Wednesday, August 24, 2011

Tropical Storm Nanmadol (Mina) Update #4

Tropical Storm Nanmadol (Bagyong Mina) continues to intensify at a constant pace as it drifts across the Philippine Sea. It was last located approximately 400km northeast of Virac, Catanduanes or about 540km east of Casiguran, Aurora. Maximum sustained winds have increased to 100kph with gusts of up to 130kph. TS Nanmadol/Mina has been drifting to the west at around 5kph.

Latest Visual Satellite and IR Imagery show an improving circulation with flaring convection right over the center. Cloud tops continue to be cold (around -80C). Recent microwave images also suggest that an eye might be forming on the mid-level circulation. The low-level center, on the other hand, is still slightly displaced to the northeast. Nevertheless, we still expect this intensification to continue, albeit at slow pace.

IR image from NOAA

The forecast for Nanmadol remains vague and uncertain as computer models continue to diverge and be inconsistent on their solutions. What is throwing the computers off is the possible direct-cyclone interaction of Fujiwhara effect this weekend between Nanmadol and a developing system northwest of Guam (Invest 97W). The trends tonight have actually lessened the effect of this DCI; some models actually take Nanmadol towards Taiwan!

Because of this, we have shifted our forecast track a little bit to the north. We now expect Nanmadol to continue moving northward longer than previously thought. We are still expecting this system to turn northeastward this weekend. Just a warning, though--we still have low confidence on this forecast track due to the numerous uncertainties regarding Nanmadol and 97W so please continue to stay with us for the latest updates and possible changes with the track. Obviously, anyone from Taiwan all the way to Kyushu/Shikoku needs to monitor this storm constantly. The projected timing (if it hits any of the areas mentioned) would be Sunday or Monday so we still have time to adjust the track accordingly.

We will have our Video Update up in about an hour. Our next Text Update will be around 12am tonight.
Issued (08 UTC) 4pm PhT 082411

No comments:

Post a Comment