NANMADOL Prognosis

[Jeb]

WDPN31 PGTW 020300

MSGID/GENADMIN/NAVPACMETOCCEN PEARL HARBOR HI/JTWC//

SUBJ/PROGNOSTIC REASONING FOR SUPER TYPHOON 30W WARNING NR 14//

RMKS/

1. FOR METEOROLOGISTS.

2. PROGNOSTIC REASONING FOR 020000Z2 DEC TO 060000Z6 DEC 2004.

A. SUPER TYPHOON (STY) 30W (NANMADOL), LOCATED APPROXIMATELY 220

NM EAST OF MANILA, PHILIPPINES, HAS TRACKED WEST-NORTHWESTWARD AT

19 KNOTS OVER THE PAST 06 HOURS. THE WARNING POSITION IS BASED ON

012330Z9 MULTISPECTRAL SATELLITE IMAGERY. THE WARNING INTENSITY IS

BASED ON SATELLITE CURRENT INTENSITY ESTIMATES OF 115 AND 140 KNOTS.

RECENT MICROWAVE IMAGERY REVEALS A RAGGED EYE AND INCREASED CLOUD

COVER.

B. STY 30W IS FORECAST TO CONTINUE TRACKING RAPIDLY WEST-

NORTHWESTWARD ALONG THE SOUTHWESTERN PERIPHERY OF THE SUBTROPICAL

RIDGE ANCHORED TO THE NORTHEAST FOR THE NEXT 12 TO 24 HOURS. STY 30W

IS FORECAST TO MAKE LANDFALL ALONG THE EAST COAST OF THE NORTHERN

PHILIPPINES WITHIN THE NEXT 12 TO 18 HOURS AND WILL SLOW DOWN AS IT

INTERACTS WITH LAND. ONCE STY 30W CROSSES THE NORTHERN PHILIPPINES

IT WILL MOVE OUT OVER THE SOUTH CHINA SEA AND BEGIN TO RECURVE

POLEWARD IN RESPONSE TO A DEVELOPING WEAKNESS IN THE STEERING RIDGE.

THIS WEAKNESS WILL BE CREATED BY A TROUGH MOVING OVER THE EASTERN

COAST OF SOUTHEAST ASIA. THE AVAILABLE DYNAMIC AIDS CONSISTING OF

NOGAPS, COAMPS, GFDN, AFWA MM5, NCEP GFS, JGSM, JTYM, TCLAPS, UKMET,

AND WBAR ARE IN FAIR AGREEMENT WITH THIS SCENARIO. HOWEVER, COAMPS,

TCLAPS, AND WBAR ARE SLIGHTLY SLOWER IN RECURVING STY 30W. THIS

FORECAST IS BASED ON A CONSENSUS OF ALL AVAILABLE DYNAMIC AIDS.

C. THE INTENSITY OF STY 30W IS FORECAST TO SLOWLY DECREASE AS IT

INTERACTS WITH LAND. AFTER TAU 24 AS THE SYSTEM ENTERS AN ENVIRONMENT

OF MODERATE VERTICAL WIND SHEAR IT WILL BEGIN TO WEAKEN MORE RAPIDLY.

THE SYSTEM WILL BECOME EXTRA-TROPICAL BETWEEN TAUS 48 AND 72.

D. CURRENT WIND RADII ARE BASED ON A 012122Z8 QUIKSCAT PASS AND

A 012132Z9 SSMI MICROWAVE PASS. IN THE PAST 12 HOURS THE WIND RADII

HAS INCREASED SUBSTANTIALLY. CURRENT AND FORECAST WIND RADII ARE

BASED ON CLIMATOLOGY FOR A LARGE SIZED SYSTEM.

E. STY 30W WILL RAPIDLY TRACK NORTHEASTWARD AS IT WILL HAVE

BECOME EXTRA-TROPICAL AND WILL BECOME EMBEDDED IN THE BAROCLINIC

ZONE.

3. FORECAST TEAM: PITTS/KLINZMANN/FUNK//

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