WDXS31 PGTW 061500
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL CYCLONE 11S (FREDDY) WARNING NR 049//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 24.1S 42.9E
   INITIAL INTENSITY: 50 KTS
   GEOGRAPHIC REFERENCE: 188 NM SOUTHEAST OF EUROPA ISLAND
   MOVEMENT PAST 6 HOURS: WESTWARD AT 03 KTS
   SIGNIFICANT WAVE HEIGHT: 20 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) DEPICTS AN IMPROVING
MASS OF CONVECTION BLOOMING OVER AN ASSESSED LOW LEVEL CIRCULATION
CENTER (LLCC). A 061058Z AMSR2 89 GHZ IMAGE SHOWS FRAGMENTED BANDS
OF CONVECTION IN THE SOUTHEASTERN PERIPHERY WRAPPING INTO THE
EVALUATED LLCC. A PARTIAL 060608Z ASCAT-C PASS AND A PARTIAL
060656Z ASCAT-B PASS REVEAL 40-45 KT WINDS IN THE SOUTHERN
PERIPHERY. ENVIRONMENTAL ANALYSIS REVEALS TC 11S CONTINUES TO
STRUGGLE WITH A GOOD AMOUNT OF DRY AIR ENTRAINMENT IN THE WESTERN
PERIPHERY, HOWEVER, THE SYSTEM IS ACTIVELY GAINING MID-LEVEL
MOISTURE. TC FREDDY IS IN A FAVORABLE ENVIRONMENT FOR FURTHER
TROPICAL DEVELOPMENT. THESE CONDITIONS ARE CHARACTERIZED BY
CONSISTENT EASTWARD OUTFLOW ALOFT, LOW (05-10 KTS) VERTICAL WIND
SHEAR (VWS), A HEALTHY 850 MB VORTICITY SIGNATURE, AND VERY WARM
(29-30 C) SEA SURFACE TEMPERATURES (SST). THE INITIAL POSITION IS
PLACED WITH HIGH CONFIDENCE BASED ON THE AFOREMENTIONED MSI,
MICROWAVE IMAGERY, AND MULTI-AGENCY FIXES. THE INITIAL INTENSITY OF
50 KTS IS ASSESSED WITH HIGH CONFIDENCE BASED OFF THE PREVIOUSLY
MENTIONED ASCAT DATA ALONG WITH AN IMPROVING STRUCTURE. THE INITIAL
INTENSITY IS SET SLIGHTLY HIGHER THAN MULTI-AGENCY AND AUTOMATED
DVORAK ESTIMATES.

INITIAL WIND RADII BASIS: SCATTEROMETER DATA 

CURRENT STEERING MECHANISM: THE NEAR EQUATORIAL RIDGE (NER) TO THE
NORTHEAST AND THE SUBTROPICAL RIDGE (STR) TO THE SOUTHWEST

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T2.5 - 35 KTS
   KNES: T2.5 - 35 KTS
   DEMS: T2.5 - 35 KTS
   FMEE: T3.5 - 55 KTS
   CIMSS ADT: 35 KTS AT 061300Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: FAVORABLE
   VWS: 05-10 KTS
   SST: 29-30 CELSIUS
   OUTFLOW: MODERATE EQUATORWARD
   OTHER FACTORS: DRY AIR ENTRAINMENT

ANALYSIS CONFIDENCE:
   INITIAL POSITION: HIGH
   INITIAL INTENSITY: HIGH
   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 FREDDY HAS SLOWED DOWN IN TRACK SPEED AND
SHIFTED ITS DIRECTION WESTWARD AS THE RESULT OF TWO COMPETING
STEERING MECHANISMS: THE NER TO THE NORTHEAST AND THE STR TO THE
SOUTHWEST. THIS WILL CHANGE IN THE NEAR FUTURE AS TC FREDDY WILL
TAKE A NORTHWESTWARD TRACK DUE TO THE STR IN THE SOUTHWEST RIDGING
INTO THE AREA. BETWEEN TAUS 12 AND 24, TC 11S WILL BEGIN TO HEAD
NORTHWESTWARD AND SLOWLY INCREASE IN INTENSITY TO 55 KTS DUE TO AN
IMPROVING STRUCTURE AND REGAINING MORE MID-LEVEL MOISTURE. BETWEEN
TAUS 36 AND 48, TC 11S WILL CONTINUE TO INTENSIFY AND REACH 65
KNOTS DUE TO ENTERING AN INCREASINGLY FAVORABLE ENVIRONMENT. IN
ADDITION, TC FREDDY WILL PICK-UP TRACK SPEED WHILE HEADING INTO THE
CENTRAL MOZAMBIQUE CHANNEL. BY TAUS 72 AND 96, TC 11S WILL REACH 75
KNOTS AS THE SYSTEM PASSES OVER A POOL OF HIGHER OCEAN HEAT CONTENT
(OHC) JUST OFF THE COAST OF MOZAMBIQUE. BY TAU 120, THE SYSTEM WILL
REACH ITS MAX INTENSITY OF 80 KNOTS AS IT MAKES ITS APPROACH TO THE
COAST NORTHEAST OF QUELIMANE, MOZAMBIQUE.

MODEL DISCUSSION: THE JTWC TRACK CONSENSUS MEMBERS ARE IN AGREEMENT
AS FAR AS TRACK DIRECTION, HOWEVER, THEY DISAGREE WITH TRACK SPEED.
THE EC AND GFS SOLUTIONS DISPLAY THE FASTEST TRACK SPEEDS, WHEREAS
NAVGEM AND AFUM SHOW SLOWER TRACK SPEEDS. DUE TO THIS, THE JTWC
FORECAST TRACK IS SET WITH MEDIUM CONFIDENCE OUT TO TAU 72, AND LOW
CONFIDENCE THROUGHOUT THE REMAINDER OF THE FORECAST TRACK. THE JTWC
INTENSITY CONSENSUS MEMBERS ALL AGREE ON AN INTENSIFYING SCENARIO
THROUGH TAU 72, THEN A DECREASE AFTERWARDS. THE DECREASE IS DUE TO
SOME MEMBERS BELIEVING THE SYSTEM WILL MAKE LANDFALL BETWEEN TAUS
96 AND 120. THE JTWC INTENSITY FORECAST IS SET WITH MEDIUM
CONFIDENCE ABOVE CONSENSUS THROUGH TAU 72, THEN EVEN HIGHER ABOVE
CONSENSUS OUT TO TAU 120 TO ACCOUNT FOR THE PREVIOUSLY MENTIONED
WARM POOL OF OHC.

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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