WDIO31 PGTW 112100
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL CYCLONE 01B (MOCHA) WARNING NR 
004//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 12.8N 88.1E
   INITIAL INTENSITY: 60 KTS
   GEOGRAPHIC REFERENCE: 618 NM SOUTH-SOUTHWEST OF COX'S BAZAR
   MOVEMENT PAST 6 HOURS: NORTHWARD AT 08 KTS
   SIGNIFICANT WAVE HEIGHT: 27 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY DEPICTS A
GRADUALLY IMPROVING CONVECTIVE SIGNATURE ASSOCIATED WITH TROPICAL
CYCLONE 01B (MOCHA). DEEP CONVECTION IS FLARING AROUND AND OVER THE
LOW-LEVEL CIRCULATION CENTER (LLCC) WITH A RAGGED EYE STRUCTURE
OCCASIONALLY APPEARING. THE INITIAL POSITION IS PLACED WITH HIGH
CONFIDENCE BASED ON A DEFINED MICROWAVE EYE IN THE 1115530Z AMSU-B
89GHZ MICROWAVE IMAGE. THE INITIAL INTENSITY IS ASSESSED WITH
MEDIUM CONFIDENCE BASED ON A BLEND OF AGENCY DVORAK ESTIMATES AND
AN EARLIER 111200Z SMAP PASS DEPICTING A SWATH OF 55-60 KNOTS IN
THE SOUTHERN SEMICIRCLE. THE ENVIRONMENT IS FAVORABLE WITH MODERATE
VERTICAL WIND SHEAR (10 TO 15 KNOTS), GOOD RADIAL OUTFLOW
RESTRICTED ONLY TO THE EAST, AND WARM SEA SURFACE TEMPERATURES (30
TO 31 DEGREES C).

INITIAL WIND RADII BASIS: SCATTEROMETER DATA 

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

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T3.5 - 55 KTS
   KNES: T4.0 - 65 KTS
   DEMS: T3.5 - 55 KTS
   CIMSS ADT: 55 KTS AT 111800Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: FAVORABLE
   VWS: 10-15 KTS
   SST: 30-31 CELSIUS
   OUTFLOW: MODERATE RADIAL

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

3. FORECAST REASONING.

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

FORECAST DISCUSSION: TROPICAL CYCLONE MOCHA IS CURRENTLY TRACKING
TOWARD THE NORTH AND WILL SOON BEGIN TO TURN TOWARD THE NORTHEAST
AS IT IS STEERED BY A DEEP-LAYER SUBTROPICAL RIDGE (STR) TO THE
EAST. AS IT DOES SO, THE ENVIRONMENT WILL BECOME INCREASINGLY
FAVORABLE FOR CONTINUED INTENSIFICATION. WITH LOW VERTICAL WIND
SHEAR, WARM SEA SURFACE TEMPERATURES, AND GOOD OUTFLOW, RAPID
INTENSIFICATION IS LIKELY TO OCCUR. PEAK INTENSITY IN THE OFFICIAL
FORECAST HAS BEEN RAISED TO 110 KNOTS AT TAU 60, BUT THE ACTUAL
PEAK INTENSITY OF TROPICAL CYCLONE MOCHA WILL LIKELY OCCUR BETWEEN
TAU 60 AND 72 BEFORE LANDFALL, SO THE PEAK INTENSITY MAY NEED TO BE
RAISED FURTHER IN FUTURE WARNING CYCLES AS THE TAU 60 POINT
APPROACHES THE COAST. LANDFALL IS EXPECTED PRIOR TO TAU 72 NEAR THE
BORDER OF BANGLADESH AND MYANMAR. AFTER LANDFALL, RAPID DISSIPATION
OF THE SYSTEM IS EXPECTED AS IT INTERACTS WITH THE RUGGED TERRAIN
OF MYANMAR.

MODEL DISCUSSION: NUMERICAL MODELS ARE IN GOOD AGREEMENT WITH A
CROSS-TRACK SPREAD OF ONLY 100 NM AT LANDFALL, LENDING HIGH
CONFIDENCE TO THE JTWC FORECAST UP TO THAT POINT. AFTERWARD, THE
MODEL ENVELOPE INCREASES DUE TO LAND INTERACTION, SO THERE IS
MEDIUM CONFIDENCE IN THE EXACT TRACK OF THE LLCC BEYOND TAU 72. THE
INTENSITY FORECAST CONFIDENCE IS ASSESSED AT MEDIUM THROUGH THE
FORECAST PERIOD BECAUSE OF THE UNCERTAINTIES ASSOCIATED WITH THE
TIMING OF THE LIKELY ONSET OF RAPID INTENSIFICATION, BUT STEADY
INTENSIFICATION THROUGH THE HOURS JUST PRIOR TO LANDFALL IS
EXPECTED.

FORECAST CONFIDENCE:
   TRACK 0 - 72 HR: HIGH
   TRACK 72-120 HR: MEDIUM
   INTENSITY 0 - 72 HR: MEDIUM
   INTENSITY 72-120 HR: MEDIUM//
NNNN