The Final Countdown To The End

It is now the final countdown... for the rest of this storm system to pass on through the Southeast.  Did you think I was talking about the end of the world?  Earlier this morning there was a line of strong thunderstorms that pushed through the Southeast and caused quite a bit of ruckus and some damage.  But the ruckus and damage is not done yet as there is still a high risk for East-Northeast Mississippi, Central and Northern Alabama, extreme Southeast Tennessee, and extreme Northwest Georgia.  Storms are now beginning to rapidly intensify in western Mississippi and will continue to do so as the cold front and the storm system pushes eastward.  Here are my forecast areas of high and moderate risk at 18Z (1PM CDT), 21Z (4PM CDT), 00Z (7PM CDT), 03Z (10PM CDT), and 06Z (1AM CDT tomorrow morning).  Here is the 18Z forecast risk areas.

I expect a high risk to still stay in effect for the same general areas as mentioned earlier because all of the lifting mechanizisms and highest areas of instability are located in that general area which is where the highest risk of significant severe weather will occur.  Keep in mind that severe weather will occur in the moderate risk area as well too.  The 21Z forecast risk shows a similar scenario.

Now the high risk area has "sqeezed" itself in a more confined area and primarily centering over Northern AL, Central and Eastern TN, and Northwest GA.  Major cities to really keep an eye on around this time period are Birmingham, Huntsville, Chattanooga, and Nashville.  The area of high risk would be a likely area for a tornado watch to be issued and it could be considered as a PDS (Particular Dangerous Situation).  Continue monitoring Northern and Central Alabama for significant severe weather.  Another similar scenario will still be in affect at 00Z.

Still seeing a high risk area, but it is smaller and gradually diminishing away as the day wears off into the night.  The darker shade of red has no significant meaning to it, it's just an overlap of moderate risk areas.  Although, I will state that along the Gulf Coast of Mississippi, Alabama, and the Panhandle of Florida could be of interest at around this time because of a lot of CAPE, surface lifting, and high dewpoint values.  The area of high risk would be the most likely spot to see a tornado watch in the near future.  Things really start to look different at 03Z or around 10PM CDT tonight.

There is now only a moderate risk that spreads over a large area of the Southeast and Mid-Atlantic regions.  The reason why it is so big is because there is still a chance of severe weather, but it will likely be more spread out than what has been experienced so far.  Chances of significant severe weather is much lower around this time which is why there is not a high risk anywhere.  However, there is still the chance of tornadoes, strong winds, and hail throughout this risk area.  Finally, a risk area that is located completely different than all of the others before at 06Z.

The Southeast is going to be out of the moderate risk area finally with the Mid-Atlantic now going to be experiencing some severe weather.  A much smaller risk area because the system should be pushing off into the Atlantic Ocean leaving the highest risk to be from North Carolina to Pennsylvania.

Keep in mind that the shaded areas do not limit where severe weather will be.  It's more of a general area of where most of the severe weather will occur.  Stay safe and continue monitoring your local TV stations and your radio.

New Day, New Risk

Another day, another dollar!  Not exactly.  Today is looking to be more exciting than yesterday.  Although there was a tragic time period yesterday where a very strong, unrated tornado tore through Vilonia, AR and did incredible damage and took away some lives.  One of the most incredible damage reports about it was where the tornado scoured some of the road!  It takes a lot for a tornado to do that so it could be our first EF-5 of the year, but we will find out as surveyors scope out the area.  In the mean time, there are other areas that are now in the interest of severe weather.  I looked at 3 different times throughout today to analyze for areas of severe weather, which are 18Z (1:00 PM CDT), 00Z (7:00 PM CDT), and 06Z (1:00 AM CDT Wednesday morning).  Here is the 18Z:

Areas to watch out for this afternoon are circled in red and shows where the moderate risk for severe weather would occur.  I don't have percentages or which type of severe weather to expect, but I can tell you that the circle covering parts of Louisiana, Arkansas, Texas, Oklahoma, and Mississippi has the highest probability of tornadoes, strong winds, and large hail than the other moderate risk circle does.  The other moderate risk area will likely have more wind and hail reports than tornadoes. 

Now for 00z:

At this time we are getting into the max heating of the day because the sun has not set yet and still adding heat to the surface after adding a lot already during its peak time.  There is a high risk now that covers mainly the Mississippi Delta, Southern Arkansas, and Northern Louisiana.  I anticipate the worst of the weather to occur around this time period with significant severe weather to occur in the high risk area.  The reason for it is because all of the variables needed for large, long-lasting tornadoes lineup all together for this kind of setup to happen.  Keep your eyes focused on this region as time gets closer to this period which this is at 7PM CDT so a time range from 3PM-9PM need to be monitored heavily.

Finally, 06Z:

At this time things should be calming down some because it's 1AM tomorrow morning and the air should be cooling off some and instability should be diminishing a little, but still keeping some instability to allow a moderate risk area to exist.  There is one small area to watch for that I didn't put a high risk on because that would be to rash, but the black circle indicates an area that the risk of severe weather could be a little bit higher than the risk surrounding it.  This area needs to be monitored just incase something significant does brew up there.  The reason for the possible increased risk is because that area could have everything it needs to spawn up tornadoes including decent CAPE values with small CIN values.

Remember to always be aware of severe weather around your area and when you are under a tornado warning please take cover as soon as possible and don't wait until you can see the tornado.

Tornado Outbreak Repeat?

Things have quiet down some since the last major tornado outbreak occured in the Southeast.  This isn't to say that there was no active weather in the U.S. because the Lambert-St. Louis International Airport shut down for a day.

No, this had nothing to deal with Samuel L. Jackson and snakes being on the planes, but because of a tornadot that reached EF-4 status and caused a lot of problems and damage.  The biggest concern now is the current setup of the weather that could possibly give us another major outbreak.  Before we go in-depth on the likelihood of the situation, let's recap on the last outbreak event.  Before, I mentioned of the number of tornadoes being 153 with 120 of those being confirmed and rated leaving 33 to be unrated.  After a week and a half of the event things are official and now tallied up.  There are still 153 tornadoes reported, but the number of each rated tornado intensity has changed.  These are the updated numbers now:

EF-0: 40

EF-1: 70
EF-2: 29
EF-3: 14

Clean up and picking up after the destruction has been the main focus after these passed 9-11 days, but should those people be concerned about this next storm system?  Let's find out!

Here is what's happening right now.

Now this is a double low system with a dryline.  These lows are attached to a stationary front that isn't wanting to budge at all which is why there has been so much flooding around Missouri, Illinois, and Kentucky.  It's setup right now is already creating somewhat of a scare as it's upper air setup seems very favorable for severe weather.  There is a moderate risk for today, tomorrow, and Wednesday for certain areas each day.  To save time, we will only look at the remaining risk areas for today.  Here is a 250mb for 00Z (7:00 PM CDT tonight) and 06Z (1:00 AM CDT tomorrow morning) that shows where the jet stream is forecasted to be.

The 00Z forecast is on the left and the 06Z is on the right.  The circled areas are areas of interest because that is where lifting would be found.  Now let's go a little lower in the atmosphere and see where some more lifting is likely to be by looking at the 500mb at these same times with 00Z on the left and 06Z on the right.

The circled areas indicate areas of lifting at the mid-levels.  If you notice, these circled areas do overlap each other in certain spots.  Let's go closer to the surface and see what else lines up with these areas.  Now we will look 850mb at the low-level jet and warm air advection.  First the low-level jet at 00Z on the left and 06Z on the right.

Now the warm air advection for the same times.

What the low-level jet helps us out with is where moisture and inflow is coming from in the low-levels of the atmosphere and can help initiate strong updrafts in thunderstorms if strong enough.  The LLJ is reaching winds of about 70 knots in some areas so there is forecasted significant lifting.  The warm air advection (WAA) is important for the same reasons.  Now, as for dewpoint values I'm not going to show you maps of that because that would be needful space used, but I can tell you that the Southeast, Ohio River Valley, Mid-Atlantic, and Southern Mississippi Valley have dewpoint temperatures between 60 and 70 degrees F and the actual air temperatures will range from 65 to 75 degrees F.

To conclude for today's event here is SPC's outlook for the rest of today (keep in mind this will change as they update the site throughout the rest of the evening).

Here are the most up-to-date storm reports from SPC. 

So far SPC has hit the moderate area right on the dot with the current observed storm reports, but these storms will continue to move eastward and northward.  Here is my version of the moderate risk area for the continuing round of storms for the rest of the day called SVRPROB.

This is just based upon the previous estimated areas from earlier.

So keep your eyes focused on this general area for severe weather for the remaining of the day and most likely into the early morning hours of Tuesday.

Historic April 14-16 Tornado Event

April started off active and still remains to be a very active month, but the 14th thru the 16th proved how active April is really wanting to be.  14th-16th has now became known as a historic tornado event for weather history.

Let's have a peak.

Here are all of the reports for the 14th.

The storm reports for the 15th.

The storm reports for the 16th.

Now keep in mind these are updated as of the time I am posting this.  These numbers will likely go up as survey crews continues to investigate the destruction in the all of these areas.  One other thing to keep in mind is the number of storm reports compared to what each storm produced.  May seem like there isn't any difference, but you can have multiple reports of the same storm.  To really get down to the meat of the number of tornadoes is to look at the track of each tornado.  Here are the numbers so far for the number of tornadoes that either touched down or were on the ground (according to Wikipedia).
Total # of Tornadoes: 153
# of EF0: 27
# of EF1: 59
# of EF2: 21
# of EF3: 13
# of Unrated: 33

The last time that this many tornadoes were reported in a multiple day event like this was back in 1974!  What caused so many tornadoes?  Good question.  If you remember my previous blog about this event showing different levels of the atmosphere and different things that show the environment is favorable for tornadoes to spin up then that explains why things lined up so well for this event.  To recap, there was a lot of moisture coming in from The Gulf of Mexico, there was some good lifting in the mid-levels in the atmosphere where PVA was found, there was some good lifing in the upper atmosphere with divergence and diffluence, and on top of all of that there was a strong low-level jet (LLJ) and warm air advection (WAA) in the low levels of the atmosphere.  You could almost say that the planets lined up perfectly to allow this event to be so dramatic.  Are we likely to see another event like this in the Southeast?  There is not a "yes" or "no" answer to that because there is always a chance that this could happen again.  To give some reassurance, don't count on something like this happening for a while for this month.  The jet stream has moved north of the southern part of the U.S. and doesn't look to be dipping back down into the Southeast like this past event anytime soon.  To really give you the image and the feeling of some of the most intense tornadoes that occured here are some videos in various locations in each day of this historic event.

Tushka/Atoka, OK EF3 Tornado

Jackson, MS EF3 Tornado

Scooba, MS EF3 Tornado

Videos are courtesy of http://www.tornadovideos.net/ and my friend Greg Nordstrom.

Remember, anytime you are under a tornado warning and/or hear a siren please take cover and protect yourself!

Spring Time Brings Spring Weather

Normally, I would inform you on specific weather phenomena's that are experienced on a day to day basis, but this one calls for more than one phenomena and more of a serious situation than the others.  Now I am sure you are thinking that the NWS is crying wolf on this because the last two storm systems have been considered as tornado outbreak risks, but the most that came out of it were wind reports.  This storm, however, actually and literally has the potential and ingredients to create a tornado outbreak for the Southeast.  What makes things so different this time?  Good question.  Here is the current surface chart that shows you how things are setup right now. 

There is a surface low that is centered over the Oklahoma and Kansas borders.  Now this is an interpretation from HPC, but they typically are not too far off of what is actually going on.  The unique thing about this low is that there are about 5 fronts attached to it.  The important ones are the cold front in western Texas, the dryline in central Texas, and the warm front in eastern Texas.  Right now it may not seem like much, but the dryline is expected to move as far east as MS.  Not impressive enough?  How about if I tell you that typically drylines will make it close to eastern Texas before they go away?  Impressed now?  Good.  Now why would it be different than usual this time?  Drylines are typically common this time of year for western Texas, but western Texas has been under a drought period and have had a lot of fires burning several hundreds of acres of land.  With a westerly wind, this pushes all of the dry air from the fires eastward creating drier air to push further east than usual.  Along with that, the Gulf of Mexico is gradually getting warmer and, with the surface low being somewhat close to the Gulf, will bring in a lot of warm and moist air from the Gulf inland by the rotation of the low.

If this isn't enough information to show the signifcance of this event allow me to go into more details.  We covered temperatures and moisture near the surface, but what about everything else in the atmosphere?  First I will show you where SPC is showing to be at the highest risk of severe weather and significant severe weather. 


The first one shows the area with the highest risk of severe weather.  The second image shows the probability of severe weather and where the moderate risk is is where the highest chance of severe weather is and on top of that it is hatched which means a probability of 10% or higher of significant severe weather.  Keep in mind that the time issued for this is between Friday morning at 7 AM CST to Saturday morning at 7 AM CST.  I will show you the best time that the NAM model is showing what that area us under such a high risk.  The NAM was chosen because it compared better to the current data than the other models did.  Here are the wind speeds at 850mb to show where the low level jet (LLJ) will be.  

This may look like a bunch of colors, lines, and wind barbs, but what this is showing is that the area under the moderate risk has winds ranging from 45 knots to 60 knots.  This is important because the direction of the winds are from the south/southeast which enhances warm air advection and moisture into the moderate risk area.  This can help generate rotation for the possibility of tornadoes.  Now let's look a little higher in the atmosphere at 500mb.  

This is showing relative vorticity and what it's good for is showing areas of lifting and sinking.  The red outline indicates that the area inside of it is an area of lifting which will increase the chance of severe storms to develop.  If you remember where the moderate risk area it is you will see that the center of the red outline is in the same location.  So now you have seen that there will be more moisture, warm temperatures, southerly winds, warm air advection, and lifting in the mid-levels of the atmosphere.  Seems like a great setup so far, what else needs to be in place?  Excellent question.  We will go higher in the atmosphere where we look at the jet stream. 

The jet stream is pushing pretty all the way to the Gulf Coast which is pretty far for this time of the year, but this is a good setup for severe weather.  Reason for that is because there is a jet streak, an area of strong winds, to the west of Mississippi.  The area that is enclosed in the orange outline is an area of divergence and diffluence in the upper levels of the atmosphere.  What this means is that there is lifting in the upper levels of the atmosphere.

So now let's recap, there is, and will be, a lot of moisture at the surface with warm temperatures which is important because storms feed off of moisture that they can bring in, there is southerly winds and warm air advection with the low level jet at 850mb which help promote rising or lifting of air, there is positive vorticity advection at 500mb which further promotes rising of the air, and there is divergence and diffluence at 250mb which further enhances the rising of air.  All of these are right over the moderate risk area.  Now all that we can do is keep monitoring the models, the current weather, and continue to watch this event unfold.

Stay safe and keep your eyes and ears to the tv, radio, and NOAA weather radio if you have them.

Lightning: The Static Charge in the Sky

Lightning is one of the most powerful, beautiful, and amazing phenomenas that exists on Earth.  The question is what is it and where does it come from?  How much does the Greek god Zues play a role in it?  Is it a living creature?

 

Well for all of the Greek mythology guru's Zeus has nothing to do with lightning.  For all of the Syfy junkies lightning is not a living creature as much as Kevin Sorbo would like to believe it to be.  Lightning is a large scale version of us rubbing our sock covered feet on carpet and touching someone to shock them.  It is an atmospheric discharge created by the friction of water molecules being forced to clash against ice crystals creating a positive charge.  These charges create an immense amount of electricity that can sometimes reach the ground, but most of the time it doesn't.  Lightning has 3 amazing factors to it that truly make it a spectacular phenomena to see.  It can travel at speeds of 140,000 mph, reach temperatures has hot as 54,000°F, and carry as much electricity as 1 trillion watts!!  These are some incredible statistics about a single bolt of lightning that is just the version of static electricy to the atmosphere.

               

This is faster than a space shuttle (100,000 mph), over 5 times hotter than the surface of the sun (9941°F), and could supply Beijing, China, the world's largest city, with electricity for 77 days straight.  Beijing uses about 13 billion watts in a day.  This is all from one bolt of lightning.

Now let's make things a little more interesting and say lightning comes in various forms and colors.  Yes, I said colors.  Lightning is typically categorized as either cloud-to-cloud, cloud-to-air, or cloud-to-ground.  What each category means is rather simple.  Cloud-to-cloud lightning is lightning that starts in a cloud and ends in a cloud.  Cloud-to-air lightning is lightning that starts in a cloud and ends in the air.  Cloud-to-ground lightning, the deadliest lightning, starts in a cloud and ends at the ground.  Cloud-to-ground lightning is unique because it is common for the lightning bolt in the clouds to not reach the ground all the way, but what causes the ones that don't reach the ground all the way to strike the surface is when electricity from the surface reaches upward to the main lightning bolt and completes the entire lightning strike.  There are far more other types of lightning such as the rare "ball lightning", the so-called "heat lightning", a positive flash, and even upper-atmospheric lightning that creates optical phenonemas known as sprites, elves, and blue jets.

So what's up with lightning having a color?  Interestingly enough, lightning will have a distinct color to it based upon the surrounding environment.  The main colors are red, blue, yellow, and white.  Now keep in mind these colors are not like the shade of yellow on a school bus or the shade of red of a stop sign or the shade of blue like police lights.  These are more color tints to the lightning.

     

What do these colors mean?  If you see lightning that appears red then there is rain in the cloud.  If it appears blue then there is hail in the cloud.  If it appears yellow then there is significant amount of dust particles in the air.  Finally, if it appears white, the most commonly seen color, then there is low humidity in the air.

Now you know some interesting facts and information about lightning.



Try not to get struck.