WTPN31 PGTW 190900
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE WARNING//
RMKS/
1. TROPICAL STORM 04W (LEEPI) WARNING NR 007
01 ACTIVE TROPICAL CYCLONE IN NORTHWESTPAC
MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
WIND RADII VALID OVER OPEN WATER ONLY
---
WARNING POSITION:
190600Z --- NEAR 22.6N 125.3E
MOVEMENT PAST SIX HOURS - 345 DEGREES AT 12 KTS
POSITION ACCURATE TO WITHIN 045 NM
POSITION BASED ON CENTER LOCATED BY SATELLITE
PRESENT WIND DISTRIBUTION:
MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT
WIND RADII VALID OVER OPEN WATER ONLY
REPEAT POSIT: 22.6N 125.3E
---
FORECASTS:
12 HRS, VALID AT:
191800Z --- 25.2N 125.1E
MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 034 KT WINDS - 030 NM NORTHEAST QUADRANT
030 NM SOUTHEAST QUADRANT
025 NM SOUTHWEST QUADRANT
025 NM NORTHWEST QUADRANT
VECTOR TO 24 HR POSIT: 005 DEG/ 12 KTS
---
24 HRS, VALID AT:
200600Z --- 27.6N 125.3E
MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 034 KT WINDS - 040 NM NORTHEAST QUADRANT
040 NM SOUTHEAST QUADRANT
035 NM SOUTHWEST QUADRANT
035 NM NORTHWEST QUADRANT
VECTOR TO 36 HR POSIT: 025 DEG/ 11 KTS
---
36 HRS, VALID AT:
201800Z --- 29.6N 126.3E
MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 034 KT WINDS - 050 NM NORTHEAST QUADRANT
055 NM SOUTHEAST QUADRANT
050 NM SOUTHWEST QUADRANT
045 NM NORTHWEST QUADRANT
VECTOR TO 48 HR POSIT: 065 DEG/ 23 KTS
---
EXTENDED OUTLOOK:
48 HRS, VALID AT:
210600Z --- 31.6N 131.1E
MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT
WIND RADII VALID OVER OPEN WATER ONLY
BECOMING EXTRATROPICAL
VECTOR TO 72 HR POSIT: 075 DEG/ 32 KTS
---
72 HRS, VALID AT:
220600Z --- 33.9N 146.0E
MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT
WIND RADII VALID OVER OPEN WATER ONLY
EXTRATROPICAL
---
REMARKS:
190900Z POSITION NEAR 23.3N 125.2E.
TROPICAL STORM 04W (LEEPI), LOCATED APPROXIMATELY 271 NM SOUTH-
SOUTHWESTWARD OF KADENA AB, OKINAWA, JAPAN, HAS TRACKED
NORTH-NORTHWESTWARD AT 12 KNOTS OVER THE PAST SIX HOURS. MAXIMUM
SIGNIFICANT WAVE HEIGHT AT 190600Z IS 15 FEET. NEXT WARNINGS AT
191500Z, 192100Z, 200300Z AND 200900Z. //
NNNN
WDPN31 PGTW 190900
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 04W (LEEPI)
WARNING NR 07//
RMKS//
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
TROPICAL STORM 04W (LEEPI), LOCATED APPROXIMATELY 271 NM SOUTH-
SOUTHWESTWARD OF KADENA AB, OKINAWA, JAPAN, HAS TRACKED
NORTH-NORTHWESTWARD AT 12 KNOTS OVER THE PAST SIX HOURS. ANIMATED
MULTISPECTRAL SATELLITE IMAGERY (MSI) SHOWS FRAGMENTED CONVECTIVE
BANDS WRAPPING INTO A POORLY DEFINED LOW-LEVEL CIRCULATION CENTER
(LLCC). THE INITIAL POSITION IS BASED ON THE MSI LOOP WITH POOR
CONFIDENCE. THE INITIAL INTENSITY IS BASED ON CONGRUENT DVORAK
ESTIMATES FROM PGTW AND RJTD. UPPER-LEVEL ANALYSIS INDICATES A
FAVORABLE ENVIRONMENT WITH LIGHT TO MODERATE (10-20 KNOT) VERTICAL
WIND SHEAR (VWS) ENHANCED BY STRONG RADIAL OUTFLOW. ALONG-TRACK SEA
SURFACE TEMPERATURES (SSTS) ARE ALSO FAVORABLE AT 28-30 DEGREES
CELSIUS. TS 04W CONTINUES TO TRACK ALONG THE WESTERN PERIPHERY OF A
DEEP-LAYERED SUBTROPICAL RIDGE (STR) TO THE EAST.
3. FORECAST REASONING.
A. NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE PREVIOUS
PROGNOSTIC REASONING MESSAGE.
B. TS LEEPI WILL CONTINUE TO TRACK POLEWARD OVER THE NEXT 24
HOURS. AFTERWARDS, IT WILL ROUND THE STR AND ACCELERATE NORTHEASTWARD
AS IT BECOMES EMBEDDED IN THE PREVAILING WESTERLIES. TS 04W WILL
EXPERIENCE MODERATE INTENSIFICATION AS FAVORABLE VWS AND SSTS
PERSIST. PEAK INTENSIFICATION IS EXPECTED AT TAU 24-36 WITH
INCREASED OUTFLOW FROM INITIAL EXPOSURE TO THE STRONG WESTERLY WINDS.
INCREASING VWS AND DECREASING SSTS WILL LEAD TO THE DETERIORATION OF
THE SYSTEM SOON AFTER. AFTER TAU 48, TS 04W WILL FURTHER ACCELERATE
INTO THE MID-LATITUDES AND COMMENCE EXTRATROPICAL TRANSITION,
BECOMING A COLD-CORE LOW BY TAU 72. DYNAMIC MODEL GUIDANCE CONTINUES
TO BE IN TIGHT AGREEMENT, LENDING HIGH CONFIDENCE TO THE FORECAST
TRACK, WHICH IS INITIALLY LAID SLIGHTLY RIGHT OF MODEL CONSENSUS
(CONW) AND THEN FASTER THAN CONW AFTER TAU 36. //
NNNN