2001 Spotter Training Season a Success

The 2001 storm spotter training campaign was the first at the Fort Worth/Dallas NWS office for Warning Coordination Meteorologist Gary Woodall. As it was his first go-around, he felt that he should visit as many of the counties as possible, not only to present the training programs but to get to know our Emergency Management partners, our media outlets, and our storm spotters.

Those of you who attended one of our programs noticed some significant changes in the spotter training and weather safety presentations. We spent a great deal of time during the winter "off season" converting the training materials into an integrated multimedia program. We felt this would make the program more dynamic, with arrows and labels moving across the screen. In addition, we believed this would make the program "flow" better, as we could discuss specific subjects then illustrate those subjects with video clips.

We feel that the campaign was a success. Over 4,100 spotters attended our training programs. These sessions were conducted by Gary and staff members Al Moller, Mark Fox, and Lance Bucklew. Several of the training sessions were videotaped, which will allow us to provide copies of the program on loan to groups who were unable to attend in person. In the coming weeks, we plan on posting the "slide show" portion of the program, without the video clips, onto our web site.

We would like to thank everyone who participated in the 2001 Skywarn training sessions. Storm spotters are literally our "eyes and ears" in the field, complementing the radar and other data we utilize. We truly appreciate your efforts before and during severe weather. If we can assist your spotter training or operations efforts in any way, please feel free to contact us.

February was a fairly active month for hazardous weather across north Texas. During the predawn hours of February 9, a line of fast-moving thunderstorms swept across the area. Wind gusts estimated as high as 85 mph caused damage to homes, buildings, trees, and power lines. In addition, 29 railroad cars were blown over just south of Gainesville. Total damage estimates were over $400,000, but fortunately, only two injuries resulted.

A large area of rain and thunderstorms moved across north Texas from the morning of February 15 through midday on the 16^th. The rain caused widespread flooding, especially from the Dallas-Fort Worth Metroplex northward and eastward.

Another fast-moving area of severe thunderstorms developed in the early morning hours of February 24 and raced eastward. Wind damage was reported from Montague, Jack, and Comanche counties eastward through the Metroplex to Hunt and Lamar counties. The strong winds from these storms damaged roofs and fences, blew down radio towers and power poles, and caused over half a million dollars’ worth of damage.

Weather 101 - - The Cap

"The atmosphere over north Texas is unstable. However, the presence of a mid-level cap will likely prevent thunderstorms from forming this afternoon or tonight...".

This phrase has been repeated many times this spring here at the Forecast Office. As we moved into the heart of the severe weather season, the cap became established over north Texas. The cap has been a major factor in the relatively inactive severe weather season we’ve experienced through mid April.

What exactly is the cap? It is a layer of very warm air at mid-levels in the atmosphere, approximately 2 to 3 miles (10,000 to 15,000 feet) above the earth’s surface. Recall from our spotter training sessions that in order to get thunderstorms, we need warm, moist air near the ground with relatively cold air in the upper atmosphere.

The cap is found just above the layer of warm, moist air near the ground. The cap literally blocks the low-level air from rising. If the low-level air can’t rise, then storms cannot form.

When looking from the thunderstorm’s point of view, there are times when a weak cap can be beneficial. A weak cap will allow the low-level air to become very warm and unstable underneath. During the mid to late afternoon, a few strong updrafts which form in the low-level air may be able to break through the cap, while the weaker updrafts will be blocked. This will result in a few storms which can become very strong, rather than a widespread area of moderate-intensity storms.

Are there ways that the atmosphere can overcome the cap and generate storms? Yes, there are a few possibilities. First, we can heat the air near the ground to the point where it rises and is not stopped by the cap. Second, we can add more moisture to the air, which adds more energy (heat) to the rising air as the moisture condenses into water droplets (clouds). Third, we can bring an upper-level storm across the area, which will cool the mid-level air and reduce the strength of the cap.

Contact us if there is a storm-related topic you’d like to see discussed in Weather 101.

New NWR Voice in the Works

For about two years now, the Fort Worth/Dallas NWS Office has been using the Console Replacement System (CRS) to generate the programming for our NOAA Weather Radio transmitters. CRS is an automated system which automatically formats and assembles the warnings, statements, hourly roundups, and forecasts which are played on NOAA Weather Radio.

CRS is much faster at performing this task than our human staff members. While CRS can format and broadcast a warning within a few seconds after the warning is transmitted, a human manually recording the warning may be delayed by 3 minutes or more. Obviously, these few minutes may mean the difference between people being caught off guard and being safely in shelter when the severe weather strikes. Unfortunately, the most visible part of the CRS system...the voice...has been the weak link in the system.

Plans are underway to replace the stilted, mechanical weather radio voice with a more ‘personal’ sounding voice. Several companies have bid for the new voice contract and have submitted samples of their voices. If you have internet access, you can hear these sample voices for yourself. Point your web browser to the Southern Region Headquarters page at

http://www.srh.noaa.gov

and click on the "New NWR Voices" link at the bottom-left of the page.

The new voice should be decided upon by late summer. Hopefully, we will have the new voice on our weather radio transmitters by early next year.

As we start the transition from Spring to Summer, we will soon begin seeing the heat build over north Texas. The summer heat can have a dramatic impact on our area, from large-scale agricultural losses to personal effects such as sunburn and heat exhaustion.

In anticipation of the heat, we have put together a section on our web page which discusses north Texas’ hottest summers. This section contains statistics and safety tips to help you make it through the summer. Check it out at:

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then click on the "Heat Wave" banner.