WDXS31 PGTW 100300
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL CYCLONE 19S (GOMBE) WARNING NR 
006//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 15.3S 43.6E
   INITIAL INTENSITY: 60 KTS
   GEOGRAPHIC REFERENCE: 311 NM NORTHWEST OF ANTANANARIVO,
MADAGASCAR
   MOVEMENT PAST 6 HOURS: WESTWARD AT 07 KTS
   SIGNIFICANT WAVE HEIGHT: 18 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY DEPICTS A
COMPACT SYSTEM WITH AN IRREGULAR CENTRAL DENSE OVERCAST OBSCURING
THE LOW-LEVEL CIRCULATION CENTER (LLCC) AND SPIRAL BANDING OVER THE
WESTERN PERIPHERY. A 092253Z AMSR2 89GHZ MICROWAVE IMAGE, HOWEVER,
SHOWS A DEVELOPING EYEWALL WITH A SMALL MICROWAVE EYE FEATURE WHICH
SUPPORTS THE INITIAL POSITION WITH HIGH CONFIDENCE, AND ALSO
PROVIDES ADDITIONAL EVIDENCE THAT THE SYSTEM HAS CONTINUED TO
CONSOLIDATE. THE 34-KNOT AND 50-KNOT WIND RADII WERE ADJUSTED
SLIGHTLY BASED ON THE AMSR2 25KM RESOLUTION WINDSPEED PRODUCT THAT
SHOWS NUMEROUS 50-55 KNOT WINDS OVER THE NORTHERN SEMI-CIRCLE. THE
INITIAL INTENSITY OF 60 KTS IS ASSESSED WITH MEDIUM CONFIDENCE
BASED ON AN AVERAGE OF DVORAK ESTIMATES RANGING FROM 55 TO 65
KNOTS. RECENT ADT AND SATCON ESTIMATES REMAIN SLIGHTLY LOWER AT
53-54 KNOTS. ENVIRONMENTAL CONDITIONS REMAIN VERY FAVORABLE WITH
LOW VERTICAL WIND SHEAR, WARM SST (29-30C) AND NEAR-RADIAL OUTFLOW.

INITIAL WIND RADII BASIS: OTHER (ADJUSTED USING AMSR2 WINDSPEED
PRODUCT)

CURRENT STEERING MECHANISM: DEEP-LAYERED SUBTROPICAL RIDGE (STR)
ENTRENCHED TO THE SOUTH.

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T3.5 - 55 KTS
   FMEE: T4.0 - 65 KTS
   CIMSS SATCON: 54 KTS AT 092244Z
   CIMSS ADT: 53 KTS AT 100015Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: HIGHLY FAVORABLE
   VWS: 5-10 KTS
   SST: 29-30 CELSIUS
   OUTFLOW: MODERATE RADIAL

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

3. FORECAST REASONING.

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

FORECAST DISCUSSION: TC 19S IS TRACKING WESTWARD UNDER THE STEERING
INFLUENCE OF THE DEEP-LAYERED STR TO THE SOUTH, AND IS EXPECTED TO
TRACK GENERALLY WESTWARD OVER THE NEXT 48 HOURS. VERY FAVORABLE
ENVIRONMENTAL CONDITIONS SUPPORT RAPID INTENSIFICATION THROUGH
LANDFALL NEAR TAU 24 OVER THE EASTERN COAST OF MOZAMBIQUE WITH A
PEAK INTENSITY OF 100 KNOTS AT TAU 24. AFTER TAU 48, THE STEERING
RIDGE IS EXPECTED TO WEAKEN WITH THE APPROACH OF A DEEP MIDLATITUDE
TROUGH AND, CONSEQUENTLY, TC 19S SHOULD SLOW OVER MOZAMBIQUE WHICH
WILL LIKELY LEAD TO SIGNIFICANT RAINFALL AND MAJOR FLOODING AS THE
SYSTEM STALLS. TC 19S WILL DISSIPATE QUICKLY OVERLAND, HOWEVER,
AFTER TAU 72, THE STR WILL RE-ORIENT NORTH-SOUTH AND WILL PRODUCE A
SOUTHWARD TO SOUTH-SOUTHEASTWARD TRACK WITH THE SYSTEM REMNANTS
EXPECTED TO RE-EMERGE OVER THE MOZAMBIQUE CHANNEL. THERE IS
MODERATE PROBABILITY THAT THE SYSTEM MAY RE-DEVELOP INTO A WEAK
TROPICAL CYCLONE UNDER GENERALLY FAVORABLE CONDITIONS.       

MODEL DISCUSSION: NUMERICAL MODEL GUIDANCE SUPPORTS THE JTWC
FORECAST TRACK WITH HIGH CONFIDENCE THROUGH TAU 48 WITH A 35NM TO
45NM SPREAD IN SOLUTIONS FROM TAU 36 TO TAU 48. AFTER TAU 72,
MODEL GUIDANCE DIVERGES WITH LOW OVERALL TRACK CONFIDENCE DUE TO
THE RAPIDLY WEAKENING STR AND INITIAL INTERACTION WITH THE
MIDLATITUDE TROUGH. RELIABLE INTENSITY GUIDANCE SUPPORTS THE JTWC
FORECAST PHILOSOPHY WITH HWRF AND COAMPS-TC (GFS VERSION)
INDICATING A PEAK OF 90-95 KNOTS BY TAU 24. ADDITIONALLY, RAPID
INTENSIFICATION AIDS HAVE TRIGGERED SUPPORTING THE INCREASING
PROBABILITY OF RAPID INTENSIFICATION (RI) OCCURRING WITHIN THE NEXT
24 HOURS. THE JTWC INTENSITY FORECAST IS POSITIONED ABOVE THE JTWC
INTENSITY CONSENSUS (ICNW), WHICH PEAKS AT 83 KNOTS. THE LATEST
COAMPS-TC ENSEMBLE GUIDANCE (091800Z) INDICATES A 70 TO 75 PERCENT
PROBABILITY OF RI OCCURRING WITHIN THE NEXT 24 HOURS, WHICH FURTHER
BOLSTERS THE JTWC INTENSITY FORECAST PHILOSOPHY. JTWC INTENSITY
GUIDANCE IS MIXED ON REGENERATION WITH SOME GUIDANCE INDICATING A 35-
40 KNOT INTENSITY AT DAY 5. THE COAMPS-TC ENSEMBLE ALSO SHOWS A
20 TO 40 PERCENT PROBABILITY OF MODERATE INTENSIFICATION.   

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

FORECASTER: BARLOW//
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