WPAC: CHABA - Post-Tropical

[1900hurricane]

65 kt is egregious.

[1900hurricane]

[Yellow Evan]

CDG is eye number of T7.0.... Not 65 knots.

[1900hurricane]

Little late there JTWC.

TPPN11 PGTW 012139

A. TYPHOON 21W (CHABA)

B. 01/2100Z

C. 19.27N

D. 132.09E

E. ONE/HMWRI8

F. T6.0/6.0/D3.5/24HRS STT: D2.0/03HRS

G. IR/EIR

H. REMARKS: 05A/PBO SML EYE/ANMTN. B EYE SURROUNDED BY CMG YIELDS AN
E# OF 6.5. SUBTRACTED .5 FOR EYE ADJUSTMENT TO YIELD A DT (NO
BANDING) OF 6.0. PT AGREES. MET YIELDS A 4.5. DBO DT.

I. ADDITIONAL POSITIONS: NONE

DREW

[1900hurricane]

[mrbagyo]

Must be atleast a cat 4.
The eye is still in the clearing out process, Chaba has a legitimate shot at cat 5.

[euro6208]

When Matthew was at 5.5 and 6.0, recon found winds of 125 to 135 knots. I'd go with 130 knots now.

[euro6208]

6.8 RAW.

CI# /Pressure/ Vmax
4.4 / 976.3mb/ 74.6kt


Final T# Adj T# Raw T#
4.4 4.4 6.8

[euro6208]

WOW.

[1900hurricane]

[euro6208]

105 knots is too low.

[NotoSans]

Looks like Chaba's intensity may have leveled off at the moment with the eye struggling to clear out. JTWC is still catching up with the storm - they have adjusted the 18Z intensity estimate to 75 knots and assess the current intensity at 105 knots. Still looks a bit conservative to me though.

JTWC has increased the forecast intensity to 135 knots as well, while JMA no longer forecasts any intensification and brings Chaba to Okinawa as a 90-knot typhoon (corresponding to 1-minute sustained winds of around 105 knots). Although Okinawa is frequently hit by tropical cyclones, a high-end cat 4 may still cause significant troubles there.

[Kingarabian]

Dormant EPAC's ACE lead about to evaporate shortly.

[dexterlabio]

Euro has been showing this to go bonkers once it moves closer to Okinawa... now that Chaba exploded into a major at this point, I wonder how much strong it could get.

[euro6208]

WDPN32 PGTW 020300
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TYPHOON 21W (CHABA) WARNING NR 17//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
TYPHOON (TY) 21W (CHABA), LOCATED APPROXIMATELY 462 NM
SOUTH-SOUTHEAST OF KADENA AB, OKINAWA, JAPAN, HAS TRACKED
NORTHWESTWARD AT 16 KNOTS OVER THE PAST SIX HOURS. ANIMATED
MULTISPECTRAL SATELLITE IMAGERY (MSI) SHOWS THE SYSTEM HAS RAPIDLY
DEEPENED AND BECOME MORE SYMMETRICAL AS FEEDER BANDS WRAPPED AND
COALESCED INTO THE SUPER-DEEP CENTRAL CONVECTION. THE INITIAL
POSITION IS BASED ON A SHARPLY OUTLINED 5-NM EYE IN THE MSI LOOP WITH
HIGH CONFIDENCE. THE INITIAL INTENSITY OF 105 KNOTS IS BASED ON
AGENCY DVORAK ESTIMATES RANGING FROM T5.5 TO T6.0 AND REFLECTS THE
RAPID INTENSIFICATION. TY 21W IS TRACKING IN A VERY FAVORABLE
ENVIRONMENT WITH STRONG DIFFLUENCE ALOFT, LOW (05-10 KNOT) VERTICAL
WIND SHEAR (VWS), AND VERY WARM (30C) SEA SURFACE TEMPERATURES
(SSTS). THE CYCLONE IS TRACKING ALONG THE SOUTHWESTERN PERIPHERY OF
THE DEEP-LAYERED SUBTROPICAL RIDGE (STR).
3. FORECAST REASONING.
A. THE FORECAST PEAK INTENSITY HAS BEEN RAISED TO 130 KNOTS AND
THE TRACK HAS BEEN WIDENED FURTHER WEST OF KADENA AB AND FURTHER
NORTH ALONG THE JAPANESE ISLANDS. OTHERWISE, NO SIGNIFICANT CHANGE TO
THE FORECAST PHILOSOPHY SINCE THE PREVIOUS PROGNOSTIC REASONING
BULLETIN.
B. TY 21W WILL CONTINUE NORTHWEST TO NORTH-NORTHWESTWARD OVER THE
NEXT 36 HOURS TOWARDS OKINAWA. AFTERWARDS, IT WILL ROUND THE STR AXIS
AND RE-CURVE TO THE NORTHEAST. ENVIRONMENTAL CONDITIONS WILL REMAIN
FAVORABLE FOR CONTINUED INTENSIFICATION IN THE NEAR TERM, PEAKING AT
135 KNOTS BY TAU 36 PARTLY DUE TO AN APPROACHING MID-LATITUDE TROUGH
THAT WILL FURTHER ENHANCE POLEWARD OUTFLOW. JUST BEFORE TAU 72, THE
CYCLONE WILL MAKE LANDFALL OVER NORTHERN KYUSHU, JAPAN NEAR SASEBO
AND BEGIN TO WEAKEN MOSTLY DUE TO INCREASING VWS AND LAND
INTERACTION.
C. IN THE EXTENDED FORECAST, TY CHABA WILL ACCELERATE
NORTHEASTWARD AND DRAG ACROSS THE RUGGED JAPANESE ISLAND CHAIN AND
RAPIDLY ERODE DUE TO LAND INTERACTION IN ADDITION TO STRONG (30-40
KNOT) VWS. CONCURRENTLY, THE SYSTEM WILL UNDERGO EXTRA-TROPICAL
TRANSITION (ETT) AND IS EXPECTED TO COMPLETE ETT BY THE END OF THE
FORECAST PERIOD AFTER IT TRACKS BACK INTO THE PACIFIC OCEAN SOUTH OF
MISAWA. DYNAMIC MODEL GUIDANCE IS IN GOOD AGREEMENT UP TO TAU 36,
AFTERWARDS, IT SPREADS SIGNIFICANTLY BOTH IN TERMS OF SPEED AND
DIRECTION. IN VIEW OF THIS, THERE IS LOW CONFIDENCE IN THE JTWC TRACK
FORECAST BEYOND TAU 36.//
NNNN

[euro6208]

Cat 4 for Okinawa.

WDPN32 PGTW 020900
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TYPHOON 21W (CHABA) WARNING NR 18//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
TYPHOON 21W (CHABA), LOCATED APPROXIMATELY 371 NM SOUTH-SOUTHEAST
OF KADENA AB, HAS TRACKED NORTHWESTWARD AT 16 KNOTS OVER THE PAST
SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) AND
ENHANCED INFRARED IMAGERY (EIR) SHOW AN ASYMMETRIC AREA OF DEEP
CONVECTION WRAPPING AROUND A RAGGED EYE. A 020706Z GMI 89GHZ
MICROWAVE IMAGE DEPICTS A LOW-LEVEL CIRCULATION CENTER THAT IS
PARTIALLY FILLED AND SURROUNDED BY DEEP CONVECTION. THE INITIAL
POSITION IS PLACED WITH HIGH CONFIDENCE BASED ON AN EYE FIX FROM MSI
AND EIR. THE INITIAL INTENSITY IS SET AT 110 KNOTS BASED ON DVORAK
ESTIMATES OF T6.0 FROM PGTW AND RJTD. THE CONVECTIVE STRUCTURE OF TY
CHABA HAS NOT IMPROVED OVER THE LAST 6 HOURS, INDICATING THAT THE
PERIOD OF INTENSIFICATION HAS PLATEAUED. ENVIRONMENTAL CONDITIONS
ARE FAVORABLE, WITH WARM SSTS (29C) AND LOW WIND SHEAR (10-15
KNOTS). POLEWARD OUTFLOW IS EXCELLENT, BUT IT IS SOMEWHAT RESTRICTED
TO THE EAST AND SOUTH. TY CHABA CONTINUES TO TRACK ALONG THE
SOUTHWESTERN PERIPHERY OF A DEEP-LAYERED SUBTROPICAL RIDGE (STR).
3. FORECAST REASONING.
A. NO SIGNIFICANT CHANGE TO THE FORECAST PHILOSOPHY SINCE THE
PREVIOUS PROGNOSTIC REASONING BULLETIN, EXCEPT FOR A SLIGHT DOWNWARD
ADJUSTMENT OF THE PEAK INTENSITY TO 125 KNOTS, GIVEN THE RECENT
CONVECTIVE EVOLUTION OF TY CHABA.
B. TY CHABA WILL CONTINUE TRACKING TOWARD THE NORTHWEST WITH A
GRADUAL TURN TOWARD THE NORTH-NORTHWEST OVER THE NEXT 24 HOURS AS IT
APPROACHES OKINAWA. IT WILL TURN TOWARD THE NORTH AFTER TAU 24 AND
RECURVE TO THE NORTHEAST BEYOND TAU 48 AS IT ROUNDS THE STR AXIS.
LANDFALL IN WESTERN KYUSHU IS FORECAST TO OCCUR AROUND TAU
60. ENVIRONMENTAL CONDITIONS WILL REMAIN FAVORABLE FOR CONTINUED
INTENSIFICATION IN THE NEAR TERM, PEAKING AT 125 KNOTS BY TAU 24,
PRIMARILY DRIVEN BY THE WARM SSTS AND EXCELLENT POLEWARD OUTFLOW
THAT MAY EVEN INCREASE AS TY CHABA TURNS NORTHWARD. HOWEVER, OUTFLOW
IS RESTRICTED IN OTHER QUADRANTS, ESPECIALLY TO THE EAST AND SOUTH,
SO IT APPEARS THAT THE EARLIER DEEPENING PHASE OF TY CHABA HAS
REACHED A TEMPORARY PEAK. IF THE CONVECTION REMAINS ASYMMETRIC
AROUND A RAGGED EYE, THEN THE FORECAST PEAK INTENSITY MAY NEED TO BE
LOWERED IN FUTURE WARNING CYCLES.
C. IN THE EXTENDED TAUS, TY CHABA WILL ACCELERATE NORTHEASTWARD
AND WEAKEN DUE TO LAND INTERACTION WITH JAPAN. EXTRATROPICAL
TRANSITION IS FORECAST TO BEGIN AROUND TAU 72, WITH THE STORM
EXITING THE EASTERN COAST OF JAPAN SOUTH OF MISAWA AND BECOMING
FULLY EXTRATROPICAL BY TAU 96. DYNAMIC MODEL GUIDANCE IS IN GOOD
AGREEMENT THROUGH TAU 36, BUT THE TIMING OF THE RECURVE TOWARD THE
NORTHEAST AND EVENTUAL LANDFALL POSITION IS STILL HIGHLY UNCERTAIN
AT THIS TIME. THUS, THERE IS LOW CONFIDENCE IN THE JTWC TRACK
FORECAST BEYOND TAU 36.//
NNNN

[euro6208]

[euro6208]

GFS peaks this at 930 mb as it makes it's approach to Okinawa and does something we rarely see. Passes between South Korea and Japan right through Tsushima Island and making landfall over Western Honshu.

[euro6208]

Pretty sad how this got to 6.0 from PGTW and peak still under the value of 115 knots.

Matthew and many other atlantic storms led all dvorak estimates by a huge mile. dvorak is nothing.

Can't wait till the world's most active and powerful basin gets recon.

[1900hurricane]

Man, once the fully clears out...