WDIO31 PGTW 041500
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL CYCLONE 08B (MICHAUNG)
WARNING NR 007//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 13.8N 80.8E
   INITIAL INTENSITY: 60 KTS
   GEOGRAPHIC REFERENCE: 683 NM SOUTHWEST OF KOLKATA, INDIA
   MOVEMENT PAST 6 HOURS: NORTHWESTWARD AT 05 KTS
   SIGNIFICANT WAVE HEIGHT: 24 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
AS DEPICTED IN ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY AND
RADAR IMAGERY, TROPICAL CYCLONE (TC) 08B HAS CONTINUED TO CONSOLIDATE
WITH TIGHTLY-CURVED BANDING WRAPPING INTO A FORMATIVE RAGGED EYE.
THEREFORE, THERE IS HIGH CONFIDENCE IN THE INITIAL POSITION. A
041226Z SSMIS 37 GHZ COLOR COMPOSITE MICROWAVE IMAGE REVEALS A CYAN
RING SURROUNDING A WELL-DEFINED MICROWAVE EYE. CONSEQUENTLY, THE PGTW
DVORAK INTENSITY ESTIMATE HAS INCREASED TO T4.0 (65 KNOTS). THE KNES
FINAL-T ESTIMATE IS CURRENTLY AT T4.0 AS WELL (CURRENT INTENSITY IS
AT 4.5 (77 KNOTS)). THE INITIAL INTENSITY IS ASSESSED SLIGHTLY LOWER
THAN 65 KNOTS BASED ON THE CIMSS OBJECTIVE INTENSITY ESTIMATES
RANGING FROM 51 KNOTS TO 67 KNOTS.

INITIAL WIND RADII BASIS: PERSISTENCE

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

AGENCY DVORAK AND AUTOMATED FIXES:
   PGTW: T4.0 - 65 KTS
   KNES: T4.0 - 65 KTS
   CIMSS SATCON: 56 KTS AT 041030Z
   CIMSS ADT: 51 KTS AT 041300Z
   CIMSS AIDT: 55 KTS AT 041300Z
   CIMSS DPRINT: 55 KTS AT 041300Z
   CIMSS DMINT: 67 KTS AT 041229Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: FAVORABLE
   VWS: 5-10 KTS
   SST: 28-29 CELSIUS
   OUTFLOW: STRONG POLEWARD

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.

FORECAST DISCUSSION: TROPICAL CYCLONE (TC) 08B IS FORECAST TO TRACK
POLEWARD ALONG THE WESTERN PERIPHERY OF A NORTH-SOUTH ORIENTED STR
THROUGH TAU 48. THE SYSTEM SHOULD INTENSIFY SLIGHTLY OVER THE NEXT
12 HOURS DUE TO THE FAVORABLE ENVIRONMENTAL CONDITIONS, WITH A PEAK
OF 65 KNOTS ANTICIPATED BY TAU 12. AFTER TAU 12, TC 08B WILL
GRADUALLY WEAKEN AS IT SKIRTS THE EASTERN COAST OF INDIA WITH
LANDFALL EXPECTED NEAR TAU 24. AFTER LANDFALL, THE SYSTEM WILL
RAPIDLY WEAKEN AND DISSIPATE AS IT TRACKS INLAND AND RECURVES
NORTHEASTWARD, INTERACTING WITH THE MIDLATITUDE WESTERLIES AND
INCREASING VERTICAL WIND SHEAR. THE REMNANTS COULD POSSIBLY TRACK
OVER THE NORTHERN BAY OF BENGAL AFTER DAY 4 BUT ARE NOT EXPECTED TO
REGENERATE DUE TO UNFAVORABLE CONDITIONS AND STRONG UPPER-LEVEL
WESTERLIES.

MODEL DISCUSSION: BOTH DETERMINISTIC AND PROBABILISTIC GUIDANCE ARE
IN GOOD AGREEMENT THROUGH TAU 48. THERE IS CURRENTLY A 35 NM CROSS-
TRACK SPREAD IN NUMERICAL GUIDANCE FROM TAU 12 TO TAU 24. AFTER TAU
24, GUIDANCE DIVERGES SLIGHTLY BUT REMAINS IN GOOD AGREEMENT.
THEREFORE, THERE IS HIGH OVERALL CONFIDENCE IN THE JTWC TRACK
FORECAST. THE JTWC INTENSITY FORECAST IS SUPPORTED BY RELIABLE
INTENSITY GUIDANCE INCLUDING THE HAFS-A AND COAMPS-TC MESOSCALE MODEL
GUIDANCE.

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