San Francisco State University

Department of Earth & Climate Sciences

Name ______________________________________

ERTH 260: Physical Processes of the Atmosphere

Lab Exercise 1 Key: Establishing the Significance of the Joplin Tornado and the Effectiveness of the Forewarning (100 points)

Answer on separate sheets of paper. 100 points. Each answer is worth 8 points (except where noted). This exercise involves student access of the Storm Prediction Center (SPC) Storm Report Database entires for May 22, 2011

A. Using the Storm Prediction Center (SPC) Storm Report Database entires for May 22, 2011, provide the following information:

1. The number of states that reported severe weather. 12
2. The number of tornado reports that occurred across the country. 75
3. The number of reports of "giant" hail. 50
4. The number of fatalities and injured associated with the Joplin MO tornado. 122 dead and 750 injured.
5. The time (UTC) of the Joplin tornado. 2241 UTC
6. The diameter (inches) of the hail stone reported in adjacent Oklahoma (Carter County) at 2217 UTC. 4.5 in.

B. Examine the text information given for Tornado Watch #325.

1. What was the categorical likeliehood (descriptor in colored boxes) attached to the Tornado Hazard in the Watch area?
There was a High likeliehood of tornadoes in the Watch area.
2. What was the categorical likeliehood(descriptor in colored boxes) attached to the Hazard of EF2 or greater tornadoes in the Watch Area?
There was a Moderate likeliehood of strong and violent tornadoes in the Watch area.
3. When (UTC) was the Watch issued?
The Watch was issued at 1830 UTC.
4. How much "lead time" were the residents of Joplin given (hours and minutes) between when the Watch was issued and when the tornado occurred?
The Watch as issued 4 hr, 11 min before the tornado occurred.

C. Examine the text information given in the Public Severe Weather Outlook (1627 UTC).

1. How many hours before the Joplin tornado occurred was the Public Severe Weather Outlook issued?
The Public Severe Weather Outlook was issued 6 hr 14 min before the tornado occurred.

2. In your opinion, if this severe weather outlook was distributed to the public and you lived in the highlighted area ("areas most likely to experience this activity"), do you feel that your attention to the possilbity of damaging severe weather, tornadoes in particular, would have been heightened.

The statement " THE NWS STORM PREDICTION CENTER IN NORMAN OK IS FORECASTING THE
DEVELOPMENT OF TORNADOES...DAMAGING WINDS AND LARGE HAIL OVER PARTS
OF THE MID AND UPPER MISSISSIPPI VALLEY THIS AFTERNOON AND EVENING.

THE AREAS MOST LIKELY TO EXPERIENCE THIS ACTIVITY INCLUDE

NORTHWEST ARKANSAS
SOUTHWEST TO NORTHEAST MISSOURI
NORTHEAST OKLAHOMA"