The first main severe weather event of the season should start to take shape tomorrow evening into the overnight hours. An arctic cold front will be making its way to the south and to the east along with its associated trough. Air out ahead of this cold front is warm..
As you can see by looking at the first image the air behind the front is colder ..of course it will not be that cold into the south. However .. the front will cause temperatures to drop from the warmer levels.
Timing. Timing of the front looks to be in the over night areas and should be pass the Falls region of TX by 12 Z wednesday or 8 AM wednesday morning.
During the day across the south we will be dealing with a CAPPED environment. You can see this when you look at the CINH which is an inhibitor to severe weather.
So we are really expecting nothing to fall across that area thru about 8 PM. The guidance is in good agreement with this as well..
The above is what falls by 2 AM.. and there after by 8 AM (which is when the front will have passed thru NC TX)
So lets take a look at the severe parameters that will be in place. And the first one we are going to look at is the shear. There is no doubt about it that the shear would certainly support a severe weather event with shear as high as 100 Knots.. Keep in mind though there is a CAP thru about 8 PM
CAPE is greatest at 30 hrs and again this is when things are just starting to get going in the south around the TX area. As you see they develop over the Falls to Jacks County area .. So this is the CAPE for 30-36 hrs ..
Now you can see here by 33 hrs the CAPE has shifted east away from the Falls region and is very minimal at about 250 ..
And by 36 it continues to shift further to the east. So the CAPE is supportive of severe weather and especially in areas to the east.
Next Parameter we are going to look at is the Lift Index which again there is plenty of lift in the atmosphere..
The final parameters we are going to look at is the EHI and the Helicity index. These are the parameters that are specifically used to look at what areas are likely to see tornadic activity.
You can see by these images that the EHI is greatest to the east of the Falls region and the areas that are above 1 stretch as far north as Iowa.
Just as the CAPE progressed east so does the EHI. Lets look at the helicity quickly..
Now this is at 33 hrs ..and remember by this point the EHI has shifted east so the Helicity while in place to the west is no longer lined up with the Greatest EHI but it is further to the east and stretching to the North as well.
So we have severe parameters in place that will create a severe weather event. With the CAP in place across the south till at least 8 PM and the timing of the precipitation being in the over night hours we think areas across the west in Tx with the parameters decreasing will end up having the risk of Large Hail and gusty winds. It is to the east and then north where the greatest CAPE, EHI, and Helicity is that we anticipate all modes of severe from Winds to Hail to Tornado potential.
The front will cross the south by about 8 AM wednesday morning but the area will continue to see rain falling across the region.
So with all the above stated...this is the day 1 outlook for the 9th
We will be monitoring the situation later in the afternoon and all evening long!
We apologize for the late timing on this but we are in the process of moving our headquarters..However we did not want to go without issuing an outlook. The front you see draped across the southeast it will be to the south side of this front where we will have iur severe weather chances occur today.
Radar shows at the present time we have one severe cell that is in Oklahoma.. This piece of energy is moving East Southeast so that means that the rains and storms will also be moving east southeast . The warm front will start to lift northwards introducing the chance of rain further North while a cold front works its way southeast (energy represented on radar associated with that cold front)..it will be this front that will serve as the focus for severe weather..South of the warm front ... in advance of the cold front..
The main threats with this system look to be heavy rain with any of the severe cells, damaging winds and large hail.
The rest of the overnight period until 12 Z we could continue to see some more severe in OK as this was one of the regions highlighted yesterday with the better parameters..
Because the cold front will be crossing between 6 Z and 12 Z we are not expecting any severe into North Central TX in the remaining overnight hours though they can expect some rainfall and non severe storms. The cold front will then be thru that region and most action should take place in southern TX to Dallas and then Eastward along the Gulf coast!
We want to start off by explaining the two different colored zones on the map .
1. The Yellow Zone is where we think the best severe potential will occur based on the parameters and the all important moisture return.
2. The Gray zone is where there is no moisture return ..though the area does have decent parameters in place..without moisture ..even with parameters it is difficult to achieve severe weather.
3. The severe threats will be mainly large Hail and winds but a Tornado can not be ruled out especially across Eastern OK and into Eastern Ks.
Now lets look at some images ..first of all lets look at the moisture return off the GFS tonight..
So you can clearly see why we have the Gray zone the way we do despite the severe parameters such as CAPE being favorable.
The other reason that we do not think that region will see severe as well is because the shear is quite low in that region or marginal at best around 30 knots..
As you can see shear is relatively low in that area with around 25-30 knots.
There are two other parameters that are favorable for that area which are the CAPE and the Lifted Index..
And here is the lifted index...
So there is decent lift across the region..however once again there is no moisture so you can have decent parameters but not end up with severe weather.
Now lets look at the parameters that are looked at when it comes to tornado's. Helicity is not an issue across any of the severe region..
However EHI is a slightly different story..
Remember anything above a 1 indicates that super cells are likely and also indicates that there is a potential for Tornado's . The potential for Tornado's would be higher we feel if there was actually more Helicity involved ..so that is a plus. However the region for the potential whirlie twirlies would be eastern OK and eastern KS.
The trigger will be a cold front that will be on the move south ward across the region from the north.
If anything changes we will update this scenario but we are fairly confident with what we have portrayed here.
With Hurricane Season fast approaching us ..we have decided to do a little research into this hurricane season and come out with a outlook for named storms, hurricanes and Major Hurricanes.
One of the first things we look at is the ENSO Status and we see that currently we are in a neutral ENSO status and this looks to be the case with majority of the guidance though there are a few models that take us into an El Nino and a few that take us into a La Nina but the over all clustering of models keeps us in Neutral conditions.
So we take a look back thru the years going back to 1950 to see what those Neutral Seasons looked like to get a rough picture of how many systems form during Neutral years and the # is rather quite low ..between 7 and roughly 11 .. Lets look at the years
1952 Neutral Year result 7 storms
1959 Neutral Year 11 storms
1960 Neutral Year 7 storms
Perhaps an important thing to note in here is that each of the years so far had storms that impacted the east coast.
1961 Neutral Year 11 storms
1962 Neutral Year 5 storms
1966 Neutral Year 11 storms
1967 Neutral Year 8 storms
1978 Neutral year 11 storms
1979 Neutral Year 8 storms
1980 Neutral Year 11 storms
1981 Neutral Year 11 storms
1990 Neutral Year 14 storms
1993 Neutral Year 8 storms
Last but not least is the year 2012 which was also a neutral year and that had an astonishing 19 named systems..
Looking back thru history to 1950 at Neutral years you can see that the main two regions that were under the gun were the GOM region and storms up the eastern seaboard. The other interesting thing we note is that all the neutral years were relatively low on the storm numbers until we got to the year 2012 when we seen a substantial jump.
We think this can be largely contributed to the fact that since 1995 we have been in a positive phase of the AMO.
In the positive phase of the AMO the water temperatures tend to run higher and this adds fuel to the fire when it comes to tropical cyclone formation. You can see the sea surface temperatures here as of the 25th and how along the coast they are running warmer then normal..
Interestingly enough we also find that the Caribbean has already obtained substantial Tropical Cyclone heat potential.
So the things that we see standing out that is since 1995 cyclones have been on the rise as far as quantity but not necessarily quality. We also see that the GOM and the east coast were in play quite frequently so we are thinking that at least another storm along the east coast will occur this Tropical season. We also see things were relatively below average to average up until 2012 but since 95 they have been increasing despite the ENSO and that we feel is AMO related.
So with the AMO in a positive phase..the Atlantic waters warmer then normal.. ENSO status being neutral we think that this year could be a rather active year with 13-16 Named Storms ..which 5-7 would be hurricanes and 3-4 would become Major Hurricanes. We also with looking back at past history think that the East Coast could come into play once again..and the GOM would be the other hot spot. Of course we will also be dealing with the disappointing recurves that effect nothing but the ocean.
All and all looks to be another active season on tap for the 2013 hurricane season..
Stay tuned as we will be covering each and every season and pinpointing where we think the storms will make landfall..
