Mini Tropical Storm Dorian Update 7/25/13

I Think despite what NHC just said in there most recent discussion...I think the question now that needs to be answered and observed is whether or not DORIAN can survive the dry air that is to the immediate west of the system...

This has been the difference maker between the GFS and the ECM models and why one has the system virtually weakening from this point forward and the other maintains the system...

Tropical Storm Dorian - The Storm That Was Said It Couldn't

Tropical Storm Dorian the storm that was said it could not or would not develop if you read around the internet the past few days. Of course we had said on our Facebook page that this would be the next Tropical Depression which it became and then upgraded to a tropical storm.

As you can see tropical storm Dorian looks pretty good in this early part of the overnight... Considering that Dorian is not really over any TCHP and also cooler waters are being straddled.. we think she looks fairly good and should more then likely be increased in intensity with the next update...

TCHP

TCHP increases as it would head towards the Lesser Antilles ...and the sea surface temps...

Again it is straddling the cooler waters but then there is warmer waters ahead of it .. we think that the speed that the system is traveling at the present time will be fast enough that it will have little effect on Dorian. Dorian as of 11 PM was moving 20 MPH to the WNW and this is to the south of a mid level ridge.. And the steering currents would keep this west to northwest to west track in place..

You can also see looking at the vorticities in the 850 mb level, 700 mb level and 500 mb level that they are stacked and vertically aligned...

A little stretched out to the southwest at 850 mbs ..

So this is just another reason why Dorian is looking pretty good tonight. The question really becomes what is ahead.. Well lets take a look at some more images before we get to the guidance...

While Dorian is just out of the picture here you can see that the wind shear presently is light at about 5-10 mph. This is conducive for further strengthening.. You can see that the shear has been dropping around the system by looking at the shear tendency map which tells you whether shear is increasing or decreasing..

So wind shear right now is favorable.

You can also see that the system is moving into decent convergence and the same can be said about divergence as well..

So this is just another factor that would favor some intensification of the system.

Track wise ... fairly well clustered at the 00z time frame..

Majority of the guidance has this moving west northwest to west and missing the shredder islands.. this is a good thing for those who would like to see if Dorian can make it to the East Coast...

Intensity however is divided as some weaken the system and some strengthen the system..

The GFS says that the Southeast should keep an eye out on this system...

The above is 192 hours and its interesting to note that the GFS must have really weak steering currents because the run just meanders Dorian towards the Southeast coast because this is 240 hours out below..

We think right now its not really all that important as to "where this may end up" because the question is whether or not the intensity of the system holds in check with the questionable TCHP and the cooler waters. 
We think for the near term and time being that conditions are pretty much ideal otherwise for this system to at least maintain if not gain some in intensity and if the guidance continues to suggest the Bahamas and then the Southeast region and the system continues to maintain or increase ...at that time we would suggest that we would have to keep an eye out for the Southeast coast or somewhere on the east coast. 

We would like to see some other of the global guidance come around to what the GFS is showing. Though we are not sure we buy the meandering of the system beyond 192 hours but remember this is where the GFS loses resolution even further.

July 23rd Severe Weather Outlook

A cold front is dropping thru the central part of the country and this cold front could bring severe weather along its boundary. At the very least there will be heavy rain associated with this cold front.
Presently some very heavy rain is falling across the PA area with some non severe thunderstorms as well. However..tomorrow we think there will be a wind potential along with the possibility of a tornado or two and we will highlight where we think that could happen..

Lets start with the temperatures which will be in the 70s to 90s depending on where you are located ...but as has been the case the dew points will be on the sticky side 

With the dps being in the 60s and 70s so that will make it feel more hot then what the actual air temperature is.

When we look at the Convective Available Potential Energy we see some pretty high numbers with the CAPE going all the way to 5000-6000 in a small isolated area..but never the less quite high elsewhere as well.

Lift index is also going to be quite negative showing plenty of lift in the atmosphere with numbers of -8 to negative 12 over a large area..

Wind shear will be in place from about 30 knots to as much as 60 knots across the region..

With the SWEAT index as high as what it is showing into Kanas & Missouri and parts of ARK (Northern) this is the region where there could be a tornado or two to occur ...
Also the EHI is highest over Kansas..

So with the severe weather parameters in place .. we are highlighting the following region...

Again the main threats are going to be damaging winds but some tornado's are possible in the areas mentioned above... 

Severe Potential July 19th 2013

The cold front that we mentioned yesterday is continuing to move its way towards the south and east and this is the position it is expected to be in by 8 AM early morning friday.  This is also the cold front that we anticipate will serve as a trigger for severe storms as it moves to the south and east.  Yesterday the CAP ended up being a little stronger then anticipated while there was severe there was nothing in the way of Major severe or no tornados had occurred despite the parameters that were in place.
Today will continue to be a hot and humid day and it should be the day where the heat "peaks". Temperatures once again will be in the 80s and the 90s....with the dewpoints in the 60s and 70s..

Where the temperatures are in the 90s with the dewpoints in the 70s the heat indexes will be between 100-105 degrees.

Convective Available Potential energy is anywhere from 1000 to as high as 4000 .

Lift in the atmosphere is as low as negative 8...

NAM shows the greatest SWEAT being across the Northeast part of the country along with MI and Wisconsin..

EHI is highest over Maine... and the greatest shear still lies across the northern tier into MAINE as well..

We think that today will be mainly a wind threat however with high SWEAT showing up over parts of the NE and high EHI showing up over parts of Maine we would not rule out an isolated tornado in those locations. Also a chance of a tornado or two in Lower MI...

Despite the chance of severe weather we think that the biggest story to draw the attention will be the continuation of the heat and humidity. Once again we urge all our readers in this hot and humid air mass to drink plenty of liquids and wear light , loose colored clothing....Stay safe and stay indoors in the AC if at all possible!

Severe Weather July 18 2013

For the past several days we have had a Bermuda High Pressure in control and the result has been a very hot and humid air mass across the vast majority of the country. Temperatures have been in the 90s and real feel temperatures have been even higher. With an air mass in place like this to get severe weather you need  a cold front with a temperature difference behind that cold front and when you have these two air masses colliding one with another it brings about the chance of severe weather.. We have a cold front that will be dropping south and east from the Canadian Border and this front will serve as the necessary trigger for severe weather to occur. We expect today that all modes of severe will be possible ...

As we noted the temperatures are hot across the vast majority of the region with temperatures in the 80s and the 90s and the real feel temperatures in some locales will be between 100-105 degrees.

Factor in dew points in the 60s and 70s and once again you have the recipe for some very hot weather.
Moving on to the severe parameters that will be in place....

Convective Available Potential Energy or CAPE is essentially fuel that gets thrown on the fire. This will range from 1000 to as much as 4000

Lift in the atmosphere or the Lift Index will be from about negative 2 to negative 8..

Wind Shear with this system coming down across the lakes is essentially from 35 knots to 60 knots. 

Energy Helicity Index is relatively high across Northern Minnesota and across Northern Wisconsin and Upper Michigan . In tandem with this the HELICITY is also on the higher side...

So these areas mentioned above are the regions that we think have the potential for Tornadoe's. Elsewhere we think the main threats will be heavy rain, damaging winds and the potential for Hail...

So this is the zone we have highlighted...

Keep in mind that over the next couple days that this front will be moving south and east and this means that the severe potential will also move south and east .

For those that are in the areas that are extremely hot ... we want to stress that you should drink plenty of liquids and if at all possible stay indoors and in the Air Conditioning. If you must venture outdoors take Water with you and wear light colored and loose fitting clothing...

Invest 96 L ..The Remnants of Chantal

There is some confusion out in the world of weather on the internet with Invest 96 L. Invest 96 L is simply the remnants of Chantal ..so if it were to regenerate into a tropical storm it would acquire the name of Chantel.
National Hurricane Center has this at a 30% chance of re developing..

Some graphical images of the remnants of Chantal ..

Right now we do not view conditions as all that favorable for redevelopment...

Wind shear which is a deterrent to tropical cyclones strengthening is at about 20 knots..

You can also see this looking at the wind shear tendency image and see that there is shear all around this system..

Some things are in favor however of possible development and that would be the convergence and divergence that is presently over the system..

And another factor in favor is that the vorticity is not elongated ..

However you can see that the vorticities are not vertically aligned or stacked at the 850 level ,700 level or 500 level..

These centers would have to become vertically aligned or stacked if we want to see redevelopment out of this system. We think with the shear being at about 20 knots that any development of this system will be slow to occur...

The tracks as of 00z for this system become kind of interesting:

They take the system up along the east coast of Florida (majority) and then inland and this would be because of interaction with the upper level low in the southeast.
Intensity forecasts , all but one model take this back to tropical storm strength...

This would be between 24 and 48 hours out in time. However...like we mentioned above we would like to see the wind shear ease up some in order for redevelopment to take place. 

The steering currents that are in place indeed would support a movement almost due NNW as it moves around the Western Atlantic Ridge.

So we do not think that Chantal is a factor that we should just ignore as we do think that she could regenerate back into a Tropical Depression or a Tropical storm but we just think that it may take a little longer until the wind shear lets up a  little bit. Those in Florida should be keeping an eye on this system. Irregardless of development or not she should provide some heavy rain across Florida...

We will continue to monitor the situation and see where we are with this by this time later tonight.