Tropical Storm Emily-The Latest

First thing you notice about the most recent visible image above is that the center of emily has been exposed. In other words you are looking at a naked circulation. Many people are surprised by this as they have been thinking that this is going to become a hurricane. We have been talking about the problems Emily has been facing from day 1 and how this would only cause slow development. Quite frankly, we were a little surprised to even see this become organized enough to get upgraded beyond depression stage. Its convection has been mainly in a pulsing style from its conception and it has always been a complete disorganized mess.

As you can see from the above images besides the center being exposed you can see shear of 10-20 knots and close to above 20 knots and dry air. This dry air has been around since the beginning and has been and will continue to plague Emily.

Vorticity is still tilted from SW to NE and while there is some convergence the best lies to the SE while the COC (exposed) continues to move west. The best divergence also lies behind the system.

As you can see the steering currents would continue to track this off to the west. Perhaps somewhat north of west.

Emily is still expected to track off to the NW but if she continues to remain weak she may just keep tracking off towards the west. This would mean she would miss the islands and perhaps if she ever does start to turn NW she may become more of a GOM threat.

We think the more likely course is that if the COC continues to move west and decouple away from the convection then Emily is just going to diminish into an open wave trough.

Stay tuned for more information

Tropical Storm Emily Latest Thoughts!

While away from the internet yesterday Invest 91 L was upgraded to a Tropical Storm. While appearance is looking pretty good the latest recon shows winds at the surface are only 31 MPH…Folks this would not be a tropical storm yet alone a depression if this continues to be the case.

D. Estimated (by SFMR or visually) Maximum Surface Wind: 27kts (~ 31.1mph)

The same problem that has existed from day 1 with this invest continues to keep development very slow and we can not say that we are surprised by this occurring.

Now, from the last time we updated on this at that point and time shear was only at 5-10 knots. Latest shear suggests that we are actually at 10-20 knots now

Convergence and divergence is good at the present time and the vorticity has decreased ..however..we are still dealing with a broad and elongated system..

Steering winds continue to suggest that this should move off to the west northwest…

As far as guidance is concerned ..ECM essentially opens this up and keeps it as a weak wave and slides it away from the east coast..

You can see this reflected in the 12 Z ECM above.

And the latest guidance curves this away from the USA. Now latest recon since that last report posted above has boosted winds to 50 mph. From what I can see via satellite and water vapor it would appear to be more a pulsating causing the higher winds of 50 MPH. Though recon mentions this is not well organized and they had difficulty with locating the center.

The question becomes what happens with emily? How does hispanola effect it and these recurves would need to start pretty soon and it does not appear that right now steering currents would support a turn to the NW..

If Emily continues heading west then starts to turn NW it could take it directly over Hispanola and Hispanola kind of acts like a shredder due to higher terrain when it comes to tropical systems. IF Emily can manage to maintain a weaker inner core then there is a greater chance of surviving Hispanola and possibly re intensifying.

At the present time..we still do not like the idea of a Category 1 hurricane and are leaning more or less towards the ECM scenario.

Stay tuned for further information!

August 1st Severe Weather Potential

Low pressure is located over the SE coast with a stationary front attached to it. This front is expected to stay across the SE area and this front should serve as a mechanism for showers and garden variety type storms with isolated severe possible.

Elsewheres: A cold front will be dropping across the Great Lakes region tomorrow and should be crossing into and towards the coast by evening time. This front will serve as the mechanism for severe potential in the form of damaging winds and large hail across the mid atlantic/Northeast and the midwest and plains states where the cold front turns into a warm front and will be lifting across that region.

In the midwest & plains a tornado or two could be possible ..however the main threat there will be winds.

Invest 91 L Now @ 80% But Have Things Changed Any?

The title reflects the discussion. National hurricane center has this now at a 80% chance of developing within the next 48 hrs.  So have conditions actually improved with this system?

AS of last update..shear was not an issue and shear continues to be not an issue with this particular system trying to develop.

If you remember last night the greatest area of convergence was off to the NW of the system and that continues to be the case at this point and time. The system is in decent divergence which was also the case when we updated last about this system.

Latest vorticity shows it continues to have the same problem as it did at last update which was a very elongated or broad system. Now last night the center of circulation was closer to the best area of vorticity but as you can see that area is now further to the west of the COC.

Perhaps the greatest problem that has to be overcome by this system is the dry air which you can see is encroaching on all sides of this system. A tropical wave trying to develop does not want to ingest dry air into it because it simply will not develop.

So as you can see ..nothing has really changed with this system. We still do not have a vertically stacked low pressure area, we still have low shear, outside the best area of convergence, decent divergence and still an astronomical amount of dry air in place.

Steering also shows the ridge in place that is still guiding this system and it should continue to mainly head off to the west north west towards the islands.

Guidance is still split as well with the 12 Z GFS showing a recurve and the ECM showing a weaker system.

We will continue to keep the chances for development at 50% for this system . If 91 L is able to overcome the obstacles in its path we still do think it can obtain Tropical Depression status. However..beyond that with the guidance split we will continue to monitor the system for any further development!

Invest 91 L ..70 % development chances..some things to overcome!

This is the latest look at Invest 91 L . The next tropical system that we have to keep a watch on.

91 L definitely has some “spunk” to it but as you know we like to look at the environment that surrounds the system that we are watching..

First problem that lies ahead is the dry air that is to the north and to the south and to the east and to the west of this system.

Second problem which is only a temporary problem we believe is that the best convergence lies to the NW of the system. Divergence is good ..

Another problem is that right now the vorticity is very broad in nature or elongated. Whenever you have something that is this broad in nature it always takes more time for it to tighten up and this is the case as this system is not vertically stacked..

Shear is not an issue what so ever with this system at the current time..

So as you can see there is some issues that have to be overcome before this can develop. If it can overcome these issues mentioned above then it should be able to develop but once it develops the next question is where does it go?

Well guidance has been pretty much split. There really is no sense in looking at the hurricane models because until there is a center of circulation for them to pinpoint and feed off its going to go back and forth between no development/development.

So we look to the GFS and at 12 Z it shows a strong system that recurves and so does the 00z ..Here it is below:

So if the GFS is correct we have a hurricane on our hands that will do nothing more to the USA then rough surf possible along the coast.

However..the ECM says not so quick. At 12 Z it was not impressed at all with the system…and 00z we see this:

And 144 it looks like this:

Still continues to be unimpressed with the system over all. The problems already start at 120 hrs out in the guidance…here is the GFS at 120

So you can see the difference…right from 120 hours out! ECM is generally the better performing model in the 3-5 day range..

One thing for certain is that because of the high pressure in the Atlantic this invest should continue to head off on a west track and the antille islands would be the first that will have to deal with whatever becomes of Invest 91 L.

National hurricane center has this developing in the next 48 hrs to a tropical depression at 70%. We feel that 50% would be more accurate at this point and time.

If this keeps heading on a westerly track it will take it across the islands and this would more or less favor a weaker system AKA ECM..this is what we are going with right now as our thinking.. Depression status will probably occur within the next 36-60 hrs …

Stay tuned for more information over the coming days!

July 28th Severe Weather Outlook

Currently a warm front is pushing thru the western half of PA with a low pressure area back over eastern Iowa. This warm front is attached to a low pressure moving across southern Canada and is part of a complex frontal situation. A cold front also extends from the low pressure in Canada and this cold front trails back to another area of low pressure over Wyoming!

As the warm front lifts to the North the cold front will begin to drop southward and should be approaching western PA by about 2 PM in the afternoon. A couple different waves or impulses of low pressure will develop along this front .

By 8 PM this front will have cleared western PA and western NY.

This front will be the focus of severe weather potential. Across portions of SE NY and into portions of eastern PA and NE PA it could be possible that in addition to the winds and hail potential that even an isolated tornado could occur. This will be possible because of the low level shear that will be in place in that region and the timing of the low pressure area. So that is something to keep in the back of your mind as we go thru the day tomorrow!

Stay tuned for more information should it become needed!

Tropical Storm Don Thoughts

As the above satellite image shows DON we can see that DON had gone thru some issues as of late yesterday afternoon. We think this was contributed to being so close to land. In other words interaction with land contributed to what we seen yesterday afternoon and evening. Overnight DON started to take on a slightly better appearance. However, as you can see he is very small in size..Tropical cyclones this size usually do one of two things:

1. They can ramp up very quickly and become microcanes

2. They can just go poof.

Original thinking was that this had potential to become the first hurricane of the Atlantic Season. We think that this potential is still possible but expectations for this occurring have become lower then what they originally were.

If you go back to the first discussion we mentioned about the TCHP and how you generally want the TCHP to be at 80 or above. While there is no denying the warm water temperatures of the GOM..the TCHP is a different case..

If you can compare the TCHP image to the above satellite image you can see that DON for the moment is travelling to the south of the greatest TCHP. However, off to his NW is warmer TCHP. If DON can continue on a NW movement he would be travelling over the greater area of TCHP and this could allow DON to restrengthen.

Lets look at the rest of the surroundings to see if there is anything that could hinder further strengthening from occurring.

Shear is not an issue at this present time because it is only in 5-10 knots of shear. This is certainly not detrimental to development.

You can see some dry air off the Tx coast and the Mx coast and it is possible that DON could be ingesting some of this dry air which is holding back intensification..however..we have seen systems develop with more dry air then what is shown above.

Convergence and divergence is good across the COC of DON.

Here is another possible problem as you can see that the greatest area of vorticity is south of where the center is. There is no doubt that some weakening has occurred since the inception as the pressure went from 1001 MBS to 1005 mbs as of current update.

So as you can see there are some issues that potentially could be holding DON back from intensifying.

Movement should continue to maintain a NW or WNW track and this is due to the ridge that is in place and will persist at least for the next 48 hrs.

Anyone from the Southern TX coast to the TX/MX border needs to keep an eye on this system. Tropical cyclones are entities that seem to have a mind of their own and small compact ones are capable of rapidly intensifying or going “poof”..

Next update will be issued this evening on Tropical Storm Don!