Naval Oceanographic Portal - Public Facing
Joint Typhoon Warning Center (JTWC)
Current Northwest Pacific/North Indian Ocean* Tropical Systems

TC Warning Text

WTPN31 PGTW 051500
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE WARNING//RMKS/

1. TROPICAL STORM 07W (OMAIS) WARNING NR 005
01 ACTIVE TROPICAL CYCLONE IN NORTHWESTPAC
MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE

WIND RADII VALID OVER OPEN WATER ONLY
---
WARNING POSITION:
051200Z --- NEAR 22.3N 147.4E
MOVEMENT PAST SIX HOURS - 020 DEGREES AT 13 KTS
POSITION ACCURATE TO WITHIN 060 NM
POSITION BASED ON CENTER LOCATED BY SATELLITE
PRESENT WIND DISTRIBUTION:
MAX SUSTAINED WINDS - 050 KT, GUSTS 065 KT
WIND RADII VALID OVER OPEN WATER ONLY

RADIUS OF 034 KT WINDS
220 NM NORTHEAST QUADRANT
245 NM SOUTHEAST QUADRANT
245 NM SOUTHWEST QUADRANT
170 NM NORTHWEST QUADRANT

REPEAT POSIT: 22.3N 147.4E

Prognostic Reasoning

2. 6 HOUR SUMMARY AND ANALYSIS.

DVORAK INTENSITY ESTIMATES HAVE INCREASED TO T3.0 (45 KNOTS) FROM ALL AGENCIES WITH RECENT SATCON ESTIMATES AT 58 KNOTS. THE CURRENT INTENSITY IS ASSESSED AT 50 KNOTS BASED ON THIS DATA AS WELL AS A 051147Z ASCAT IMAGE SHOWING AN AREA OF 50 KNOT WINDS EAST OF THE ELONGATED BUT WELL-DEFINED CENTER. OVERALL, THIS ASCAT IMAGE PROVIDES EVIDENCE THAT THE VERY LARGE SYSTEM IS STRENGTHENING AND BECOMING MORE SYMMETRIC WITH AN EXTENSIVE AREA OF GALE FORCE WINDS EXTENDING OUT TO 220 TO 245NM OVER THE NE, SE AND SW QUADRANTS (THE NW QUADRANT IS CURRENTLY ABOUT 170NM RADIUS BUT IS EXPECTED TO EXPAND AS THE SYSTEM CONSOLIDATES OVER THE NEXT FEW DAYS). BASED ON THE ASCAT DATA, THERE IS IMPROVED CONFIDENCE IN THE CURRENT POSITION. OVERALL, ENVIRONMENTAL CONDITIONS REMAIN FAVORABLE WITH LOW VERTICAL WIND SHEAR, EXCELLENT POLEWARD OUTFLOW (ENHANCED BY AN UPPER TROUGH TO THE NORTHEAST), AND WARM SST (30 TO 31C).

3. FORECAST REASONING.

A. NO CHANGES TO THE FORECAST PHILOSOPHY SINCE THE PREVIOUS PROGNOSTIC REASONING MESSAGE. HOWEVER, 34-KNOT WIND RADII HAVE BEEN EXPANDED SIGNIFICANTLY BASED ON A DETAILED ANALYSIS OF THE ASCAT DATA.

B. TS 07W IS FORECAST TO INTENSIFY TO A PEAK OF 70 KNOTS BY TAU 48 UNDER FAVORABLE ENVIRONMENTAL CONDITIONS. DUE TO THE LARGE EXPANSE OF GALE-FORCE WINDS AND TIGHT SEA LEVEL PRESSURE GRADIENT ALONG THE WESTERN PERIPHERY OF THE SYSTEM, THE 34-KNOT WIND RADII HAVE BEEN EXTENDED OVER LAND, JUST EAST OF TOKYO.

TC Warning Graphic

IR Satellite Imagery