WDIO31 PGTW 152100
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL CYCLONE 07A (SEVEN) WARNING NR 
005//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 14.0N 65.7E
   INITIAL INTENSITY: 35 KTS
   GEOGRAPHIC REFERENCE: 551 NM SOUTHEAST OF MASIRAH ISLAND
   MOVEMENT PAST 6 HOURS: WESTWARD AT 08 KTS
   SIGNIFICANT WAVE HEIGHT: 12 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY DEPICTS AN
EXPOSED LOW LEVEL CIRCULATION CENTER (LLCC) APPROXIMATELY 55 NM TO
THE SOUTHWEST OF DEEP CONVECTION UNDER THE PRESENCE OF STRONG 20 TO
25 KNOT SOUTHWESTERLY VERTICAL WIND SHEAR (VWS). THIS ASSESSMENT IS
MIRRORED IN A 151724Z METOP AMSU-B MICROWAVE IMAGE. THE
ACCOMPANYING ASCAT DATA DEPICTS A WELL DEFINED SURFACE CIRCULATION
WITH A BROAD FIELD OF 30 KNOT WINDS CONSTRAINED TO THE NORTHERN
SEMICIRCLE. THE INITIAL POSITION IS BASED ON THIS ASCAT PASS WITH
HIGH CONFIDENCE. THE INITIAL INTENSITY WAS ROUNDED UP TO 35 KNOTS
ACCOUNTING FOR SENSOR BIAS, AND TAKING INTO ACCOUNT THE PGTW T2.5
DVORAK INTENSITY ESTIMATE AND AN ADT 33 KNOT VALUE. THE ENVIRONMENT
IS CHARACTERIZED AS UNFAVORABLE DUE TO THE VWS AND WEAK POLEWARD
OUTFLOW CHANNEL, DESPITE 27 DEGREE C SEA SURFACE TEMPERATURES.

INITIAL WIND RADII BASIS: 151724Z ASCAT-B SCATTEROMETER DATA WITH
GOOD CONFIDENCE 

CURRENT STEERING MECHANISM: AN EXTENSION OF THE MID-LEVEL STEERING
RIDGE ANCHORED OVER CENTRAL INDIA

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T2.5 - 35 KTS
   DEMS: T2.0 - 30 KTS
   CIMSS ADT: 33 KTS AT 151815Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: UNFAVORABLE
   VWS: 20-25 KTS
   SST: 27-28 CELSIUS
   OUTFLOW: WEAK POLEWARD
   OTHER FACTORS: SIGNIFICANT MID-LEVEL DRY AIR OVER THE NORTH
ARABIAN SEA 

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

3. FORECAST REASONING.

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

FORECAST DISCUSSION: NOW THAT THE LLCC HAS BEEN DECOUPLED FROM DEEP
CONVECTION, UNFAVORABLE ENVIRONMENTAL CONDITIONS ARE EXPECTED TO
RESULT IN STEADY WEAKENING. TC 07A IS EXPECTED TO CONTINUE TRACKING
TO THE WEST ALONG LOW TO MID LEVEL STEERING FLOW, AND WEAKEN BELOW
TROPICAL STORM STRENGTH OVER THE NEXT 24 HOURS. THE REMNANT 
CIRCULATION MAY CONTINUE TO TRACK IN THE GENERAL DIRECTION OF SOCOTRA 
ISLAND.  

MODEL DISCUSSION: MODEL GUIDANCE IS IN GOOD AGREEMENT ON TRACK AND
THE EXPECTED DISSIPATION OVER WATER. CONSENSUS SPREAD AT TAU 24 IS
APPROXIMATELY 40 NM. 

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