Tropical Storm Polo

[Somerset Squall]

Invest 95E has become increasingly better organised today, with some good banding features developing along with persistant deep convection over a well defined circulation centre. Thus, NHC has initiated advisories on TD18E.

18E has formed quite far south, around 8N, which is the farthest south a tropical cyclone has formed this East Pacific season. This has some significance, as it means that on the west-northwest track, 18E has a longer journey over very warm waters than it would have if it formed further north. Shear is currently low and waters are around 28C, so strengthening to a tropical storm appears likely. NHC are going for a peak of 50kts before shear and cooler waters greet the system in about three days time. If shear remains low enough there is a chance 18E may become a hurricane as the sea temps are high for a few days yet. We'll see.

[Cookie]

image from weather underground

and sat image

thanks for the update somerset

[Somerset Squall]

Thanks for the infrared image there Cookie, shows the rotation and deep convection well. Looks like it's nearing tropical storm strength this one- could well have an upgrade next advisory.

[Cookie]

whens the next one due?

[Somerset Squall]

whens the next one due?

Around 3am our time I think.

[Cookie]

its been upgraded Tropical Storm Polo

[Somerset Squall]

Indeed, Polo was upgraded overnight. Since then, further strengthening has not occured, and Polo's intensity remains at 35kts. Polo has a small area of deep convection near the centre, but convectional coverage overall is minimal. As Polo is such a small tropical storm, it's sensitive to the environment around it. Polo could just as easily rapidly deepen as fall apart. Conditions for the next 48hrs will remain conducive for intensification, and NHC are forecasting a peak of 50kts still. Once shear increases and sea temps cool, Polo is likely to rapidly weaken.

[Somerset Squall]

Convection has increased quite a lot in association with Polo today, but intensity has remained at 35kts because the convection isn't directly over the centre, and is being displaced to the east due to moderate westerly shear. The LLC isn't exposed, but until it can locate itself further into the deep convection significant strengthening appears unlikely. Since this time yesterday, the NHC have backed off a lot on their intensity forecast and now are forecasting a modest peak of 40kts before the shear becomes even higher.

[Somerset Squall]

Polo has degenerated into a remnant low. Shear stripped the convection leaving the LLC exposed. Conditions are set to remain unfavourable so redevelopment is not expected. Polo's remnant low will wind down over the next day or so on the westward track to dissipation.