WDXS33 PGTW 032100
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL CYCLONE 23S (HONDE) WARNING NR 
013//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 28.2S 48.0E
   INITIAL INTENSITY: 45 KTS
   GEOGRAPHIC REFERENCE: 556 NM SOUTHEAST OF EUROPA ISLAND
   MOVEMENT PAST 6 HOURS: SOUTHEASTWARD AT 07 KTS
   SIGNIFICANT WAVE HEIGHT: 24 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY DEPICTS TC 23S
(HONDE) WITH A COMPLETELY EXPOSED LOW-LEVEL CIRCULATION CENTER
(LLCC), AND INTERMITTENT BUT SHORT-LIVED CONVECTION FLARING IN THE
SOUTHERN SEMICIRCLE. AN ADDITIONAL BAND OF CONVECTION HAS BEEN
OBSERVED WRAPPING CYCLONICALLY INTO THE SOUTHERN QUADRANT ALONG THE
EASTERN FLANK OF THE SYSTEMS CIRCULATION. WITHIN THE NORTHERN AND
WESTERN QUADRANTS, STRONG AND PERSISTENT DRY-AIR ENTRAINMENT OVER
THE LAST 12 HOURS HAS CONTINUED TO LIMIT ANY WIDESPREAD AND
SUPPORTIVE CONVECTION NEAR THE LLCC. WITH THAT BEING SAID, WARM SEA
SURFACE TEMPERATURES (26-27 C), LOW VERTICAL WIND SHEAR (10-15 KTS)
AND A STRONG POLEWARD OUTFLOW CHANNEL ALOFT HAS CONTINUED TO
SUPPORT SUSTAINED INTENSITIES BETWEEN 45-50 KTS. THE INITIAL
POSITION IS PLACED WITH HIGH CONFIDENCE BASED ON THE FULLY EXPOSED
LLCC, OBSERVED ON ANIMATED EIR IMAGERY. THE INITIAL INTENSITY IS
ASSESSED WITH MEDIUM CONFIDENCE BASED ON AN EARLIER 031422Z PARTIAL
SOIL MOISTURE AND OCEAN SALINITY (SMOS) IMAGE, INDICATING AN
ISOLATED AREA OF ELEVATED INTENSITIES WITHIN THE SOUTHWEST
QUADRANT.

INITIAL WIND RADII BASIS: OBJECTIVE BEST TRACK 

CURRENT STEERING MECHANISM: SUBTROPICAL RIDGE (STR) TO THE
EAST-NORTHEAST

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T2.5 - 35 KTS
   KNES: T1.0 - 25 KTS
   DEMS: T2.5 - 35 KTS
   FMEE: T3.5 - 55 KTS
   CIMSS SATCON: 39 KTS AT 031730Z
   CIMSS ADT: 34 KTS AT 031800Z
   CIMSS AIDT: 37 KTS AT 031800Z
   CIMSS D-MINT: 39 KTS AT 031536Z
   CIMSS D-PRINT: 44 KTS AT 031800Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: MARGINAL
   VWS: 10-15 KTS
   SST: 26-27 CELSIUS
   OUTFLOW: STRONG POLEWARD

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 23S IS FORECASTED TO CONTINUE ACCELERATING
SOUTH-SOUTHEASTWARD ALONG THE SOUTHWESTERN PERIPHERY OF THE
SUBTROPICAL RIDGE DIRECTLY TO THE EAST-NORTHEAST. BY TAU 48, THE TC
WILL START NEARING THE EQUATORWARD EDGE OF THE MIDLATITUDE JET,
INITIATING THE BEGINNING STAGES OF BAROCLINIC TRANSITION AS THE
TRACK BECOMES SOUTHEASTWARD THROUGH THE END OF THE FORECAST PERIOD
WITH INCREASED INFLUENCE FROM THE MIDLATITUDE WESTERLIES. WITH
REGARD TO INTENSITY, TC HONDE IS EXPECTED TO MAINTAIN 45-50 KTS
THROUGH THE NEXT 48 HOURS AS STRONG DRY-AIR ENTRAINMENT IS OFFSET
BY THE AFOREMENTIONED POLEWARD CHANNEL DRIVEN BY THE UPPER-LEVEL
JET TO THE SOUTH. AS THE CYCLONE STARTS EXTRATROPICAL TRANSITION
BETWEEN TAU 36 AND TAU 48, THE SYSTEM WILL WEAKEN AS SEA SURFACE
TEMPERATURES CONTINUE TO DECREASE WELL BELOW 26 C, DRY AIR
COMPLETELY WRAPS INTO THE CENTRAL CORE, AND PERSISTENT VERTICAL
WIND SHEAR (VWS) OF MORE THAN 30 KTS ERODES THE CYCLONES STRUCTURE.
BY TAU 72, TC 23S IS EXPECTED TO WEAKEN TO 35 KTS AS IT COMPLETES
EXTRATROPICAL TRANSITION AND BECOMES FULLY EMBEDDED WITHIN THE
MID-LATITUDE WESTERLIES AS A COLD-CORE LOW.

MODEL DISCUSSION: NUMERICAL MODEL TRACK GUIDANCE REMAINS IN TIGHT
AGREEMENT THROUGHOUT THE 72 HOUR FORECAST, WITH A CROSS-TRACK
SPREAD OF JUST 25 NM AT TAU 24, AND 75 NM AT TAU 72. THE JTWC TRACK
FORECAST IS PLACED WITH HIGH CONFIDENCE AND ALIGNED CLOSELY TO THE
JTWC CONSENSUS. INTENSITY GUIDANCE IS ALSO IN GOOD AGREEMENT THAT
THE SYSTEMS INTENSITY WILL REMAIN RELATIVELY STEADY BETWEEN 45-50
KTS THROUGH THE INITIAL 48 HOURS, AND STEADILY WEAKEN THEREAFTER
INTO BAROCLINIC TRANSITION BY TAU 72. HWRF REMAINS AS THE SINGLE
OUTLIER, PREDICTING SLIGHT INTENSIFICATION BY TAU 12, HOWEVER, IS
ALIGNED WITH THE INTENSITY CONSENSUS AS THE SYSTEM WEAKENS DURING ITS
POLEWARD TRACK AND INTERACTION WITH THE UPPER-LEVEL JET. THEREFORE,
THE JTWC INTENSITY FORECAST IS ASSESSED WITH MEDIUM CONFIDENCE DUE
TO THE EXPECTED EXTRATROPICAL TRANSITION AND INTERACTION WITH THE
BAROCLINIC ZONE.

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