The system that produced the severe weather in the central and southern plains and across the southeast the past several days has one more day of severe weather that it will be producing ..HOWEVER...today will not be an outbreak type of severe weather day as that system has been weakening and losing strength...
Here is the reports for the 21st and you can see not one tornado had occurred which is a vast improvement over the previous days. With the system weakening we are not really expecting today to be a day for tornado's either.
The main threats should be Hail and Wind across the severe zone. Lets look at the severe parameters that will be in place...
First off the temperatures will be in the 70s to 80s depending on where you are..
Dew points also once again will be in the 60s and 70s across the region..
Wind shear depending on where you are is going to be marginal at about 30-40 knots and if you are in PA it will be even less then that...highest shear is in the northeast region.
CAPE will be marginal in some areas from 500-1000 and then the highest CAPE is across eastern PA into NJ and parts of the Northeast. Unfortunately, the shear is not the greatest so despite the CAPE this could hinder severe development in that area. Super cells are possible with the stronger storms with the EHI around 1...
There is ample lift in the atmosphere with the LI index down to about negative 7..
The culprit once again will be the trough and cold front that has been slowly advancing towards the east with the severe threat slowly advancing towards the east. The difference is parameters today are a lot lower and the system has weakened compared to what it was.
The trigger across the Northeast part of the region will be the warm front that is to be draped across northern new england.
So with all the above in mind here is the outlook for today with once again winds , hail and heavy rains being the main threats.
We here have to say we are glad with the damage that has already taken place especially in places like Oklahoma. Please remember to keep them in your prayers cause even though the #s may not be as high as what they were originally thought there are still alot of families effected and without a place to live and some that lost family members!
The severe weather outbreak will continue today, Tuesday with the threat moving more to the east and still across the south central part of the USA. Once again all three severe modes are anticipated to occur with the worst being from East Central TX up thru Arkansas where the greatest threat of Tornado's will be...
The culprit will continue to be a slow moving trough and cold front moving from the west to the east and southeast..
Stationary front across the NE portion of the US will be the focal point for potentially some severe weather but in that region we only expect some winds and hail.
Further south low pressure over TX /OK border with cold front turning northwards to a low pressure up over Wisconsin.
So lets take a look at the severe weather parameters that will be in place. Starting with the temperatures which will be in the 70s and 80s ..
Convective Available Potential Energy will be on the range of 1000 +
Lift Index will be in place but not as negative as previous days with about -8 being the lowest but this is still ample for severe weather..
One thing that is a little bit different today then the previous couple days is that the shear is more marginal with the exception of East East Central TX. 30 -40 knots elsewhere but up to 70 knots in East Central Tx..
Perhaps again the most alarming parameter will be the Energy Helicity Index that will be in place first starting in East Central Tx..
Then as the night goes along spreading into Arkansas..
So do to this EHI being on the high side we are anticipating this to be the greatest area for Tornadic activity. In addition large Hail and damaging winds.
Elsewhere the severe threats will be strong gusty winds along with the potential for Large Hail.
Once again if you are in the areas anticipating a moderate risk and tornados..stay tuned to your National Wx Service and we will be monitoring things all day on our weather page
https://www.facebook.com/RWSSevereWeatherCenter
Please heed all warnings and take shelter immediately and have a safety plan in place in case you become in the path of a Tornado warned storm..
The outbreak of severe weather will continue today with Day 3 as the cold front and the trough continues to make its way slowly to the east.
This will be at 12 Z this morning and you can see where the cold front will be located with an area of low pressure over TX and this front turns to the north to a low pressure up near the Dakotas borderline. Essentially the scenario we are going to be looking at today will be the same as the last two days.. All modes of severe weather are anticipated from Large Hail to Damaging Winds and Tornado's.
Once again we will be dealing with warm to hot air out ahead of the system with temperatures in the 80s.
Dew points will once again be in the 60s and 70s
Convective Available Potential Energy is also once again fairly high with the range of 3000-4000.
Once again there is plenty of Lift in the atmosphere with values as low as -10-11 ..
Once again our main concern is the EHI or the Energy Helicity Index that shows up across parts of the region. Whenever you have EHI at or above 1 you run the risk of Tornadic Activity ..
So it looks like Eastern OK once again could be up for some tornados along with NW ARK and into Missouri and possibly Illinois and Indiana.
Shear is also once again sufficient with 40 knots or greater across the region.. So with all the above ingredients in place we have again a third day with this outbreak and this is the region we have highlighted on the map below with mention of where the Tornado's could occur up above..
Each day this will slowly make its way towards the East but it should weaken as compared to what the Midwest has been going thru but we are still anticipating widespread severe with it as it makes its way east southeast .
When it comes to TX we have included them but for the most part we think that the action should continue to stay to the North of TX..One exception could be around the Falls area.
The same complex frontal system that brought the severe weather to areas of the midwest yesterday and its associated trough will be responsible for another day of severe weather . Matter of fact this system will be responsible for at least two more days of severe in addition to today Sunday the 19th.
Once again we have several factors that will be in play and come together to help create this severe weather day. We have a warm unstable air mass out ahead of the cold front and trough..
Temperatures are in the 80s and the 90s across the region of concern. Dew points will also be high with them in the 60s and 70s..
The next ingredient which is like striking a match to a stick of dynamite is the CAPE or the Convective Available Potential Energy..
Levels once again are as high as 3000-4000 ..Adding fuel to the fire is the fact that the shear is actually going to be greater today then yesterday ..
With shear ranging from 40 to as much as 80 knots. Plenty of lift will also be available in the atmosphere..
And once again , perhaps more concerning is that the Energy Helicity Index is on the high side , well above 1 across a good portion of the area..
This in combination with all the other ingredients in place suggest that Tornados could be possible across Eastern OK , Eastern Kansas, virtually all of Missouri and Central Iowa. If we were to place a moderate risk this is the area where we were to place it.
We are expecting all modes of severe weather today from Damaging winds to Large Hail to Tornado's mentioned in the places above.
From all the guidance we have looked at it appears as though TX will once again be under a CAP but we have included them just in case the CAP were to break with the high instability in place.
With all the severe parameters out of the way this is the outlooked area we have highlighted for today Sunday the 19th..
This area will be moving East , East Northeast over the next two days....
Once again if you are in the path of any tornado take shelter immediately and please do not try and chase the storm unless you are an experienced storm chaser. This is how lives are lost in severe weather events & heed all warnings!
ABOVE ALL BE SAFE!
We use rather strong language in the title of this post but we feel by the end of the post you will understand the reasons why.
1. First we have a warm to hot air mass out ahead of a cold front that is pressing off towards the east. This is one ingredient needed for severe weather to occur.
Temperatures are in the 80s and 90s.
Secondly we have a trigger which is a cold front with two areas of low pressure. One over western Kansas and one over the border of the Dakotas with a trough pressing to the east and a dry line setting up from the low over Western Ks southward thru Eastern Tx..
Using the NAM we have quite the parameter field set up over quite a broad area...
CAPE which is convective available potential energy is quite high with values ranging at 4000-5000. In addition to this we have a lot of lift in the atmosphere...
We have lift indexes as low as negative 13 which helps to support an unstable atmosphere.
Perhaps more importantly is the EHI or the Energy Helicity Index that the NAM is showing..
If this EHI becomes a realized factor it means we could see tornados in Oklahoma, Nebraska, Kansas, Eastern South Dakota.
Shear is greatest in the areas to the north with around 40 knots plus..
Perhaps the one positive to take away from the whole over all severe scenario is that the Helicity is not all that high across the region..
Never the less with it being 200+ in combination with the EHI we think this just enhances the potential for tornados across the areas that were mentioned.
The Helicity also does increase as the night goes along...
We think the state of TX will most likely be influenced by a strong CAP in place but with the CAPE as high as it is ..we have to include them in the outlook if that CAP were to break.
All aspects of severe weather can be expected today from Large Hail to strong gusty winds to the chance for tornado's mentioned in the areas that we covered above.
If you are out and about stay tuned to your National Weather Service and heed any warnings that may be issued and take cover and shelter immediately should you be in a tornado warning .
So with all the above mentioned this is the outlook. We did not put a moderate risk area but pretty much you can figure from above where we would put it if we were to..
Looking at the surface map we see the front is relatively stationary that has provided the severe weather yesterday on the 8th. By thursday evening this front should be splitting OK in half and trailing to the SW from there..
It will be this front that will once again be the cause of severe weather and rainfall once again. Looking at the severe parameters..
CAPE
CAPE is quite high with anywhere from 1000 all the way up to about 3500.
Temperatures will be relatively in the 70s and 80s across the highlighted severe zone...
Dew points will generally be in the 50s and 60s indicating that there will be enough moisture in the atmosphere..
Wind shear will be sufficient but marginal with 30-40 knots generally being the case across the severe zone.
Where we become a little concerned is with the EHI which is relatively high in SE and Eastern OK and parts of Northern Tx.
And the Storm Relative Helicity is also greatest over the same general area of eastern OK and SE Oklahoma. If there is going to be a tornado chance today this is where we would put it with a 5% risk.
Plenty of lift in the atmosphere with anywhere from negative 4 to negative 8.
We expect storms to relatively blossom between 1 PM and 4 PM across the area in Texas. The main threats would be winds and large Hail but with the EHI on the high side extending into Northern TX we place a 2% Tor risk south of OK. Even after the storms rains may continue into the overnight across TX..
