WDIO31 PGTW 130300
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL CYCLONE 01B (MOCHA) WARNING NR 
009//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 15.3N 89.1E
   INITIAL INTENSITY: 115 KTS
   GEOGRAPHIC REFERENCE: 440 NM SOUTH OF KOLKATA, INDIA
   MOVEMENT PAST 6 HOURS: NORTHEASTWARD AT 05 KTS
   SIGNIFICANT WAVE HEIGHT: 49 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) DEPICTS A BROAD
SYSTEM WITH A CLOUD-FILLED EYE SURROUNDED BY BANDS OF DEEP
CONVECTION IN ALL QUADRANTS WRAPPING INTO THE LOW LEVEL CIRCULATION
CENTER (LLCC). A 122358Z SSMIS 91 GHZ IMAGE SHOWS THE BULK OF THE
CONVECTION IS IN THE WESTERN AND SOUTHERN QUADRANTS OF THE SYSTEM
ALONG WITH A WELL DEFINED MICROWAVE EYE. ANALYSIS OF MULTI-AGENCY
130000Z POSITIONS COMPARED TO PREVIOUS POSITIONS SUGGESTS THE
SYSTEM HAS NOW WOBBLED EQUATORWARD. THIS BEHAVIOR IS INDICATIVE OF
A RAPIDLY STRENGTHENING SYSTEM. IN ADDITION, ANALYSIS OF THE
122203Z M-PERC EYEWALL REPLACEMENT TOOL SUGGESTS AN EYEWALL
REPLACEMENT CYCLE (ERC) HAS TAKEN PLACE. ONE MAJOR CONTRIBUTING
FACTOR TO THE INITIAL INTENSITY IS AN INTENSE POOL OF OCEAN HEAT
CONTENT (OHC) THAT HAS DOMINATED THE CENTRAL BAY OF BENGAL OVER THE
PAST SEVERAL DAYS. TC MOCHA IS IN A MARGINALLY FAVORABLE
ENVIRONMENT FOR FURTHER TROPICAL DEVELOPMENT. THESE CONDITIONS ARE
CHARACTERIZED BY ROBUST RADIAL OUTFLOW ALOFT, A STRONG 850 MB
VORTICITY SIGNATURE, MODERATE (15-20 KTS) VERTICAL WIND SHEAR
(VWS), AND VERY WARM (30-31 C) SEA SURFACE TEMPERATURES (SST). THE
INITIAL POSITION IS PLACED WITH HIGH CONFIDENCE BASED ON
MULTI-AGENCY FIXES, AS WELL AS THE AFOREMENTIONED MSI IMAGERY. THE
INITIAL INTENSITY OF 115 KNOTS IS ASSESSED WITH MEDIUM CONFIDENCE
BASED OFF A BLEND OF MULTI-AGENCY DVORAK ESTIMATES.

INITIAL WIND RADII BASIS: PERSISTENCE 

CURRENT STEERING MECHANISM: SUBTROPICAL RIDGE (STR) TO THE EAST

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T6.0 - 115 KTS
   KNES: T6.5 - 127 KTS
   DEMS: T5.5 - 102 KTS
   CIMSS SATCON: 108 KTS AT 122011Z
   CIMSS ADT: 112 KTS AT 122100Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: MARGINALLY FAVORABLE
   VWS: 15-20 KTS
   SST: 30-31 CELSIUS
   OUTFLOW: STRONG RADIAL
   OTHER FACTORS: HIGH OCEAN HEAT CONTENT (OHC) AND EYEWALL
REPLACEMENT CYCLE (ERC)

ANALYSIS CONFIDENCE:
   INITIAL POSITION: HIGH
   INITIAL INTENSITY: MEDIUM
   INITIAL WIND RADII: LOW

3. FORECAST REASONING.

SIGNIFICANT FORECAST CHANGES: THERE ARE NO SIGNIFICANT CHANGES TO
THE FORECAST FROM THE PREVIOUS WARNING.

TC 01B (MOCHA) IS RIDING THE WESTERN PERIPHERY OF THE STR TO THE EAST. 
THROUGH TAUS 12 AND 24, TC 01B WILL TRACK NORTHEASTWARD AND CONTINUE 
TO INTENSIFY TO 120 KTS. THERE IS THE POSSIBILITY TC 01B WILL REACH A 
MAXIMUM INTENSITY OF 125 KNOTS BEFORE TAU 24 DUE TO THE FAVORABLE 
ENVIRONMENT, HOWEVER IT WILL BE SHORT LIVED AS THE SYSTEM WILL TRACK 
INTO LESS FAVORABLE CONDITIONS. AFTER TAU 24, PRIOR TO LANDFALL JUST 
SOUTH OF THE BANGLADESH AND MYANMAR BORDER, TC MOCHA WILL DECREASE IN 
INTENSITY TO 100 KNOTS AS THE ENVIRONMENT WILL BECOME LESS FAVORABLE. 
THESE LESS FAVORABLE CONDITIONS ARE DEFINED BY AN INCREASE IN VWS, DRY 
AIR ENTRAINMENT WRAPPING INTO THE LLCC FROM THE SOUTHERN PERIPHERY, 
THE ONSET OF LAND INTERACTION, AND COOLER (28-29 C) SST. BY TAU 30, TC 
01B WILL MAKE LANDFALL AND BEGIN ITS DISSIPATION PHASE. THROUGH TAUS 
36 AND 48, TC MOCHA WILL DISSIPATE DUE TO LAND INTERACTION OVER 
NORTHWEST MYANMAR.  

MODEL DISCUSSION: THE DETERMINISTIC AND ENSEMBLE MODELS ALL AGREE
THAT TC 01B WILL CONTINUE TO INTENSIFY AS IT TRANSITS NORTHEASTWARD
THROUGH TAU 24, THEN WEAKEN ON OR BEFORE TAU 30 AS IT CONTINUES THE
SAME TRAJECTORY. THE JTWC FORECAST TRACK CONSENSUS MEMBERS ARE IN
TIGHT AGREEMENT WITH A 36 NM SPREAD AT TAU 12 THAT GRADUALLY
INCREASES TO 87 NM JUST BEFORE LANDFALL. THE GFS, ECMWF AND NAVGEM
TRACKS ARE ON THE POLEWARD SIDE OF THE CONSENSUS ENVELOPE, WHEREAS
THE UK AND AFUM SOLUTIONS ARE ON THE EQUATORWARD SIDE. DUE TO THIS,
THE JTWC TRACK IS PLACED WITH HIGH CONFIDENCE SLIGHTLY LEFT OF
CONSENSUS THROUGHOUT THE FORECAST PERIOD. THE JTWC INTENSITY
CONSENSUS IS ALSO IN GOOD AGREEMENT WITH ALL SOLUTIONS INDICATING A
DECREASE IN INTENSITY PRIOR TO LANDFALL. THE GFS INTENSITY GUIDANCE
IS THE OUTLIER SHOWING LOWER VALUES THROUGHOUT THE FORECAST PERIOD.
THE JTWC INTENSITY FORECAST IS SET WITH MEDIUM CONFIDENCE DUE TO
THE SPREAD IN THE CONSENSUS MEMBERS AND THE RAPID INTENSIFICATION
SCENARIO.

FORECAST CONFIDENCE:
   TRACK 0 - 72 HR: HIGH
   INTENSITY 0 - 72 HR: MEDIUM//
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