny eyewall trying to form, but is eroded slightly on the east side: http://rammb.cira.colostate.edu/product ... 261601.GIF

[Hayabusa]

WDPN31 PGTW 262100
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 29W (KAMMURI)
WARNING NR 005//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
TROPICAL STORM 29W (KAMMURI), LOCATED APPROXIMATELY 155 NM SOUTH
SOUTHWEST OF ANDERSEN AFB, GUAM, HAS TRACKED WESTWARD AT 17 KNOTS
OVER THE PAST SIX HOURS. ANIMATED ENHANCED INFRARED SATELLITE IMAGERY
DEPICTS A CONSOLIDATING SYSTEM WITH IMPROVED CONVECTIVE STRUCTURE AND
ROBUST POLEWARD OUTFLOW. A 261622Z AMSR2 89GHZ IMAGE DEPICTS SPIRAL
BANDING WRAPPING INTO A DEVELOPING MICROWAVE EYE FEATURE LENDING HIGH
CONFIDENCE TO THE INITIAL POSITION PLACEMENT. THE INITIAL INTENSITY
ESTIMATE OF 50KTS IS HEDGED SLIGHTLY ABOVE THE PGTW DVORAK CURRENT
INTENSITY ESTIMATE OF 3.0(45 KTS) BASED ON DEVELOPMENT OF A MICROWAVE
EYE FEATURE ON THE 261622Z AMSR2 89GHZ IMAGE. ENVIRONMENTAL ANALYSIS
REVEALS A FAVORABLE ENVIRONMENT FOR DEVELOPMENT WITH LOW TO MODERATE
(10-20KTS) VERTICAL WIND SHEAR (VWS) OFFSET BY STRONG POLEWARD
OUTFLOW ALOFT AND WARM (29-30C) SEA SURFACE TEMPERATURES (SST). A
RECENT SOUNDING AT GUAM (26/1200Z) INDICATES DEEP EASTERLY FLOW WITH
45-55KT GRADIENT WINDS. CONSEQUENTLY, TS 29W IS TRACKING QUICKLY
WESTWARD ALONG THE SOUTHERN PERIPHERY OF THE SUBTROPICAL RIDGE (STR).
3. FORECAST REASONING.
A. THERE IS NO SIGNIFICANT CHANGE TO THE FORECAST PHILOSOPHY FROM
THE PREVIOUS PROGNOSTIC REASONING MESSAGE.
B. TS 29W WILL CONTINUE ITS CURRENT TRACK UNDER THE STR THROUGH
TAU 24. A SHORTWAVE TROUGH TO THE NORTHWEST WILL WEAKEN THE STR AND
CAUSE 29W TO TRACK NORTH-NORTHWESTWARD TO NORTHWARD THROUGH TAU 72.
LOW VWS, COUPLED WITH WARM SST AND EXTREME UPPER-LEVEL DIVERGENCE
WILL ALLOW TS 29W TO RAPIDLY INTENSIFY THROUGH TAU 24 TO 75 KNOTS. AS
THE SYSTEM TURNS POLEWARD THE UPPER-LEVEL DIVERGENCE DECREASES
LEADING TO A MORE GRADUAL INTENSIFICATION, EVENTUALLY INTENSIFYING TO
105KTS BY TAU 72. NUMERICAL MODELS ARE IN GENERAL AGREEMENT WITH A
POLEWARD TURN BETWEEN TAUS 12 AND 24, HOWEVER THE TIMING IS AMONG THE
MODELS CONTINUES TO HAVE A LARGE SPREAD OF 120 NM LENDING LOW
CONFIDENCE TO THE OVERALL JTWC FORECAST TRACK PAST TAU 12.
C. AFTER TAU 72, TS 29W WILL SLOW SIGNIFICANTLY AS IT BEGINS TO
TRACK WESTWARD ALONG A SECONDARY, BUILDING STR TO THE NORTHWEST. WITH
LIMITED STEERING BETWEEN THE TWO STRS AT TAU 72 THERE IS POTENTIAL
FOR THE SYSTEM TO STALL PRIOR TO MAKING THE WESTWARD TURN. FAVORABLE
ENVIRONMENTAL CONDITIONS WILL ALLOW THE SYSTEM TO CONTINUE GRADUAL
INTENSIFICATION TO A PEAK INTENSITY OF 120KTS BY TAU 120. DUE TO
CONTINUED DIVERGENCE IN THE MODEL TRACKERS AFTER TAU 72 THERE IS LOW
CONFIDENCE IN THE LATTER PORTION OF THE JTWC FORECAST TRACK.//
NNNN

[aspen]

Lower resolution microwave pass from 19:10z also shows a tiny eyewall: http://rammb.cira.colostate.edu/product ... 261910.GIF

[Highteeld]

[Hayabusa]

Still not STS

TS 1928 (Kammuri)
Issued at 21:45 UTC, 26 November 2019

<Analysis at 21 UTC, 26 November>
Scale -
Intensity -
Center position N11°35' (11.6°)
E143°05' (143.1°)
Direction and speed of movement W 30 km/h (16 kt)
Central pressure 992 hPa
Maximum wind speed near center 23 m/s (45 kt)
Maximum wind gust speed 35 m/s (65 kt)
≥ 30 kt wind area N 560 km (300 NM)
S 330 km (180 NM)

[aspen]

It seems like a very tiny core and eye are trying to form, and the center of Kammuri appears to be slightly further south at 11.0 N instead of 11.5 N.

[mrbagyo]

Morning rapidscan loop

[Hayabusa]

29W KAMMURI 191127 0000 11.7N 142.3E WPAC 55 986

[aspen]

Best track has been changed to 45 kt, but the pressure remains the same.

[TyphoonNara]

Best track has been changed to 45 kt, but the pressure remains the same.

And it has just been changed back to 55kt.

[dexterlabio]

I think the slowdown is already happening.

[Highteeld]