WDXS31 PGTW 112100
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL CYCLONE 03S (BLOSSOM) WARNING 
NR 007//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 9.0S 62.8E
   INITIAL INTENSITY: 35 KTS
   GEOGRAPHIC REFERENCE: 587 NM WEST-SOUTHWEST OF DIEGO GARCIA
   MOVEMENT PAST 6 HOURS: NORTHWESTWARD AT 05 KTS
   SIGNIFICANT WAVE HEIGHT: 14 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY DEPICTS A VERY
COMPACT, AND INCREASINGLY DISORGANIZED SYSTEM, WITH THE NORTHERN
HALF OF THE LOW LEVEL CIRCULATION CENTER (LLCC) FULLY EXPOSED DUE
TO PERSISTENT NORTHEASTERLY SHEAR AND DRY MID-LEVEL AIR. MODERATE
CONVECTION HAS CONTINUED TO FLARE ON A CYCLIC BASIS OVER THE PAST
24 HOURS, DEVELOPING ALONG THE SOUTHWESTERN FLANK IN THE CONVERGENT
FLOW, THEN WEAKENING AND MOVING OFF TO THE SOUTHWEST ALONG THE
STRONG SHEAR VECTOR. THE MOST RECENT FLARE-UP IS CURRENTLY IN THE
WEAKENING PHASE AND THE LLCC IS STARTING TO APPEAR ONCE MORE IN THE
EIR IMAGERY. A 111402Z RCM-1 SAR PASS REVEALED A VERY SMALL REGION
OF 35 KNOT WINDS ALONG THE SOUTHERN FLANK OF THE CIRCULATION, WHILE
AN 111711Z ASCAT-B PASS REVEALED WEAKER WINDS AROUND 30 KNOTS, BUT
LIKELY THE ASCAT RESOLUTION IS INSUFFICIENT TO PICK UP THE HIGHEST
WINDS. REGARDLESS, THE SYSTEM IS BARELY REACHING MINIMAL TROPICAL
STORM (TS) STRENGTH AT THIS POINT. ENVIRONMENTAL CONDITIONS ARE
UNFAVORABLE, WITH HIGH NORTHEASTERLY SHEAR, WEAK POLEWARD OUTFLOW,
AND SIGNIFICANT DRY AIR INTRUSION FROM THE NORTH.

INITIAL WIND RADII BASIS: SCATTEROMETER AND SAR DATA. 

CURRENT STEERING MECHANISM: NORTHERN PERIPHERY OF A DEEP-LAYER
SUBTROPICAL RIDGE (STR) TO THE SOUTH. 

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T2.0 - 30 KTS
   CIMSS ADT: 37 KTS AT 111730Z
   CIMSS AIDT: 34 KTS AT 111700Z
   CIMSS D-PRINT: 32 KTS AT 111730Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: UNFAVORABLE
   VWS: 20-25 KTS
   SST: 26-27 CELSIUS
   OUTFLOW: WEAK POLEWARD
   OTHER FACTORS: DRY MID-LEVEL AIR TO THE NORTH. 

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

3. FORECAST REASONING.

SIGNIFICANT FORECAST CHANGES: THE FORECAST HAS BEEN TRUNCATED TO 24
HOURS. 

FORECAST DISCUSSION: TC 03S WILL CONTINUE TRACKING TOWARDS THE
NORTHWEST THROUGH THE FORECAST PERIOD, ALONG THE NORTHERN PERIPHERY
OF A DEEP-LAYER STR CENTERED TO THE SOUTH. SHORT PERIODS OF ERRATIC
OR EVEN LOOPING MOTION IS POSSIBLE AS THE SYSTEM CONTINUES TO
WEAKEN AND THE VORTEX SHALLOWS OUT AND THE LOWER-LEVEL FLOW IS A
BIT WEAKER THAN THE DEEP-LAYER MEAN FLOW. IN AGGREGATE HOWEVER, THE
SYSTEM SHOULD CONTINUE ON A GENERAL NORTHWESTWARD TRACK. THE SYSTEM
IS ONLY BARELY REACHING TROPICAL STORM STRENGTH, AND EACH
SUCCESSIVE CONVECTIVE CYCLE IS WEAKER THAN THE PRIOR ONE, IMPARTING
LESS AND LESS ENERGY TO THE LOW-LEVEL WIND FIELD. ADDITIONALLY, THE
ATMOSPHERE CONTINUES TO DRY AND THE FURTHER EQUATORWARD THE SYSTEM
GETS, THE STRONGER THE SHEAR WILL BECOME. ALL OF THESE NEGATIVE
FACTORS LEAD TO A VERY SHORT, 24 HOURS FORECAST, DURING WHICH TIME
THE SYSTEM WILL CONTINUE TO WEAKEN AND ULTIMATELY DISSIPATE. 

MODEL DISCUSSION: THE TRACK GUIDANCE PACKAGE IS IN STRONG
AGREEMENT, WITH ALL CONSENSUS MEMBERS CONSTRAINED TO TIGHT
ENVELOPE, EXCEPT FOR THE NAVGEM, WHICH CONTINUES TO TRACK THE
SYSTEM FURTHER SOUTH INTO THE RIDGE. THE JTWC FORECAST IS
CONSISTENT WITH THE PREVIOUS FORECAST AND PLACED WITH HIGH
CONFIDENCE NEAR THE CONSENSUS MEAN. INTENSITY GUIDANCE, AGAIN WITH
THE EXCEPTION OF THE NAVGEM VERSION OF DECAY-SHIPS, IS IN GOOD
AGREEMENT THAT THE SYSTEM WILL LIKELY MAINTAIN MINIMAL TS STRENGTH
FOR ABOUT 12 HOURS BEFORE RAPIDLY DISSIPATING WITHIN 24 HOURS. THE
JTWC FORECAST IS POSITIONED CLOSE TO THE CONSENSUS MEAN WITH HIGH
CONFIDENCE.  

FORECAST CONFIDENCE:
   TRACK 00-72 HR: HIGH
   INTENSITY 00-72 HR: HIGH//
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