Paper , Order, or Assignment Requirements

Part 1: Find severe weather reports for the day and site you selected.

Severe weather storm reports can be found at the Storm Prediction Center. Click on Storm Reports at the top of the page. Scroll down to Past Storm Reports and enter the date of the event (yymmdd). Click the Get Data button. This shows individual severe weather reports on the chosen day plotted on a map from across the country. Individual reports are given in text tables below. The type of event, tornado, large hail, and strong wind, is categorized into separate sections. Keep this webpage handy for later use.

Part 2: Find a radiosonde sounding.

Find a radiosonde sounding on the day of, and near the area of, your selected thunderstorm activity at the University of Wyoming weather sounding website.

1. Under Type of Plot, select GIF: Skew-T. In Year and Month, select your chosen date. In From and To, select your chosen day and the 12Z time on both.
2. Click on a 3-letter ID site near the region of the thunderstorms you have chosen for this activity. (Write down this 3-letter ID; it will be needed later.) This will display the SkewT-LogP thermodynamic diagram for that site and time. You will want to start with the 3-letter ID supplied with the site in part (1), but if the storm coverage is large, you may want to look at several sites in the general area to see if one looks better than another. If possible, choose a site closest to tornado activity in the area shown on the main map of Storm Reports for that day (see part 2). Again, the valid time for a 12Z sounding is 0700 EST. Hopefully, you will be seeing the condition of the atmosphere within the same air mass of the thunderstorms, but prior to the time of storms that day. Since storms typically move from west to east, it is more likely that you will observe a conditionally unstable sounding if you choose a site at or just east of where thunderstorms occurred.
3. Copy and paste your selected SkewT-LogP chart into a document to include in your report. Be sure the text items on the right-hand side are included in what you save.

Part 3: Write a report on your selected event.

Include your name, date, and site you selected for this activity.

1. Paste the selected sounding into your report. List all pertinent information for the location, day, and time of the sounding.
2. Describe the weather event and summarize the severe weather that occurred close to your selected sounding site. Go through each text table in Storm Reports on tornadoes, large hail, and strong wind reports. Entries include the city, county, and time of the event (CST) and comments on the kinds of damage, deaths, and injuries reported. At the end of the comments is a 3-letter station ID to the National Weather Service (NWS) Forecast Office responsible for collecting these data. This may (or may not) be identical to the ID at your radiosonde site. However, looking at the radiosonde map from earlier, each radiosonde site represents approximately a 200-mile circle. So, any severe weather close to that distance is okay to include in your report. Your weather summary should say something like the following.

The radiosonde site is in Springfield, MO. Over southwestern MO, there were 5 tornadoes, about 15 hail events, and 25 damaging wind reports. The largest hail was 2.0 inches in diameter and the highest wind speed reported was 87 mph. One death and five injuries were reported, etc., etc., etc. Highlight some major specifics from the Storm Report summaries.

Please note: The daily timeframe for these reports is in Central Standard Time from 6 a.m. to 6 a.m. That is, storm reports for the day of March 23 run from 6 a.m. on March 23 until 6 a.m. on March 24. This is because a “severe weather day,” when storms are most severe, runs from about noon to midnight, lagging sunrise and sunset by a few hours. This is an attempt by NWS to keep all severe weather reports within the same 24-hour period.

1. Analyze the SkewT-LogP diagram for its ability to indicate severe weather. Was there a positive area? Explain in detail. Was there a change in wind direction or wind speed with height that would indicate wind shear that could have enhanced any severe weather that occurred? Explain in detail.