The Moore, OK Tornado: Fujita Scale vs. Enhanced Fujita Scale

Heart breaking images rooted from the extreme damage following the Moore, OK tornado earlier this week. Same occurred in Granbury, TX just a week prior. I personally cannot even imagine being in the middle of such a devastating phenomenon.

Looking at the Moore, OK tornado a bit closer, this twister cut a 17-mile path and was 1.3 miles wide at its max. Additionally, due to the damage following the National Weather Service (NWS) survey, the tornado was rated an EF-5 with winds estimated between 200-210mph.

Image: www.cnn.com

If you are not familiar with the EF-Scale, it is the scale used based on post-storm damage to rate the strength of a tornado. EF-Scale is also known as the Enhanced Fujita Scale, which was implemented on February 1, 2007. This new scale more closely represents the estimated wind speed from the tornado based on the damage it creates from the advancements in the science of physics and engineering. There are six categories that range from EF-0 to EF-5.

Note the estimated wind speed increased with and increased rating. However, if the Moore, OK tornado occurred before this new scale was revealed, it would not be rated an F-5 or even an F-4.....interesting to fathom.

Dr. Tetsuya Fujita in collaboration with Allen Pearson, introduced the original Fujita Scale back in 1971 to rate the intensity of tornadoes. The following illustrated the wind speeds from the original Fujita Scale.

F-0: 40-72mph

F-1: 73-112mph

F-2: 113-157mph

F-3: 158-206mph

F-4: 207-260mph

F-5: 261-318mph

If the Moore, OK tornado from this past week was scaled on the original F-Scale it would be in range with a high end F-3 and maybe low end F-4. On the other hand, the May 3, 1999 tornado that crossed paths with Moore, OK was a true F-5 with winds estimated over 300mph.

Its interesting to note how we perceive the weather based on scales, and numbers, especially when the same scale was drastically changed.

No matter how strong or "weak" a tornado is, always take a Tornado Watch or Warning seriously and make sure to have a safety plan in place. Tornadoes are monsters and can cause catastrophic damage.

For more news and weather you can log onto: www.facebook.com/plushnickweather or www.facebook.com/KAGSTV. You can also check out our twitter feeds: @KAGSweather and @KAGSnews. Furthermore, you can download our new weather app. Search: KAGS Weather, in the Apple App Store or Google Play for Android.

Devistation In Moore Oklahoma...Severe Threat Here Tomorrow

Words sometimes cannot even describe what has occurred in Oklahoma this afternoon. Utter devastation ripped though many communities as a large scaled severe weather event unfolded. Rain, hail, and monster tornadoes scared many lives and neighborhoods, especially in Moore, OK. Before this event, the people of Moore are very familiar with severe weather as one of the worst storms to ever occur happened back on May 3, 1999. An F-5 Tornado with winds around 318mph, leveled homes, buildings, and ripped up roads. The only positive to come of the May 3, 1999 tornado were a blossom of storm shelters built all across Oklahoma.

Nonetheless, the images were powerful this afternoon.

Image: Moore Tornado May 20, 2013 from KWTV

 

Above is a snapshot of the tornado from this afternoon in Moore, OK. Storm spotters estimated the width of the tornado around 1 mile wide, with wind speeds equivalent to an EF-4 or EF-5. Following the abatement of the tornado, the aftermath images would just shake you.

 

Image: NBC News, the aftermath of the Moore, OK

 

Homes destroyed, gas leaks creating fires, and many people losing everything they had. As a meteorologist, we wish we could control the weather to steer these type of storms away, but all we can do is report and try to inform as many as possible.

 

An additional thought comes to mind in how this tornado parallels the path of the 1999 storm. The National Weather Service (NWS) in Norman, OK put together a graphic, displaying how close the paths were.

 

Image: NWS Norman, OK. Path of 2013 and 1999 Moore, OK Tornadoes

 

 

The 1999 storm was an F-5 tornado, but the rating on today's storm will wait until the NWS surveys the damage.

 

What we have to be concerned about tomorrow is that the severe weather will shift into the Brazos Valley. Up front, I can tell you that there is a small tornado threat here, but the atmospheric condition does not favor large, long tracking tornadoes. Furthermore, the highest chance for large tornadoes will likely occur from northeast Texas to Arkansas.

 

 

The Storm Prediction Center (SPC) in Norman, OK has placed the entire Brazos Valley under a "Slight Risk" for severe weather tomorrow, with parts of Leon County and points to the northeast under a "Moderate Risk."

 

Our set up for severe weather features a cold front to our north and west, along with a tropical flow of moisture from the Gulf of Mexico.

 

 

We see this all the time, but the true kicker to generating powerful storms lays in the upper levels. The jet stream along with other mid-level features create a strong enough wind to "tilt" individual thunderstorms. In other words, this upper level wind will allow storms to grow stronger and live longer. Therefore, strong winds, large hail, and even tornadoes become a concern when these type of conditions come together.

 

 

As the cold front moves closer and interacts with the daytime heating, clouds will begin to bubble up and severe weather will begin to break out.

 

Here is what we can expect here.

 

-Storms develop late in the afternoon Tuesday.

-Storms will continue into the night.

-Strongest storms will be to our northeast.

-Low threat of flash flooding.

-High threat of strong damaging wind.

-Moderate threat of large hail.

-Low threat of an isolated tornado.

 

Make sure to be weather aware tomorrow, and I will make sure to get as much information out to you on-air and online as well. Just make sure to get indoors if you see a storm approach, or you hear any thunder.

 

For more news and weather you can log onto: www.facebook.com/plushnickweather or www.facebook.com/KAGSTV. You can also check out our twitter feeds: @KAGSweather and @KAGSnews. Furthermore, you can download our new weather app. Search: KAGS Weather, in the Apple App Store or Google Play for Android.

Devastating North Texas Tornado Outbreak

From: The Texas Chaos Storm Team

Last evenings events were hard to think about and very tough to track. It wasn't the quantity of tornadoes that made this a news headline, but rather the quality of each individual thunderstorm. Many areas in north Texas, around the Dallas/Ft. Worth Metroplex were rattled by widespread severe thunderstorms. In particular, there were two towns that were hit the hardest: Granbury and Cleburn.

The original atmospheric set up did not call for such destruction. However, as the afternoon and evening wore on, the combination of an upper level low pressure system, low level heat & humidity, as well as a quick moving jet stream, came together to hash out this event. The key was the upper level low. While it was spinning over west Texas, the low was quite disorganized. However, during it's move to north Texas, the circulation became tighter and strengthening was the result. Along with the strengthening low, very cold air was associated in the upper levels, allowing for thunderstorms to grow higher, and in turn become severe with large hail, strong wind and generating tornadoes.

Some of the images were just stunning. Check out this picture of hail in Ganbury, TX that I found on facebook last night.

From spike to spike, the hail stone measures approximately 4" in diameter. That's equivalent to an average grapefruit. I cannot image something like this falling from the sky. What this illustrates is that the updraft (or upward motion) in the thunderstorm was so strong that it could support the weight and growth of this monster. The updraft speed must have been over 100mph to keep this suspended for a long period of time before crashing down to the ground.

Not only was the above picture incredible, but what meteorologists were able to view on Doppler Radar. Looking at the structure of the precipitation was a good indication that rotation was occuring in two different supercells just joust of the Metroplex last night.

 

If you took this image for what its worth, you would think that these were rotating supercells that look like prolific lightning, rain, and hail producers. But if you take a deeper look at the "Doppler" part of the radar, you will notice a tight circulation in the "velocity" image (illustrating speed and direction of the wind).

 

 

Here, you are looking at the southern cell that ripped though Granbury and Cleburn. This is a velocity image that helped to pinpoint the location of strongest rotation, or where the tornado was spinning. Green colors denote wind moving towards the radar site, while red shows wind moving away from the radar site. When you get these green and red colors tightly together, we call this a "couplet," indicating that there is a strong rotation in the storm with a possible tornado. Its these images on radar that support a Tornado Warning issued by the National Weather Service. Unfortunately, a radar cannot see what is happening on the ground, therefore, storm spotters, and law enforcement are extremely important in reporting whether there is a tornado or not. In this case, there was and for a time, this tornado was reported to be one-mile wide while in Granbury.

 

Overall, this was a very destructive event that unfolded last night and at this time the National Weather Service (NWS) in Ft. Worth is assessing each storm where a tornado was reported. Based on the damage in each area, the NWS will qualify whether a damage was from a tornado or not. If damage was from a tornado, it will be rated based on the Enhanced Fujita Scale (EF-Scale).

 

 

Because the wind was not directly measured during each storm, the rating is used as an estimation of how strong the winds were. From the survey, the NWS will say, "it will take this wind speed to cause this type of damage." Based on that estimated wind speed, an EF rating will be placed on that particular tornado.

 

From this morning and afternoon's survey, the NWS has rated a couple of tornadoes already. Each of the following assessments are for individual tornadoes.

 

Cleburn: EF-3 tornado with max winds of 140mph, and a width of 0.6 miles.

 

Granbury: EF-4 tornado ----preliminary

 

Cleburn: EF-0, minor damage with a max wind of 85mph.

 

For the other reports, you can click here to see the latest from the National Weather Service. As of this afternoon, there are preliminary 10 reports of tornadoes from last night. This number can change.

 

In closing, this was a horrific event with many reports of destroyed homes, injuries, and fatalities. When the weather looks like its going to take a turn for the worse, make sure to use your resources to stay in the loop. Your mobile devise, computer, tablet, and television are the best ways to know whats going on. Additionally, buying a NOAA Weather radio will instantly let you know if severe weather will threaten your location. Finally, your local television meteorologist will always give you the newest information so you and your family can make the safest decision.

 

For more news and weather you can log onto: www.facebook.com/plushnickweather or www.facebook.com/KAGSTV. You can also check out our twitter feeds: @KAGSweather and @KAGSnews. Furthermore, you can download our new weather app. Search: KAGS Weather, in the Apple App Store or Google Play for Android.

 

 

From Drought To Rain Overload

For the most part of 2013, a majority of the the Brazos Valley, and in fact a big chunk of Texas has dug into a deeper drought. Several storms were able to dump an immaculate amount of rain, but as we know best, we are a "feast or famine," part of the country. Either its prolonged dry spells, or quick splashes of rain. However, last weeks event which occurred from Thursday to Friday was a true treat and invigorated our soils.

Take a look at where we started before last weeks events. The following image is from the latest Drought Monitor Report that is uploaded weekly by the USDA and NOAA.

Yikes! Most of the Brazos Valley during last Thursday's report is currently under a Severe Drought, with several areas outlined as an Extreme Drought. You don't even have to look at this image to know whats going on. Lawns have gone from a vibrant flush green, to dried out, brown weeds. Plus, for the year of 2013, Easterwood Airport's climate report noted we were a solid 3.50"+ below average.  Nevertheless, three soaking rounds of rain were able to pick up our spirits.

According to Easterwood Airport, in a 48 hour period, and incredible 4.43" of rain fell. This brings the yearly total to 13.97", and turns the 3.50" deficit into a minor surplus compared to average. Furthermore, there were several locations across the Brazos Valley, especially in Madison County which picked up close to 6.00" or rain during the same period. As good as it was to see a heap of wet weather, minor flooding caused problems all around the region. Nonetheless, I am sure there will be a huge swing from the current Drought Monitor to the new report that comes out Thursday morning.

If you thought we were done with the rain for now.....hold your horses, another dose is on the way. This time around, the rain will not be as widespread and as heavy as last week. What we are watching is an upper level feature over the northwest side of Mexico.

Slowly, but surly, this feature will rotate into Texas and spawn several showers as well as a few thunderstorms. Timing at the moment looks generally around Tuesday night and into Wednesday, with the best chance of rain coming in Wednesday. A few of these storms could have a period of brief heavy rainfall, and severe weather will no be part of the picture. Just make sure to have the umbrellas ready. In addition, by the end of the week and into the weekend, expect the temperatures to rise to levels we have not experienced yet this year......90s may be coming soon!!!!


For more news and weather you can log onto: www.facebook.com/plushnickweather or www.facebook.com/KAGSTV. You can also check out our twitter feeds: @KAGSweather and @KAGSnews. Furthermore, you can download our new weather app. Search: KAGS Weather, in the Apple App Store or Google Play for Android.



From Records To Reality

www.timesfreepresss.com

 

The beginning of May has been a struggle to get through if you are not a fan of the chill. However, the weather will get back to normal real soon and rain will move in closer to the weekend.

Nonetheless, whether you like the chill or not, its been an impressive start to May. The core of cold air was so deep that five mornings in a row began in the 40s, with four consecutive days either tying or breaking a record.

Check out the following lows officially reported at Easterwood Airport from Thursday to this morning.

Thursday Morning May 2: 47°

Friday Morning May 3: 43° (new record)

Saturday Morning May 4: 42° (tied a record for the day and lowest temperature during the month of May)

Sunday Morning May 5: 46° (new record)

Monday Morning May 6: 48° (new record)

As we continue to pull out of this atypical pattern, warmer air will win out and a disturbance to our west, in combination with a moist flow off the Gulf of Mexico could help trigger widespread rainfall going into the weekend.

I will keep you updated as changes in the forecast occur, but you may throw your heavy coat back in the closet for now.

For more news and weather you can log onto: www.facebook.com/plushnickweather or www.facebook.com/KAGSTV. You can also check out our twitter feeds: @KAGSweather and @KAGSnews. Furthermore, you can download our new weather app. Search: KAGS Weather, in the Apple App Store or Google Play for Android.

Coldest Air On Record For May

Spring is a season that helps the atmosphere transition from the harsh winter chill to the blazing heat of summer. As is typical of any transition, there are ups and downs, but there tends to be a progression. In other words, temperatures can fluctuate frequently this season, but what we have coming our way will shock you.

If you read the last post, we talked about a cold front that will drive in a huge pool of cold air which could set new record low temperatures. Now, there is high confidence this will happen, but between now and then, there is a lot to talk about.

As of this afternoon, the front crossed the Texas panhandle and took temperatures from the mid-90s yesterday, down to the 50s.

In just a 24 hour period, the temperature dropped nearly 50° from Dalhart to Amarillo. The temperature change will be drastic here too and we will feel it starting tonight.

A cold front along with additional upper level features is the main driver in this extreme May weather swing.

The cold front is responsible for the colder air, but notice the yellow line extending from low-pressure center. This is known as a dry line, and has the potential to erupt several strong to severe thunderstorms along it this evening. Due to its upward forcing, plus plenty of instability ahead of it, areas from the Hill Country to the Brazos Valley need to be alert. Thunderstorms are expected to line up west of I-35 this evening and eventually cross into the Brazos Valley around midnight. Details are not 100% determined, but this is the trend we see in the model data. One model that we use often here at KAGS, the RPM model, illustrates this complex to be here just after midnight.

 

Remember, this is the current trend, and the forecast can change. If these storms cross our path, they will produce heavy rainfall, lightning, winds over 50mph, and hail. I will make sure to keep you in the loop as this forecast comes together on Twitter, Facebook, as well as on KAGS-HD.

 

Update: There could still be a few isolated storms here, but not as likely as previously thought.

 

Nonetheless, following this line of potential storms, the cold front will be right on our doorstep early Thursday morning. Temperatures will fall all day long, several showers will fly around us, and the wind will whip up.

 

By the time you wake up tomorrow morning, temperatures will be falling from the 60s and into the 50s, where they will will hold all day long. Additionally, with a strong north wind clocking upwards of 40mph, it will feel VERY cold. Not only will an umbrella be a good idea to keep around tomorrow, also, bring out that winter coat from the back of the closet.

 

Here is where the other big story come into play. Once the sun sets tomorrow evening, temperatures will fall down into the 40s, which will be near record levels. The following image will guide you to the current records established at Easterwood Airport that could be in jeopardy:

 

 

Therefore, Friday....Saturday.....and Sunday morning coming up could feature new record low temperatures. Here is the kicker, if we break the record low on Saturday, it will not only mark a new daily record, but a new record low temperature for the entire month of May. Yeah its going to be that cold!!!! At the moment, I believe that we will tie, if not break the records Friday and Saturday. Not sure about Sunday yet, but this is not what we typically expect for May weather.

 

One final note, due to high winds and very dry air in place Friday, fire danger will be elevated. Keep that in mind as well.

 

For more news and weather you can log onto: www.facebook.com/plushnickweather or www.facebook.com/KAGSTV. You can also check out our twitter feeds: @KAGSweather and @KAGSnews. Furthermore, you can download our new weather app. Search: KAGS Weather, in the Apple App Store or Google Play for Android.