WEEKEND WESPAC

TROPICAL REPORT

1300UTC/2100PST, July 28, 2012

1st edit: July 29, 2012 1730UTC/0130PST (AOI information)

2nd edit: July 29, 2012 0130UTC/0930PST (95W and AOI information)

WEEKEND WESPAC TROPICAL REPORT MAP FOR JULY 28, 2012

TWIN STORMS THREATEN THE WESPAC…COULD IT BE TRIPLETS???!!! HOW ABOUT QUADS? 

Once again I am forced to point out what a huge difference a week makes in the tropical weather situation! Last week, I hinted at a busy time ahead for us in the tropical WESPAC. I think I got more than I bargained for with the developments of the past 48 hours. Let’s break it down…

ON THE BOARD…

Tropical Storm SAOLA (Gener)

Another strange system born from a TUTT cell, the 4^th one so far this season, is out there in the form of Tropical Storm SAOLA (Gener). SAOLA’s energy erupted from another TUTT (Tropical Upper-Tropospheric Trough) cell that moved into the WESPAC from the east in the past 7 days. While slow to develop, it appears SAOLA is now starting to get much better organized, and could become a typhoon as early as tomorrow. I’ll tell you why in a moment. First, here are the latest official numbers for the system:

TS10W SAOLA (GENER)

10W SAOLA(Gener)-15.3N, 125.3E-35kts-996mb

As with VICENTE, and with KHANUN before that, SAOLA has been born from the wild influences of the upper-level environment somehow inter-mingling with the lower-level atmosphere to create a surface system. The good news is, most times, these systems are not as strong as systems that form VIA more conventional means. The bad news is, due to our relatively limited knowledge in exactly how these air masses influence each other in all cases, once in a while a surprise can pop up, as in the case with VICENTE’s rapid intensification just prior to landfall in China earlier this week. No one saw that coming. And no one is predicting this storm to become a serious howler either…at least not yet. But, SAOLA is entering a relatively small pocket of weaker VWS (Vertical Wind Shear), which will be favorable for development for the next 24 hours. Couple that with warm SST’s, good outflow establishment, thanks in part to the TUTT cells that are nearby, and you have the ingredients for a period of intensification, which will likely be followed by slower growth, and possibly even weakening as it enters a less favorable upper-level environment. However, since TUTT’s are playing into this scenario, that is not a 100% sure thing.

The forecast track of SAOLA is quite uncertain at this time. JTWC shows a track passing just to the NW of the Philippines en route to a direct hit in Taiwan. The NOGAPS model shows something completely different, offering us an “S” style track that eventually takes it into North Korea. I think the jury is out right now on the absolute forecast movement of this system. For now, interests in the Philippines and Taiwan should stay on HIGH alert. And regardless, the Philippines are in for a pronounced, and possibly extended, southwest monsoon event through Wednesday. With the heavy rains of VICENTE having already filled the reservoirs, another event of that magnitude could be monumentally disastrous for residents of central and northern Luzon in the Philippines. 

2nd edit to update 95W information

Tropical Depression 11W DAMREY

At about the same time that SAOLA got it’s INVEST designation, another surprise popped up much farther to the north, and yes, you guessed it…it was produced by the direct influence of a TUTT cell. Tropical Storm DAMREY is getting a bit better organized, but is not expected to become a powerful storm. That being said, the JMA (Japan Meteorological Agency) and the JTWC have declared the system a tropical depression. Interests in Japan should monitor this storm VERY closely. Here are the latest official numbers for 11W DAMREY:

95WINVEST-25.6N, 146.6E-20kts-1007mb

The computer models are not giving this system much credit, so it’s difficult to for me to say exactly what will happen. The JTWC has issued a TCFA (Tropical Cyclone Formation Alert) citing favorable upper-level conditions and system movement, as well as supportive SST’s (Sea-Surface Temperatures). However the SST’s are only favorable as far as 32N, so, if this system should take a turn toward the main islands of Japan, it will likely weaken a bit as it passes over the cooler water. There is still so very much to speculate about with this system. It is safe to say that interests in Japan should monitor this system carefully for any surprises.

1st edit to update AOI information

2nd edit to update AOI information

96W INVEST

This is a term I coined on my website when I was doing my own thing last year. It marks an area that I believe we should monitor closely, but has not been recognized by any of the tropical weather monitoring agencies. We have one of those in the tropical WESPAC this evening. This system is located near 7N, 145E, or, about 800km (500mi) ESE of Yap Island. Convection is building around a very weak LLCC (low-Level Circulation Center) at this location. This circulation has been verified by OSCAT (OceanSat) satellite wind measurements. Winds are still quite weak. EDIT: The NOGAPS computer model 12z run now shows this sytem to be part of a much larger monsoon gyre system that will form over the Marianas and move north over the next 5 days, while producing several 1000mb vortices. which could lead to possible tropical storm or weak typhoon formation. Interests in the Marianas, and the Philippines, should monitor this system very carefully. 

AROUND THE NEIGHBORHOOD… 

Abundant moisture is prevalent at all levels of the atmosphere right now, the signature of the beginning off the peak of the tropical weather season in the WESPAC. And, as has been the case so far this year, many upper-level systems are entering the region and stirring up trouble. These TUTT’s, or Tropical Upper-level Tropospheric Trough cells are basically upper level low-pressure areas. They, by themselves, cannot turn into a tropical system at their peak of strength, but they can influence the surface atmosphere around their periphery, as has been the case with the last 3 storms. We have 4 TUTT cells out there this evening. One very strong TUTT is located near 25N, 166E, and is moving slowly to the west. Another TUTT is located near 31N, 152E, moving to the southwest slowly. The third TUTT is located very nearby at 24N, 142E, and is working together with the previously mentioned systems in aiding the development of 95W, providing ample outflow opportunity for the system. The last TUTT is located near 26N, 125 E, and is responsible in part for the development of SAOLA. This system is moving to the west, and away from the tropical WESPAC marine areas. In addition, a HUGE upper-level trough has been established as a result of these many TUTT systems working together. This trough starts near 39N, 151E, extending west-southwest (counter-clockwise rotation of low pressure areas) to near 29N, 115E, where it takes a turn to the south down to 20N, and then southeast to near 12N and out to near the International Date Line (180E/W). Upper-level troughs of this type enhance the VWS (Vertical Wind Shear), thus inhibiting development in tropical systems.  This large trough is responsible for the high wind shear that has been in place of much of the region so far this season. We can be thankful for that because it is just part of the balancing act that nature plays to prevent widespread catastrophe, which would have been the case if the least 4 storms had not had wind shear effects to keep their growth in check. Elsewhere, the ITCZ is going NUTS, and the Mai-Yu baroclinic zone is having no effect on the tropical scenario.

CRYSTAL BALL…

The crystal ball is broken. Seriously. It cannot say with clarity WHAT is going to happen out there. I can only guess that SAOLA will form into a moderate strength typhoon at some point in its life and move toward the Asian continent, somewhere between Taiwan and North Korea. 95W is an even bigger mystery, because forecast models aren’t handling this system very well at all. And then we have AOI 072812 which is forecast to form into a strong tropical storm or weak typhoon, while it tracks slowly to the north, parallel to the Marianas Island chain. Models are hinting at ANOTHER system developing to the east of the AOI, and tracking north along with it. This is an unlikely scenario, but I’m putting it in anyway, because as this season has shown us…ANYTHING CAN HAPPEN! 

Happy hunting!

Michael Williams Sr.

P.M.D.

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