WDPN33 PGTW 252100
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL DEPRESSION 11W (CO-MAY)   
WARNING NR 012//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 23.6N 124.9E
   INITIAL INTENSITY: 30 KTS
   GEOGRAPHIC REFERENCE: 235 NM SOUTHWEST OF KADENA AB
   MOVEMENT PAST 6 HOURS: NORTHEASTWARD AT 21 KTS
   SIGNIFICANT WAVE HEIGHT: 17 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY DEPICTS A FULLY
EXPOSED LOW-LEVEL CIRCULATION (LLC), WITH FLARING, ISOLATED CONVECTION 
OVER THE EASTERN AND SOUTHERN PERIPHERIES. EIR SATELLITE IMAGERY AND A 
251729Z GMI 37GHZ COLOR COMPOSITE MICROWAVE IMAGE REAVEAL SHALLOW 
BANDING WRAPPING INTO A WELL-DEFINED CENTER, WHICH SUPPORTS THE INITIAL 
POSITION WITH HIGH CONFIDENCE. A 251211Z ASCAT-B BULLSEYE IMAGE 
REVEALED A DEFINED CIRCULATION, WITH A SWATH OF 25-30 KNOT WINDS OVER 
THE SOUTHEAST QUADRANT AND WEAK WINDS OVER THE NORTHWEST QUADRANT. THE 
INITIAL INTENSITY OF 30 KTS IS ASSESSED WITH HIGH CONFIDENCE BASED ON 
RECENT ASCAT DATA AND THE PGTW, RCTP DVORAK ESTIMATES. CIMSS OBJECTIVE 
ESTIMATES GENERALLY SUPPORT AND RANGE FROM 23-35 KNOTS.

INITIAL WIND RADII BASIS: NOT APPLICABLE (THERE ARE NO INITIAL WIND
RADII).

CURRENT STEERING MECHANISM: LOW-LEVEL STEERING RIDGE POSITIONED TO
THE SOUTHEAST AND EAST.

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T2.0 - 30 KTS
   RJTD: T3.5 - 55 KTS
   RCTP: T2.0 - 30 KTS
   KNES: T2.5 - 35 KTS
   DEMS: T2.5 - 35 KTS
   CIMSS SATCON: 41 KTS AT 251718Z
   CIMSS ADT: 33 KTS AT 251730Z
   CIMSS AIDT: 35 KTS AT 251730Z
   CIMSS D-MINT: 25 KTS AT 251728Z
   CIMSS D-PRINT: 23 KTS AT 251830Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: MARGINAL
   VWS: 15-20 KTS
   SST: 29-30 CELSIUS
   OUTFLOW: WEAK EQUATORWARD
   OTHER FACTORS: DRY AIR ENTRAINMENT

ANALYSIS CONFIDENCE:
   INITIAL POSITION: HIGH
   INITIAL INTENSITY: HIGH
   INITIAL WIND RADII: NOT APPLICABLE

3. FORECAST REASONING.

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

FORECAST DISCUSSION: TROPICAL DEPRESSION (TD) 11W IS EMBEDDED WITHIN AN 
EXTENSIVE SWATH OF SOUTHERLY FLOW THAT RUNS FROM THE EAST PHILIPPINE 
SEA NORTHWARD ALONG THE EASTWARD PERIPHERY OF THE SYSTEM THEN NORTHWARD 
OVER THE RYUKYU ISLANDS. THIS ENHANCED FLOW PATTERN BETWEEN THE SYSTEM 
AND THE LOW-LEVEL STEERING RIDGE WILL PUSH TD 11W POLEWARD THROUGH THE 
FORECAST PERIOD. THE SYSTEM WILL STEADILY OPEN UP AND WEAKEN UNDER 
MARGINAL CONDITIONS TO INCLUDE DRY AIR AND LOW TO MODERATE VERTICAL 
WIND SHEAR. ADDITIONALLY, THE UPPER-LEVEL CIRCULATION IS DECOUPLED FROM 
THE LOW-LEVEL CIRCULATION, WHICH IS EMBEDDED WITHIN LOW- TO MID-LEVEL 
SOUTHERLY FLOW. AFTER TAU 24, THE SYSTEM IS EXPECTED TO DISSIPATE. 
HOWEVER, THE GLOBAL MODELS SHOW A BROAD TROUGH DEVELOPING ACROSS THE 
OKINAWA REGION, WITH A BELT OF 25-30 KNOT WINDS OVER THE NORTHERN 
PERIPHERY, AND POSSIBLE DEVELOPMENT OF A NEW, WEAK SURFACE LOW NEAR 
OKINAWA IN ONE TO TWO DAYS.             

MODEL DISCUSSION: DETERMINISTIC MODEL GUIDANCE IS IN GOOD AGREEMENT
THROUGH THE FORECAST PERIOD, WITH A 50NM CROSS-TRACK SPREAD AT TAU
24. RELIABLE INTENSITY GUIDANCE IS IN POOR AGREEMENT AFTER TAU 24
LIKELY DUE TO THE FORMATION OF ANOTHER LOW PRESSURE AREA NEAR
OKINAWA.  

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