
WTPN33 PGTW 170900
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE WARNING//
RMKS/
1. TROPICAL DEPRESSION 13W (THIRTEEN) WARNING NR 002
02 ACTIVE TROPICAL CYCLONES IN NORTHWESTPAC
MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
WIND RADII VALID OVER OPEN WATER ONLY
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WARNING POSITION:
170600Z --- NEAR 26.8N 129.3E
MOVEMENT PAST SIX HOURS - 275 DEGREES AT 09 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: 26.8N 129.3E
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FORECASTS:
12 HRS, VALID AT:
171800Z --- 27.5N 127.3E
MAX SUSTAINED WINDS - 030 KT, GUSTS 040 KT
WIND RADII VALID OVER OPEN WATER ONLY
VECTOR TO 24 HR POSIT: 285 DEG/ 08 KTS
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24 HRS, VALID AT:
180600Z --- 27.9N 125.6E
MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT
WIND RADII VALID OVER OPEN WATER ONLY
VECTOR TO 36 HR POSIT: 260 DEG/ 05 KTS
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36 HRS, VALID AT:
181800Z --- 27.7N 124.5E
MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT
WIND RADII VALID OVER OPEN WATER ONLY
VECTOR TO 48 HR POSIT: 225 DEG/ 04 KTS
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EXTENDED OUTLOOK:
48 HRS, VALID AT:
190600Z --- 27.1N 123.8E
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
040 NM SOUTHWEST QUADRANT
040 NM NORTHWEST QUADRANT
VECTOR TO 72 HR POSIT: 210 DEG/ 01 KTS
---
72 HRS, VALID AT:
200600Z --- 26.6N 123.5E
MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 034 KT WINDS - 035 NM NORTHEAST QUADRANT
035 NM SOUTHEAST QUADRANT
040 NM SOUTHWEST QUADRANT
040 NM NORTHWEST QUADRANT
VECTOR TO 96 HR POSIT: 195 DEG/ 02 KTS
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LONG RANGE OUTLOOK:
---
96 HRS, VALID AT:
210600Z --- 26.0N 123.3E
MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT
WIND RADII VALID OVER OPEN WATER ONLY
VECTOR TO 120 HR POSIT: 170 DEG/ 01 KTS
---
120 HRS, VALID AT:
220600Z --- 25.5N 123.4E
MAX SUSTAINED WINDS - 065 KT, GUSTS 080 KT
WIND RADII VALID OVER OPEN WATER ONLY
---
REMARKS:
170900Z POSITION NEAR 27.0N 128.8E.
TROPICAL DEPRESSION 13W (THIRTEEN), LOCATED APPROXIMATELY 82 NM
EAST-NORTHEASTWARD OF KADENA AB, HAS TRACKED WESTWARD AT 09 KNOTS
OVER THE PAST SIX HOURS. MAXIMUM SIGNIFICANT WAVE HEIGHT AT 170600Z
IS 10 FEET. NEXT WARNINGS AT 171500Z, 172100Z, 180300Z AND 180900Z.
REFER TO TROPICAL DEPRESSION 12W (TWELVE) WARNINGS (WTPN32 PGTW)
FOR SIX-HOURLY UPDATES.//
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WDPN33 PGTW 170900
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL DEPRESSION 13W (THIRTEEN)
WARNING NR 02//
RMKS//
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
TROPICAL DEPRESSION 13W (THIRTEEN), LOCATED APPROXIMATELY 82 NM
EAST-NORTHEASTWARD OF KADENA AB, HAS TRACKED WESTWARD AT 09 KNOTS
OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY
REVEALS THE STRUCTURE OF TD 13W HAS CHANGED LITTLE OVER THE PAST SIX
HOURS AS CONVECTION HAS NOT IMPROVED, ALTHOUGH MULTIPLE VORTICES
SEEM TO BE PRESENT AS AN EXPOSED CIRCULATION BRIEFLY MADE AN
APPEARANCE SOUTH OF THE SYSTEM. A 170436Z AMSU-B MICROWAVE SHOWS THE
LIMITED CONVECTION CONTINUES TO REMAIN ALONG THE NORTHERN PERIPHERY
OF THE LLCC. THE INITIAL POSITION IS BASED UPON THE MSI LOOP WITH
LOW CONFIDENCE DUE TO THE MULTIPLE CIRCULATIONS IN THE AREA. THE
INITIAL INTENSITY HAS BEEN ASSESSED AT 25 KNOTS BASED UPON DVORAK
INTENSITY ESTIMATES FROM ALL AGENCIES AND THE UNCHANGED STRUCTURE OF
THE SYSTEM. UPPER-LEVEL ANALYSIS REVEALS THE SYSTEM IS LOCATED SOUTH
OF THE SUBTROPICAL RIDGE AXIS AND IS IN A DECREASING ENVIRONMENT AS
AN UPPER-LEVEL LOW HAS BECOME MORE PRONOUNCED DIRECTLY SOUTH OF THE
SYSTEM WHICH HAS LIMITED THE OUTFLOW DESPITE VERTICAL WIND SHEAR
STAYING AT LOW TO MODERATE (05-15 KNOTS) LEVELS. TD 13W IS CURRENTLY
TRACKING WEST ALONG THE SOUTHERN PERIPHERY OF A LOW TO MID-LEVEL
SUBTROPICAL STEERING RIDGE (STR) NORTH OF THE SYSTEM.
3. FORECAST REASONING.
A. NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE PREVIOUS
PROGNOSTIC REASONING MESSAGE.
B. TD 13W IS FORECAST TO CONTINUE TO TRACK GENERALLY WEST THROUGH
TAU 36 AS IT CONTINUES TO MOVE ALONG THE PERIPHERY OF THE STR. AFTER
TAU 36, DIRECT CYCLONE INTERACTION (DCI) IS EXPECTED TO BECOME THE
DOMINANT STEERING INFLUENCE AS TD 13W BEGINS TO ORBIT AROUND TD 12W.
SLOW INTENSIFICATION IS EXPECTED THROUGH THE EARLY FORECAST PERIODS,
AS MODERATELY FAVORABLE CONDITIONS OF WARM SEA SURFACE TEMPERATURES,
LOW TO MODERATE VWS, AND IMPROVED OUTFLOW ARE EXPECTED.
C. TD 13W IS EXPECTED CONTINUE TO INTERACT WITH TD 12W IN THE
EXTENDED TAUS, AND EVENTUALLY MERGE INTO EACH OTHER BY TAU 120. SLOW
INTENSIFICATION IS EXPECTED TO CONTINUE AS THESE TWO SYSTEMS
CONSOLIDATE AND REACH TYPHOON STRENGTH BY TAU 120. DYNAMIC MODEL
GUIDANCE IS SPREAD THROUGH THE FORECAST PERIOD DUE TO THE PROXIMITY
OF TD 12W, AND THE DCI, AS TWO DIFFERENT SCENARIOS HAVE BECOME
CLEAR. SOME MODELS CONTINUE TO SHOW THE CONTINUED DCI WHILE SOME
SEEM TO INDICATE THAT TD 12W WILL BECOME THE DOMINANT CIRCULATION IN
THIS SCENARIO AND CALL FOR TD 13W TO WEAKEN AS TD 12W CREATES AN
UNFAVORABLE UPPER-LEVEL ENVIRONMENT. THERE IS LOW CONFIDENCE IN THE
FORECAST DUE TO THIS.//
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