Tropical Cyclone URMIL (23P)

WTPS31 PGTW 010900
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE 23P (URMIL) WARNING NR 011//
RMKS/
1. TROPICAL CYCLONE 23P (URMIL) WARNING NR 011    
   01 ACTIVE TROPICAL CYCLONE IN SOUTHPAC
   MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
   WIND RADII VALID OVER OPEN WATER ONLY
    ---
   WARNING POSITION:
   010600Z --- NEAR 25.7S 179.2E
     MOVEMENT PAST SIX HOURS - 135 DEGREES AT 24 KTS
     POSITION ACCURATE TO WITHIN 060 NM
     POSITION BASED ON CENTER LOCATED BY SATELLITE
   PRESENT WIND DISTRIBUTION:
   MAX SUSTAINED WINDS - 055 KT, GUSTS 070 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   BECOMING SUBTROPICAL
   RADIUS OF 050 KT WINDS - 060 NM NORTHEAST QUADRANT
                            050 NM SOUTHEAST QUADRANT
                            040 NM SOUTHWEST QUADRANT
                            050 NM NORTHWEST QUADRANT
   RADIUS OF 034 KT WINDS - 155 NM NORTHEAST QUADRANT
                            155 NM SOUTHEAST QUADRANT
                            100 NM SOUTHWEST QUADRANT
                            085 NM NORTHWEST QUADRANT
   REPEAT POSIT: 25.7S 179.2E
    ---
   FORECASTS:
   12 HRS, VALID AT:
   011800Z --- 29.7S 175.5W
   MAX SUSTAINED WINDS - 050 KT, GUSTS 065 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   SUBTROPICAL
   RADIUS OF 050 KT WINDS - 090 NM NORTHEAST QUADRANT
                            030 NM SOUTHEAST QUADRANT
                            030 NM SOUTHWEST QUADRANT
                            030 NM NORTHWEST QUADRANT
   RADIUS OF 034 KT WINDS - 230 NM NORTHEAST QUADRANT
                            220 NM SOUTHEAST QUADRANT
                            120 NM SOUTHWEST QUADRANT
                            150 NM NORTHWEST QUADRANT
    ---
REMARKS:
010900Z POSITION NEAR 26.7S 179.5W.
01MAR26. TROPICAL CYCLONE 23P (URMIL), LOCATED APPROXIMATELY 458
NM SOUTH OF SUVA, FIJI, HAS TRACKED SOUTHEASTWARD AT 24 KNOTS
OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY
(MSI) DEPICTS ELONGATED AND HEAVILY SHEARED SYSTEM, WITH MAJORITY OF
THE REMAINING CONVECTION LOCATED POLEWARD AND EASTWARD OF THE
ASSESSED LOW-LEVEL CIRCULATION CENTER (LLCC). THE SYSTEM IS
CURRENTLY ANALYZED AS UNDERGOING ITS SUBTROPICAL TRANSITION (STT),
WITH WARM CORE TEMPERATURE ANOMALY CONTAINED ONLY NEAR SURFACE,
INDICATING FRONTOGENESIS. COLD ANOMALY IS PRESENT IN WITHIN THE
UPPER-LEVELS. THE LOCATION OF TC 23P IS POLEWARD OF THE SUBTROPICAL
RIDGE AXIS AND THE SYSTEM IS APPROACHING EVEN MORE HOSTILE
ENVIRONMENT, WITH DECREASING OCEAN HEAT CONTENT AND RAPIDLY AND
DRASTICALLY INCREASING VERTICAL WIND SHEAR. AS THE SYSTEM COMPLETES
THE TRANSITION WITHIN THE NEXT 12 HOURS, IT IS EXPECTED TO MAINTAIN
WIND SPEEDS WELL ABOVE GALE FORCE (50 KTS). 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 010600Z IS 983 MB. MAXIMUM SIGNIFICANT
WAVE HEIGHT AT 010600Z IS 18 FEET.//
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WDPS31 PGTW 010300
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL CYCLONE 23P (URMIL) WARNING NR 
010//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 24.0S 177.5E
   INITIAL INTENSITY: 55 KTS
   GEOGRAPHIC REFERENCE: 358 NM SOUTH OF SUVA, FIJI
   MOVEMENT PAST 6 HOURS: SOUTHEASTWARD AT 23 KTS
   SIGNIFICANT WAVE HEIGHT: 20 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
TROPICAL CYCLONE (TC) 23P (URMIL) IS QUICKLY TRACKING SOUTHEASTWARD
UNDER THE INFLUENCE OF THE WESTERN PERIPHERY OF THE DEEP LAYER STR,
WHILE BECOMING INCREASINGLY EMBEDDED BENEATH AN UPPER-LEVEL MAJOR
SHORTWAVE TROUGH ASSOCIATED WITH THE SUBTROPICAL WESTERLIES. OVER
THE PAST SIX HOURS, THE LLCC HAS BECOME PARTIALLY EXPOSED, AS
DEPICTED BY ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI).
ENVIRONMENTAL CONDITIONS HAVE BECOME INCREASINGLY UNFAVORABLE, WITH
HIGH VERTICAL WIND SHEAR (25-30 KTS), MARGINAL SEA SURFACE
TEMPERATURES BETWEEN 26 C AND 27 C, AND INCREASED DRY-AIR
ENTRAINMENT WRAPPING INTO THE CORE FROM THE WESTERN SEMICIRCLE. THE
INITIAL POSITION IS PLACED WITH MEDIUM CONFIDENCE BASED ON ANIMATED
MSI, CONSISTENT WITH A 282134Z GMI 89 GHZ IMAGE. THE INITIAL
INTENSITY OF 55 KTS IS ASSESSED WITH MEDIUM CONFIDENCE BASED ON
SUBJECTIVE AGENCY DVORAK ESTIMATES AND CIMSS OBJECTIVE INTENSITY
ESTIMATES LISTED BELOW.

INITIAL WIND RADII BASIS: 281757Z SAR DATA AND 281828Z SMOS DATA

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

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T4.0 - 65 KTS
   KNES: T4.5 - 77 KTS
   PHFO: T4.5 - 77 KTS
   CIMSS ADT: 55 KTS AT 010100Z
   CIMSS AIDT: 52 KTS AT 010100Z
   CIMSS D-MINT: 52 KTS AT 282207Z
   CIMSS D-PRINT: 53 KTS AT 010100Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: UNFAVORABLE
   VWS: 25-30 KTS
   SST: 26-27 CELSIUS
   OUTFLOW: MODERATE POLEWARD

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

3. FORECAST REASONING.

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

FORECAST DISCUSSION: TROPICAL CYCLONE (TC) 23P (URMIL) WILL
CONTINUE ITS SOUTHEASTWARD TRAJECTORY FOR THE REMAINDER OF THE
FORECAST PERIOD, DRIVEN BY THE STR POSITIONED TO THE
EAST-NORTHEAST. TC 23P IS FORECASTED TO CONTINUE UNDERGOING
SUBTROPICAL TRANSITION INTO TAU 12, INTERACTING WITH A MAJOR
SHORTWAVE TROUGH ASSOCIATED WITH THE SUBTROPICAL WESTERLIES. DURING
THIS PERIOD, INCREASING DRY-AIR ENTRAINMENT IS FORECASTED TO
CONTINUE WRAPPING INTO THE VORTEX FROM THE WEST, RESULTING IN AN
ELONGATED LLCC, TILTED VERTICAL STRUCTURE, AND A LOSS OF
SIGNIFICANT DEEP CONVECTION. TC 23P IS FORECASTED TO COMPLETE
SUBTROPICAL TRANSITION BY TAU 24 WITH A MAXIMUM SURFACE INTENSITY
NEAR 40 KTS. 

MODEL DISCUSSION: CROSS-TRACK SPREAD AMONG JTWC CONSENSUS SOLUTIONS
REMAIN UNDER 80 NM THROUGHOUT THE FORECAST PERIOD. THE JTWC
FORECASTED TRACK IS PLACED CLOSE TO THE MULTI-MODEL CONSENSUS WITH
HIGH CONFIDENCE. INTENSITY SPREAD HAS DECREASED AND IMPROVED INTO
TAU 24, THEREFORE, THE JTWC FORECASTED INTENSITY LIES CLOSELY TO
THE MULTI MODEL CONSENSUS WITH HIGH CONFIDENCE. 

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