MATMO Approaches Taiwan Coast as Atlantic TD#2 continues Westward

(By Steve Gregory - Substituting for Dr. Masters who is on Vacation.)

Latest SAT and Radar imagery shows Typhoon MATMO approaching the Taiwanese east coast and is currently about 65 NM S-SE of Taipei. With a NW movement at 16 Kts, MATMO should hit the east coast within the next hour or so. Radar indicates strong convective bands have been impacting the Island for the last 4-6 hours.



Fig 1: IR imagery clearly shows MATMO has gotten much better organized since yesterday, but with so little time left for higher level winds to work their way to the surface, MAX winds are almost certainly still under true, CAT 2 intensity.

Imagery has also depicted a partial but distinct eye feature for the last 8 hours, with very good outflow to the north and south of the storm. This, combined with Dvorak estimates of over 80Kts, and JMA estimates of a central pressure near 965mb means MATMO should still be able to hit the coast near CAT 2 intensity.

Although conditions are still quite favorable for further intensification, interaction with Taiwan’s mountainous terrain, and effects of friction with the China mainland even as the storm traverses the Taiwan Strait, MATMO should weaken rapidly once it makes landfall and will almost certainly make its second and final landfall on the SE coast of China in 24 hrs at Tropical storm intensity. As the storm makes landfall on mainland China, it will turn northward in response to an approaching long wave TROF followed by acceleration towards the N-NE on THU as it transitions rapidly to a non-tropical Low.



Fig 2: Radar depiction from Taiwan shows a reasonably well-defined eye, with convective banding already over the central portion of Taiwan. The strongest convection appears to be in the S-SW quadrant which corresponds with the overall ‘history’ of this cyclone in which the strongest convection has generally been in the southern semi-circle.




TROPICAL DEPRESSION #2 OVER CENTRAL ATLANTIC

Very small Tropical Depression #2 is located near 12.5N / 47.8W or about 700NM east of the CARIB, moving westward (285ᵒ) at 16Kts. With the system embedded in deep easterlies, and convection remaining relatively weak, this trajectory should continue for the next 48-72 hrs.



Fig 3: TD#2 remains quite small, with a general 'circulation' diameter estimated at about 200NM (This estimate is based on VIS and microwave imagery shown in Fig 4 below.)

Despite relatively low wind shear (approximately near 10Kts), there has been very little change in the overall size and structure of TD#2 during the last 24 hours. In addition, the small cyclone will soon begin encountering significantly drier air, and as the system approaches the eastern CARIB Thursday, it is expected to encounter stronger wind shear which is likely (though not with 100% certainty) to prevent any significant intensification despite warmer SST’s that will support stronger convection. In addition, the shear may be strong enough to cause the system to open up into a wave.



Fig 4: The 85Ghz microwave image continues to support a closed low or mid-Level circulation which has been more difficult to locate on VIS or IR imagery than it was yesterday.

The large scale global models still cannot resolve/initialize this small system, but the specialized Tropical Cyclone models, initialized at 12Z, forecast the storm to continue tracking towards the CARIB, reaching the eastern CARIB late on Thursday. Interestingly, a few of the dynamical models show a slow intensification of the system to Tropical Storm intensity – though the most reliable models, and the Official NHC forecast, call for dissipation in 48-60 hours





Fig 5 & 6: The Early 12Z cycle model runs are generally a bit more aggressive in developing TD#2 into a Tropical Storm compared to yesterday's runs – but the most reliable dynamic models continue to forecast dissipation and admittedly have a high probability of verifying.



Fig 7: The official NHC Track forecast is in excellent agreement with the model consensus, but calls for dissipation prior to the system reaching the CARIB.

ELSEWHERE in the Atlantic, there are 2 Tropical Waves over the far eastern Tropical Atlantic that have brought along more ‘moisture laden air’ (versus dry, Saharan air). In addition, there are now several somewhat stronger appearing Tropical waves upstream over Africa (only 2 are shown in Fig 9) that will reach the Atlantic later this week and early next week, with one of these systems having a significantly higher potential for development next week.



Fig 8: Aside from TD#2, only 2 significant Tropical Waves are present over the eastern most Atlantic, and they are entangled in the African Monsoonal TROF and/or ITCZ.



Fig 9: Tropical Waves over Africa have become somewhat stronger over the past week, with the easternmost one in the above image showing a mid-level 'turning' on imagery loops.

In the meantime, however, no new tropical cyclone formation is expected during the remainder of the week.

The next update will be Wednesday afternoon unless conditions in the Atlantic warrant an earlier posting.

Steve Gregory