Day 144: High Plains Severe Weather
Above is a radar image taken this evening capturing the thunderstorms stretching from the US-Canada border south toward the US-Mexico border. Earlier this evening, the “hole” in west central Texas was filled in with thunderstorms. In fact, severe thunderstorm and tornado watches stretched from Mexico to Canada!
The VORTEX II armada woke this morning in Colby, KS after chasing tornado-warned thunderstorms in west central Kansas during the day before. (I must also add that one of the hotels housing the V2 armada had a small fire during the night that required several V2 people to move to a new hotel in the middle of the night. Fortunately, no one (as far as I’ve heard) was injured.) By early morning, a powerful, negatively tilted shortwave trough was already ejecting north, northeast from the southwest United States. In advance of this shortwave trough, thunderstorms were developing in a region of widespread ascent. This caused the V2 armada to quickly hold their morning meeting and then drive northward into Nebraska.
By the time V2 arrives in Nebraska, the first thunderstorms of the day were developing out of their reach. This is a shame, too, because these thunderstorms produced several tornadoes. Even though the storms were moving quickly and long-term deployment on the storms would have been difficult, I’m sure the armada would have loved the opportunity for data collection. Instead, the armada waited along I-80 in far southwest Nebraska and prayed for a miracle.
In the late afternoon it appeared that the V2 prayer would go unanswered. Tornadoes had been reported to their north in northern Nebraska and the Dakotas, as well as to their south in southwest Kansas and the Texas panhandle. Closer to the armada location, the prospects for thunderstorms looked grim. About this time the cold front collided with the dryline and thunderstorms erupted in northwest Kansas and took aim on the armada. The armada collected data on several thunderstorms that passed along I-80, including what could possibly be a small, weak, short-lived tornado near their position. This tornado was not observed visually, but possibly in the radar data. Further analysis will hopefully shed some light on this.
Day 143: Tornadoes in Northwest Kansas
For day 23 of VORTEX II operations the armada targeted west central Kansas. The day started in North Platte, Nebraska, took them as far south as Garden City, KS, and will end with them located farther north. (Check back tomorrow for the actual location.)
The armada had a difficult day with storms developing rapidly, in several locations, and moving north-northwest at high speeds. The storm motion made deployment opportunities difficult and the fact there were numerous storms to choose from (and watch out for) made data collection extremely challenging – but a challenge the armada was up to. The storm V2 targeted is circled in orange (below) and had a tornado warning on it at one point. The storm’s rotation looked fairly good on radar and spotters reported brief funnel clouds, but it never produced a tornado.
Ironically, one of the sounding units (circled in yellow) was in position to observe the storm VORTEX II targeted as well as the storm immediately to the north. The northern storm (circled in red), actually went on to produce a tornado. Because Kansas is so flat, the sounding unit was able to observe the tornado from over 15 miles away! Amazing!
This wasn’t the only tornado of the day in Kansas. In fact, it was just getting started at this point. As the armada was heading back to their hotel because of darkness, strong rotation developed to the northwest of Goodland, Kansas.
The radar images above and below (same image, just annotated below) capture the tornado (area circled in yellow) and a developing tornado (area circled in orange). The radar is sampling the tornado (yellow circle) at a height of 300 feet above the ground. In other words, the velocities being displayed in this image are what the radar believes the wind speeds are of air moving toward the radar (greens and blues) or away from the radar (reds and oranges). Whenver these colors are immediately next to each other it means that the wind is either rotating, coming together (convergence), or going apart (divergence). In the examples above, the air is rotating, and quite rapidly. (I’ll do a post on radar analysis in the near future to explain how to tell if the air is converging, diverging, or rotating.) The values of the winds in this post are approximately 70 knots away from the radar and 40 knots toward.
The orange circle has a much weaker circulation, but it is one nonetheless. In the images that followed (not displayed here), the tornado (yellow circle) weakened and the developing tornado (orange circle) took over. This is known as a “tornado cycle”, or “cycle” for short. The thunderstorm that produces these “cyclic tornadoes” is known as a “cyclic supercell”.
I should add that the forecasters at the National Weather Service office in Goodland, KS were able to see these tornadoes from their office. They were also able to see a tornado on the southwest side of the city a little bit earlier!
Day 142: Northern Plains Severe Weather
Today is day 22 of VORTEX II and the crew decided that a “down” day was necessary. After going hard for well over a week straight, maintenance on vehicles, archiving of data, etc needed to be taken care of. So even though the armada was “down” it was far from a “do nothing” day.
Several hundred miles to the north, the ingredients came together for a severe weather outbreak. Across the central United States, a large ridge (denoted by the blue N) was allowing warm, moist air to flow northward. To the west of this ridge, a large scale trough was located over the western United States, with several smaller scale troughs (denoted by red X’s) embedded in the flow (denoted by the green arrow). In between the large trough and ridge, a strong upper-level jet streak (denoted with the purple shading) was nosing into the northern plains. The lift associated with the trough(s) and jet streak(s), coupled with the warm, moist air streaming northward with the building ridge yielded thunderstorms across North and South Dakota (denoted by the yellow circle).
Earlier this afternoon, numerous storm chasers witnessed a large tornado in South Dakota. And thanks to modern technology and the excessive number of chasers, I was able to watch this tornado live from multiple angles. In other words, I was able to “storm chase” today for free, and in the comfort of my own home.
Tomorrow looks to be the day in between shortwave troughs, with the ridge poking farther north and lessening the overall severe risk (although, severe thunderstorms will still be possible). Monday looks primed for another big day as the next shortwave trough (westernmost red X) begins to move into the northern plains. I hope VORTEX II is well rested by then!
Day 141: Another Deployment on a Tornado Warned Storm
Today is day 21 of VORTEX II and, once again, V2 deployed on a thunderstorm that had a tornado warning. The storm produced several brief tornadoes before reaching the VORTEX II deployment (which was limited by a poor road network). I’m not sure what data was collected tonight because the crew is still on their way to the hotels. It appears they will have another long day and drive tomorrow.
Following on with my blog post last night, tonight’s image attempts to capture some of what I was discussing regarding chaser convergence. The image above is from far southeast Wyoming – where V2 was operating today. This is and area that is relatively rural, unlike central Oklahoma. Theoretically there should be fewer people out chasing storms up here since the number of “locals” out for a look-see would be lower. Even if this is true, the number of “chasers” (and only those who were transmitting their positions via the internet) was astonishing for such a marginal day in an out of way place.
The white letters (and a couple of the yellow ones) indicate the positions of the V2 armada vehicles. For the most part, they are all in advance of the storm. All of the car icons and video camera icons indicate the position of chasers. There are no where near the number of chasers as there were in central Oklahoma on Wednesday, but there are a lot more than I would have expected in such a remote chasing area. The number of chasers on the roads is certainly increasing rapidly…
My post regarding the incidents on Wednesday and the comments that followed on Thursday will have to wait until tomorrow. I’m currently working on around 15 hours of sleep in the last 90 hours – and almost all of this work was VORTEX II related. I promise, however, that the blog post will be coming soon.
Day 140: The Chasing Aftermath
I apologize for the late post; this will be short.
The photographs above capture the massive chaser convergence that took place during yesterday’s severe weather. If you got stuck in this long line of cars and a tornado was bearing down on you, your chances of survival would go way down. I will not chase in Oklahoma again, and quite likely almost anywhere else in the plains as a result of these photographs. To be honest, 1 real chase in 5 years indicates I’m not exactly someone who frequently chases, anyways. My real interests are found with the forecasting and evolution of severe thunderstorms, and to do that I’m much more likely to be found in a National Weather Service office or the Hazardous Weather Testbed.
I should also note that in at least one of those photographs, the mast of one of the DOWs can be seen.
I’ll post more on this topic in the coming days.
The photographs above are from J.R. Henly and Chris Novy, both very experienced chasers who are extremely frustrated with this situation.
Day 139: Another Oklahoma High Risk
Today was day 19 of VORTEX II, and Mother Nature afforded V2 a second chance. The blog post for day 130 discussed the events of 10 May 2010 and how storm motions prevented VORTEX II from achieving a successful deployment. Today’s high risk offered slower storms, and a better potential for deployment on a tornadic thunderstorm.
The armada spent several hours collecting data on yet another thunderstorm that ultimately produced a tornado. This means that the first 19 days of V2 this year have been significantly better than the entire first year of V2.
While V2 was collecting data on a tornadic thunderstorm northwest of the Oklahoma City metropolitan area, the VORTEX II Operations Center (located in the National Weather Center in Norman, OK) once again was forced to seek shelter from a potential tornado. Unlike 10 May, no tornado has been confirmed in the city of Norman.
These thunderstorms continued to slowly move east at the same time new thunderstorms developed over eastern Oklahoma and western Arkansas. The image below captures a view from the Fort Smith, AR National Weather Service radar of all the thunderstorms in the vicinity. There is nothing like being sandwiched between two sets of very intense thunderstorms!
Also, if you have been a reader of this blog for any length of time, you might have noticed that the quality/scientific content of the posts has been a lower lately than you might have become accustomed to. I apologize for that – you can blame VORTEX II. Hopefully in the next day or two I can get some rest and begin thinking clearly again!
Day 138: VORTEX II Finds Hail…and a lot of it…
Today was day 18 of VORTEX II’s second year, and boy was it a day to remember. A single supercell thunderstorm developed in far western Texas panhandle and slowly tracked toward Oklahoma. This storm is still ongoing at this late hour.
The image above is when the storm was about to produce one of it’s many tornadoes of the evening. This tornado developed to the north and west of the armada, and was briefly visible by several members before becoming wrapped in rain. The image below captures the rotation a few minutes later. This rotation was probably the best rotation during data collection by the mobile mesonets, but was too far away from most of the good road network to be sampled. Alas, Mother Nature teased the armada once again.
Although there were several tornadoes today, the big story was the hail. Extremely large hail once again fell on many members of the armada resulting in lost windows. Part of the problem today was that there was only one main west-east road and the storm tracked right down this road. This might not have been a problem in and of itself, but a numerous chasers were also present. I am not blaming chasers for being there, they have as much right to be there as VORTEX II. However, the combination of one main road, the VORTEX II armada, and numerous chasers resulted in extremely slow going for vehicles which, in turn, allowed the slow moving storm to catch up to those stuck and unload giant balls of ice.
It will be interesting to see what happens tomorrow. Tomorrow’s target area appears to require quite a drive for VORTEX II to be in place for operations. This means that all the vehicles with damage will need to be repairs ASAP or will have to miss out on operations. We’ll know more in the morning…
About Patrick
Patrick Marsh is a Ph.D. student at the University of Oklahoma's School of Meteorology. He earned a Bachelors of Science in Mathematics and Physics (cum laude) from the University of Arkansas in 2005 and a Masters of Science in Meteorology in 2007. In addition to working on his doctorate, Patrick serves as the National Severe Storms Laboratory Liaison to the Hazardous Weather Testbed where his research interests lie in working with operational forecasters, data mining, data visualization, and all things high-impact weather. For more about Patrick's work, check out his complete CV!
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