Severe Weather Outlook for 10/13/12

Severe Weather Outlook for October 13th....

We are going to begin by taking a look at the water vapor..

You can see that over the TX region at the present time there is a black color and this black color represents dry air ..you also see brown as well representing dry air to the west into New Mexico...
When you put this in motion you can actually see some of that dry air from the west moving towards TX...

Now lets look at the latest surface map..

You can see where the low pressure is developing to the west of the Panhandle of TX and you can also see where the warm front is located which is well north of the TX region... The outflow boundary is set up over that same region (panhandle region) and hence why you have the severe reports generally in that area..

Not many reports on the day a total of 20 (though there day goes to 7 AM) we end our day at midnight here...As now technically we are on Saturday morning.. We do see there was two tornado reports... 
Now lets look at the guidance the first image is 18 hrs out which means it covers from 8 AM to 2PM and the second image is 24 hrs out which means it covers from 2 PM - 8 PM..

You can see that the low is coming out of the colorado rocky regions and this low splits a piece of energy goes to the Lakes while another piece is over the same region and this 2nd low generally takes the same track. Breaking it down by 6 hrs it looks like this:

You can see that most of the day this blended solution keeps TX dry until between 18 Z and 00z or 2 PM to 8pm. We think this dryness will be due to the dry air we see located on the water vapor up above...
Temperature wise we are only looking at temperatures in the 70s to lower 80s..

Dewpoints are in the 60s....

You can see the instability  (CAPE) is relatively meager with 500 to about 2500 with the higher amounts more in isolated small pocket regions...
Shear is one ingredient that is not lacking...

We have 30-60 knots of shear across the region highlighted for severe...

Lift index goes from about 0 to negative 6 with the greatest lift being Oklahoma North and this is important because this is an indication of where there is greater spin in the atmosphere...

EHI is 1 in above from about N Central Tx but then you see the yellow colors in OK and then more isolated locations N / NE of there which is where the indication of tornado's are possible.. based on just the EHI..
We also see that is where the highest Helicity is located as well from OK and points north...

So with the Helicity aligned with the greatest EHI region...that is why we have the red zone which means greatest risk of severe weather which would include the potential for isolated tornado's as well as winds and Large hail...

Outside of this region is the yellow zone and this is where we feel the lowest risk will be because of the significantly weaker parameters..other then the shear so this is where we feel that the threats will be of winds and possible hail.
On the southern end we still are thinking moisture will be a problem at first...because of the dry air but then some moisture should occur towards the afternoon...
The other threat involved in the areas from OK north is also heavy rain potential... we think that this should coincide with the greatest severe threat...

Tropical Update 10/13/12

Let me introduce you to Tropical storm Patty. Yes this is the water vapor image of Tropical storm Patty. Personally we think this is a stretch to consider this a tropical storm... We find it kind of odd that the latest HPC surface analysis map does not even recognize this...

However..officially the National Hurricane Center has this listed as a tropical storm and the name is Patty.. 
We have been being asked if Patty is going to be a threat to the east coast... the answer is quite simply no..  With the conditions that are currently effecting Patty she is not going to last very long...

You can see that shear is increasing pretty much in the general area of where Patty is by looking at the most recent shear tendency map or by looking at the latest shear map. This is pretty much the reason why Patty looks the way Patty does..
The other reason is when you look at the 700 mb vorticity , 500 and 200 mb vorticity levels you notice that these are not vertically stacked...

In other words we have a system that essentially is trying to develop but has very unfavorable conditions to develop in. 

Essentially the system is trapped in very weak flow which essentially means that the system should meander for the next 12-24 hrs. What this also does is makes the system bring cooler waters up from underneath and helps to also disrupt a developing system.. This should open into an open wave as it begins to move southwest ....

Now in addition to Patty we have the following:

This is 98 L. Again, using the same images above we see the 98 L is also very close to some high shear and you can see this on the water vapor image above ..how the system is stretched out and elongated almost in a SW to NE type fashion.. The vorticity also shows this quite well..

Also looking at the same steering currents this should generally move in a NW fashion. This means it will be moving towards a higher shear location as well. 
We do not think at this present time that this system will have an effect on the east coast either as a cold front that will be moving off the east coast should be enough to push this system and keep it out to sea...
Convergence and divergence is decent across this system..

So if the shear off to its NW can decrease we are looking at the potential for a more interesting system at least as far as watching on the satellite. However..if the shear does not decrease ..with elongation stretched out then this may not develop. We will continue to keep an eye on both these systems. This should at least make depression status with in the next 48 hrs. However.. we are not very bullish for tropical storm status until we see that shear begin to relax some....

As far as severe weather is concerned we will be doing an outlook later today for Saturday.. 

This is the only map we have made so far and this is just to show the tracking from 12 Z saturday to 00z Sunday which is actually Saturday evening..

We have seen the words Major Tornado outbreak being forecasted. 
Folks let me stress that something like that is not going to be known a week in advance ... if you see anyone suggesting something like that a week in advance they are simply hyping/wishcasting or forecasting what they want to happen and this is simply wrong. 

People need to be accountable for what they put across to the public. Just because it is on Facebook does not mean it is private. Facebook is public which makes the information public.

There is a real fear out there that people have and it is called Astrophobia where they fear severe weather. We provide counseling to these type of people. So when they see things like Major Tornado Outbreak because of that fear it sends them into a Panic Attack of which they then need to be talked thru and down out of.

Folks there is a reason why we do not issue a severe weather outlook until 24 hrs before...because it is not until this time that the parameters become more "reliable!" Guidance changes every 6 hrs. 
So next time you see a Major tornado Outbreak etc a week in advance or 72 hrs in advance ask yourself how this person knows this with the guidance changing every 6 hrs? 

Will 96 L Develop or Not Before Time runs out?

What we are looking at here is a image of 96 L. As of tonight the National Hurricane center has the chances of development at 80% or other wise a very high probability, Judging by the image above we actually think that this could be a tropical depression. Wunderground was showing winds at 35 MPH..This would be enough to classify...
However...National Hurricane center has decided to keep it listed at 80%. 

While certain conditions have improved since last night at this time (24 hrs later) .. other conditions remain the same and are pretty hostile. One of these is the increasing shear around the system ..

You can see how the shear is increasing all to the north and to the west of the system that is trying to develop. And these conditions are expected to continue over the next couple days. And you can really see how high this shear is ...

You can see that very near the developing cyclone is shear from 30 to as high as 50-60 knots..And keep in mind this system is moving the same direction west north west..
Now the other positive is the vorticity has become a little bit tighter ..in other words not as stretched out and elongated...and dry air is not really a concern for development..

And finally the convergence and divergence across the system is decent as well..

However we see the ECM model is not very enthusiastic with the system. You can see that it shows the system at 24 and 48 hrs out..

 However..by 72 hours the system is all but vanished..

And you can see that the GFS is in relative agreement with the ECM on this system essentially fading away or getting tangled up into the upper level low to the north of the system..

So even if this system does manage to develop it looks like its going to be a very short lived system with about 72 hrs or so in existence to remain. 
Now there is always the remote possibility that because there really is not yet a closed center of circulation that this could change once it officially becomes a tropical cyclone..
However it seems that just about all guidance is in agreement with this not lasting beyond 72 hours..

Here is the GGEM and the UKMET ...
GGEM is at 48 hrs and 66 hrs and the UK is at 48 and 72

So with all guidance pretty much stacked against any real development of this system we think that the furthest this will get in development will be a Tropical Depression (which as stated it could be there already now..) but with a increasingly hostile environment this will be a very short tracking storm system....

Tropical Discussion Ramblings on 96 L

If you were not aware we have another invest in the Atlantic Ocean and the National Hurricane Center has this at a 60% chance of developing in the next 48 hrs..

The above is the national Hurricane Center showing the AOC with a 60% chance of developing ..However..we think that is being just a little generous considering the look at the first image at the top. .
There are several things now that are at work against this developing...

1. First none of the global guidance models really do anything with 96 L.

More importantly is the size of the vorticity and we do not yet have a closed system which means we do not have a vertically stacked system . But lets look at the vorticity ..

 As you can see the vorticity is very elongated from SE to NW ..Whenever you have an elongated system it always takes longer to organize. Unlike other systems however this does not really have much dry air standing in its way to developing...

However what we do see when looking at the shear tendency map that we see increasing shear not only to its west but also to its north and pretty much across the whole atlantic. This shear is the reason why NADINE (long lived) has once again weakened along with the cooler SSTS which Nadine created..
So we have increasing shear and you can see that this is anywhere from 20 knots or more..

So this factor along with the elongated vorticity are really actually going to put a hinder to development. Another factor that we have to consider is the tropical cyclone heat potential chart..

Now as you can see we have some pretty low TCHP  that 96 L is going to be going across if continuing to head on a west north west heading. The  greatest TCHP is actually east of the Lesser Antilles Islands. So if it were to head on a mainly make it into the Carribean it would have a much higher chance of developing. 
Convergence and divergence across the system are actually pretty decent at the present time..

As we mentioned however...there are some pretty strong signals from the environment that this will have a much more difficult time organizing due to the strong shear, increasing shear and the vorticity being stretched out and elongated & the lower TCHP as depicted above.

Which way should this 96 L move. For that we have to look at the steering currents for the flow which 96 L would be subjected to and that is mainly a west north west projection..

This should mean a west Northwest movement however you can clearly see that thanks to Nadine there is a weakness in the ridge and this should begin to move more off to the NNW and then N and then NNE and not really have any impact on the USA...

So right now we are putting the chances of development for this system at a 30 % chance and we would not be surprised to see this never develop since it does not have a COC (Center of Circulation.
This system has a lot of improvement to accomplish in order to be able to develop...

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
This section is going to be in reference to severe weather today which is Tuesday the 13th. We are going to look at the two most important images from the Storm Prediction Center to start..

You can see that we have SPC showing a 5% risk area and I would think they have to be contributing this to one single Parameter which would be the shear.

And without a doubt there is impressive shear ..However bear in mind yesterday when they issued a tornado watch for parts of TN and to the south of TN that not one single report occurred tornado wise in that region and over all we only had 7 reports on the day...

 So the question is what caused the severe outlook by SPC to bust so bad yesterday. Essentially CAPE was marginal ..looking at the CAPE once again we see the same thing with about 500-1000 CAPE and less into Ohio region.. 

 Another reason was that the EHI and the Helicity which are two tornado parameters were just not present and with the one  above being the EHI and the one below being the Helicity you can see that they are not really supportive of the tornado outlook that was issued..

There was still yet one other reason and that was because the region that was highlighted yesterday already had cloud cover in place and ongoing rain in the over night period and if one were to take a look at the current radar as of 4:45 AM here you will see once again that the same scenario is once again occurring. Whenever this happens and occurs you end up with that rain helping to stabalize the atmosphere and helping with keeping day time heating from actually occurring which will generally keep the temperatures in the 70s.

So we are not going to issue an actual map but at the present time we are going to say we are going to disagree with their outlook and say that any severe would be more isolated in nature.