JTWC backed off by 15kt on peak forecast intensity and no longer expecting this to be a typhoon with the 03Z update:
WTPN31 PGTW 040300
MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC//
SUBJ/TROPICAL CYCLONE WARNING//
RMKS/
1. TROPICAL STORM 16W (SIXTEEN) WARNING NR 004
02 ACTIVE TROPICAL CYCLONES IN NORTHWESTPAC
MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
WIND RADII VALID OVER OPEN WATER ONLY
---
WARNING POSITION:
040000Z --- NEAR 27.6N 151.9E
MOVEMENT PAST SIX HOURS - 010 DEGREES AT 35 KTS
POSITION ACCURATE TO WITHIN 060 NM
POSITION BASED ON CENTER LOCATED BY SATELLITE
PRESENT WIND DISTRIBUTION:
MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 034 KT WINDS - 140 NM NORTHEAST QUADRANT
140 NM SOUTHEAST QUADRANT
120 NM SOUTHWEST QUADRANT
130 NM NORTHWEST QUADRANT
REPEAT POSIT: 27.6N 151.9E
---
FORECASTS:
12 HRS, VALID AT:
041200Z --- 31.9N 151.8E
MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 034 KT WINDS - 140 NM NORTHEAST QUADRANT
120 NM SOUTHEAST QUADRANT
115 NM SOUTHWEST QUADRANT
130 NM NORTHWEST QUADRANT
VECTOR TO 24 HR POSIT: 350 DEG/ 16 KTS
---
24 HRS, VALID AT:
050000Z --- 35.0N 151.0E
MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 034 KT WINDS - 145 NM NORTHEAST QUADRANT
155 NM SOUTHEAST QUADRANT
135 NM SOUTHWEST QUADRANT
130 NM NORTHWEST QUADRANT
VECTOR TO 36 HR POSIT: 355 DEG/ 14 KTS
---
36 HRS, VALID AT:
051200Z --- 37.7N 150.8E
MAX SUSTAINED WINDS - 050 KT, GUSTS 065 KT
WIND RADII VALID OVER OPEN WATER ONLY
BECOMING EXTRATROPICAL
RADIUS OF 050 KT WINDS - 030 NM NORTHEAST QUADRANT
030 NM SOUTHEAST QUADRANT
030 NM SOUTHWEST QUADRANT
030 NM NORTHWEST QUADRANT
RADIUS OF 034 KT WINDS - 150 NM NORTHEAST QUADRANT
160 NM SOUTHEAST QUADRANT
140 NM SOUTHWEST QUADRANT
135 NM NORTHWEST QUADRANT
VECTOR TO 48 HR POSIT: 005 DEG/ 22 KTS
---
EXTENDED OUTLOOK:
48 HRS, VALID AT:
060000Z --- 42.1N 151.4E
MAX SUSTAINED WINDS - 055 KT, GUSTS 070 KT
WIND RADII VALID OVER OPEN WATER ONLY
BECOMING EXTRATROPICAL
RADIUS OF 050 KT WINDS - 035 NM NORTHEAST QUADRANT
035 NM SOUTHEAST QUADRANT
030 NM SOUTHWEST QUADRANT
030 NM NORTHWEST QUADRANT
RADIUS OF 034 KT WINDS - 155 NM NORTHEAST QUADRANT
165 NM SOUTHEAST QUADRANT
150 NM SOUTHWEST QUADRANT
140 NM NORTHWEST QUADRANT
VECTOR TO 72 HR POSIT: 360 DEG/ 27 KTS
---
72 HRS, VALID AT:
070000Z --- 52.7N 151.0E
MAX SUSTAINED WINDS - 030 KT, GUSTS 040 KT
WIND RADII VALID OVER OPEN WATER ONLY
EXTRATROPICAL
---
REMARKS:
040300Z POSITION NEAR 28.7N 151.9E.
TROPICAL STORM 16W, LOCATED APPROXIMATELY 595 NM EAST-NORTHEAST OF
IWO TO, JAPAN, CONTINUED TO ACCELERATE AND TRACK NORTHWARD AT 35 KTS
OVER THE PAST SIX HOURS. MAXIMUM SIGNIFICANT WAVE HEIGHT AT 040000Z
IS 15 FEET. NEXT WARNINGS AT 040900Z, 041500Z, 042100Z AND 050300Z.
REFER TO TROPICAL DEPRESSION 15W (TALAS) WARNINGS (WTPN32 PGTW) FOR
SIX-HOURLY UPDATES.//
NNNN
WDPN31 PGTW 040300
MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 16W WARNING NR 04//
RMKS/
1. FOR METEOROLOGISTS.
2. 12 HOUR SUMMARY AND ANALYSIS.
A. TROPICAL STORM (TS) 16W, LOCATED APPROXIMATELY 595 NM EAST-
NORTHEAST OF IWO TO, JAPAN, CONTINUED TO ACCELERATE AND TRACKED
NORTHWARD AT 35 KTS OVER THE PAST SIX HOURS. ANIMATED INFRARED
SATELLITE IMAGERY SHOWS THAT CONVECTIVE BANDS HAVE BECOME FRAGMENTED
AND DETACHED BEHIND THE MAIN AREA OF DEEP CENTRAL CONVECTION.
HOWEVER, ANIMATED MULTISPECTRAL IMAGERY SHOWS THE LOW LEVEL
CIRCULATIN CENTER REMAINS INTACT ALTHOUGH PARTIALLY EXPOSED AND
LAGGING BEHIND THE MAIN CONVECTION. THIS IS EVIDENT ON A 032314Z
METOPA MICROWAVE IMAGE. THE INITIAL POSITION WAS BASED ON THE ABOVE
ANIMATIONS AND FROM THE MICROWAVE IMAGE WITH HIGH CONFIDENCE. THE
INITIAL INTENSITY IS SUPPORTED BY DVORAK ESTIMATES FROM PGTW, RJTD
AND KNES. UPPER LEVEL ANALYSIS INDICATES THE SYSTEM IS JUST TO THE
EAST OF A TROPICAL UPPER TROPOSPHERIC TROUGH (TUTT) AND TO THE WEST
OF AN ANTICYCLONE THAT IS ENHANCING NORTHEASTWARD OUTFLOW, ALBEIT
IN AN AREA OF MODERATE (15-20 KT) VERTICAL WIND SHEAR (VWS). THE
TUTT LIMITING OUTFLOW ALONG THE WESTERN PERIPHERY. THE STORM IS
BEING STEERED BY A DEEP-LAYERED SUBTROPICAL RIDGE TO THE EAST.
3. FORECAST REASONING.
A. THERE IS NO SIGNIFICANT CHANGE TO THE FORECAST PHILOSPHY.
B. TS 16W IS FORECAST TO INITIALLY WEAKEN AS CONVECTION ERODES
DUE TO ITS ABNORMALLY FAST STORM MOTION AND INCREASING VERTICAL
WIND SHEAR AHEAD OF AN APPROACHING MID-LATITUDE TROUGH FROM THE
NORTHWEST. THIS TROUGH WILL WEAKEN THE STEERING RIDGE AND CAUSE
THE CYCLONE TO MOMENTARILY RECURVE SLIGHTLY EAST OF TRACK. AFTER
TAU 36, THE SYSTEM IS EXPECTED TO TURN MORE POLEWARD AS A HIGH
AMPLITUDE SUBTROPICAL RIDGE TO THE EAST OF NORTHERN JAPAN WILL
BUILD AND ASSUME STEERING. THE INITIAL EXPOSURE TO STRONG WESTERLIES
WILL ENHANCE OUTFLOW AND SLIGHTLY INTENSIFY THE STORM, ALBEIT FOR A
SHORT PERIOD. AFTER TAU 48, THE SYSTEM WILL BEGIN EXTRA-TROPICAL
TRANSITION (ET) AND WEAKEN AS VWS INCREASES AND SEA SURFACE
TEMPERATURES COOL. THE SYSTEM WILL COMPLETE ET BY END OF FORECAST.
GIVEN THE EXCEEDINGLY FAST STORM MOTION, THERE IS A DISTINCT
POSSIBILITY THAT THE SYSTEM WILL DISSIPATE BEFORE TAU 36. THE
NUMERICAL MODEL GUIDANCE IS IN FAIR AGREEMENT UP TO TAU 48 BEFORE
IT FANS OUT TO APPROXIMATELY 30 DEGREES WITH EGRR TO THE LEFT OF
AND JGSM AND WBAR TO THE RIGHT OF THE ENVELOPE. THIS TRACK FORECAST
IS TO THE RIGHT OF CONSENSUS. NEXT WARNINGS AT 040900Z, 041500Z,
042100Z AND 050300Z. REFER TO TROPICAL DEPRESSION 15W (TALAS)
WARNINGS (WTPN32 PGTW) FOR SIX-HOURLY UPDATES.//
NNNN
