| CoconutCandy |
| (User) |
| Fri Oct 16 2009 07:33 AM |
|
'Lupit' Now a Typhoon - High End Cat 4 for Philippines?
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Tropical Storm 'Lupit' has steadily strengthened over very warm waters in excess of 30C in the vast oceanic expanse WSW of the Mariana Islands, and has now crossed the threshold for it to become classified as a typhoon.
The following animated visible satellite loop taken just before sunset, local basin time, clearly portrays an increasingly well organized cyclone, with a nascent, ragged-looking, partially cloud-filled eye taking shape at 14N and 136E.
You may also notice from this visible loop that 'Lupit' has jogged a bit to the NW and has gained about a degree of latitude (60 miles) since the animated visible loop presented in an earlier post, as it proceeds generally to the WNW, with some wobble seemingly apparent from time to time.
However a recent polar orbiting, passive-microwave imaging satellite is depicting a considerably more organized system since the visible loop was taken earlier in the day.
Here you can clearly see an inner, clear, eye-like feature surrounded by inner-core convection looking more and more like a fusing eyewall structure, surrounded by many far-flung concentric spiral banding structures, quickly evolving in the apparently rapidly expanding tropical-storm-force wind field.
From the latest JTWC Advisory #10 Prognostic Reasoning ...
Quote:
"... TROPICAL STORM LUPIT ... CONTINUES TO CONSOLIDATE AND DEEPEN ... ANIMATED INFRARED IMAGERY SHOWS MULTIPLE BANDS OF DEEP CONVECTION WRAPPING TIGHTER INTO THE LOW LEVEL CIRCULATION CENTER.
ANIMATED WATER VAPOR IMAGERY ALSO DEPICTS VERY GOOD RADIAL OUTFLOW AND IMPROVING OVERALL SYMMETRY. UPPER LEVEL ANALYSIS DEPICTS A MESOSCALE ANTICYCLONE OVER THE SYSTEM WITH THE RIDGE AXIS JUST A FEW DEGREES TO THE NORTH. THESE DYNAMICS ARE SUPPRESSING VERTICAL WIND SHEAR AND CONTRIBUTING TO THE SIGNIFICANT DEVELOPMENT OF THE STORM.
LUPIT WILL GRADUALLY SLOW DOWN BUT WILL CONTINUE TO TRACK WEST-NORTHWESTWARD ... THEN, AFTER 36 HOURS, THE SYSTEM WILL SLOW DOWN EVEN MORE AS IT VEERS POLEWARD IN RESPONSE TO A MID-LATITUDE TROUGH APPROACHING FROM THE NORTHWEST.
HOWEVER, THIS STAIR-STEP MOVEMENT WILL BE MOMENTARY AND LUPIT WILL RESUME ITS WESTWARD TRACK TOWARDS THE NORTHERN PHILIPPINES (AND) IS EXPECTED TO FURTHER INTENSIFY AS THE ENVIRONMENT IS FORECAST TO REMAIN FAVORABLE WITH LOW VWS, WARM SEA SURFACE TEMPERATURES, AND HIGH OCEAN HEAT CONTENT."
There is currently some spread in the numerical model guidance with regard to 'Lupit's forecast track over the next 5 days, depending largely on amount 'poleward jog' induced by the aforementioned mid-latitude trough around about 36 hours from now. Some models have 'Lupit' recurving towards Japan, while others still have it on track towards an eventual landfall in the extreme NE Philippines, while peaking in intensity as a high-end Cat 4 with sustained winds of 125 Kts., or 145 mph.
It will be interesting to see how all this plays out, and hopefully the Philippines will be largely spared a direct impact (thought flooding rains over mountainous terrain still seems quite likely), while southern Japan in that case would become more at risk, should 'Lupit' track to the right of it's currently forecast path from the JTWC.