Looks like an “I told you so” is in order. When I looked at Typhoon Lupit before midnight EDT on October 22, the Joint Typhoon Warning Center had indicated that dry air had gotten into the circulation and so they downgraded Lupit to a Tropical Storm. The forecast still called for the storm to linger just north of Luzon, Philippines for a few days until a trof developed in a weakness in the ridge to the north and then it would pick up the storm and take it north. I had noted last night that I had observed on the Total Precipitable Water loop that it appeared that Lupit had already begun moving north, though it was so few frames worth, I could not be certain that it wasn’t just a wobble.
Well, it wasn’t just a wobble. It has indeed been drifting north and now north-northeast, or away from the Philippines. The trof will continue to pick up the storm and it will slowly increase forward speed to the north-northeast and then northeast. So much so that I doubt this guy ends up being any problems for anything beside shipping interest. The storm simply took too much time to get to the Philippines. It stuck around long enough for the steering environment to change and now it would appear that the Philippines, and everyone else is in good shape. Or, you may say that prayers were answered. Either way, it seems very unlikely that Lupit will be adversely affecting any major land masses, though coastal regions of Japan will probably monitor the storm closely until it has moved sufficiently north to northeast to eliminate any landfall potential there.
WDPN31 PGTW 231500 MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC// SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 22W (LUPIT) WARNING NR 039// RMKS/ 1. FOR METEOROLOGISTS. 2. 12 HOUR SUMMARY AND ANALYSIS. A. TROPICAL STORM (TS) 22W (LUPIT), LOCATED APPROXIMATELY 345 NM NORTH-NORTHEAST OF MANILA, PHILIPPINES, HAS TRACKED NORTH- NORTHEASTWARD AT 03 KNOTS OVER THE PAST SIX HOURS. CURRENT POSITION IS BASED ON A 230937Z WINDSAT AND 231006Z SSMI IMAGE. BASED ON THE MICROWAVE IMAGERY SHOWING THAT THE LOW LEVEL CIRCULATION CENTER (LLCC) IS STILL MAINTAINING ITS STRUCTURE, AND BASED ON PERSISTENCE OF THE IMAGERY, THE INTENSITY HAS BEEN HELD AT 55 KNOTS. ANIMATED INFRARED IMAGERY SHOWS THAT THE DEEP CONVECTION LOCATED OVER THE LLCC HAS BECOME FRAGMENTED AND DISORGANIZED. ANIMATED ENHANCED WATER VAPOR IMAGERY SHOWS THAT AN UPPER LEVEL MID-LATITUDE JET HAS BEEN IMPACTING THE NORTHWESTERN QUADRANT OF LUPIT, CAUSING DRY AIR INTRUSION IN THE MID AND UPPER LEVELS. A SHORTWAVE TROUGH IS ALSO VISIBLE IN THE IMAGERY, IS NOW LOCATED OVER TAIWAN AND IS BRIEFLY ALLOWING TS 22W TO FORM A POLEWARD OUTFLOW CHANNEL. THIS CHANNEL APPEARS TO BE HELPING TS 22W TO MAINTAIN ITS INTENSITY IN LIGHT OF THE DRY AIR ALONG THE NORTHWESTERN QUADRANT. LUPIT IS CURRENTLY TRACKING SLOWLY ALONG THE WESTERN EXTENT OF A DEVELOPING SUBTROPICAL RIDGE (STR). 3. FORECAST REASONING A. THE FORECAST REASONING HAS CHANGED SIGNIFICANTLY SINCE THE PREVIOUS PROGNOSTIC REASONING BULLETIN. THE CURRENT FORECAST HAS SHIFTED TO A NORTH-NORTHEAST TRACK AS THE STR TO THE EAST OF LUPIT HAS STARTED TO ENHANCE, BECOMING THE DOMINANT STEERING INFLUENCE. THE TRACK SPEEDS REMAIN SLOW AS THE STR HAS ONLY STARTED TO BUILD. B. TS 22W IS EXPECTED TO CONTINUE TO TRACK SLOWLY TO THE NORTH- NORTHEAST UNDER THE INFLUENCE OF THE STR TO THE EAST. DUE TO THE WEAKNESS OF THE RIDGE, THE TRACK SPEEDS ARE EXPECTED TO REMAIN SLOW THROUGH THE FORECAST PERIOD. INTENSITY WILL SLOWLY DECREASE OVER THE NEXT 72 HOURS AS DRY AIR ALONG THE WESTERN PORTION OF LUPIT CONTINUES TO INTRUDE UPON THE CENTRAL PORTIONS OF THE SYSTEM AT THE MID- AND UPPER-LEVELS. NUMERICAL GUIDANCE REMAINS IN GOOD AGREEMENT THROUGH TAU 72 HOWEVER, WBAR, ECMF AND GFS SHOW THE SYSTEM ACCELERATING RAPIDLY TO THE NORTHEAST. THIS DOES NOT SEEM LIKELY UNDER THE CURRENT WEAK STEERING ENVIRONMENTAL CONDITIONS. THERE IS THE POSSIBILITY THAT INCREASED MID-LATITUDE INTERACTION COULD POSSIBLY LEAD TO DISSIPATION OF THIS SYSTEM MORE QUICKLY THAN CURRENTLY FORECAST. C. AFTER TAU 72, THE SYSTEM WILL REMAIN ON A SLOW TRACK TO THE NORTH-NORTHEAST WITH CONTINUED WEAKENING. INCREASING INTERACTION WITH THE MID-LATITUDE WESTERLIES WILL CONTINUE TO BE THE PREDOMINANT ELEMENT IN THE WEAKENING OF TS 22W.// NNNN