WPAC: KAMMURI - Post-Tropical

[aspen]

It looks like a band is forming in the northern quadrant. An additional sign that Kammuri’s structure is improving?

[aspen]

If Kammuri’s internal structure is ever going to improve, it will need to lose that enormous but rather impressive CCC. This may happen tonight (in EST), or it could happen tomorrow, as diurnal max could cause multiple hot towers to pop up.

[Hayabusa]

WDPN31 PGTW 300300
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TYPHOON 29W (KAMMURI) WARNING NR 018//
RMKS/
1. FOR METEOROLOGISTS.
2. TYPHOON 29W (KAMMURI), LOCATED APPROXIMATELY 885 NM EAST
OF MANILA, PHILIPPINES, HAS TRACKED WESTWARD AT 11 KNOTS OVER THE
PAST SIX HOURS. ANIMATED ENHANCED INFRARED SATELLITE IMAGERY REVEALS
AN ASYMMETRIC CENTRAL DENSE OVERCAST (CDO) OBSCURING THE LOW LEVEL
CIRCULATION CENTER (LLCC). THERE IS FAIR CONFIDENCE IN THE INITIAL
POSITION BASED ON AN ELONGATED LLCC APPARENT IN A 300101Z METOP-B
ASCAT PASS. A 292152Z SSMIS 37GHZ IMAGE REVEALED A BROAD, ILL-
DEFINED MICROWAVE EYE FEATURE WITH THE MAJORITY OF THE CONVECTION
SHEARED TO THE WEST AND WRAPPING INTO THE CENTER. MULTI-AGENCY
DVORAK CURRENT INTENSITY ESTIMATES OF T4.5 (77 KTS) FROM PGTW AND
RCTP, AND T5.5 (102 KNOTS) FROM RJTD, ARE WELL ABOVE A 300140Z ADT
ESTIMATE OF 63 KNOTS, GIVING LOW CONFIDENCE TO THE INITIAL INTENSITY
OF 75 KNOTS, WHICH IS BASED ON THE SUSTAINED OBLONG CDO STRUCTURE.
THE AFOREMENTIONED ASCAT PASS SHOWED A BROAD AREA OF 45-49 KT WINDS
TO THE WEST, AND SOME 50 KT WIND BARBS. AFTER 50 KTS, HOWEVER,
SCATTEROMETRY BECOMES LESS ACCURATE DUE TO THE ROUGH SEAS, SO THERE
COULD POSSIBLY BE HIGHER WINDS. LOW TO MODERATE (15-20 KNOTS)
VERTICAL WIND SHEAR IS CURRENTLY HINDERING ORGANIZATION AND
INTENSIFICATION. HOWEVER, FAIR WESTWARD AND EXCELLENT POLEWARD
OUTFLOW AND WARM (28-29 CELSIUS) SEA SURFACE TEMPERATURES HAVE
ALLOWED THE CDO TO GROW TO OVER 300 NM WIDE. TY 29W IS TRACKING
ALONG THE SOUTHEASTERN PERIPHERY OF A SUBTROPICAL RIDGE (STR)
POSITIONED TO THE NORTHWEST, AND HAS ACCELERATED WEST-SOUTHWESTWARD
OVER THE PAST 6 HOURS AS THAT STR BUILDS IN TO WHAT WAS A WEAK
STEERING ENVIRONMENT BETWEEN TWO STRS.
3. FORECAST REASONING.
A. THERE IS NO SIGNIFICANT CHANGE TO THE FORECAST PHILOSOPHY FROM
THE LAST PROGNOSTIC REASONING MESSAGE.
B. THROUGH TAU 36, TY 29W WILL CONTINUE WEST-SOUTHWESTWARD TO
WESTWARD WITH THE STR POSITIONED TO THE NORTHWEST AS THE PRIMARY
STEERING INFLUENCE. AFTER TAU 36, A PASSING SHORTWAVE TROUGH TO THE
NORTH ERODES THE WESTERN STR AND CAUSES A SUBTROPICAL RIDGE TO THE
NORTHEAST TO RE-ORIENT AND BECOME THE PREDOMINANT STEERING
MECHANISM. THIS BREAK IN THE STR WILL ALLOW FOR ENHANCED POLEWARD
OUTFLOW AND REDUCED VWS, AND TY 29W WILL INTENSIFY TO A PEAK OF 100
KTS BY TAU 48. SHORTLY THEREAFTER, THE STEERING STR TO THE NORTHEAST
BUILDS IN, OUTFLOW WILL WANE, AND TY 29W WILL BEGIN TO ENCOUNTER DRY
AIR FROM THE SURFACE NORTHEASTERLY SURGE, BEGINNING A WEAKENING
TREND BY TAU 72. THERE IS STRONG AGREEMENT IN MODEL TRACK GUIDANCE,
LENDING HIGH CONFIDENCE TO THIS PORTION OF THE TRACK FORECAST.
HOWEVER, THERE IS SIGNIFICANT SPREAD IN INTENSITY FORECASTS. HWRF
PEAKS 29W FAR ABOVE THE MULTI-MODEL INTENSITY CONSENSUS, AS DOES
ECMWF. THE INTERPOLATED ECMWF ENSEMBLE MEAN AND GFS SOLUTIONS
PRESENT A MORE MODEST INTENSIFICATION SCENARIO, ALTHOUGH BOTH STILL
EXCEED THE MULTI-MODEL INTENSITY CONSENSUS BY 5-15 KTS. THE JTWC
INTENSITY FORECAST IS HEDGED SLIGHTLY ABOVE THE MULTI-MODEL
INTENSITY FORECAST, BUT WITHIN THE 70% PROBABILITY CURVE. THE
UNCERTAINTY IN CURRENT INTENSITY CONTRIBUTES TO UNCERTAINTY IN THE
JTWC INTENSITY FORECAST AS WELL.
C. AROUND TAU 72, TY 29W WILL CONTINUE TO TRACK WESTWARD TO WEST-
NORTHWESTWARD AND MAKE LANDFALL EAST OF MANILA, PHILIPPINES. TY 29W
WILL CONTINUE TO TRACK WESTWARD INTO THE SOUTH CHINA SEA. TY 29W
WILL WEAKEN MORE RAPIDLY AFTER TAU 72 DUE TO FRICTIONAL EFFECTS FROM
THE RUGGED TERRAIN OF LUZON AND DRY AIR ENTRAINMENT FROM THE
NORTHEASTERLY SURFACE SURGE. MODEL TRACK GUIDANCE REMAINS IN STRONG
AGREEMENT THROUGH THE REMAINDER OF THE FORECAST AND CONFIDENCE IN
THIS PORTION OF FORECAST TRACK IS HIGH.//
NNNN

[1900hurricane]

This might be the most textbook CCC I've ever seen.

[ejeraldmc]

This CCC looks ominous.

[aspen]

While I have been using the term, what exactly is a CCC, and how does it differ from a CDO in terms of the storm’s internal structure?

[dexterlabio]

Guessing game where the real center is located in that enormous blob of convection.

[1900hurricane]

CCC, or Central Cold Cover, is when a huge cold cirrus shield obscures the TC structure. It seems to be related to shear just below the anvil layer and is a sign of interrupted TC development. Worth noting that a CCC and CDO may look similar, but are actually rather different. You can read a little about CCCs here.

With Kammuri, you can see the undercutting shear coming in from the ESE fairly clearly on a water vapor loop. Notice how the flow comes towards and then appears to slip beneath the large cloud shield.

[Hayabusa]

It's extremely cold

2019NOV30 031000 3.9 979.8 63.0 3.8 3.8 3.8 NO LIMIT ON OFF OFF OFF -84.94 -86.10 UNIFRM N/A 1.2 13.43 -135.59 ARCHER HIM-8 16.8
2019NOV30 034000 3.9 979.6 63.0 3.8 3.7 3.7 NO LIMIT ON OFF OFF OFF -85.24 -85.58 UNIFRM N/A 1.2 13.90 -135.59 FCST HIM-8 17.3

[dexterlabio]

I suppose shear out there is brutal Kammuri is starting to look like a rubber duck

[Hayabusa]

Aggressive forecast from CMA

[NotoSans]

 https://twitter.com/philipslau681/status/1200659418670518273

[1900hurricane]

 https://twitter.com/1900hurricane/status/1200683869156065280

[Hayabusa]

It seems to be being squeezed

[Hayabusa]

[doomhaMwx]

Intensity slightly lowered to 70kts at 06Z by JTWC.



Estimates of 75kts within the last 24hrs were also revised to 70kts.

29W KAMMURI 191130 0600 13.6N 135.3E WPAC 70 976
29W KAMMURI 191130 0000 13.9N 136.2E WPAC 70 976
29W KAMMURI 191129 1800 14.1N 137.1E WPAC 70 977
29W KAMMURI 191129 1200 14.1N 137.9E WPAC 70 975
29W KAMMURI 191129 0600 14.3N 138.0E WPAC 70 977

[ManilaTC]

Eye appearing to close off now.

[Highteeld]

The euro is completely locked in on a cat 5 landfall

[mrbagyo]

JMA slightly lowered the anticipated peak.
95 knots - 935mb

[aspen]

There goes the CCC. Will we see some more structural improvements today?