Subject: Pacific-NW: Ampn/ref A Is A Tropical Cyclone Formation Alert//

From: SIU Weather Processor <[email-masked]>
Date: Mon, 20 Sep 2010 04:06:08 -0500

WTPN32 PGTW 200900
MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC//
SUBJ/TROPICAL CYCLONE WARNING//
REF/A/NAVMARFCSTCEN PEARL HARBOR HI/200251Z SEP 10//
AMPN/REF A IS A TROPICAL CYCLONE FORMATION ALERT//
RMKS/
1. TROPICAL DEPRESSION 13W (THIRTEEN) WARNING NR 001
   02 ACTIVE TROPICAL CYCLONES IN NORTHWESTPAC
   MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
   WIND RADII VALID OVER OPEN WATER ONLY
    ---
   WARNING POSITION:
   200600Z --- NEAR 18.7N 146.2E
     MOVEMENT PAST SIX HOURS - 325 DEGREES AT 08 KTS
     POSITION ACCURATE TO WITHIN 060 NM
     POSITION BASED ON CENTER LOCATED BY SATELLITE
   PRESENT WIND DISTRIBUTION:
   MAX SUSTAINED WINDS - 025 KT, GUSTS 035 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   REPEAT POSIT: 18.7N 146.2E
    ---
   FORECASTS:
   12 HRS, VALID AT:
   201800Z --- 20.0N 145.2E
   MAX SUSTAINED WINDS - 030 KT, GUSTS 040 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   VECTOR TO 24 HR POSIT: 325 DEG/ 08 KTS
    ---
   24 HRS, VALID AT:
   210600Z --- 21.3N 144.2E
   MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   VECTOR TO 36 HR POSIT: 330 DEG/ 07 KTS
    ---
   36 HRS, VALID AT:
   211800Z --- 22.5N 143.4E
   MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   RADIUS OF 034 KT WINDS - 040 NM NORTHEAST QUADRANT
                            035 NM SOUTHEAST QUADRANT
                            035 NM SOUTHWEST QUADRANT
                            040 NM NORTHWEST QUADRANT
   VECTOR TO 48 HR POSIT: 330 DEG/ 11 KTS
    ---
   EXTENDED OUTLOOK:
   48 HRS, VALID AT:
   220600Z --- 24.5N 142.2E
   MAX SUSTAINED WINDS - 050 KT, GUSTS 065 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   RADIUS OF 050 KT WINDS - 025 NM NORTHEAST QUADRANT
                            020 NM SOUTHEAST QUADRANT
                            020 NM SOUTHWEST QUADRANT
                            020 NM NORTHWEST QUADRANT
   RADIUS OF 034 KT WINDS - 080 NM NORTHEAST QUADRANT
                            075 NM SOUTHEAST QUADRANT
                            070 NM SOUTHWEST QUADRANT
                            075 NM NORTHWEST QUADRANT
   VECTOR TO 72 HR POSIT: 015 DEG/ 11 KTS
    ---
   72 HRS, VALID AT:
   230600Z --- 28.6N 143.3E
   MAX SUSTAINED WINDS - 055 KT, GUSTS 070 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   BECOMING EXTRATROPICAL
   RADIUS OF 050 KT WINDS - 025 NM NORTHEAST QUADRANT
                            025 NM SOUTHEAST QUADRANT
                            025 NM SOUTHWEST QUADRANT
                            025 NM NORTHWEST QUADRANT
   RADIUS OF 034 KT WINDS - 100 NM NORTHEAST QUADRANT
                            100 NM SOUTHEAST QUADRANT
                            095 NM SOUTHWEST QUADRANT
                            095 NM NORTHWEST QUADRANT
   VECTOR TO 96 HR POSIT: 040 DEG/ 19 KTS
    ---
   LONG RANGE OUTLOOK:
   NOTE...ERRORS FOR TRACK HAVE AVERAGED NEAR 250 NM
   ON DAY 4 AND 350 NM ON DAY 5... AND FOR INTENSITY
   NEAR 20 KT EACH DAY.
    ---
   96 HRS, VALID AT:
   240600Z --- 34.6N 149.1E
   MAX SUSTAINED WINDS - 055 KT, GUSTS 070 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   BECOMING EXTRATROPICAL
   VECTOR TO 120 HR POSIT: 055 DEG/ 23 KTS
    ---
   120 HRS, VALID AT:
   250600Z --- 39.4N 159.2E
   MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   EXTRATROPICAL
    ---
REMARKS:
200900Z POSITION NEAR 19.0N 145.9E.
TROPICAL DEPRESSION (TD) 13W (THIRTEEN), LOCATED APPROXIMATELY 205
NM NORTH OF SAIPAN, HAS TRACKED NORTHWESTWARD AT 08 KNOTS OVER THE
PAST SIX HOURS. RECENT ANIMATED MULTI-SPECTRAL SATELLITE IMAGERY
SHOWS IMPROVED ORGANIZATION OF THE SYSTEM WITH DEEP CONVECTION
CONSOLIDATING OVER THE LOW LEVEL CIRCULATION CENTER (LLCC). THE
CURRENT POSITION IS BASED ON A 200532Z PGTW SATELLITE FIX AND A
200335Z 36 GHZ AMSRE MICROWAVE PASS INDICATING CURVED BANDING
WRAPPING INTO AN APPARENT LLCC. THE CURRENT INTENSITY IS BASED ON
DVORAK ESTIMATES FROM PGTW AND KNES RANGING FROM 25 TO 30 KNOTS. THE
UPPER LEVEL ENVIRONMENT REMAINS FAVORABLE FOR DEVELOPMENT WITH
ENHANCED DIFFLUENCE ALOFT ASSOCIATED WITH AN ANTICYCLONE DIRECTLY
OVER THE SYSTEM AS WELL AS INCREASED POLEWARD AND EASTWARD OUTFLOW
ASSOCIATED WITH TROPICAL UPPER TROPOSPHERIC TROUGH (TUTT) CELLS TO
THE NORTH AND EAST OF THE SYSTEM. TD 13W IS CURRENTLY TRACKING ALONG
THE SOUTHWESTERN PERIPHERY OF A LOW TO MID-LEVEL SUBTROPICAL
STEERING RIDGE ANCHORED OVER THE NORTHERN PACIFIC. TD 13W IS
FORECAST TO CONTINUE TRACKING NORTHWESTWARD THROUGH TAU 36, THEN
BEGIN TURNING POLEWARD AS AN APPROACHING MID-LATITUDE TROUGH WEAKENS
THE STEERING RIDGE NEAR TAU 48. AFTER TAU 48, THE SYSTEM IS EXPECTED
TO RECURVE INTO THE MID-LATITUDE WESTERLIES AND BEGIN EXTRA-TROPICAL
TRANSITION. TD 13W IS EXPECTED TO GRADUALLY INTENSIFY AS IT TRACKS
NORTHWESTWARD OVER FAVORABLE SEA SURFACE TEMPERATURES. AVAILABLE
NUMERICAL MODEL GUIDANCE IS IN FAIR AGREEMENT WITH THE SLOW
NORTHWESTWARD TRACK AND RECURVATURE INTO THE MID-LATITUDE
WESTERLIES, HOWEVER, GFS WEAKENS THE SUBTROPICAL STEERING RIDGE
SOONER AND TRACKS THE SYSTEM POLEWARD IN THE INITIAL TAUS. THIS
FORECAST IS IN AGREEMENT WITH MODEL CONSENSUS. MAXIMUM SIGNIFICANT
WAVE HEIGHT AT 200600Z IS 12 FEET. NEXT WARNINGS AT 201500Z,
202100Z, 210300Z AND 210900Z. THIS WARNING SUPERSEDES AND CANCELS
REF A, NAVMARFCSTCEN 200251Z SEP 10 TROPICAL CYCLONE FORMATION
ALERT. REFER TO TROPICAL STORM 12W (FANAPI) WARNINGS (WTPN31 PGTW)
FOR SIX-HOURLY UPDATES.//

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