WDIO31 PGTW 141500
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL CYCLONE 02A (BIPARJOY) WARNING 
NR 034//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 22.0N 66.7E
   INITIAL INTENSITY: 70 KTS
   GEOGRAPHIC REFERENCE: 169 NM SOUTH OF KARACHI, PAKISTAN
   MOVEMENT PAST 6 HOURS: NORTHEASTWARD AT 04 KTS
   SIGNIFICANT WAVE HEIGHT: 29 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) DEPICT A MASS OF
CONVECTION BEING DISPLACED TO THE SOUTHWEST OF A PARTIALLY EXPOSED
LOW LEVEL CIRCULATION CENTER (LLCC). A PARTIAL 141042Z SSMIS 37 GHZ
IMAGE REVEALS AN OPENED MICROWAVE EYE FEATURE WITH THE DEEPEST
CONVECTION IN THE SOUTHERN SEMI-CIRCLE OF THE LLCC. TC BIPARJOY IS
IN AN UNENDEARING ENVIRONMENT FOR FURTHER TROPICAL ACTIVITY. THESE
CONDITIONS ARE CHARACTERIZED BY MODERATE WESTWARD OUTFLOW ALOFT, A
STRONG 850 MB VORTICITY SIGNATURE, VERY WARM (29-30 C) SEA SURFACE
TEMPERATURES (SST), OFFSET BY UNFAVORABLE (20-25 KTS) VERTICAL WIND
SHEAR (VWS). MOREOVER, AS A RESULT OF THE PREVIOUS QUASI-STATIONARY
BEHAVIOR, THERE IS UPWELLING TO THE SOUTHEAST OF THE LLCC WHICH IS
COOLING THE SURFACE AIR NEAR THE CORE. THE INITIAL POSITION IS
PLACED WITH HIGH CONFIDENCE BASED ON MULTI-AGENCY FIXES, ALONG WITH
THE AFOREMENTIONED MSI REVEALING THE EXPOSED LLCC. THE INITIAL
INTENSITY OF 70 KNOTS IS ASSESSED WITH MEDIUM CONFIDENCE SET
SLIGHTLY HIGHER THAN THE SUBJECTIVE AND AUTOMATED DVORAKS.

INITIAL WIND RADII BASIS: PERSISTENCE 

CURRENT STEERING MECHANISM: SUBTROPICAL RIDGE TO THE EAST-SOUTHEAST

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T4.0 - 65 KTS
   KNES: T4.0 - 65 KTS
   CIMSS SATCON: 64 KTS AT 140903Z
   CIMSS ADT: 45 KTS AT 141200Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: MARGINALLY FAVORABLE
   VWS: 25-30 KTS
   SST: 29-30 CELSIUS
   OUTFLOW: MODERATE WESTWARD
   OTHER FACTORS: DRY AIR ENTRAINMENT AND UPWELLING

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

3. FORECAST REASONING.

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

FORECAST DISCUSSION: TC 02A (BIPARJOY) CONTINUES TO BATTLE ITS
ENVIRONMENT AS IT RIDES THE WESTERN EDGE OF THE STR TO THE EAST. BY
TAU 12, THE SYSTEM WILL DECREASE IN INTENSITY TO 60 KNOTS AS A
RESULT OF MORE DRY AIR ENTRAINMENT FROM THE NORTHEAST AND THE
CONTINUED EFFECTS OF THE PREVIOUSLY STATED UPWELLING. BY TAU 24, TC
02A WILL CONTINUE TO DECREASE IN INTENSITY TO 55 KNOTS DUE TO LAND
INTERACTION BEFORE MAKING LANDFALL NEAR THE INDIA-PAKISTAN BORDER.
THROUGH TAUS 36 AND 48, TC 02A WILL DISSIPATE INLAND OVER NORTHERN
INDIA.

MODEL DISCUSSION: THE DETERMINISTIC AND ENSEMBLE MODELS ARE ALL IN
TIGHT AGREEMENT THAT TC BIPARJOY WILL TRACK NORTHEASTWARD WHILE
RIDING THE NORTHWESTERN PERIPHERY OF THE STR TO THE EAST. THERE IS
A 41 NM SPREAD AMONG THE MEMBERS ALONG THE COAST. DUE TO THIS, THE
JTWC FORECAST TRACK IS SET ALONG WITH CONSENSUS WITH HIGH
CONFIDENCE. THE JTWC INTENSITY CONSENSUS MEMBERS ALL AGREE WITH A
DECAYING TREND THROUGH AFTER TAU 12 AS THE SYSTEM TRANSITS CLOSER
TO LAND. THE JTWC INTENSITY FORECAST IS SET WITH HIGH CONFIDENCE
THROUGHOUT THE FORECAST PERIOD.

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