METR 361                                                                                                                         Spring, 2017

Exam 2      

                                                           

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 all questions in the blue books except where you are directed to draw on the paper copies. If you like, you may instead send me your electronic answers in a text, Word, or Open Office Writer (.odt) file. 

 

1. ( 8%) Which of the following are considered by the Storm Prediction Center to be severe weather?  

(Choose all that apply):  

Lightning

Hail < 0.75 inches 

Hail > 1.00 inches

EF-0 tornadoes 

Tornadoes of EF2 or greater

Flooding of minor streams

Flooding of major rivers

All flooding

Wind < 50 mph

Wind > 58 mph

Snow > 4 inches

   

2. This is an ASOS question.  In the surface observations for 0123Z on April 2, 2017, one station in northern Idaho stands out.  The station is labeled MLP (KMLP, Mullen Pass, Idaho) and it is reporting heavy fog with ¼ mile visibility.

 

       a. ( 5%) Is the ASOS report for KMLP possible?  Use the additional resources to answer:  KMLP ‘hourly” observations as reported by the University of Wyoming (assume these are the data as reported by the ASOS array), the visible satellite loop, and the infrared satellite loop.

       b. ( 5%) What if this observation is not exactly what a person would report?  Explain how the way ASOS determines fog to be present can account for KMLP’s heavy fog while stations all around it show none.

 

     c. ( 6%) Copy and Paste the following address into your browser:

https://www.google.com/maps/@42.7475307,-73.7976519,3019m/data=!3m1!1e3

 

You should be seeing a Google maps image of the Albany County Airport, whose ASOS is designated KALB. If you can’t get there, search Google maps for Albany International Airport. You have a paper copy of the map version.  On that paper copy, mark the place where you think KALB’s ASOS sensor installation is located. Assuming it is properly sited, explain why the NWS put the sensors in that location.

 

 

3. For this question, consider the severe thunderstorm outbreak of April 2, 2017.  The Day 2 convective outlook from April 1 and the Day 1 convective outlook from the morning of April 2 had areas marked MDT, SLGT, ENH, and MRGL

 

       a. ( 4%) Precisely what does the label ”MDT” mean?  Define it as the SPC would.

       b. ( 48%) Write a forecast discussion, intended for other meteorologists, justifying the MDT area.  Include all relevant ingredients found in the PowerPoint loops for 200 mb, 300 mb, 500 mb temperature, 500 mb vorticity, 700 mb, 850 mb temperature, 850 mb relative humidity, and MSLP temperature.

c. ( 8%) Using the forecast sounding for Lake Charles, Louisiana (KLCH) for 21Z Sunday, April 2, calculate the Lifted Index and the SWEAT index. Estimate what you need from the forecast sounding and show your work in making the calculations.  Click here for a map showing the location of KLCH.

 

d. ( 12%) What severe weather ingredients (plural) is the forecast sounding showing that justifies KLCH being is in the area marked MDT on the convective outlook?

 

     e. ( 4%)  The actual KLCH sounding from 12Z (not 21Z) on April 2 showed some features very favorable for severe thunderstorms but failed to show two that we normally look for. Name the two features that the sounding did NOT show (or were quite weak).  You don’t have to explain, just name them.