Before we can use hodographs for our forecasting and analysis, we first must have at least a basic understanding of vectors. A vector is a quantity that, unlike a scalar which has just a magnitude, consists of both a magnitude and a direction. Let’s relate these terms to meteorology! When you check your local forecast, the first thing you may see that your forecast high is 52°F. This quantity is a scalar, because it has only a magnitude. What do you look for next, most likely, the chance of rain! A 70% chance of rain has no direction, just a magnitude, so this value too is a scalar. But what are you likely to look for next? The wind, of course. For the sake of this example, let’s say that the wind today will be 20 miles per hour out of the north-northwest. This value, unlike the other two examples, is a vector. With a magnitude of 20 mph and a direction of south-southeast, or 158°. Important: When people refer to a “north wind,” they usually are talking about wind that is blowing from north to south. When talking direction, north is 0°/360°, east is 90°, south is 180°, and west is 270°. The NNW wind in this is example is blowing to the SSE, and because the direction of a vector is given as the direction it points, we assigned it a direction of 158°. However, to stay consistent with the way things are done in meteorology, from here on out all winds will refer to the direction they are coming from, so a NNW wind will be about 338°.

What does this have to do with hodographs? We’ll get to that! First, let’s show you a blank hodograph just to get that image in your head.

The above image is the most common of several ways a hodograph may be presented. It is the same concept as a polar coordinate chart. The lines directed outward from the center indicate direction, and the different sized rings encircling the center represent wind speed. This is the fundamental part of hodographs that must be understood. Two things: speed, direction. Does that sound familiar? Speed and direction? It should! Remember that wind is a vector, so it has both a magnitude (speed) and a direction.

Let’s start by plotting the wind speed at the surface on this hodograph. Let’s say the wind outside is blowing at 20 knots out of the east, toward the west.

The red dot on the hodograph indicates where the surface wind in this situation would be plotted! This represents the wind vector. In case this is difficult to visualize, here’s what the hodograph would look like with the vector drawn in as an arrow.

Technically, this first image we posted could be used as a real hodograph! It has the chart, with the wind at at least one level plotted. But we will almost never encounter a hodograph with only one level plotted, as it defeats the purpose of such a useful graphical display. Let’s plot the wind speeds in a hypothetical atmosphere all the way up to six kilometers above the ground! We will use the same easterly surface wind, and add in a few more points to show other levels of the atmosphere at the same time.

We can now see the wind direction at five different heights above one location on a single plot! The wind at the surface is blowing at 20 knots from the east. One kilometer above the ground, the wind is blowing 30 knots from the ESE. At 3 km, the wind is 35 knots from the SE. At 4.5 kilometers above the ground, the wind is blowing at 40 knots from the SSW, and at 6 km the wind is blowing 60 knots from the WSW! As before, to help us visualize all of these directions, let’s take a look at the same diagram, but with the vectors plotted.

Like before, the longer the arrow and the farther the plotted point from the center, the higher the wind speed! Without knowing what the atmosphere looks like before hand, we would have no idea which point was which, so points on a hodograph will usually be labeled with either a height or a pressure for reference.

Now that we’ve plotted several points from 0-6 kilometers, there is one more step before we are done. While digitally generated hodographs will usually have more than five data points, this illustrate the same point just as effectively. When a hodograph is created, it is helpful to “connect the dots” of all of the plotted points. This helps visualize how the atmospheric wind profile actually looks more effectively than to just look at several dots. To do this, we will draw a line from the lowest point (the surface), to the second-lowest point (1 km), and continue this all the way to the highest point (6 km). Let’s take a look!

There we have it! This is what a hodograph would look like in the environment we used. The line used to connect the dots shows perfectly that the wind speed increases with height, and the wind direction veers with height. A veering wind profile is one that rotates clockwise with height, like this one. When the wind turns counter-clockwise with height, it is said to be backing. A wind profile that veers and increases with height like this one is extremely favorable for supercells and tornadoes! Here are a couple more examples of hodographs that can be useful for forecasting.

Straight-line hodograph:

This is often called a straight-line hodograph. These do not have to be, and almost never will be, perfectly straight, but hodographs that generally exhibit a straight line fit into this category. Even though significant speed shear can be present, the lack of directional wind shear tends to favor splitting supercells that are more likely to produce large hail than tornadoes.

Weak wind shear environments

In environments like this, winds are weak and sporadic throughout all levels. Coming from several different directions, this hodograph has no winds that exceed 10 knots. Environments with weak wind shear can still have severe weather if instability is high, but it will likely be in the form of multicellular storms with hail and wind as the main threads. Supercells and tornadoes are rare in these environments, but they can happen, especially with extreme instability and local boundaries. For example, the environment near Jarrell, TX, on 5/27/97 looked much like this, but the presence of incredible instability along with a gravity wave moving through the region helped a southward-moving supercell produce a violent F5 tornado.

Values that can be drawn from hodographs

In addition to the assumptions that can be made simply by glancing at a hodograph, a slightly more in-depth look at an environment’s hodograph can reveal a bit extra at times. Here we’ll discuss a couple of these!

Bulk shear and bulk wind difference

Bulk wind difference is the difference between the wind vectors at two levels of the atmosphere. We usually see 0-6 km bulk wind difference, which means the difference between the winds at 6 km and at the surface. We can see this easily on a hodograph by drawing a vector from the surface wind to the 6 kilometer wind! Once we’ve drawn this vector, we can redraw an identical vector that originates at the center of the hodograph.

From the vector we’ve added at the origin of the plot, we can see that this hodograph has an 80 knot 0-6 km bulk wind difference in the ENE direction. When taken into consideration with other factors, this is very favorable for severe thunderstorms! Bulk shear is very similar to bulk wind difference, except that “shear” is normalized over the depth over which it is taken. A wind difference of 100 m/s over 6 km, or 6000 meters, results in a bulk shear value of .0167 s^-1. ((100 m/s)/(6000 m) = .0167 s^-1)

Storm Motion and Storm Relative Helicity

When forecasting for severe weather and possibly supercells, storm motion and storm relative helicity (SRH) are two very important factors that must be considered. The two are related, and both can be estimated using hodographs, although exact values are difficult to ascertain with out help from a computer! Storm motion tends to be near the “mean wind” of the environment, so without going into too much detail, we can estimate that the storm motion in this environment will be somewhere near this area:

The actual mean wind in an environment like this would likely be a bit more northerly and possibly a bit faster, but because tornadic supercells often move right of the mean wind, we have placed our estimated storm motion a bit farther to the east. Once we’ve plotted our storm motion, we can begin finding our storm relative helicity. SRH is typically measured either from 0-1 km or from 0-3 km, and represents the amount of “spin” in the atmosphere between those levels. For supercells in general, many meteorologists use 0-3 km SRH, while 0-1 km SRH can be very helpful when forecasting tornado potential. To calculate 0-3 SRH using this hodograph, we will draw two lines from the storm motion data point to the 0 km (surface) and 3 km data points. The area between these lines and the plotted hodograph represents the SRH in meters-squared per second-squared (m²/s²). It would be difficult to calculate an exact SRH by hand for a hodograph like this, but this would be an environment with a significantly high value! Over time, after observing many hodographs, it becomes easier to estimate SRH by looking at the hodograph. 0-3 km SRH values over 250 m²/s² and 0-1 km SRH values over 100 m²/s² are considered by many to be guidelines for the minimum needed for tornado formation with supercells, but there is no exact threshold. It all depends on the environment!

We hope this has been educational and you have learned something about hodographs. We plan to add more educational postings here with time. If you have any questions or special requests, let us know through Facebook, Twitter, or our contact page. Thanks!

When a weather balloon is launched, it records data that is displayed on what is called a Skew-T/Log-P diagram. Two images of a blank Skew-T are shown here, with labels for what each line means:

Here’s an overview of each of the labeled terms:

• Isobars – Lines of constant pressure. Pressure, in millibars, is on the Y-axis as the blue horizontal lines on this Skew-T. It is shown on a logarithmic scale, hence the “Log-P” in the name. As height increases in the atmosphere, pressure decreases, which is why the numbers decrease as you go up the axis.
• Isotherms – Lines of constant temperature. The red diagonal lines represent temperature in degrees Celsius. They are skewed to the side (giving the name of Skew-T) because temperature decreases so rapidly with height that if they were straight up and down on the X-axis, temperature would drop off so quickly that most of the atmosphere would be off to the left of the chart.
• Constant Mixing Ratio – I’m not sure what the actual name for these is, but if anyone is then let us know! Mixing ratio is the amount of water in the atmosphere in grams of water vapor per kilogram of dry air. This is shown as the pink/purple dashed lines.
• Dry Adiabats – Lines that show the temperature an unsaturated, or “dry” parcel of air would have if lifted adiabatically (essentially, no heat energy gained or lost). In Earth’s atmosphere, a parcel cools at about 9.8 degrees Celsius for each kilometer it is lifted adiabatically.
• Moist Adiabats – Lines that show the temperature a saturated, or “moist” parcel of air would have if lifted adiabatically.

There you go! Hopefully that wasn’t too confusing. We’ll go into a bit more detail about adiabatic processes and the role that they play in severe thunderstorm development in this page. When a sounding is displayed on these charts, what you will see plotted will be temperature and dewpoint temperature. A sample I tossed together can be seen here:

The red line represents the temperature throughout the atmosphere, and the green line represents the dewpoint temperature. The dewpoint is the temperature to which you would have to cool a parcel of air with a given mixing ratio in order to reach saturation. For example, let’s say you the temperature outside is 74F, and the dewpoint is 68F. That night, if the temperature falls 6 degrees to reach 68F (assuming the dewpoint remains unchanged), the air will become saturated, and you will see fog. Now just to explain a little more and make sure you can understand how to read this sounding, find the temperature at 500 millibars. To do this, you find the isobar that represents 500 mb, follow it to the right to where it intersects with the environmental temperature line (the red line), and follow the isotherms down and to the left to see which one it intersects with (note: it usually won’t be right on a drawn isotherm, so you have to estimate how far it is between two that you can see). In this case, the 500 mb temperature would be about -22C! It will also be important to understand what a lapse rate is. The lapse rate is how rapidly the atmosphere cools with height. This is expressed in degrees Celsius per kilometer. A lapse rate of 4 C/km means that if the temperature at the surface is 30C, the temperature one kilometer above the surface will be 26C.

You will also want to know what an adiabatic process means and what it has to do with this! An adiabatic process is one that does not involve a change in internal energy, or heat energy. This does not mean the temperature doesn’t change! When parcels of air are lifted from a level of the atmosphere, they expand. Due to some physics that we won’t go into right now, air cools when it expands if no heat is added to it, and warms when it shrinks given the same condition. This is very important to understand!

Note: The lessons below are based off of a parcel lifted from the surface. Realistically, the parcel you want to lift will typically be “mixed” through the lowest 100 millibars or so, but using a surface parcel will make things easier.

Now we’ll discuss how this affects severe weather. In order for thunderstorms to form, we all know we want warm moist air below cool, dry air. But there’s a catch. The air above the surface can’t just be cooler than the air at the surface. It usually is, so we would have thunderstorms all the time if this was the case! For surface based storms, the air at the surface must be warm and moist enough that when lifted adiabatically, it remains warmer than the air around it and keeps rising on its own! In this situation, you are said to have an unstable atmosphere. This is difficult to do, since air cools fast enough when lifted that it typically will become cooler than the air around it and sink back to its original position. In this situation, the atmosphere is considered to be stable. When an unsaturated parcel is lifted from the surface, it will cool at the dry adiabatic lapse rate until it reaches saturation. This elevation is called the lifted condensation level, or LCL, and represents the level of cloud bases for parcels rising from the surface. To find the LCL on a Skew-T, you follow the dry adiabat from the temperature at the surface, and follow the mixing ratio line up from the dewpoint at the surface, until the two meet each other. This level is the LCL. Once a parcel reaches its LCL, it is saturated and will from that point cool at the moist adiabatic lapse rate. Parcels usually are cooler than the atmosphere around them when they reach the LCL, so you need something to lift them. Once they are lifted to the point where the parcel temperature is greater than the environmental temperature, the air is unstable and will continue to rise on its own. This is called the Level of Free Convection, or LFC. It then rises freely, without needing a source of lift, cooling adiabatically until it cools below the environmental temperature and stops rising. The level at which it reaches the environmental temperature and becomes stable again is called the Equilibrium Level, or EL. This whole process is shown below:

Next I’ll discuss how to identify instability from a sounding once you’ve found these. On most severe weather days, a cap will exist for at least part of the day. The cap is a region where warm air above the surface prevents thunderstorms from forming, even with very cold temperatures aloft. Until a parcel breaks the cap, it cannot freely convect. The strength of a cap can be approximated by the amount of CINH, or Convective Inhibition. Once the parcel breaks the cap and is above the LFC, the amount of CAPE, or Convective Available Potential Energy, determines how much instability is shown in a sounding. The CINH in a sounding can be calculated from the area between the parcel temperature and the environmental temperature below the LFC. The CAPE is calculated similarly, except that it is the area between the environmental temperature and the parcel temperature when the parcel is above the LFC and below the EL, so the environment is cooler than the parcel and the parcel is unstable. These areas are both shaded below. More CAPE means more instability and more severe thunderstorms, and more CINH means more difficulty in initiating thunderstorms. CINH is helpful in preventing storms from forming early, so that the surface can heat up and create more CAPE. Too much CINH, however, can prevent storms from forming now matter how unstable the environment is. Another measure of instability that can be easily calculated from a Skew-T is the Lifted Index, or LI. Lifted Index is the environmental temperature and 500 millibars minus the parcel temperature at the same level. In this sounding, the environmental temperature is about -22C, and the parcel temperature at 500 mb is about -7C, so the LI would be -15. This is considered to be extremely unstable! A positive lifted index is stable, a negative LI is unstable, and the more negative the LI gets, the more unstable the atmosphere is.

When forecasting for tornadoes, you want lower LCLs and LFCs so that you can have lower cloud bases and more CAPE near the surface. Hail and wind can occur with higher cloud bases, but tornadoes will rarely occur with LCLs above 1500 meters, and even that is very high.

There you have it! If you’ve made it this far, you should have a pretty good idea of how to read a Skew-T. It takes a lot of practice to learn to interpret them for use in forecasting, but you’ll get the hang of it soon, so just keep on practicing!

Unlike Don, which managed to stay fairly south and west, this system looks like it will probably curve back to the north and east a bit earlier. It is possible that it will stay far enough south to make it under the ridge that kept Don moving west, but it appears more likely that future-Emily will encounter a weakness in the Atlantic ridging near the Leeward Islands and will move recurve away from the USA. While this is good news in that it prevents the damage a hurricane can do from occurring, it does mean that people in drought-ravaged areas like Texas and Georgia will have to do without for a little while longer. No matter what path it takes, this system will be in conditions that favor intensification into a hurricane for a little while now, and model guidance agrees that this is a distinct possibility.

We will be back later today with much more information regarding Invest 91L and its potential impacts, so don’t go anywhere!

For an hour or two after initiation, storm mode should be discrete supercells with a tornado threat. Before too long, however, storms should grow upscale into an MCS due to strong forcing, less than ideal veering wind profiles, and shear vectors that are (for the majority of the area affected) nearly parallel to the dryline/warm front. There will still be a threat for tornadoes embedded in the line, but our best shot at tornadoes tomorrow will have to be near the triple point and within an hour or two of initiation. I need to get some sleep tonight, so I don’t have time to go into too much detail. The main points of this discussion are that there is a significant threat of tornadic supercells early tomorrow afternoon across the central and northern plains, before a severe squall line forms and moves east. Another update will be posted tomorrow morning, so check back often and make sure to watch the live stream when it is up!

-Connor

While we prepare to chase Wednesday, we will be keeping an eye firmly set on Thursday. The moisture and upper level flow that Wednesday lacks will both be in place for Thursday. While instability will actually be somewhat low for the time of year, there will still be more than enough for supercells, some of which could produce strong tornadoes given large cyclonically curved hodographs.

There is potential for severe weather beyond Thursday, but it’s late and I need to sleep! We’ll be preparing our vehicle to chase throughout the day tomorrow, and we’ll be making another more detailed blog post at some point as well. Stay tuned as we gear up for a huge week!

The GFS has been strongly hinting at an Omega Block towards mid-May in recent runs, which is something that would essentially kill most severe weather prospects for the plains for a week or two. While late May and June could easily heat up, it always makes chasers nervous to see a pattern like this at such a prime part of the season. The term “Omega Block” refers to an upper level pattern that consists of two cyclones separated by a large, strong ridge. The pattern has a tendency to hold for an extended period of time, before it finally breaks down after a couple of weeks.

Shown above is tonight’s GFS output valid at 168 hours. This clearly shows the developing blocking pattern, with a large upper level low over Michigan slowly drifting south, a ridge over the Rocky Mountains settling eastward, and another large trough deepening as it moves south. Should this pattern materialize, don’t expect much chasing for a week or two minimum. The plains would be trapped underneath northwest flow, if any flow at all, and would likely have nothing but blue skies for quite some time.

While the GFS has been very consistent in developing this pattern, the ECMWF has other things in mind. Shown below is the ECMWF output for the same hour.

As you can tell, both models advertise a large trough digging south/southeast in a week or so off of the west coast. There are differences with strength and placement, but the idea is the same. However, while both models show the secondary upper low near the midwest, they are drastically different in how it is handled to this point. The GFS shows a sub-5460 meter 500 millibar low over Michigan at 168 hours. The ECMWF, however, has the same low sitting over the KS/NE border, and at 5672 meters, much weaker by comparison. Should this play out, I would expect a more favorable pattern to take hold much sooner, possibly as soon as next weekend. In the past, I’ve tended to rely on the ECMWF much more heavily when judging patterns in this range. A great example of this would be the tornado/severe outbreaks that began with the 5/22/08 Kansas high risk.  After a powerful cold front wiped out the Gulf of Mexico a little over a week in advance, the GFS said it would be quite some time before another system would come through with the strength needed to return much moisture from the Gulf. The ECMWF, however, showed the trough associated with these outbreaks for several days before the GFS caught on. That may not be the case this time, but as a storm chaser with all of May free, I certainly hope it is! It is important to remember, however, that even if the GFS output is correct, this is not a “death ridge,” and it is certainly not the end of the season. We’ve had an incredibly active year so far, and there will be plenty of time after this pattern passes for another round of severe weather or three for the plains!

-Connor

The potential for severe thunderstorms was very apparent on the morning of March 28th. The Storm Prediction Center issued a Moderate Risk over the Dallas/Fort Worth Metroplex in the morning, stating the potential for thunderstorms with very large hail, and isolated tornadoes near the warm front. This clearly was warranted, and the tornado threat was even more significant than originally thought.

By late afternoon, conditions were very favorable for supercells capable of producing tornadoes in north Texas. A warm, moist airmass was in place, especially for late March. At 23Z (6:00 pm), temperatures in Ft. Worth were 80°F, and dewpoints were 65°F. This led to a very unstable airmass, capable of supporting vigorous updrafts. The 00z FWD sounding unfortunately only extends up to about 400 millibars, but it is quite clear from this portion of the atmosphere that a deep, moist airmass was in place in the low levels, which combined with lapse rates that were nearly dry adiabatic from the surface to 900 millibars, as well as from 800 to 550 millibars, would provide ample instability for severe thunderstorms.

Meanwhile, very favorable directional shear was in place, along with sufficient speed shear for tornadoes. At 00Z (7:00 pm), surface winds were out of the southeast at 15 kts, 850 millibar winds were out of the south-southwest at 15 kts, and 500 millibar winds were out of the west-southwest at 45 kts. The relatively weak 850mb winds were clearly a limiting factor in tornado formation, but they proved to be more than enough on this day.

With a dryline mixing eastward towards D/FW, a shortwave trough rotated through north Texas, providing enough lift to initiate numerous severe thunderstorms in the area. This shortwave can be seen quite easily on the 00z 700 millibar analysis:

With all of these factors coming together on the evening of March 28th, 2000, the atmosphere was primed for supercells with the potential for very large hail and tornadoes. This next section will discuss the tornado itself and the radar presentation this supercell displayed.

At 6 pm, the supercell was entering northwestern Tarrant county. At this point, a large hail core is visible, denoted by the 65+ DBZ returns which is often indicative of hail. At this point, the supercell is on the northwest side of Fort Worth and is displaying a classic look for a supercell, with the inflow region clear of precipitation and a rather ‘dirty’ hook echo visible.

At the same time, no organized couplet is visible on the lowest tilt (0.5 degrees). Note that the radar is just off I-35W in southern Tarrant county, so we do have fairly high resolution and quality of data with such a low altitude scan.

As we fast-forward ten minutes (now 6:10 pm) we can see that the supercell has tracked further to the southeast, as it was a right-mover. A large precipitation area with large hail is impacting areas along and north of I-820 with a more obvious hook echo developing to the NW of Fort Worth.

At the same time, this 4-panel (lowest tilt in the top left, progressively increasing in tilt/altitude from top left to bottom right) shows a organized low level circulation in progress on the western sides of Fort Worth. While not completely obvious on the lowest tlit (top-left box) due to clutter, a strong and very organized mesocyclone with low level rotation is visible on the following three tilts. At this point, a wall cloud was spotted five miles west of Meacham Airport and a Tornado Warning was issued. The next two images (a reflectivity and 4-panel velocity image) show the increasing organization and strength of the circulation.

The first report of a tornado on the ground came at 6:18 pm where a tornado was reported just west of Fort Worth near the Castleberry high school.The two images below from 6:20 pm show several indicators that a tornado is very likely on the ground, even if a report was not received. Looking at the base reflectivity image, you can see the well-defined hook echo just northwest of downtown Fort Worth. In the tip of this hook, increased reflectivity of 50+ DBZ is noted. This is actually debris being picked up by the radar; because the debris is solid, it produced a increased radar signature. When looking at the 4-panel, a strong, well-defined couplet is visible with the lowest tilt having a 100+ knot couplet. By this point, the tornado was just west of the Montgomery Ward building and was producing damage.

That ended up being the most impressive velocity image captured for the Fort Worth tornado. For the next ten minutes (until 6:28 PM) the tornado moved through the business district of Fort Worth, producing up to low-end F3 tornado damage. Here are the reflectivity images from 6:25 pm and 6:30 pm.

From about 6:30 to 7:00 pm a series of events, including the occlusion of the mesocylcone that produced the Ft. Worth tornado, a cell merger, and the development of a new mesocyclone, led to very large hail and rainfall across Tarrant county, but these processes prevented any more tornadoes from developing.

This reflectivity image at 7 pm shows that a very large supercell was present over eastern Tarrant county with the highest reflectivies near the Ballpark in Arlington and Six Flags (just west of 360 and south of I-30). An inflow notch is visible just east of the radar site.

The 4-panel at the same time (7:00 pm) shows that a strong gate to gate circulation is located just north of Sublett, and a strong mesocyclone is visible on all of the tilts. This was the scan fives minutes later:

By 7:05 pm, the RFD had cut in slightly. The hook-echo has become very obvious and by this point, local TV stations had broken in from their damage coverage in Fort Worth to warn residents of Arlington and Grand Prairie that a new tornado was developing. The velocity 4-panel by this point shows a strong circulation at all levels, including the lowest tilt. At this point, the tornado was on the ground and doing damage to a neighborhood just east of Matlock and south of I-20. A multi-story building that housed a business just south of I-20 was completely destroyed, and several homes lost their top stories. Damage was being done at the time of these scans.

This reflectivity image was taken at 7:10 pm and shows perhaps the most interesting scan (structure-wise) of the night. The most obvious object on the image is the hook echo, which shows several aspects you can only get from a radar from close range, the first of which is the ‘donut hole’ in the hook echo. Note where the higher reflectities surround the area of weaker reflectivites. This is actually where the tornado is located, crossing I-20 just west of what was at the time the Johnson and Johnson factory, which sustained severe damage to its exterior walking bridge.

The velocity shows that the circulation has begun to weaken slightly as it crosses over I-20, but is still significant as it hopscotches over to a neighborhood in Grand Prairie. Just east of Great Southwest Parkway, an oddity typical of tornadoes occurred, as some houses were significantly damaged, while those next door were left completely unscathed.

By the time all was said and done, this storm caused hundreds of millions of dollars worth of damage, and two people lost their lives. One person was killed by the Fort Worth tornado itself, and the other was killed by a giant hail stone. The Fort Worth tornado was a stark reminder that no area is safe from tornadoes, even downtown areas of large cities. The local NBC affiliate in D/FW was on the air when the tornado struck Fort Worth. As the chief meteorologist was doing the 5 day forecast, the shot quickly changed to a live scene out of Fort Worth, where debris was airborne and power flashes were quite evident. Until recently, this video had been lost, but it was re-uploaded around New Years this year. This is a great clip that will bring back memories for those experienced this day, and you can watch it below.

For those who are interested in more specifics about the damage the Fort Worth tornado produced and the specific timeline it followed, there is a great paper that was published by Texas Tech University in August of 2000. This paper discusses the well-documented damage from the tornado in more detail, especially the effects on the Bank of America building in downtown. This paper can be viewed here.

Finally, we would like to remind everyone that we are entering severe weather season. While it has been fairly quiet in North Texas the past few years, please do not forget that Texas receives more tornadoes than any other state, and that the D/FW area lies in a hotspot for tornado activity. The “big outbreak” hasn’t been seen in north Texas in quite sometime, but be prepared for the day that it does!  Be ready, and stay with us as we’re out there in the elements!