METEOROLOGY 361                                                                                    Spring, 2009

Exam 1                                                             

 

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 the questions in the blue books unless otherwise directed.  If you don’t want to write it out in the blue books, you may write a text file and e-mail it to me at blechmjb@oneonta.edu

 

  Got everything you need?  If not, ASK ME!

 

1. The NAM MSLP loop shows a storm forming to the lee of the Colorado Rocky Mountains.  It looks impressive with a 992 mb central pressure at 12Z on December 14, 2008.  The 12Z US surface analysis shows that the storm actually verified at that pressure in the forecast location.  Yet Denver only recorded 1.9 inches of snow so this was NOT a repeat of the snowstorms we studied in class.  You may also view the 850 mb map, 700 mb map, 500 mb map, 300 mb map, and 200 mb map for 12Z December 14, 2008.  In addition, you have forecasts: the NAM 300 mb loop, 500 mb loop, and 850 mb loop.

 

So that you can refer to places throughout this exam, here’s a link to a map of U.S. cities.

 

            a. (15%) Analyze the situation with your focus being to explain why this apparently strong storm was a very minor snow producer.  You must contrast the synoptic features of the December 2008 storm with those of the December 1982 and 2006 storms that we studied.  You must include features from at least 3 levels in the atmosphere and one of those must be the surface (ground) level.

            b. (8%) From these forecasts, what cities in the U.S. should have received significant snowfall from the 2008 storm?

            c. (5%) What was the effect of the December 2008 Colorado storm on weather for the east coast of the U.S.? 

2. This question refers to the cross section from Green Bay to Miami.   You have a cross section with isotachs and isentropes.  You also have a second cross sectional view of the same stations (same time and day) with wind flags,  isentropes, and mixing ratios.  You may also want to view a map of  upper air stations in North America.  Answer the following:

        a. ( 5%) Where is the surface front?  Refer to the stations. 

        b. ( 8%) What kind of front is the one from part a?  How do you know?  Give more than one reason for your answer.

        c. ( 4%) What is your vantage point?  In other words, from what geographical location would you be viewing this cross section?

        d. ( 8%) There is an obvious jet stream over ILX. What kind of jet is it?  Give two reasons for your answer.

3. According to the NAM, there will be another in the current series of storms forming in Colorado.

            a. ( 8%) The current storm showed cyclogenesis in Colorado around 00Z on Feb 9.  On the blank U.S. map provided, draw a schematic with arrows showing your best estimate of the path of the warm conveyor belt.  You have the surface map, 850 hPa map, 700 hPa map, 500 hPa height map and 500 hPa vorticity map, 300 hPa map, and 200 hPa map for reference.  The upper air maps are from the University of Wyoming and are easier to read than the usual NCAR-RAP images.

            b. ( 5%) From the loop of surface maps, how did the track of the storm differ from the classic Colorado storms in 1982 and 2006 that we studied?  You may need a link to the class home page.

            c. (10%) Using any forecast maps or data you can find, forecast the central location and pressure of the low pressure system in the central U.S. at 00Z Thursday, Feb 12, 2009.  Draw them on the second blank U.S. map provided.  Scoring:  1% lost for every 3 mb you are off, either above or below the verification.  2% lost for every 100 miles you are in error in any direction.  All errors will be rounded to the nearest 1% (no decimals will be given, maximum total deduction = 10%).

            d. ( 24%) Assuming a perfect 12 hour forecast from today's 12Z Wednesday initialization (so the forecast for 00Z Thursday will verify perfectly), what is the appropriate forecast for precipitation type and 6-hour amount for the following cities:    Oneonta, Detroit, Chicago, Nashville?

 

Exam ends at 4 p.m. sharp.  Map discussion will follow (don’t go away).  If you finish early, you may go to the restroom.