Typhoon Songda Threatens Traffic in the South Pacific

Saipan (HDW) August 29, 2004 - TYPHOON (TY) 22W (SONGDA), LOCATED APPROXIMATELY 665 NM
EAST OF SAIPAN, HAS TRACKED WEST-NORTHWESTWARD AT 15 KNOTS
OVER THE PAST 06 HOURS. THE WARNING POSITION IS BASED ON
291130Z6 ENHANCED INFRARED SATELLITE IMAGERY. THE WARNING
INTENSITY IS BASED ON SATELLITE CURRENT INTENSITY ESTIMATES
OF 55 AND 65 KNOTS.
B. TY 22W IS FORECAST TO CONTINUE TRACKING WEST-NORTHWESTWARD
ALONG THE SOUTHERN PERIPHERY OF THE LOW TO MID-LEVEL STEERING
RIDGE LOCATED NORTH OF THE SYSTEM. THE AVAILABLE DYNAMIC AIDS
CONSISTING OF NGPS, GFDN, WBAR, JGSM, JTYM, COAMPS, AFWA MM5,
NCEP GFS AND UKMET EGRR ARE IN GOOD AGREEMENT WITH THIS SCENARIO.
THIS FORECAST IS BASED ON A BLEND OF ALL THE AVAILABLE DYNAMIC
AIDS.
C. TY 22W IS EXPECTED TO INTENSIFY AT A NEAR CLIMATOLOGICAL
RATE IN A FAVORABLE ENVIRONMENT OF WEAK VERTICAL WIND SHEAR AND
GOOD DIFFLUENCE ALOFT.
D. CURRENT AND FORECAST WIND RADII ARE BASED ON CLIMATOLOGY
FOR AN AVERAGE SIZED SYSTEM.
E. THE EXTENDED GUIDANCE INDICATES THAT TY 22W WILL TRACK
SLIGHTLY MORE WESTWARD AS THE STEERING RIDGE STRENGTHENS AND
BUILDS TO THE WEST. TY 22W IS FORECAST TO WEAKEN SLIGHTLY IN
THE LATER TAUS AS IT TRACKS UNDER THE SOUTHEAST QUADRANT OF THE
UPPER LEVEL RIDGE AND EXPERIENCES LESS FAVORABLE OUTFLOW CON-
DITIONS AND INCREASED EASTERLY SHEAR.