WDPN33 PGTW 100300
MSGID/GENADMIN/NAVPACMETOCCEN PEARL//JTWC//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 11W (NAKRI) WARNING 
NR 07//
RMKS/
1. FOR METEOROLOGISTS.
2. PROGNOSTIC REASONING FOR 100000Z1 TO 130000Z4 JUL 02.
   A. TROPICAL STORM (TS) 11W (NAKRI) IS JUST NORTH OF THE TIP OF 
TAIWAN AND HAS TRACKED NORTHEASTWARD AT 09 KNOTS OVER THE PAST SIX 
HOURS. THE WARNING POSITION IS BASED ON 092330Z7 VISIBLE AND 
ENHANCED INFRARED SATELLITE IMAGERY, SYNOPTIC DATA, AND RADAR 
IMAGERY. THE WARNING INTENSITY IS BASED ON SATELLITE CURRENT 
INTENSITY ESTIMATES OF 30 AND 35 KNOTS. OVER THE PAST 12 HOURS 
TAIWAN RADAR IMAGERY DEPICTED A SEPARATION BETWEEN THE DEEP 
CONVECTION AND THE LOW-LEVEL CIRCULATION CENTER. IN THE PAST THREE 
HOURS THE RADAR SIGNATURE APPEARS TO HAVE MOVED BACK UNDER THE  
CONVECTION ALONG THE NORTHERN COAST OF TAIWAN. SATELLITE IMAGERY 
INDICATES NEW DEEP CONVECTION HAS DEVELOPED OVER THE CENTER IN THE 
PAST THREE HOURS. SYNOPTIC DATA ALSO SHOWS A WEAK LOW PRESSURE AREA  
DEVELOPING ALONG THE CENTRAL EAST COAST OF TAIWAN. 
   B. MODERATE MID-LEVEL SOUTHWESTERLIES IN RESPONSE TO A QUASI-
STATIONARY SUB-EQUATORIAL RIDGE OVER MINDANAO WILL INFLUENCE 
THE TROPICAL CYCLONE MOTION THROUGHOUT THE FORECAST PERIOD. AFTER 48 
HOURS THE APPROACH OF TY 10W IS EXPECTED TO MODIFY THE MID-LEVEL 
STEERING FLOW, STEERING TS 11W SOUTHEASTWARD THROUGH 72 HOURS. ALL 
NWP SHOW VARYING DEGREES OF MODIFICATION TO THE STEERING ENVIRONMENT 
DUE TO THE APPROACH OF TY 10W.  THE GFDN, JMA GLOBAL AND UKMET GRID 
POINT MODELS SHOW A SLOW SOUTHEASTWARD TRACK BETWEEN 48 AND 72 
HOURS. THE COAMPS, NOGAPS, AVN AND MM5 CONTINUE TO HAVE HAVE 
DIFFICULTY RESOLVING THE SMALL TROPICAL CYCLONE AND SHOW A 
SOUTHWESTWARD TURN BETWEEN 36 AND 48 HOURS. OUR FORECAST IS BASED ON 
A BLEND OF ALL NUMERICAL MODELS BUT FOLLOWS THE SOUTHEASTWARD TRACK 
SOLUTION AFTER 48 HOURS.
   C. LITTLE INTENSITY CHANGE IS FORECAST OVER THE NEXT 12 HOURS AS 
THE SYSTEM CONTINUES TO INTERACT WITH THE TAIWAN COAST. AFTERWARD, 
FURTHER STRENGTHENING IS EXPECTED AS IT MOVES OVER WARMER WATER EAST 
OF TAIWAN AND BENEATH THE UPPER SUBTROPICAL RIDGE.
   D. FORECAST WIND RADII ARE BASED ON CLIMATOLOGY FOR A SMALLER 
THAN AVERAGE SIZE SYSTEM.
3. FORECAST TEAM: JEFFRIES/SMITH/KENDALL/SCHAEFER/EDBERG//