WDXS31 PGTW 191500
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL CYCLONE 24S (IALY) WARNING NR 
007//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 7.4S 45.2E
   INITIAL INTENSITY: 55 KTS
   GEOGRAPHIC REFERENCE: 350 NM EAST OF DAR ES SALAAM, TANZANIA
   MOVEMENT PAST 6 HOURS: WESTWARD AT 07 KTS
   SIGNIFICANT WAVE HEIGHT: 22 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) SHOWS THE SYSTEM HAS
MAINTAINED OVERALL CONVECTIVE STRUCTURE, WRAP, AND A PINHOLE EYE.
THE MSI LOOP ALSO SHOWS LOW LEVEL STRATOCUMULUS CLOUD LINES
WRAPPING IN COUNTER-CLOCKWISE TOWARD THE CENTER. THE INITIAL
POSITION IS PLACED WITH HIGH CONFIDENCE BASED ON THE PINHOLE EYE.
THE INITIAL INTENSITY IS ALSO PLACED WITH HIGH CONFIDENCE BASED ON
THE OVERALL ASSESSMENT OF AGENCY AND AUTOMATED DVORAK ESTIMATES AND
REFLECTS THE SUSTAINED CONVECTIVE SIGNATURE. ANALYSIS INDICATES A
MARGINALLY FAVORABLE ENVIRONMENT WITH WARM SST AND MODERATE OUTFLOW
OFFSET BY MODERATE TO STRONG VWS AND COLD DRY AIR INTRUSION AT THE
LOW LEVELS.

INITIAL WIND RADII BASIS: SCATTEROMETER DATA. 

CURRENT STEERING MECHANISM: EXTENSION OF A DEEP LAYERED SUBTROPICAL
RIDGE (STR) TO THE SOUTHEAST. 

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T3.5 - 55 KTS
   KNES: T3.5 - 55 KTS
   DEMS: T3.5 - 55 KTS
   FMEE: T4.0 - 65 KTS
   CIMSS SATCON: 60 KTS AT 191030Z
   CIMSS DPRINT: 40 KTS AT 19120Z
   CIMSS DMINT: 53 KTS AT 191014Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: MARGINALLY FAVORABLE
   VWS: 20-25 KTS
   SST: 28-29 CELSIUS
   OUTFLOW: MODERATE POLEWARD
   OTHER FACTORS: COLD DRY AIR INTRUSION AT THE LOW LEVELS. 

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: TC IALY WILL TRACK MORE NORTHWESTWARD AS A
SECONDARY STR TO THE WEST OVER AFRICA ASSUMES STEERING. THE
ENVIRONMENT WILL BECOME MORE UNSTABLE AS STR AND THE COLD DRY AIR
INTRUSION INCREASE LEADING TO A GRADUAL EROSION AND EVENTUAL
DISSIPATION BY TAU 48. 

MODEL DISCUSSION: NUMERICAL MODELS ARE IN GOOD AGREEMENT WITH
NAVGEM THE SOLE LEFT-OF-TRACK OUTLIER. THE MAIN PACK GRADUALLY AND
EVENLY SPREADS OUT TO 104NM BY TAU 48, LENDING MEDIUM CONFIDENCE TO
THE JTWC TRACK FORECAST THAT IS LAID JUST TO THE RIGHT OF CONSENSUS
TO OFFSET NAVGEM.  

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