Friday, August 12, 2011

Tropical Weather Update for 8-12-11

1313171930

We have a lot to talk about in the tropics today..or do we? That is really a trick question. As you can see the NHC has 4 different invests or areas of interest in the Atlantic. We are going to look at each one and we are going to determine the chances of development with in the next 48 hrs.

First up on the tropical tour of the atlantic is 93 L ..

at201193_sat

You can see the latest satellite photo suggests that there is nothing much happening or occurring with 93 L . Yet NHC has this at a 40% chance of developing. Is the environment surrounding this invest showing this to be the case?

93 L vort

As you can see the greatest area of vorticity with this is off to the east of the system which is the exact opposite direction from which this is moving.

93 L conv

Convergence and divergence is definitely lacking over the system. The greater the divergence and convergence the greater the system has a chance to develop.

93 L shear

Shear across the system is 10-20 knots. While this is not detrimental to the system development it will definitely cause it to develop slower. However…dry air appears to be a greater problem for development as this image will show :

93ldry

Surrounded by dry air on all sides this will cause dry air to be ingested into the developing system and hinder development.

We do not agree with 40% chance of development with this system…rather we put this at 10% chance of developing within the next 48 hrs.

Next up is 92 L on the tropical atlantic update:

92lwatervapor

Again you can tell pretty much by looking at the water vapor image here. There is not much convection with this system and you can also see that dry air is also going to be a problematic feature..

92 L dry

image

The above image while it does show some divergence near the system (on the western edge of it) the system is completely lacking in convergence.

92 L vort

You can also see in the above image that there is no area of vorticity near the system which means this is not a vertically stacked system.

NHC places the chance of this developing in the next 48 hrs at 50%. We place this at 10% chance of developing over the next 48 hrs as there are some issues that the system clearly needs to resolve.

Next up is 94 L and we will look at the latest water vapor image…

94lwatervapor

NHC places this at a 20% chance of developing over the next 48 hrs.

94 L convdivergegood

In this systems favor is that it is located in some decent convergence and divergence.

94 L shear

However, slowing down the potential for development will be 10-20 knots of shear across the system. Also another problem the system has to over come is dry air.

94ldry

As you can see pretty much this invest is also surrounded by dry air on all sides of it.

94 L vort

The vorticity of this is also broad and elongated and tilted as well. The more elongated the system the more difficult to tighten a COC up and develop. So we would actually place the chances of this developing at 10%….

One last system to look at and this system was at a 60% chance of developing at the beginning of this outlook but since has been upgraded to a tropical depression #6.

wv-l

A couple problems we have with this is that you can clearly see that this is associated with a stationary front.

A_sfc_full_ocean

This image shows that it is associated with a front and even the most recent updated image for 5 PM shows the same thing though labeled a depression..

A_sfc_full_ocean (1)

Now lets let the images speak for themselves

tdcon

Notice there is no convergence however the divergence is stretched out and elongated and this is because it’s the stationary front..

tdvort

Vorticity is very broad and elongated. Once again this would be because it is still attached to a front..

TDshear

The shear is 30-40 knots over the system and even greater amounts north..Again this would be because of the front.

tddry

And last but not least the dry air that is in place around the system.

As is clearly obvious by the data above if this should be classified as anything it should be classified as a subtropical system do to its association with the stationary front.

It clearly has not lost all its frontal characteristics..

As for the guidance we will continue to lean upon the ECM for guidance as over the next 48 hrs it still does not show any development of the other three invests..

12zeurotropical500mbSLP048

We will continue to monitor these systems and keep you updated with the latest!

No comments:

Post a Comment