Typhoon Choi-Wan

Typhoon Choi-Wan is packing 75-kt (85-mph) winds, moving NE at 30 kt (35 mph). Expected to stay over open water.

TYPHOON 26W (CHOI-WAN), LOCATED APPROXIMATELY 461 NM EAST-SOUTHEAST OF MISAWA, JAPAN, HAS TRACKED NORTHEASTWARD AT 30 KNOTS OVER THE PAST SIX HOURS. ANIMATED ENHANCED INFRARED SATELLITE IMAGERY (EIR) DEPICTS 26W WITH A REMNANT, COMPACT INNER CORE, WHICH IS UNDERGOING A RAPID DECOUPLING WITH THE LOWER-LEVEL VORTEX DUE TO PERSISTENT, HIGH SOUTHWESTERLY SHEAR. THE DECOUPLING HAS NOT YET PROGRESSED FAR ENOUGH TO SEE CLEAR EVIDENCE OF IT IN THE EIR, AND A LACK OF RECENT MICROWAVE IMAGERY OR SCATTEROMETER DATA LIMITS ANALYSIS CONFIDENCE. HOWEVER, THE OUTER EDGES OF THE LOW-LEVEL BANDING FEATURES CAN BE SEEN STARTING TO EMERGE ON THE SOUTHWESTERN EDGE OF THE SMALL CDO FEATURE WHICH IS VERY RAPIDLY TRANSLATING OFF TO THE NORTHEAST. PHASE-SPACE ANALYSES SUGGEST 26W IS ALREADY BEGINNING THE PROCESS OF EXTRATROPICAL TRANSITION (ETT) AND ITS TRANSITION IS EXEPECTED TO OCCUR VERY RAPIDLY NOW THAT IT HAS COMMENCED. THE SYSTEM WILL CONTINUE TO ACCELERATE NORTHEASTWARD THROUGH THE FORECAST PERIOD, REACHING OVER 50 KNOTS OF FORWARD SPEED BY THE END OF THE FORECAST. IN TERMS OF INTENSITY, WHILE THE BULK OF THE SUBJECTIVE AND OBJECTIVE INTENSITY ESTIMATES HAVE BEGUN A SHARP DECLINE DUE TO THE DECREASE IN DEEP CONVECTIVE ACTIVITY, THE SATCON REMAINS NEAR 77 KNOTS WHICH IS VERY LIKELY VERY CLOSE TO REALITY, AS THE SYSTEM WILL TAKE TIME TO SPIN DOWN. THE ADDITION OF BAROCLINIC FORCINGS WILL SLOW THE RATE OF WEAKENING EVEN MORE, AND 26W IS FORECAST TO REMAIN AT TYPHOON STRENGTH AS IT COMPLETES ETT WITHIN THE NEXT 12 HOURS. THIS IS THE FINAL WARNING ON THIS SYSTEM BY THE JOINT TYPHOON WRNCEN PEARL HARBOR HI. THE SYSTEM WILL BE CLOSELY MONITORED FOR SIGNS OF REGENERATION. MINIMUM CENTRAL PRESSURE AT 061800Z IS 959 MB. MAXIMUM SIGNIFICANT WAVE HEIGHT AT 061800Z IS 42 FEET. REFER TO TYPHOON 15E (NOLO) WARNINGS (WTPN31 PGTW) FOR SIX-HOURLY UPDATES. REFER TO TROPICAL STORM 27W (KOGUMA) WARNINGS (WTPN33 PGTW) FOR SIX-HOURLY UPDATES.— Joint Typhoon Warning Center · warning 28

This is the West Pacific · 35°N–52°N, 148°E–169°E. Choi-Wan’s forecast track is the dotted spine — the labelled dots mark its position each day. Every cell is shaded by how many hours it spends inside Choi-Wan’s gale-force (≥34 kt · 39 mph) wind across the whole forecast, the damaging core counted double.

Read it two ways at once. Colour is the total — the hours of gale-force wind a place piles up. A slow storm writes its danger in duration, not in any single gust, so the longer the wind sits over a place, the deeper its colour. Opacity is uniform here — this basin publishes no wind-speed-probability field, so the map claims no confidence it has not earned.