Typhoon Songda is Now Approaching Japan After Lashing Marianas Islands

Japan (HDW) September 1, 2004 - TYPHOON (TY) 22W (SONGDA), LOCATED APPROXIMATELY 475 NM
SOUTHEAST OF IWO JIMA, HAS TRACKED NORTHWESTWARD AT 07 KNOTS
OVER THE PAST 06 HOURS. THE WARNING POSITION IS BASED ON 312330Z2
MULTISPECTRAL SATELLITE IMAGERY. THE WARNING INTENSITY IS BASED
ON SATELLITE CURRENT INTENSITY ESTIMATES OF 115 AND 127 KNOTS.
B. TY 22W IS FORECAST TO TRACK NORTHWESTWARD ALONG THE SOUTHERN
PERIPHERY OF THE SUBTROPICAL STEERING RIDGE ANCHORED NORTH OF THE
SYSTEM FOR THE NEXT 24 HOURS. AFTER THIS TIME THE TRACK WILL TAKE
A MORE WEST-NORTHWESTWARD TRACK AS THE RIDGE BUILDS WESTWARD. THE
AVAILABLE DYNAMIC AIDS CONSISTING OF UKMET EGRR, NCEP GFS, JGSM,
COAMPS, JTYM, AFWA MM5, NOGAPS, GFDN, AND WBAR ARE IN POOR TO FAIR
AGREEMENT. THIS FORECAST IS BASED ON A BLEND OF ALL OF THE AVAILABLE
DYNAMIC AIDS.
C. INTENSITY DURING THE INITIAL 48 HOURS WILL HOLD RELATIVELY
STEADY AS THE SYSTEM EXPERIENCES RADIAL OUTFLOW. AFTER TAU 36 TY 22W
WILL SLOWLY DECREASE IN INTENSITY FOR THE REMAINDER OF THE FORECAST
PERIOD DUE TO LITTLE CHANGE IN THE ENVIRONMENT AS IT MOVES POLEWARD.
D. CURRENT WIND RADII ARE BASED ON A 312132Z2 SSMI SATELLITE PASS.
FORECAST WIND RADII ARE BASED ON CLIMATOLOGY FOR AN AVERAGE TO
LARGE SIZED SYSTEM.
E. THE EXTENDED FORECAST REMAINS UNCERTAIN DUE TO A TWO SOLUTION
CLUSTER OF AIDS. THE FIRST CLUSTER OF NOGAPS, GFDN, AND WBAR CONTINUE
TO CALL FOR RECURVATURE DUE TO THE PASSAGE OF A STRONG SHORTWAVE OVER
THE SEA OF JAPAN DEVELOPING A SIGNIFICANT WEAKNESS IN THE SUBTROPICAL
RIDGE. THE SECOND SOLUTION CONSISTING OF UKMET EGRR, NCEP GFS, AND JGSM,
CALLS FOR MORE OF A WEST-NORTHWESTWARD TRACK BEFORE RECURVING POLEWARD
DUE TO LESS INTERACTION WITH THE PASSING SHORTWAVE TROUGH. THE ECMWF
ALSO CONTINUES TO SUPPORT THE SECOND SOLUTION CLUSTER. THE OFFICIAL
FORECAST IS BLENDING CONTINUITY OF PRIOR FORECASTS WITH A TRANSITION
TOWARDS THE SECOND SOLUTION CLUSTER.