WDPN31 PGTW 190300 
MSGID/GENADMIN/NAVPACMETOCCEN PEARL//JTWC//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL DEPRESSION 26W WARNING NR 1//
RMKS/
1. FOR METEOROLOGISTS.
2. PROGNOSTIC REASONING FOR 190000Z0 TO 220000Z4 OCT 01.
   A. TROPICAL DEPRESSION (TD) 26W HAS DEVELOPED OVER A SURFACE 
TROUGH APPROXIMATELY 270 NM EAST-SOUTHEAST OF CHUUK. TD 26W HAS BEEN 
QUASI-STATIONARY DURING THE PAST SIX HOURS. THE WARNING 
POSITION IS BASED ON 182330Z7 INFRARED AND VISIBLE SATELLITE 
IMAGERY. THE WARNING INTENSITY IS BASED ON SATELLITE CURRENT 
INTENSITY ESTIMATES OF 25 AND 30 KNOTS. MULTI-SPECTRAL ANIMATION AND 
A RECENT TRMM PASS DEPICTED A PARTIALLY EXPOSED LOW-LEVEL 
CIRCULATION CENTER DECOUPLED TO THE EAST OF THE ASSOCIATED 
CONVECTION. 
   B. LOW/MID LEVEL SUBTROPICAL RIDGE SITUATED SOUTHEAST OF JAPAN 
SHOULD GRADUALLY WEAKEN THROUGH THE FORECAST PERIOD. THEREFORE, TD 
26W IS FORECAST TO TRACK GENERALLY NORTHWESTWARD THROUGH THE PERIOD.
THE AVAILABLE DYNAMIC AIDS OF NOGAPS, THE UKMET-O GLOBAL SPECTRAL, 
AVIATION, AND THE JMA GLOBAL SPECTRAL MODEL ARE POORLY INITIALIZED. 
ALL OF THE MODELS INITIALIZE THE VORTEX FURTHER EQUATORWARD THAN 
IMAGERY AND SYNOPTIC DATA ACTUALLY INDICATE. THERE IS ALSO AN 
ERRONEOUS BINARY INTERACTION REVEALED BETWEEN THE TD AND A TROPICAL 
DISTURBANCE SOUTHEAST OF PAPUA, NEW GUINEA. THE AGGRESSIVE 
INTERACTION OVER DEVELOPS THE LOW/MID LEVEL SOUTHWESTERLIES BETWEEN 
THE SYSTEMS CAUSING AN IMMEDIATE NORTH TO NORTHEASTWARD TRACK. THE 
MID-LEVEL REFLECTION OF THE TD ON NOGAPS AND THE UKMET RUN, HOWEVER, 
DOES REFLECT A GENERALLY NORTHWESTWARD TRACK SOUTH OF THE RIDGE, 
SIMILAR TO THE COLORADO STATE STATISTICAL (CSUM) AND THE BETA 
ADVECTION MODELS. OUR FORECAST IS BASED ON PERSISTENCE, THE BETA 
ADVECTION MODELS, CSUM, AND NOGAPS.
   C. TD 26W IS EXPECTED TO INTENSIFY AT A NEAR CLIMATOLOGICAL RATE 
AS IT TRACKS SOUTH OF THE UPPER-LEVEL RIDGE. 
   D. WIND RADII ARE BASED ON CLIMATOLOGY FOR AN AVERAGE SIZE 
TROPICAL CYCLONE. 
FORECAST TEAM: ROBERTS/LEEJOICE/HARRISON/EDBERG//