METEOROLOGY 361                                                                                                                                                    Spring, 2008

Exam 2                                                                                                                 Name ____________________________________

Directions: This is an Open-notes exam.  Use anything you want, including the Internet.  You can’t ask each other questions but you can ask me for clarifications (no guarantee that I’ll be able to answer). Answer all parts of questions in the blue books unless otherwise directed. Here is some information you may or may not need:

1. For this question, refer to the U.S. surface map for 00Z March 21, 2008, the surface map loop, the 300 mb loop, the U.S. radar loop, and a loop of 24 hour NAM MSLP forecasts.  Note that the forecast loop should not be viewed as a time series the way the surface map loop is.  It’s just a convenient way to work with all four separate 24-hour NAM forecasts.  Minneapolis, Minnesota is marked MSP on the 00Z still U.S. surface map, but there is no station circle at MSP on that map or on the surface loop to show you what was observed.

            a. ( 4%) One of the mornings shown on the NAM MSLP forecasts was much colder at MSP than any of the others.  Which one? Pick a date.

            b. ( 12%) Explain your reasoning for the very cold 12Z temperature at MSP on your day.

2. For this question you have loops of NAM forecasts at various levels for several days during the first week of February, 2008.  As in question 1, these are a series of forecasts, in this case all for 48 hours, starting with the 48 hour forecast made on Feb 1 at 12Z (so the first map in each loop is valid for 12Z on Feb 3). These are NOT loops of successive maps in time.  Expect them to jump around.  You have a surface map forecast loop, an 850 mb forecast loop, a 500 mb forecast loop, and a 300 mb forecast loop.

            One of the days in this set of forecasts was a spectacular severe weather day with over 300 reports, including 67 tornadoes. 

            a. ( 4%) Identify the date with the most severe weather reports in 24 hours from 12Z to 12Z.

            b. ( 25%) Explain why that day was so severe.  You must have at least one reason from each loop and from one of the loops you must have two reasons.  That's a total of 5 reasons for the major severe weather outbreak.

3. For this question you are given the date of the severe weather.  It was March 14, 2008, the day you went to the Storm Conference.  Only one tornado occurred that day, but since it happened in Atlanta, the Weather Channel gave it lots of air time.  The SPC storm reports graphic showed 1 red dot at Atlanta and 183 other severe weather events on that day.

            a. ( 4%) The Atlanta storm was reported to have an EF2 tornado.  What does EF2 mean?  This is a short answer.  Do not be specific about that particular Atlanta tornado but you should write a few words of explanation about EF2 in general.

            b. (32%) Construct a composite chart of the conditions at 12Z on March 14, 2008.  You must use the Surface map, the 850 mb map, the 700 mb map, the 500 mb map, the 300 mb map, and the 200 mb map.  Devise symbols for all the conditions from these maps which are appropriate for a composite chart.  Draw your composite chart on the blank U.S. map provided.  Be sure to include a key to the symbols, i.e., what do they mean?  If I don’t have that, I can’t give you credit for any symbol because I won’t know what they mean.

4. Here is yet another day with reports of severe weather, April 14, 2007.  On the 00Z surface map, Jacksonville, FL is marked JAX.  You also have the 850 mb map, the 700 mb map, the 500 mb map, the 300 mb map, and the 200 mb map.

            a. ( 6%) What is the Lifted Index at JAX at 00Z on April 14?  What does your LI mean for the chances of severe thunderstorms?

            b. ( 5%) What is the K Index at JAX at 00Z on April 14? What does your K index mean for the chances of severe thunderstorms?

            c. ( 8%) What is the SWEAT Index at JAX at 00Z on April 14?  What does your SWEAT mean for the chances of severe thunderstorms?

For all calculations, show your work if you want partial credit.

Watch your time.

This exam ends at 4 p.m. sharp.