for an update on Parma and Typhoon Melor CLICK HERE
Tropical Storm Parma appears to be on the verge of recovering from the influence of an upper level trof that appeared out of nowhere out of China and dove down to mess up the storm. So much did it disrupt Parma (pepeng) that it fell from the classification of a typhoon to that of a tropical storm. Now that the trof is lifting out to the northeast, satellite imagery is indicating perhaps some re-development of convection which would coincide with intensification. This is not totally unexpected as, even when Parma got zapped, the low level mean circulation remained strongly in tact. So, as Super Typhoon Melor moves quickly across the Philippine Sea, Parma will drift to the south or southwest. The official forecast from the Joint Typhoon Warning Center has been consistent for 24 hours for the first time in days, which tells me that their confidence is increasing. They indicate that most models show a big ridge over China becoming a dominant feature to steer Parma away to the west. Indeed the US Navy NOGAPS shows depicts exactly that and takes small, compact storm into Viet Nam.
However, the GFS continues to not play along. Previously, it was insisting on a track drifting to the south and then southeast around the periphery of Typhoon Melor as it went by to the east. Now, what it seems to want to do is have Parma more or less get cut off from everything else. Not influenced by an ridge over China, nor anything else and too far from Melor to be affected except that it drifts south to the northern tip of the Philippines and then it just sits there for a few days. It tends to feature heavy banding on the backside whacking the western coast of Luzon…which is not good. As it stands now, at least 15 have been killed by Parma and more rain is expected in Luzon.
A couple of things here…first off the JTWC points out that, while they re-intensify Parma to minimal typhoon status in the next 24-36 hours, they mention that upwelling may mess that up and, if it doesn’t and follows thier forecast, then it would run into a sheering environment and cooler water as it approach Viet Nam. If Parma were to do what the GFS suggests,then upwelling I would think would be a factor and so it may not be a typhoon in that instance. But, so what…Ketsana wasn’t a typhoon either. It’s the rain potential that is the fear.
As for Typhoon Melor (JTWC Discussion) its a super typhoon with winds of 140 kts kicking up gusts to 160 kts. For those of us in the United States that would be about 160 mph winds with 185 mph gusts or a category 5 hurricane. It’s still a long way off but the forecast track has shifted some with the big curve to the northeast when it is in the Luzon Strait coming a tad later, which means that the track now takes it right over Tokyo Bay instead of just offshore.
However, by that time, Melor would have run into an unfavorable upper level environment and it would have weakened to a minimal typhoon. But, it would have also picked up forward speed. In this scenario, I would think that the storm would create a storm surge higher than one might associate with a minimal typhoon due to its forward momentum and the fact that it had been such an intense storm prior to passing over Tokyo Bay. But, were talking about 3 or 4 days out and there are many things that can happen. Intensity forecasts are notoriously difficult to pin down that many days out.
WDPN33 PGTW 050300 MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC// SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 19W (PARMA) WARNING NR 30// RMKS/ 1. FOR METEOROLOGISTS. 2. 12 HOUR SUMMARY AND ANALYSIS. A. FOLLOWING THE PASSAGE OF A MID- TO UPPER LEVEL SHORTWAVE TROUGH, TROPICAL STORM (TS) PARMA HAS BEGUN TO REDEVELOP DEEP CONVECTION AROUND ITS LOW LEVEL CIRCULATION CENTER (LLCC) AND IN THE BANDING TO THE NORTH OF THE LLCC. DVORAK ESTIMATES FROM PGTW HAVE REMAINED AT A 3.0/4.0. THE FINAL-T NUMBER IS BASED ON THE PATTERN-T, VICE A WRAP, BECAUSE THE CONVECTION IS TOO WEAK. THE SYSTEM HAS ALSO BECOME LARGELY QUASI-STATIONARY WITHIN A WEAK STEERING ENVIRONMENT, HAVING ONLY MOVED 30NM OVER THE PAST 12 HOURS. 3. FORECAST REASONING A. THE FORECAST PHILOSOPHY HAS NOT CHANGED SINCE THE LAST PROGNOSTIC REASONING BULLETIN. B. THE SYSTEM IS STILL EXPECTED TO MEANDER TO THE NORTHWEST OF LUZON IN THE SOUTH CHINA SEA FOR THE NEXT 4 DAYS. THE POTENTIAL FOR MILD RE-INTENSIFICATION EXISTS NOW THAT THE TROUGH MENTIONED IN PARA 2.A. HAS PASSED TO THE EAST. HOWEVER, UPWELLING OF COOLER WATER WILL BEGIN TO STALL INTENSIFICATION OR EVEN BEGIN TO WEAKEN THE SYSTEM. THERE IS STILL SOME UNCERTAINTY IN THE TRACK OF TS 19W GIVEN THAT IT IS IN A WEAK AND ILL-DEFINED STEERING ENVIRONMENT. IF RIDGING BUILDS TO THE WEST OF THE SYSTEM, THEN THE STORM WILL GRADUALLY BEGIN TO PULL OUT TO THE SOUTHWEST, AS THE MAJORITY OF THE DYNAMIC AIDS INDICATE. ON THE OTHER HAND, IF THE RIDGE TO THE EAST REBUILDS FASTER (AND STRONGER) THAN THE RIDGE TO THE WEST THEN THAT WILL BECOME THE PREDOMINANT STEERING MECHANISM FOR PARMA. C. IN THE LATER PERIOD THE SYSTEM SHOULD START TO ACCELERATE ALONG THE FAVORED TRACK TO THE SOUTHWEST ALONG THE SOUTHEASTERN PERIPHERY OF THE SUBTROPICAL RIDGE LOCATED OVER SOUTHERN CHINA. 19W WILL MOVE INTO LOWER AMOUNTS OF FAVORABLE OCEAN HEAT CONTENT AND INCREASING VERTICAL WIND SHEAR ALONG THIS TRACK AND START TO SLOWLY WEAKEN.// NNNN