WDXS31 PGTW 160900
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL CYCLONE 19S (FABIEN) 
WARNING NR 009//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 6.7S 75.5E
   INITIAL INTENSITY: 95 KTS
   GEOGRAPHIC REFERENCE: 180 NM EAST OF DIEGO GARCIA
   MOVEMENT PAST 6 HOURS: SOUTHWESTWARD AT 08 KTS
   SIGNIFICANT WAVE HEIGHT: 39 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) DEPICTS A SMALL
TIGHTLY WRAPPED CIRCULATION, CURRENTLY REFORMING AN EYE FEATURE
WHICH IS FURTHER EVIDENCE OF A RECENTLY COMPLETED ERC AS TC 19S
RECONSOLIDATES ITS CORE STRUCTURE. OVER THE LAST HOUR, EYE
TEMPERATURES HAVE WARMED FROM -22C TO -12C WHILE CLOUD TOPS REMAIN
-80C. A BULLSEYE 160400Z ASCAT-B SCATTEROMETRY PASS INDICATES TC
19S REMAINS FAIRLY COMPACT WITH THE STRONGEST WINDS EVIDENT IN THE
NORTHEASTERN QUADRANT. WITH THE REEMERGENCE OF AN EYE FEATURE
COUPLED WITH MSI AND SCATTEROMETRY DATA, THE INITIAL POSITION IS
PLACED WITH HIGH CONFIDENCE. THE INITIAL INTENSITY OF 95 KTS IS
ASSESSED WITH MEDIUM CONFIDENCE BASED ON AGENCY DVORAK INTENSITY
ESTIMATES RECOGNIZING THE NEWLY FORMED EYE FEATURE AND GENERALLY
CONSOLIDATING NEAR T5.0. KEEPING IN MIND THAT THE DVORAK METHOD
DOES HAVE TROUBLE WITH SMALLER SYSTEMS AND NEWLY DEVELOPING EYE
FEATURES CAN BE MISSED BY SOME AUTOMATED INTENSITY ESTIMATES, THE
VERACITY OF ANY NEW INTENSITY ESTIMATE SHOULD BE SCRUTINIZED.

INITIAL WIND RADII BASIS: SCATTEROMETER DATA 

CURRENT STEERING MECHANISM: SUBTROPICAL RIDGE (STR) TO THE
SOUTHEAST

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T5.0 - 90 KTS
   KNES: T5.0 - 90 KTS
   DEMS: T5.0 - 90 KTS
   FMEE: T4.5 - 77 KTS
   FIMP: T4.5 - 77 KTS
   CIMSS ADT: 82 KTS AT 160300Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: FAVORABLE
   VWS: 0-5 KTS
   SST: 28-29 CELSIUS
   OUTFLOW: STRONG 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 (FABIEN) IS FORECAST TO CONTINUE
TRACKING SOUTHWESTWARD UNDER THE STEERING INFLUENCE OF THE STR TO
THE SOUTHEAST. THROUGH TAU 24, 19S IS FORECAST TO REMAIN IN A
FAVORABLE ENVIRONMENT CHARACTERIZED BY WARM SSTS, LOW VERTICAL WIND
SHEAR (VWS) AND STRONG OUTFLOW ALOFT WHICH IS ANTICIPATED TO PEAK
THE SYSTEM NEAR 100KTS AND POSSIBLY A BIT HIGHER. FOLLOWING TAU 24,
DRY AIR ENTRAINMENT IS FORECAST TO BEGIN TO DEGRADE THE ENVIRONMENT
WHICH WILL RESULT IN SLIGHT WEAKENING THROUGH TAU 36. BY THIS TIME,
19S WILL BEGIN TO TRANSITION PRIMARY STEERING INFLUENCE TO THE STR
OVER SOUTHEASTERN AFRICA. AS THIS TAKES PLACE, 19S WILL STEADY UP
ON A GENERALLY WESTWARD COURSE AS THE SYSTEM CONTINUES TO SLOWLY
WEAKEN. BY TAU 72, A NEAR-EQUATORIAL RIDGE (NER) BUILDING JUST
SOUTH OF INDIA WILL HALT MOST OF THE SYSTEMS FORWARD MOMENTUM. BY
TAU 96 AND THROUGH THE FORECAST PERIOD, HAVING WEAKENED TO 70KTS,
TC 19S WILL BE IN A COMPETING STEERING ENVIRONMENT BETWEEN THE STR
TO THE SOUTHWEST AND NER TO THE NORTH WHICH IS FORECAST TO TURN THE
SYSTEM EQUATORWARD OR POSSIBLY QUASI-STATIONARY.

MODEL DISCUSSION: WITH THE EXCEPTION OF COAMPS-TC TO THE NORTH,
NUMERICAL MODELS ARE IN FAIR AGREEMENT THROUGH TAU 72, WITH ALL
OTHER MEMBERS SHOWING A SOUTHWESTERLY TRACK SOUTH OF DIEGO GARCIA
AFTER WHICH GENERALLY WESTWARD. BY TAU 72, AS THE NER BUILDS TO THE
NORTH AND THE TWO DOMINANT RIDGES FIGHT FOR CONTROL, ALL BETS ARE
OFF WITH VARIOUS MEMBERS RECURVING THE SYSTEM NORTHWARD AND
SOUTHWARD. THE JTWC FORECAST TRACK IS THEREFOR PLACED NEAR THE
MULTI-MODEL CONSENSUS WITH MEDIUM CONFIDENCE THROUGH TAU 72 AND
WITH LOW CONFIDENCE IN THE EXTENDED TRACK FORECAST. RELIABLE MODEL
INTENSITY GUIDANCE IS IN FAIR AGREEMENT WITH A BULK OF THE MEMBERS
SHOWING MARGINAL TO MODERATE INTENSIFICATION THROUGH TAU 24, AFTER
WHICH ALL MEMBERS GRADUALLY WEAKEN THROUGH THE FORECAST PERIOD.
HWRF IS A NOTABLE EXCEPTION TO THIS TREND, SHOWING IMMEDIATE
WEAKENING THROUGH TAU 48 AFTER WHICH BRIEF INTENSIFICATION AND
EVENTUAL DECLINE IN THE EXTENDED FORECAST. FOR THESE REASON THE
JTWC INTENSITY FORECAST IS PLACED WITH MEDIUM CONFIDENCE.

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