WDXS31 PGTW 140300
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL CYCLONE 04S (CHIDO) WARNING NR 
012//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 12.1S 46.7E
   INITIAL INTENSITY: 115 KTS
   GEOGRAPHIC REFERENCE: 541 NM SOUTHEAST OF DAR ES SALAAM,
TANZANIA
   MOVEMENT PAST 6 HOURS: WEST-SOUTHWESTWARD AT 09 KTS
   SIGNIFICANT WAVE HEIGHT: 35 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
A 131506Z SAR PASS THAT SHOWED 120-130KT WINDS IN THREE QUADRANTS
OF THE STORM AS IT CLEARED MADAGASCAR AND ENTERED THE MOZAMBIQUE
CHANNEL LOOKS TO HAVE CAPTURED THE PEAK INTENSITY OF THE STORM, AT
LEAST OVER THIS RECENT LEG. SAR INCIDENT ANGLES WERE CLEAN AND
MICROWAVE IMAGERY FROM TWO SSMIS PASSAGES NEAR THE SAME TIME SHOW
ORGANIZED BANDS OF DEEP CONVECTION THAT STRONGLY QUALITATIVELY
SUPPORT THE SAR. WARMING CLOUD TOPS AND A FILLING EYE IN ANIMATED
SATELLITE IMAGERY DURING THE TIME CONTRASTED STRONGLY WITH 
LOWER AGENCY DVORAKS, BUT A REAL-TIME REVIEW OF BOTH DATA
SETS SUPPORTS ALIGNING THE INTENSITY CLOSE TO THE SAR IMAGERY. TC
04S CHIDO CONTINUES TO FIGHT OFF 20-30 KTS OF VERTICAL WIND SHEAR ON
THE EASTERN FLANK AND THRIVE IN A NARROW FIELD OF DEEP MOISTURE.
ANIMATED WATER VAPOR IMAGERY SHOWS THE SMALL SYSTEM TO BE
COMPLETELY ENSCONCED FROM THE DRY AND HARSH ENVIRONMENT COVERING
THE REST OF THE SOUTHWEST INDIAN OCEAN. THE WATER VAPOR ALSO SHOWS
THAT THE SYSTEM IS APPROACHING AN AREA OF SOUTHWESTERLIES ALOFT
THAT MAY PROVIDE A POLEWARD OUTFLOW CHANNEL. DURING THE PAST SIX
HOURS THE EYE HAS RE-EMERGED AND THE SYSTEM IS MOVING DEEPER INTO A
REGION OF HIGHER SEA SURFACE TEMPERATURES AND OCEAN HEAT CONTENT.
THE RE-EMERGENCE OF THE SATELLITE EYE AND A MICROWAVE EYE IN A
132239Z AMSR2 COLOR37 GIVE A CONFIDENT ASSESSMENT OF THE SYSTEM
CENTER. THE INTENSITY IS GROUNDED IN THE EARLIER SAR PASS BUT
TAPERED OFF DUE TO OBSERVED BEHAVIORS OF THE STORM SINCE THE PASS.

INITIAL WIND RADII BASIS: PERSISTENCE 

CURRENT STEERING MECHANISM: THE NORTHWESTERN FLANK OF THE
SUBTROPICAL RIDGE.  THE RIDGE AXIS EXTENDS ALONG THE 20TH LATITUDE.
 

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T5.5 - 102 KTS
   KNES: T5.0 - 90 KTS
   DEMS: T5.5 - 102 KTS
   CIMSS SATCON: 97 KTS AT 132030Z
   CIMSS ADT: 77 KTS AT 140000Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: MARGINALLY FAVORABLE
   VWS: 25-30 KTS
   SST: 30-31 CELSIUS
   OUTFLOW: MODERATE RADIAL

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

3. FORECAST REASONING.

SIGNIFICANT FORECAST CHANGES: ALTHOUGH THE INTENSITY HAS BEEN
RAISED A NOTCH SINCE THE PREVIOUS WARNING, THERE ARE NO OTHER
SIGNIFICANT CHANGES TO THE FORECAST.

FORECAST DISCUSSION: TC 04S WILL PROCEED STEADILY THROUGH THE
CHANNEL AND RAMP UP MILDLY AS IT TRACKS INTO A MORE FAVORABLE
ENVIRONMENT. THE SYSTEM WILL PROCEED AT A STEADY BEARING AND SPEED
OF ADVANCE ALL THE WAY THROUGH ITS LANDFALL NEAR PEMBA. 29-30
DEGREE CELSIUS SEA WATERS AND HIGHER OCEAN HEAT CONTENT WILL AID IN
INTENSIFICATION THROUGH THE MIDDLE OF THE CHANNEL WITH THE SYSTEM
TAPERING OFF ONLY SLIGHTLY ON ITS TERMINAL LEG TO LANDFALL. 
THERE IS ALSO INCREASING LIKELIHOOD OF AN ENHANCEMENT TO POLEWARD 
OUTFLOW OVER THE SOUTHWEST QUADRANT AS THE SYSTEM APPROACHES A DEEP 
SHORTWAVE TROF COMING OFF OF AFRICA, AND THE RELATIVELY SMALL SIZE OF 
CHIDO WILL AID IN KEEPING THE SYSTEM COCOONED IN DEEP MOISTURE ALL 
THE WAY ACROSS THE CHANNEL. DESPITE ITS SMALL SIZE, THE INTENSITY AND
TRACK OF THE SYSTEM FOREBODES DAMAGING EFFECTS ON MOST OF THE
COMOROS ISLANDS AS WELL AS A STRETCH OF COASTAL MOZAMBIQUE FROM
MOCIMBOA THROUGH NACALA. A LULL IN SCATTEROMETERY PASSES HAS
REDUCED CONFIDENCE IN THE CURRENT WIND FIELDS AREAL COVERAGE, BUT A
CONSERVATIVE OUTLOOK SHOWS GALE FORCE WINDS NOT ARRIVING ALONG THE
COAST UNTIL ROUGHLY 142100Z. THE SYSTEM IS EXPECTED TO WEAKEN ONLY
SLIGHTLY PRIOR TO LANDFALL AND MAY WELL GO ASHORE NEAR 100KTS.  


MODEL DISCUSSION: TRACK GUIDANCE HAS BEEN OUTSTANDING AND THE JTWC
FORECAST STAYS NEAR THE MULTI-MODEL CONSENSUS.  INTENSITY GUIDANCE
CONTINUES TO LAG WITH THE ONLY SUITABLE PERFORMERS BEING COUPLED
OCEAN-ATMOSPHERIC MODELS, AND EVEN THEY HAVE BEEN LIGHT. THE JTWC
INTENSITY FORECAST FOLLOWS THE TREND OF THE HAFS BUT STAYS HIGHER
THROUGHOUT THE FORECAST. ALTHOUGH RAPID INTENSIFICATION (RI)
GUIDANCE DID NOT TRIGGER ON THE LATEST RUN, THERE ARE ANOTHER 12
HOURS TO GO BEFORE THE RI THREAT CAN BE ELIMINATED AND WE CAN BE
CONFIDENT THAT THE GHOST OF FREDDY WILL NOT RISE AGAIN. 

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