WDPN33 PGTW 240300
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 25W (NEOGURI) WARNING NR 
023//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 30.4N 154.3E
   INITIAL INTENSITY: 60 KTS
   GEOGRAPHIC REFERENCE: 791 NM EAST-SOUTHEAST OF YOKOSUKA, JAPAN
   MOVEMENT PAST 6 HOURS: EASTWARD AT 05 KTS
   SIGNIFICANT WAVE HEIGHT: 25 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) DEPICTS A PARTIALLY
EXPOSED LOW-LEVEL CIRCULATION WITH DEEP CONVECTIVE BANDING
PERSISTING OVER THE NORTHERN PORTION. A FIELD OF STRATOCUMULUS
CLOUDS WRAPPING AROUND THE WESTERN BOUNDARY OF 25W MARKS DRIER AND
MORE STABLE AIR THAT IS WRAPPING INTO THE SOUTHWESTERN PORTION OF
THE SYSTEM. THE INITIAL POSITION IS PLACED WITH MEDIUM CONFIDENCE
BASED ON A 232330Z PGTW SATELLITE POSITION FIX, 232238Z GMI 37 GHZ
MICROWAVE IMAGERY, AND A 232301Z METOP-C ASCAT PASS. THE INITIAL
INTENSITY OF 60 KTS IS ASSESSED WITH MEDIUM CONFIDENCE BASED ON A
CONSENSUS OF AVAILABLE SUBJECTIVE DVORAK AND AUTOMATED INTENSITY
ESTIMATES LISTED BELOW.

INITIAL WIND RADII BASIS: OBJECTIVE BEST TRACK AND 232301Z METOP-C
ASCAT SCATTEROMETER DATA 

CURRENT STEERING MECHANISM: TRANSITIONING TO SUBTROPICAL RIDGING TO
THE SOUTHEAST

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T4.0 - 65 KTS
   RJTD: T4.0 - 65 KTS
   RCTP: T3.0 - 45 KTS
   KNES: T3.5 - 55 KTS
   CIMSS SATCON: 52 KTS AT 232024Z
   CIMSS ADT: 53 KTS AT 232040Z
   CIMSS AIDT: 62 KTS AT 232040Z
   CIMSS D-MINT: 52 KTS AT 232023Z
   CIMSS D-PRINT: 45 KTS AT 240120Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: MARGINAL
   VWS: 10-15 KTS
   SST: 27-28 CELSIUS
   OUTFLOW: STRONG POLEWARD

ANALYSIS CONFIDENCE:
   INITIAL POSITION: MEDIUM
   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: 25W IS EXPECTED TO FOLLOW A MEANDERING TRACK
PATTERN OVER THE NEXT 72 HOURS. FOR THE NEXT 24 HOURS, SUBTROPICAL
RIDGING TO THE EAST AND SOUTH WILL TURN THE SYSTEM NORTHEASTWARD.
THEREAFTER, A SHORTWAVE TROUGH CURRENTLY ANALYZED TO THE NORTH OF
25W WILL TRANSLATE EASTWARD AND AWAY FROM THE SYSTEM, ALLOWING
RIDGING TO BUILD IN ITS PLACE. THIS RIDGING TO THE NORTH OF 25W
WILL TURN THE SYSTEM WESTWARD THROUGH TAU 72. SLOW AND MEANDERING
MOTION WILL ABRUPTLY END AFTER TAU 72 AS A SHORTWAVE THROUGH
DEVELOPING WITHIN THE LONGWAVE PATTERN TO THE NORTHWEST DIGS
EQUATORWARD AND BREAK THE STEERING RIDGE. THE SYSTEM WILL
ACCELERATE NORTHEASTWARD IN THE FLOW BETWEEN THIS APPROACHING
SHORTWAVE TROUGH AND SUBTROPICAL RIDGING TO THE SOUTHEAST, JOINING
THE MID-LATITUDE WESTERLY FLOW PATTERN AND COMPLETING EXTRATROPICAL
TRANSITION BY TAU 120 ALONG THE WAY. INTENSITY WILL REMAIN FAIRLY
STEADY OVER THE NEXT 24 HOURS WITH SUPPORT FROM GENERALLY FAVORABLE
VERTICAL WIND SHEAR AND UPPER-LEVEL OUTFLOW DESPITE A NEAR-TERM
INJECTION OF DRIER AIR FROM THE SOUTHWEST. AS THE SYSTEM TURNS BACK
TO THE WEST, IT WILL PASS OVER ITS OWN COLD WAKE AND THE INTENSITY
SHOULD CORRESPONDINGLY DROP. IN THE EXTENDED PERIOD, FAVORABLE
BAROCLINIC INTERACTION WILL ALLOW 25W TO REINTENSIFY DURING
EXTRATROPICAL TRANSITION.

MODEL DISCUSSION: NUMERICAL MODEL TRACK GUIDANCE IS IN VERY GOOD
AGREEMENT THROUGH TAU 72 WITH ALL MODELS DEPICTING THE WESTWARD
TURN AFTER TAU 24. HOWEVER, THE EXACT TIMING OF THE NORTHEASTWARD
TURN AND SUBSEQUENT RAPID ACCELERATION IS UNCERTAIN, CONTRIBUTING
TO HIGH ALONG-TRACK SPREAD AMONG THE MODEL SOLUTIONS AFTER TAU 72.
THE JTWC TRACK FORECAST IS CONSISTENT WITH THE MULTI-MODEL
CONSENSUS THROUGH TAU 72 AND SLIGHTLY FASTER THEREAFTER, CONSISTENT
WITH THE PREVIOUS JTWC TRACK FORECAST. NUMERICAL INTENSITY FORECAST
GUIDANCE SUPPORTS THE OVERALL FORECAST SCENARIO OF A STEADY STATE
TO SLIGHT DOWNWARD TREND IN THE NEAR TO MEDIUM TERM WITH THE
POTENTIAL FOR REINTENSIFICATION DURING EXTRATROPICAL TRANSITION.
THE RANGE OF INTENSITIES BRACKETED BY THE GUIDANCE ENVELOPE HAS
NARROWED FROM THE PREVIOUS MODEL RUN, SUPPORTING THE CURRENT
INTENSITY FORECAST. 

FORECAST CONFIDENCE:
   TRACK 00-72 HR: HIGH
   TRACK 72-120 HR: MEDIUM
   INTENSITY 00-72 HR: MEDIUM
   INTENSITY 72-120 HR: MEDIUM//
NNNN