Tropical Cyclone Activity Report – Pacific Ocean / Indian Ocean / Arabian Sea
Apr 20, 2021
CURRENT TROPICAL CYCLONES
Typhoon 02W (Surigae)…is located 295 NM northeast of Manila, Philippines
Typhoon 02W (Surigae)
Sustained 120 knot winds…with gusts to 145 knots (as of Warning Number 31)
Here’s what the computer models are showing
According to the JTWC, satellite imagery shows that TY Surigae continues to maintain a large 65 NM wide eye, which has a warm center.
Through 24 hours, Surigae will continue tracking north-northwestward to the east of Luzon along the western periphery of an upper-level ridge to the east. Surigae’s forward speed has increased to a slightly brisker 07 knots, which is likely fast enough to prevent ocean cooling beneath the typhoon from causing weakening,
although slow enough that intensification is not expected.
The large and stable core size also favors little intensity change until the atmospheric environment becomes more hostile. This is expected to occur beginning around 36 hours, as a shortwave trough within the subtropical jet approaches from southeastern china, dramatically increasing wind shear to around 30 knots. Steady weakening is expected to ensue after 36 hours, as the typhoon accelerates northeastward and then eastward into the mid-latitude westerlies.
Around 72 hours, the aforementioned shortwave is expected to interact directly with Surigae. Model solutions diverge at this point. The GFS positions Surigae directly beneath the base of the shortwave, inducing rapid weakening as the trough axis outruns the typhoon. Other models such as the Japanese GSM and Canadian GEM position Surigae farther ahead of the shortwave, allowing intensity to remain higher for longer. the current forecast splits between these outcomes, showing weakening below typhoon force after 72 hours.
After 72 hours, Surigae will interact with a low-level thermal gradient south of Japan, as well as the upper-level
shortwave to its northwest. While models depict a range of possible arrangements of these features, the increasingly baroclinic environment around the cyclone is expected to induce the onset of extratropical transition (et).
The forecast is highly dependent on the details of et, and thus both model track and intensity spread is high after 72 hours. The current forecast track has been nudged southward at 96 and 120 hours toward the multi-model consensus, which has shifted southward during the past 24 hours. Weakening to 45 knots by 120 hours…within a high shear environment
There’s a tropical disturbance being referred to as Invest 95S, which is located approximately 410 NM east-northeast of Comoros Islands
Here’s was the computer models are showing
According to the JTWC, satellite imagery shows deep flaring convection building over a consolidating low-level circulation center.
Invest 95S is in an environment conducive for intensification, with fair equatorward outflow aloft, low to moderate 15-20 knot wind shear, and warm sea surface temperatures.
Global models are in general agreement that invest 95S will track westward as it intensifies and passes north of Madagascar over the next 24 hours.
Maximum sustained surface winds are estimated at 30-35 knots.
The potential for the development of a significant tropical cyclone within the next 24 hours remains high.
Here’s a link to the Joint Typhoon Warning Center (JTWC)
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