WDPN33 PGTW 040415 COR
MSGID/GENADMIN/NAVPACMETOCCEN PEARL HARBOR HI/JTWC//
SUBJ/PROGNOSTIC REASONING FOR TYPHOON 22W WARNING NR 31//
RMKS/
1. FOR METEOROLOGISTS.
2. PROGNOSTIC REASONING FOR 040415Z4 TO 090000Z9 SEP 2004.
   A. TYPHOON (TY) 22W (SONGDA), LOCATED APPROXIMATELY 300 NM SOUTH-
EAST OF OKINAWA, JAPAN, HAS TRACKED WEST-NORTHWESTWARD AT 11 KNOTS
OVER THE PAST 06 HOURS. THE WARNING POSITION IS BASED ON 032330Z1
MULTISPECTRAL SATELLITE IMAGERY. THE WARNING INTENSITY IS BASED ON
SATELLITE CURRENT INTENSITY ESTIMATES OF 102 AND 115 KNOTS.
   B. TY 22W CONTINUES TO TRACK WEST-NORTHWEST ALONG THE SOUTHWESTERN
PERIPHERY OF THE SUB-TROPICAL RIDGE LOCATED EAST OF JAPAN. THE
STEERING RIDGE IS FORECAST TO CONTINUE BUILDING WESTWARD INTO SOUTHERN
JAPAN, KEEPING TY 22w ON A WEST-NORTHWESTWARD TRACK FOR THE NEXT 48
HOURS. AFTER 48 HOURS, THE TRACK WILL TURN POLEWARD IN RESPONSE TO
INTERACTION WITH A MID-LATITUDE TROUGH FORECAST TO MOVE EASTWARD OVER
THE SEA OF JAPAN. THE AVAILABLE DYNAMIC AIDS CONSISTING OF JGSM, JTYM,
UKMET EGRR, GFDN, AFWA MM5, COAMPS, NOGAPS, AFWA MM5 AND WBAR ARE IN
GOOD AGREEMENT THROUGH TAU 48. THIS FORECAST IS BASED ON A CONSENSUS
OF ALL AVAILABLE DYNAMIC AIDS WITH LESS EMPHASIS ON AFWA MM5.
   C. TY 22W IS FORECAST TO MAINTAIN CURRENT INTENSITY AS IT CONTINUES
UNDER THE INFLUENCE OF A POLEWARD OUTFLOW CHANNEL PRODUCED BY A
LONGWAVE TROUGH LOCATED OVER THE EASTERN COAST OF JAPAN. TY 22W WILL
GRADUALLY WEAKEN AS THE LONGWAVE TROUGH MOVES NORTHEASTWARD AND THE
POLEWARD OUTFLOW LINK IS BROKEN.
   D. CURRENT WIND RADII ARE BASED IN PART ON RECENT QUIKSCAT DATA.
FORECAST WIND RADII ARE BASED ON CLIMATOLOGY FOR AN AVERAGE TO LARGE
SIZED SYSTEM.
   E. THE EXTENDED FORECAST TRACKS TY 22W POLEWARD TOWARDS A WEAKNESS
IN THE SUBTROPICAL RIDGE THAT DEVELOPS AS A RESULT OF A PASSING
MAJOR SHORTWAVE TROUGH OVER THE SEA OF JAPAN. INTENSITY IS FORECAST TO
CONTINUE WEAKENING SLOWLY AS THE SYSTEM ENCOUNTERS HIGHER VERTICAL WIND
SHEAR AS IT INTERACTS WITH THE BAROCLINIC ZONE.
3. JUSTIFICATION FOR COR: CHANGED LONGWAVE TO MAJOR SHORTWAVE IN 2.E.
4. FORECAST TEAM: MOHAMMED/LEFFLER/HEATH/LEWIN//

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