WDIO31 PGTW 032100
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL CYCLONE 08B (MICHAUNG) WARNING 
NR 004//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 12.9N 81.8E
   INITIAL INTENSITY: 45 KTS
   GEOGRAPHIC REFERENCE: 693 NM SOUTHWEST OF KOLKATA, INDIA
   MOVEMENT PAST 6 HOURS: NORTHWESTWARD AT 08 KTS
   SIGNIFICANT WAVE HEIGHT: 19 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY DEPICTS A
CONSOLIDATING TROPICAL STORM STRENGTH CIRCULATION WITH FLARING
CONVECTION PARTIALLY OBSCURING THE LLCC AND DEEP CONVECTIVE BANDING
FEATURES TO THE NORTH AND WEST STRUGGLING TO MAINTAIN COHESION AS
THEY PASS OVER MAINLAND INDIA. A 031536Z AMSU-B 89GHZ MICROWAVE
IMAGE SHOWS A PARTIALLY EXPOSED LLCC WITH FRAGMENTED DEEP
CONVECTIVE BANDING FEATURES WRAPPING THE NORTHERN SEMICIRCLE WHILE
LOW LEVEL CLOUD LINES CAN BE SEEN AROUND THE LLCC. A PARTIAL
031539Z ASCAT-B SCATTEROMETERY PASS REVEALS A SLIGHTLY ELONGATED
CIRCULATION WITH A BELT OF 35-40 KT WINDS TO THE NORTHWEST OF THE
LLCC. THE INITIAL POSITION IS PLACED WITH HIGH CONFIDENCE BASED ON
EIR, AMSU-B AND ASCAT DATA. THE INITIAL INTENSITY OF 45 KTS IS
ASSESSED WITH HIGH CONFIDENCE BASED ON A PREPONDERANCE OF AUTOMATED
AND DVORAK INTENSITY ESTIMATES INDICATING 45KTS, FURTHER REINFORCED
BY THE PARTIAL ASCAT PASS.

INITIAL WIND RADII BASIS: PARTIAL SCATTEROMETER DATA 

CURRENT STEERING MECHANISM: DEEP-LAYERED SUBTROPICAL RIDGE (STR)
POSITIONED TO THE EAST AND NORTHEAST.

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T3.0 - 45 KTS
   KNES: T3.0 - 45 KTS
   DEMS: T2.5 - 35 KTS
   CIMSS ADT: 43 KTS AT 031500Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: FAVORABLE
   VWS: 5-10 KTS
   SST: 29-30 CELSIUS
   OUTFLOW: STRONG POLEWARD

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

3. FORECAST REASONING.

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

FORECAST DISCUSSION: TROPICAL CYCLONE 08B (MICHAUNG) IS FORECASTED
TO CONTINUE ITS GRADUAL MARCH TOWARDS SOUTHEASTERN INDIA IN A
FAVORABLE ENVIRONMENT. OVER THE NEXT 24 HOURS, FUELED BY LOW
VERTICAL WIND SHEAR (VWS), WARM SSTS AND STRONG OUTFLOW ALOFT, 08B
IS FORECASTED TO INTENSIFY TO ROUGHLY 60KTS. AS THE SYSTEM
APPROACHES THE AXIS OF THE STR, IT WILL BEGIN TO TURN DUE NORTH AND
JUST AFTER TAU 36, THE SYSTEM WILL MAKE LANDFALL OVER SOUTHEASTERN
INDIA NEAR 55KTS. NEAR TAU 48, AS 08B CONTINUES INLAND, VWS BEGINS
TO INCREASE AND 08B WEAKENS TO AROUND 40KTS. AFTER TAU 48,
TOPOGRAPHY BECOMES A MAJOR OBSTACLE AS THE SYSTEM ATTEMPTS TO
TRAVERSE THE EASTERN GHATS WHICH FURTHER WEAKENS THE SYSTEM AND
RESULTS IN ITS EVENTUAL DISSIPATION BY TAU 72.   

MODEL DISCUSSION: NUMERICAL MODELS ARE IN GOOD AGREEMENT, SHOWING A
100NM SPREAD IN SOLUTIONS AT THE TIME OF LANDFALL. AFTER LANDFALL,
THE MAJORITY OF MEMBERS TREND WITH THE JTWC FORECAST TRACK, THOUGH
COAMPS-TC AND NVGM INDICATE A MORE WESTWARD TRAJECTORY THROUGH
DISSIPATION. FOR THESE REASONS THE JTWC FORECAST TRACK IS PLACED
WITH OVERALL MEDIUM CONFIDENCE. RELIABLE MODEL INTENSITY GUIDANCE
IS IN GOOD AGREEMENT WITH A MAJORITY OF THE MEMBERS INDICATING
INTENSIFICATION THROUGH TAU 24 AFTER WHICH A GRADUAL DECLINE THAT
WORSENS WITH LANDFALL UNTIL DISSIPATION. FOR THESE REASONS, THE
JTWC INTENSITY FORECAST IS PLACED WITH OVERALL HIGH CONFIDENCE.

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