WDXS31 PGTW 090900
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL CYCLONE 19S (GOMBE) WARNING 
NR 004//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 14.8S 46.0E
   INITIAL INTENSITY: 45 KTS
   GEOGRAPHIC REFERENCE: 261 NM NORTH-NORTHWEST OF ANTANANARIVO,
   MADAGASCAR
   MOVEMENT PAST 6 HOURS: WESTWARD AT 09 KTS
   SIGNIFICANT WAVE HEIGHT: 14 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) DEPICTS A
MEDIUM-SIZED SYSTEM THAT IS BEGINNING TO REFORM OVER THE MOZAMBIQUE 
CHANNEL.  FEEDER BANDS HAVE BECOME LARGER IN THE NORTHERN SECTOR 
WITH THINNING BANDS IN THE SOUTHERN SECTOR OVER MADAGASCAR COAST. 
THE INITIAL POSITION IS BASED WITH HIGH CONFIDENCE IN THE MSI LOOP, 
MULTIPLE AGENCY FIXES, AND A WELL-TIMED BULLSEYE FROM A 090555Z 
METOP-C ASCAT. THE INITIAL INTENSITY OF 45KTS IS SLIGHTLY HIGHER 
THAN THE PREVIOUSLY MENTIONED ASCAT IMAGE AND IS MORE IN LINE WITH 
MULTIPLE AGENCY DVORAK ESTIMATES AND SATELLITE CONSENSUS (SATCON). 
ANALYSIS INDICATES AN IMPROVING AND FAVORABLE ENVIRONMENT WITH LOW 
(10-15KT) VWS AND MODERATE RADIAL OUTFLOW, SLIGHTLY OFFSET BY 
MINIMAL LAND INTERACTION WITH THE MADAGASCAR COAST. TC GOMBE IS 
TRACKING SLOWLY ALONG THE NORTHERN PERIPHERY OF THE STR TO THE SOUTH.

INITIAL WIND RADII BASIS: SCATTEROMETER DATA.

CURRENT STEERING MECHANISM: SUBTROPICAL RIDGE (STR) TO THE SOUTH. 

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T3.0 - 45 KTS
   FMEE: T3.5 - 55 KTS
   CIMSS SATCON: 44 KTS AT 090315Z
   CIMSS ADT: 39 KTS AT 090615Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: FAVORABLE
   VWS: 10-15 KTS
   SST: 29-30 CELSIUS
   OUTFLOW: MODERATE RADIAL

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 GOMBE IS NOW MOVING OVER THE MOZAMBIQUE
CHANNEL UNDER THE INFLUENCE OF THE STR TO THE SOUTH. TC 19S IS
EXPECTED TO CONTINUE TRACKING OVER THE VERY WARM MOZAMBIQUE CHANNEL
WITH FAVORABLE VWS AND RADIAL OUTFLOW. THE FAVORABLE ENVIRONMENT
WILL CONTINUALLY FUEL STEADY INTENSIFICATION TO A PEAK OF 75KTS.
THERE REMAINS AN EXTREME POSSIBILITY FOR RAPID INTENSIFICATION (RI)
JUST BEFORE LANDFALL NEAR TAU 48. AFTERWARDS, INCREASING VWS AND
LAND INTERACTION WILL RAPIDLY WEAKEN THE CYCLONE DOWN TO
DISSIPATION BY TAU 96.

MODEL DISCUSSION: NUMERICAL MODELS ARE IN TIGHT AGREEMENT UP TO TAU
96 WITH A GRADUAL AND EVEN SPREAD TO 105NM. AFTERWARD, THE MODELS
DIVERGE SIGNIFICANTLY DUE TO LOSING THE VORTEX OVER LAND. GIVEN 
THIS, THERE IS OVERALL HIGH CONFIDENCE IN THE JTWC TRACK AND HIGH
CONFIDENCE FOR THE INTENSITY FORECASTS UP TO TAU 48 AND MEDIUM
THEREAFTER, DUE TO THE POSSIBILITY OF RI. 

FORECAST CONFIDENCE:
   TRACK 0 - 72 HR: HIGH
   TRACK 72-120 HR: HIGH
   INTENSITY 0 - 72 HR: MEDIUM
   INTENSITY 72-120 HR: MEDIUM//
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