Tropical Cyclone 28P (28P)

WTPS31 PGTW 240300
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE 28P (TWENTYEIGHT) WARNING NR 003//
RMKS/
1. TROPICAL CYCLONE 28P (TWENTYEIGHT) WARNING NR 003    
   01 ACTIVE TROPICAL CYCLONE IN SOUTHPAC
   MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
   WIND RADII VALID OVER OPEN WATER ONLY
    ---
   WARNING POSITION:
   240000Z --- NEAR 23.6S 163.8E
     MOVEMENT PAST SIX HOURS - 175 DEGREES AT 22 KTS
     POSITION ACCURATE TO WITHIN 040 NM
     POSITION BASED ON CENTER LOCATED BY SATELLITE
   PRESENT WIND DISTRIBUTION:
   MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   SUBTROPICAL
   RADIUS OF 034 KT WINDS - 050 NM NORTHEAST QUADRANT
                            070 NM SOUTHEAST QUADRANT
                            050 NM SOUTHWEST QUADRANT
                            040 NM NORTHWEST QUADRANT
   REPEAT POSIT: 23.6S 163.8E
    ---
   FORECASTS:
   12 HRS, VALID AT:
   241200Z --- 28.0S 164.0E
   MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   SUBTROPICAL
   RADIUS OF 034 KT WINDS - 075 NM NORTHEAST QUADRANT
                            160 NM SOUTHEAST QUADRANT
                            140 NM SOUTHWEST QUADRANT
                            075 NM NORTHWEST QUADRANT
    ---
REMARKS:
240300Z POSITION NEAR 24.7S 163.8E.
24MAR26. TROPICAL CYCLONE 28P (TWENTYEIGHT), LOCATED
APPROXIMATELY 156 NM SOUTHWEST OF NOUMEA, NEW CALEDONIA, HAS
TRACKED SOUTHWARD AT 22 KNOTS OVER THE PAST SIX HOURS.
THE SYSTEM HAS BEEN ANALYZED AS SUBTROPICAL. ANIMATED
MULTISPECTRAL SATELLITE IMAGERY DEPICTS AN ASYMMETRIC STRUCTURE
WITH CONVECTIVE ACTIVITY SHEARED POLEWARD AND EASTWARD OF THE
LOW-LEVEL CIRCULATION CENTER. THE CENTER IS POSITIONED NEAR THE
SUBTROPICAL RIDGE AXIS WITH 30+ KNOTS OF SHEAR OVER THE VORTEX.
THE SYSTEM WILL CONTINUE SOUTHWARD INTO THE BAROCLINIC ZONE OVER
THE NEXT 12 HRS WHERE SEA SURFACE TEMPERATURES ARE BELOW 24C.
THIS IS THE FINAL WARNING ON THIS SYSTEM BY THE JOINT TYPHOON
WRNCEN PEARL HARBOR HI. THE SYSTEM WILL BE CLOSELY MONITORED FOR
SIGNS OF REGENERATION. MINIMUM CENTRAL PRESSURE AT 240000Z IS 994
MB. MAXIMUM SIGNIFICANT WAVE HEIGHT AT 240000Z IS 18 FEET.//
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WDPS31 PGTW 231500
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL CYCLONE 28P (TWENTYEIGHT) 
WARNING NR 002//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 20.1S 162.9E
   INITIAL INTENSITY: 45 KTS
   GEOGRAPHIC REFERENCE: 216 NM WEST-NORTHWEST OF NOUMEA, NEW
CALEDONIA
   MOVEMENT PAST 6 HOURS: SOUTHWARD AT 16 KTS
   SIGNIFICANT WAVE HEIGHT: 18 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY DEPICTS TROPICAL
CYCLONE 28P PASSING JUST TO THE WEST OF NEW CALEDONIA WITH DEEP
CONVECTION SLIGHTLY OFFSET TO THE SOUTH OF THE LOW-LEVEL
CIRCULATION CENTER (LLCC). STRONG NORTHWESTERLY SHEAR CAUSED BY AN
UPPER-LEVEL TROUGH TO THE WEST IS THE CULPRIT FOR THE ENHANCED
SHEAR OVER THE TOP OF THE SYSTEM. A 231121Z METOP-C ASCAT PASS
REVEALED A COMPACT CORE OF 40-45 KNOT WINDS WITH THE NORTHWESTERN
QUADRANT CONTAINING THE WEAKEST WINDS. THE INITIAL POSITION,
INTENSITY, AND WIND RADII ARE ALL PLACED WITH HIGH CONFIDENCE BASED
ON THE ASCAT PASS. ENVIRONMENTAL ANALYSIS INDICATES THAT 28P IS IN
A MARGINALLY FAVORABLE ENVIRONMENT CHARACTERIZED BY STRONG OUTFLOW
ALOFT AND WARM (27-28 C) SEA SURFACE TEMPERATURES OFFSET BY DRY AIR
ENTRAINMENT AND HIGH (25-30 KTS) NORTHWESTERLY VERTICAL WIND SHEAR.

INITIAL WIND RADII BASIS: 231121Z METOP-C ASCAT SCATTEROMETER DATA 

CURRENT STEERING MECHANISM: WESTERN PERIPHERY OF A DEEP-LAYER
SUBTROPICAL RIDGE (STR) POSITIONED SOUTH OF FIJI.

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T3.0 - 45 KTS
   KNES: T3.5 - 55 KTS
   PHFO: T3.0 - 45 KTS
   CIMSS SATCON: 47 KTS AT 230930Z
   CIMSS ADT: 51 KTS AT 231200Z
   CIMSS AIDT: 42 KTS AT 231200Z
   CIMSS D-MINT: 35 KTS AT 230814Z
   CIMSS D-PRINT: 45 KTS AT 231200Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: MARGINALLY FAVORABLE
   VWS: 25-30 KTS
   SST: 27-28 CELSIUS
   OUTFLOW: STRONG POLEWARD AND EQUATORWARD
   OTHER FACTORS: DRY AIR ENTRAINMENT FROM THE WEST

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

3. FORECAST REASONING.

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

FORECAST DISCUSSION: TC 28P IS FORECAST TO CONTINUE TRACKING
SOUTHWARD, ALONG THE WESTERN PERIPHERY OF THE STR THROUGH TAU 24.
ROBUST POLEWARD OUTFLOW INTO A JET MAX TO THE SOUTH WILL ALLOW FOR
28P TO MARGINALLY INTENSIFY OVER THE NEXT 12 HOURS EVEN THOUGH
NORTHERLY SHEAR AND DRY AIR ENTRAINMENT WILL ONLY WORSEN. THE
SYSTEM IS EXPECTED TO STAY NORTH OF THE 26 C SST ISOTHERM, WHICH
LINES UP WITH THE 25TH LATITUDE, UP UNTIL TAU 12. COOLING SEA
SURFACE TEMPERATURES, VERY STRONG SHEAR, AND DRY AIR ENTRAINMENT
WILL CEASE FURTHER INTENSIFICATION AFTER TAU 12. SUBTROPICAL
TRANSITION IS FORECAST TO BEGIN AT TAU 12 WITH COMPLETION OCCURRING
AT TAU 24 AS SHEAR INCREASES TO OVER 50 KTS AND SEA SURFACE
TEMPERATURES DROP TO AROUND 23-24 C. 

MODEL DISCUSSION: NUMERICAL MODEL TRACK GUIDANCE IS IN GOOD
AGREEMENT THROUGHOUT THE SHORT FORECAST PERIOD WITH A CROSS-TRACK
SPREAD OF 70 NM AT TAU 24. AS A RESULT, THE JTWC TRACK FORECAST IS
PLACED CLOSE TO THE MULTI-MODEL CONSENSUS WITH HIGH CONFIDENCE.
INTENSITY GUIDANCE AGREES ON SLIGHT INTENSIFICATION THROUGH TAU 12,
TO ABOUT 50 KTS, FOLLOWED BY A STEADY INTENSITY THROUGH TAU 24 WITH
LITTLE VARIATION BETWEEN MODELS. THE JTWC INTENSITY FORECAST IS
ALSO PLACED NEAR THE CONSENSUS WITH HIGH CONFIDENCE. 

FORECAST CONFIDENCE:
   TRACK 00-72 HR: HIGH
   INTENSITY 00-72 HR: HIGH//
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