Tropical Cyclone Freddy

[Somerset Squall]

Tropical Cyclone 14S has formed, located almost 400 miles north of Learmonth, NW Australia. The new cyclone is located far away from the coast of NW Australia and is forecast to continue moving west so it shouldn't be a threat to the Australian mainland. Initial intensity is 30kts. 14S has a well defined LLC, with convection wrapping into the western quadrant. However, the majority of convection is located to the west of the LLC due to moderate-high shear affecting the system. High shear will compete against fair westward outflow, warm sea temps and high moisture to allow some slight intensification of 14S over the next 48hrs. If shear becomes any stronger though, then there is a chance 14S will dissipate quickly. The life of 14S does hang in the balance, with fair outflow and hot waters being the only things sustaining it in this highly sheared environment. Shear is not expected to ease significantly for the next few days so rapid development is not expected.

[Somerset Squall]

14S is certainly doing well in the high shear conditions and has strengthened to 35kts, and been given the name Freddy. Freddy will continue west as a ridge persists to the south of the storm. Freddy will also maintain intensity or show some slight intensification over the next day or so as shear remains moderate to high but sea temps remain warm, outflow fair and moisture availability high. Often storms that stay too close to Australia weaken as they take in dry air off the continent but there will be no such problem for Freddy as he is spinning away far from land at the moment, and is likley to continue heading out into the open Indian Ocean.

[Cookie]

Freddy or not her he comes. * i will get my coat*

moving away from land

[Somerset Squall]

Oh dear Cookie, oh dear

Freddie's intensity remains at 35kts this morning, but he is struggling in the high shear. The LLC is partially exposed with convection remaining confined to the west. However, slight intensification is still forecast due to the otherwise favourable factors such as warm sea temps, good poleward outflow and plenty of moisture. The bottom line is however, high shear should always cap any significant intensification.

[Cookie]

I couldn't resist sorry

[Somerset Squall]

Freddy has strengthened a little this morning, and intensity is now at 40kts. Although the majority of deep convection is to the west of the centre, Freddy has managed to wrap a little around to the eastern quadrant too and the centre is no longer exposed. In fact, convection has been quite explosive over the last several hours with a rather shapeless but large and deep mass of convection associated with the storm. Freddy is expected to remain a weak tropical storm for the next couple days until he reaches cooler waters on the west-southwest track which may induce weakening.

Edited February 7, 2009 by Somerset Squall

[Somerset Squall]

Freddie continues to fight the easterly shear, and has managed to intensify a little more this evening, with intensity now at 45kts. JTWC expect a peak of 50kts in the next 24 hours before sea temps taper off on the southwesterly track. This wind shear chart from CIMSS shows the strong shear to the northwest of Australia well, and as it's not expected to ease anytime soon, the combination of this and cooler waters should eventually dissipate Freddy in a couple days time.

As you can see, shear is around 20kts at the moment. Whilst this may not be strong enough to cancel out the otherwise favourable conditions and cause Freddy to dissipate now, it is prohibiting any major intensification. If we look at the shear tendancy chart it shows that whilst shear probably won't get any stronger, it's not forecast to lessen either, so ultimately the cooler waters will dissipate Freddy in the end.

You can see Freddy marked in the image. Solid lines shows increasing shear, broken lines show decreasing shear. You can see by this chart therefore that shear will remain in a steady state over Freddy in the next couple days.

This sea temperature map from Wunderground shows the cooler waters to the southwest of Freddy, which he should reach after 24 hours:

Therefore, unless Freddy can turn more westward or northwestward he will inevitably meet these colder waters. Freddie is forecast to turn southwestward as a approaching trough erodes the subtropical ridge to the south which is steering Freddy westwards. Freddie will head towards the weakness in the ridge taking him over those cooler waters.

So the long term outlook is bleak for Freddy. However, as I already mentioned he is looking healthy at the moment and has put up an impressive fight so far.

[Cookie]

nice images mate. and great update well done

[Cookie]

moving into cooler waters shear is easing.

[Somerset Squall]

Freddy peaked at 55kts this morning, but is now back to 50kts. Shear continues to be a problem, and waters are getting cooler. Therefore, we can expect continued weakening over the next couple of days. Freddy is now turning southwestward and will probably dissipate beyond 48hrs.

[Cookie]

time up for Freddy.

[Somerset Squall]

Indeed Cookie. JTWC have issued their last advisory on Freddy, as convection is minimal with the LLC. The shear remains strong, and waters are below 25C now. Freddy has done well to survive this long to be honest, the shear has been consistantly at 20kts or above which is very disruptive for any tropical cyclone. As the waters are getting increasingly colder, the final nail has been secured in the Freddy's coffin so to speak.

[Cookie]

until we get proved wrong.

[Somerset Squall]

until we get proved wrong.

Funny you should say that, convection has increased near the remnant low of Freddy this morning. If shear eased, then I wouldn't entirely rule out redevelopment (it's unlikely) as waters are still around 25C which is just about enough to support a TC, although maybe a hybrid one. Interesting that BOM are still classifying Freddy as a TC, wheras JTWC have him as a 25kt remnant low. I certainly agree with JTWC at the moment, the convection isn't persistant enough for Freddy to still be a tropical cyclone.