a. Copy and paste your selected SkewT-LogP chart as the first item of your individual report. Be sure the variables listed on the right-hand side of the figure are included in what you copy. Introduce the figure in your report with appropriate text so a reader can understand what is being presented. Include your name as well as the date and site you selected for this activity.
b. Describe the weather event you selected 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 events. Entries include the city, county, and time of the event (UTC) and comments on the kinds of damage, deaths, and injuries reported. The city selected is May 6th, 2010 Lincoln, IL (ILX).
c. Highlight some major specifics from the Storm Report summaries. You should seek out news reports for the day, if available. At a minimum, your weather summary should say something like the following, but feel free to expand on this summary if you find more extensive information:
The radiosonde site is in Springfield, MO. Over southwestern MO, there were 15 tornadoes, 25 hail events, and 45 damaging wind reports. The largest hail was 2.5 inches in diameter and the highest wind speed reported was 87 mph. One tornado was rated as EF-3 and caused massive damages in Columbia, MO. There were 5 deaths and 15 injuries within this event, etc., etc., etc.
Please note: The daily timeframe for these 24-hour reports is in UTC from 12 Z to 12 Z or from 7 a.m. to 7 a.m. Eastern Standard Time. That is, storm reports for say March 23 run from 7 a.m. on March 23 until 7 a.m. on March 24. This structure is used because a “severe weather day,” when storms are most severe, runs from about noon to midnight. The desire by NWS is to keep all severe weather reports on a particular day, attributed to a particular severe weather air mass, centered within the same 24-hour period.
d. Analyze the SkewT-LogP diagram for its ability to indicate severe weather.
1) Was there a positive area? Explain in detail.
2)Was there a change in wind direction or wind speed with height that would indicate wind shear was present, which could have enhanced any severe weather that occurred? Explain in detail.
e. Give the values for the following variables shown on the right-hand side of the chart in your report. Include a definition of each term. These variables will assist you with the sounding analysis.
1) LCLP – Lifted condensation level (mb) – This is the level where a lifted parcel reaches saturation.
2) LFCT – Level of free convection (mb) – This is the level where the lifted parcel temperature exceeds the sounding temperature, the bottom of the positive area.
3) EQLV – the equilibrium level (mb) – This is the level where the parcel temperature equals the sounding temperature at the top of the positive area.
4) PWAT – precipitable water (mm) – This is the depth of precipitation that would occur if the entire amount of water vapor in the sounding were precipitated out and converted to liquid. A high amount (55 mm) means that very heavy rain is possible.
