Advisories

WDXS31 PGTW 212100
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL CYCLONE 02S (AGUEDA) WARNING 
NR 
004//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 6.0S 50.8E
   INITIAL INTENSITY: 50 KTS
   GEOGRAPHIC REFERENCE: 687 NM EAST OF DAR ES SALAAM, TANZANIA
   MOVEMENT PAST 6 HOURS: WEST-SOUTHWESTWARD AT 09 KTS
   SIGNIFICANT WAVE HEIGHT: 16 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY DEPICTS TROPICAL 
CYCLONE (TS) 02S (AGUEDA) WITH PARTIALLY EXPOSED LOW-LEVEL BANDING ON 
THE EASTERN FLANK AND A CENTRAL DENSE OVERCAST (CDO) COMPRISED OF 
FLARING CONVECTION OFFSET TO THE WEST OF THE ASSESSED LOW LEVEL 
CIRCULATION CENTER (LLCC). ENVIRONMENTAL CONDITIONS ARE ASSESSED AS 
MARGINALLY FAVORABLE WITH 27-28 C SEA SURFACE TEMPERATURES, MODERATE 
OUTFLOW ALOFT, AND LOW TO MODERATE (15-20 KTS) OF VERTICAL WIND 
SHEAR, MOST PROMINENT IN THE MID-LEVELS, CAUSING SOME DRY AIR 
ENTRAINMENT INTO THE SYSTEM. THE INITIAL POSITION IS ASSESSED WITH 
LOW CONFIDENCE BASED ON THE OBSCURED LLCC. THE INITIAL INTENSITY IS 
ASSESSED WITH MEDIUM CONFIDENCE USING A BLEND OF AGENCY DVORAK AND 
CIMSS OBJECTIVE ESTIMATES LISTED BELOW.

INITIAL WIND RADII BASIS: PERSISTENCE 

CURRENT STEERING MECHANISM: WESTERN PERIPHERY OF A SUBTROPICAL
RIDGE CENTERED TO THE EAST

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T3.5 - 55 KTS
   CIMSS SATCON: 53 KTS AT 211422Z
   CIMSS ADT: 51 KTS AT 211800Z
   CIMSS AIDT: 50 KTS AT 211700Z
   CIMSS D-MINT: 53 KTS AT 211759Z
   CIMSS D-PRINT: 39 KTS AT 211800Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: MARGINALLY FAVORABLE
   VWS: 15-20 KTS
   SST: 27-28 CELSIUS
   OUTFLOW: MODERATE WESTWARD
   OTHER FACTORS: DRY AIR ENTRAINMENT

ANALYSIS CONFIDENCE:
   INITIAL POSITION: LOW
   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: TC 02S IS FORECAST TO TRACK SOUTHWESTWARD
UNTIL TAU 24 AS IT REMAINS WITHIN THE PERIPHERAL FLOW OF THE WESTWARD 
EXTENSION OF A SUBTROPICAL RIDGE (STR) CENTERED TO THE EAST. 
FOLLOWING TAU 24, 02S WILL TRACK GENERALLY WESTWARD AND THEN TURN 
NORTHWESTWARD AT TAU 60 AS AN STR CENTERED TO THE SOUTHWEST BECOMES 
THE PRIMARY STEERING MECHANISM. REGARDING INTENSITY, TC 02S IS 
EXPECTED TO MAINTAIN INTENSITY OUT TO TAU 12 BEFORE BEGINNING A 
WEAKENING TREND FOR THE REMAINDER OF THE FORECAST PERIOD AS MID-LEVEL 
SHEAR INCREASES, PREVENTING VORTEX ALIGNMENT AND ENTRAINING FURTHER 
DRY AIR INTO THE SYSTEM. TC 02S IS EXPECTED TO DISSIPATE OVER WATER 
NO LATER THAN TAU 72.

MODEL DISCUSSION: TRACK MODEL GUIDANCE IS IN GOOD AGREEMENT ON A
SOUTHWESTWARD TO WESTWARD TRACK OUT UNTIL TAUS 48 TO 60, FOLLOWED BY 
A NORTHWESTWARD TURN THEREAFTER, WITH THE ONLY EXCEPTION BEING NAVGEM 
AS AN OUTLIER TO THE SOUTH. DISREGARDING NAVGEM, CROSS-TRACK SPREAD 
AT TAU 72 IS 75 NM BETWEEN THE MOST EQUATORWARD SOLUTION OF ECMWF AND 
GOOGLE DEEPMIND AS THE MOST POLEWARD. THE OFFICIAL JTWC TRACK IS THUS 
LAID WITH HIGH CONFIDENCE, IN GOOD AGREEMENT WITH THE MULTI-MODEL AND 
AI CONSENSUS. MODEL INTENSITY GUIDANCE IS IN FAIR AGREEMENT, WITH ALL
BUT COAMPS-TC SHOWING AN INITIAL PLATEAU OR WEAKENING. COAMPS-TC 
COMES INTO AGREEMENT AFTER TAU 24 AND SHOWS DISSIPATION BY TAU 60. 
THE OFFICIAL JTWC INTENSITY FORECAST IS LAID WITH HIGH CONFIDENCE,
IN LINE WITH THE MULTI-MODEL CONSENSUS OUT TO TAU 60 AND SLIGHTLY
BELOW THE CONSENSUS AT TAU 72.

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