METR360                                                                                                                         Fall, 2016

Final Exam                                  

 

Directions:  Answer all parts of all questions.  Use the blue books or write a text file where required. Write on the paper copy of the exam where requested. For calculations, show all work.  You may use any source, including your notes, any textbook or the Internet.  You may NOT talk during the exam, except to me.  Raise your hand if you have a question.

 

The following information may (or may not) be useful:

A map of U.S. states and their names is provided here.

 

1. For this question, refer to the plotted but unanalyzed U.S. surface map. You have a black and white paper map of this.

     a. ( 6%) On the paper map, draw the 50°F and 60°F isotherms only.  Label all ends.

     b. ( 4%) Also on the paper map, draw the cold front based on the plotted data using the proper symbols.

 

 

2. (10%) This question is about the NAM guidance shown at this link.  KXYZ is a real place, although obviously that is not its real ICAO designation.  Assume the guidance is perfectly correct. Using only that guidance, complete the following table on the paper copy, including units:

 

Forecast parameter

Value at 12Z Nov 27

Surface Temperature

12-hour liquid precipitation amount

700 mb  vertical velocity

Surface Wind Direction (º)

6-hour probability of precipitation

 

 

 

3. The spectacular Buffalo lake effect storm of November 17-18, 2014 was well forecasted by the meteorologists at NWS-Buffalo. 

     a. ( 9%) Looking at the NAM MSLP forecasts for 24 hour, 48 hour, and 72 hours, forecast surface winds, the 850 mb forecast loop, and the 500 mb loop, what elements would have shown the forecasters that an intense lake effect event was about to occur?  Find one thing at each of these levels:  surface, 850 mb, and 500 mb.  You don’t have to explain how each element would have worked, just find and identify them.

     b. ( 5%) Propose a meteorological or other type of feature that would have explained an historic snow event, but does NOT appear on the maps shown?  For this one, you must explain why the feature would change an ordinary lake effect snow event into a spectacular one.  You may need to do some research since you don’t have the maps to show your feature.

 

 

4. For this question, refer to the vorticity map for 00Z November 18, 2016

     a. ( 5%) If that vortmax is at 35°N, what is the value of the relative vorticity in the vortmax?  This will require a calculation.  Show all work.

     b. ( 4%) Find  two geographical locations (states or parts of states) are experiencing PVA associated with the vortmax in southeast Colorado.  Do not restrict yourself to the maximum but rather, find PVA from that particular system. 

     c. ( 4%) Just from this vorticity map, what do you expect will be the weather being observed at the surface in the central High Plains at that time?

 

 

5. Refer to the maps of Nov 25-28, 2016.  You have NAM forecast loops of MSLP/thickness, 850 mb, 500 mb heights/absolute vorticity, and 250 mb.

     a. ( 6%) During the 63 hour timeframe of this forecast, there are two storms, one in the west and one off the east coast.  What kind of developments are these?  Name each and the area where each one develops.

     b. ( 6%) Pick either one of the developments from part b.  Using maps from at least two of the map sets given, explain why your storm develops in that place.

     c. ( 5%) From the 850 mb map for 00Z Monday Nov 28, what kind of temperature advection is occurring at Grand Island, Nebraska and what does that mean for the vertical motion?
 

 

6. On December 5, the NAM forecast for 12Z the next morning on December 6 showed a distinctive sounding near the town of Harrisonburg, VA. You also can view the maps for the MSLP forecast and the 500 mb forecast.  Harrisonburg is marked HBG on MSLP.  Assume these are good forecasts and will verify.

     a. ( 3%) What meteorological phenomenon caused the unusual temperature sounding, particularly with respect to the lowest half of the atmosphere (up to 500 mb)?

     b. ( 7%) The winds change direction with height.  What type of temperature advection does the sounding indicate and why does it appear to contradict the MSL forecast for HBG at 12Z on Dec 6?

  

 

7. For this question you have the 250 mb map for 12Z Feb 14, 2016.

     a. ( 4%) There are areas within the contiguous United States (CONUS) which have jet streams.  Name one geographical location with a Polar Jet and one with a Subtropical Jet.  Use the state names.

     b. ( 3%) In the long jet stream extending from the Gulf of Mexico across Texas, New Mexico, and Arizona, where is the Jet Streak?  Pick an upper air station and name it.

     c. ( 4%) There is an area with some darker shading in Missouri and Kansas.  Is this a jet stream?  Justify your answer using as few sentences as you can.

 

 

8. For this question, use the following guidance products for 12Z on an unspecified day this semester:  WPC surface prog, NAM MSLP/wind/temperatures, NAM MSLP/1000-500 thickness, NAM simulated radar, NAM 850 mb heights/temperature, NAM 500 heights/vorticity, NAM 250 mb heights/isotachs

     a. (10%) Make a forecast for Oneonta, NY.  You must forecast the 2 meter temperature, wind direction, sky cover, 6-hour precipitation amount, and precipitation type.

     b. ( 5%) Write a forecast discussion in which you describe the synoptic situation at 12Z (don’t make any specific forecasts here – you already did that in part a).