METR 361                                                                                                                                                            Spring, 2019

BUFKIT

 

A radiosonde sounding can be a very valuable tool in many situations.  As sounding analyses can be time-consuming and difficult, especially under the deadline of putting out forecasts and warnings, a computerized sounding analysis package would be helpful.  Fortunately, forecasters at the Buffalo Weather Service Office have designed such a program, mainly for analysis of lake effect situations.  BUFKIT, as the program is called, is also very useful during synoptic snowstorms and severe weather situations.  It has been adopted by the NWS and is available free at the Warning Decision Training Branch (http://wdtb.noaa.gov/tools/BUFKIT/ ).

 

Lab assignment:

 

1. Your professor will have BUFKIT running on the computers in 308 when you arrive for lab.  If you wish, you may install BUFKIT on your personal laptop.  Unfortunately, BUFKIT won’t run on a Mac.  

 

2. Familiarize yourself with the BUFKIT screens in lab before continuing.   The main window is a sounding which is generated by a computer forecast, perhaps NAM or GFS. BUFKIT supports many model types, like RAP, SREF, NAMm and, of course NAM and GFS (listed as nam and GFS3).  For practice today, we have a NAM profile on the screen. What you see is the model’s forecast of the vertical properties of the atmosphere at one location. You can choose that location, given that you have the BUFKIT profile for that place.  So, for example, in the top left box, you could click on the green namm link and two different cities show up next to the model box (KJFK and KPHX).  If you click the RAP model, you get a message that there are no RAP profiles since none have been downloaded for you.  Click the nam link again and switch to the EON nam profile.  EON is Oneonta. An alumnus who is now the Science and Operations Officer (SOO) at NWS-OKX has set up Oneonta BUFKIT profiles for us.  He lists them as EON. Other BUFKIT profiles can be found at http://www.meteo.psu.edu/bufkit/CONUS_NAM_00.html and others on the web.

 

3. Once you have BUFKIT running and have selected a model and station, you will see the initial time sounding. Click the slider bar above the sounding to move from time to time manually. The time and date are located at the bottom.  You may need to move the entire program window up to see it. Once you have clicked in the slider bar, you can also advance the times using the keyboard left and right arrow keys.  NOTE: for some reason, time advances to the left, unlike most other applications. 

 

4.  Click the “Map” button to change the left-hand display.  Notice there are several other choices (Data, Indices, Precip type, Lapse rates, etc).  Try them to see what you get.  Each display shows a different aspect of the forecast sounding. 

 

5. The sounding is drawn on a skew T – log P diagram.   You can add or subtract features after clicking the Overlays button.  Try Dry Adiabats or click Clouds.  The sounding display will change. Click again to remove.

 

6. Add a display of vertical motion, i.e., Omega, also from Overlays. It’s a thin white curved line.  Negative values show upward vertical motion (do you know why?). 

 

7. Click some of the other boxes and notice what happens to the sounding.  In general, all buttons and boxes are toggles which allow you to design a sounding which makes you comfortable with the information displayed. 


 

Questions 8, 9, and 10 are the graded part of this lab.  Type your answers to a text file.  Put your name at the top and send it to Jerome.Blechman@oneonta.edu

 

8. Based on the NAM BUFKIT forecast for New York (KJFK), initialized at 00Z Sunday, February 1, 2015, answer the following (Note, first check the box for Bourgouin Precip Type): 

          a. During what hour (UTC) and on what date is precipitation forecast to begin?

          b. What is the type of precipitation at the beginning, and to which types does it change at which times to the end of the forecast period?  Be sure to note from what precipitation type to what other precipitation type.  Do NOT note intensity changes, so if 4 dot rain becomes 3 dot rain, don’t report that.  But if the rain becomes snow, you must report the time when BUFKIT shows it.

          c. From the class website, download a text file of observed conditions at KJFK.  Time increases from bottom to top in this list.  Contrast the predicted precipitation type to the observed values. As in part b, do not report intensity but you must pay attention to timing. What can you say about the BUFKIT precipitation type predictions?

          d. Turn on Omega at 12 UTC on Feb 2 if it is not already on.  What does that display tell you about what’s going on in the atmosphere at that time? Be quantitative in your answer.  Include units.  BUFKIT shows the numbers at the top, in microbars/sec.

          e. A key meteorological event that you could see on a MSLP map of temperature, fronts, etc. (if you had one) happens between 13 UTC and 15 UTC on Feb 2. What is that event and what happens on the profile sounding to tell you what it is?  Cite two sounding features that are useful in identifying that synoptic event.

          f. Just from the BUFKIT profiles, how much snow will fall and what is the total liquid equivalent of the entire event?  Hint: you may have noticed this number in a previous screen.  For snow, use an appropriate snow:liquid ratio to estimate how many inches and be sure to report the value of the ratio you used. 

 

9. Based on the NAM BUFKIT forecast for Philadelphia, PA (KPHL), initialized at 12Z Saturday, January 12, 2019, answer the following questions:

          a. This is a situation that is, in some respects similar to the KJFK events of February 2015, shown in the KJFK BUFKIT profile from question 8.  What probably happened in terms of Highs, Lows, and fronts, based solely on the BUFKIT profile?

          b. What very important changes didn’t happen to the profile at KPHL in 2019 that did happen at KJFK in 2015?

          c. Based on the KPHL BUFKIT file, make a rough forecast of the most important weather to occur in the following 48 hours (up to 12Z January 14).

 

 

10. One of the great advantages to BUFKIT is that data may be generated for any point in the model, not just upper air stations like KBUF, KOKX, and KALB.  At http://www.meteo.psu.edu/bufkit/CONUS_NAM_00.html, with the NAM model selected, pick Oneonta, which is EON.  It’s from today’s 12Z NAM.

          Analyze the situation for the next 84 hours (12Z today through 00Z Sunday) for Oneonta.  You may also use the 12Z NAM forecasts at the usual NCEP site using a browser (http://mag.ncep.noaa.gov/). Do NOT use any guidance other than the 12Z NAM and BUFKIT profile. Analyze the corresponding BUFKIT forecast from the perspective of the vertical atmospheric temperature, dew point, and wind structure.  You must report why and how much (liquid equivalent) precipitation is forecast to fall at Oneonta during the 84 hour period.  Also, use the BUFKIT forecast soundings to discuss the coming Arctic air incursion in central New York.