SECTION 1: PROJECT OBJECTIVES AND ACCOMPLISHMENTS
The first objective of the proposal was to thoroughly examine the climatological characteristics of heavy snowfalls in Northwest Missouri over a region encompassing the Pleasant Hill, Missouri WFO zone of responsibility. This included examining long-term trends and interannual variability related to the El Nino/La Nina cycle. The second objective was to examine the dynamic character of heavy snowfalls, including typical flow regimes that produce heavy snows and a general description of their dynamics. The last objective was to examine the success and false alarm rates of forecasts generated by the Pleasant Hill WFO.
The specific tasks that were to be accomplished included:
A. Snowfall data collection
B. Statistical Calculations
C. Synoptic Characteristics
D. Dynamic Characteristics
E. Heavy Snowfall Verification
The University was to complete tasks A,B,D, and E under the guidance of the PI's, a graduate student, and two undergraduate students. The WFO was to complete tasks B,C,D,E under the guidance of the PI's and one WFO forecaster. Research meetings were held alternating the site between the Pleasant Hill WFO and University of Missouri personnel in order to discuss progress, exchange information, and determine the agenda for the immediate future.
Tasks A and B were completed by using data available from the Missouri Climate Center. Long term trends and interannual variability in heavy snowfall throughout Northwest Missouri (NWMO) were examined. This part of the work expanded from the original proposal to also include central Missouri stations and cover a complete 50-year time period. In summary, the initial major findings were these:
1) There were 391 events found over the 50-year study. All events occurred between October and April. While most events occurred during the winter, a significant number of events occurred during the spring season.
2) Long term trends demonstrated that there has been a decrease in snowfall events over the 50-year period of study, especially over the last 20-years and for the number of more extreme events. There has also been an increase (decrease) in the number of early (late) season or fall (spring) season events.
3) There is significant interannual variability in the annual number of snowfall events, with fewer events occurring during El Nino years and more snowfalls during La Nina and "neutral" years. El Nino events have occurred more often in recent years and a more complete examination of ENSO-related variability explains the findings in #2.
The work expanded on tasks A and B by attempting to explain longer time scale variability found in the dataset after applying time series analyses. This variability was related to the North Pacific Oscillation, a 50-70 year variation in Pacific Ocean Basin SSTs, which, in short, modulates El Nino events. This showed that:
4) During the low phase of the NPO (El Nino impacts on the North American continent are muted), there was little ENSO-related variability in NWMO snowfalls during the 1947 - 1976 time period. From 1977 - 1997 during the high phase of NPO (El Nino impacts on the North American continent are stronger), there was significant ENSO-related variability in NWMO snowfalls.
Tasks C and D were completed with Missouri Climate Center data and NCEP re-analysis archived on CD-ROM available at the Pleasant Hill WFO. Work on this portion of the proposal was expanded to include statistics on the heavy snowfall regimes found by the work. In summary, this part of the project accomplished the following:
1) Composite synoptic maps were constructed describing four flow regimes which are heavy snow producers in NWMO, they are 1) the southwest low, 2) the deepening low, 3) northwest flow events, and 4) progressive troughs. Each type was described in the context of their tendency to produce heavy snowfall.
2) The dynamic forcing contributing to each event was described for each. Similarities and differences in the Q-G and jet streak kinematics and dynamics of each type were described. Most cases required cold air to be in place before the event, except for the deepening low in which cold air could be generated through adiabatic cooling. This is important for spring and fall events. The heavy snow cases involved significant low-level warm advection coupled with upper-level divergence, although the relative strength and locations of relevant dynamics with respect to the surface features may vary between categories.
3) Statistics on the frequency of heavy snowfall regimes revealed that progressive trough events were the most common type of event, but there was also ENSO-related variability in the frequency of the type of event that dominates a season.
Only one major change in the scope of the work was made. Specific task E was not accomplished by either the University or the WFO. If a lesson was learned in this change, it was that the PI's now have a better understanding of how much work can be accomplished (without sacrificing quality and thoroughness) versus the time table given ourselves. Also, more was accomplished for specific tasks A through D than was proposed despite the lack of adequate computing equipment at both facilities.
One major accomplishment of this Partners Project is that this work will provide a catalog of climatological and dynamic information for heavy snowfalls in Northwest Missouri that will be housed at and be used by forecasters at the Pleasant Hill WFO. It is necessary for forecasters, especially those new to an area, to understand the climate and weather for their forecast region in order to develop better weather forecasts. Personnel at the NWS Training Center in Kansas City, MO were complimentary of this work in light of the fact that the future of the NWS is a younger and more mobile work force.
SECTION 2: SUMMARY OF UNIVERSITY/ NWS EXCHANGES
We presented (or will present) this work at several conferences and seminars. Many of these talks resulted in preprint papers and were prepared with input from both the University and WFO personnel. By discussing these presentations in addition to our bi-monthly research meetings, we have fostered a spirit of cooperation between personnel at the Pleasant Hill WFO and the University of Missouri Atmospheric Science Program.
The following is a list of the presentations or seminars that resulted from this work. The work was presented at; 1) The 11th Conference for Applied Climatology, with the 79th Annual Meeting of the American Meteorological Society in Dallas, TX (13 January, 1999), 2) The Annual meeting of the Missouri Academy of Science (17 April, 1999), 3) The KU-MU-Valpariso student workshop sponsored by the National Weather Service Training Center in Kansas City, Missouri, 4) The Eighth AMS Conference of Climate Variations in Denver, CO (14 September, 1999), 5) Seminar presented at the Pleasant Hill WFO to a joint meeting of the WFO and University Personnel (28 September, 1999), 6) The 25th conference of the National Weather Association in Biloxi, MS (18 - 22 October, 1999).
SECTION 3: PRESENTATIONS AND PUBLICATIONS
Our COMET Partners Project produced several works that can be cited. The list is as follows:
Berger, Cynthia L., 1999: A Climatology of Heavy Snowfalls in Northwest Missouri (MS Thesis)., Department of Soil and Atmospheric Sciences, University of Missouri - Columbia, Columbia, MO, 65211, 60 pp.
2. Reviewed Publications (Including planned submissions).
Berger, C.L., A.R. Lupo, P. Browning, M. Bodner, C.C. Rayburn, M.D. Chambers, 1999: The Climatology of Heavy Snowfall Events in Northwest Missouri. Part 1: Long Term Trends and Interannual Variability. Submitted to Transactions of the Missouri Academy of Science, June 1999.
Berger, C.L., A.R. Lupo, P. Browning, M. Bodner, C.C. Rayburn, M.D. Chambers, 1999: The Climatology of Moderate and Heavier Snowfall Events in Northwest Missouri. Part 1: Long Term Trends and Interannual Variability. Submitted to Bulletin of the American Meteorological Society, June 1999.
Browning, P., M. Bodner, A.R. Lupo, C.L. Berger, C.C. Rayburn, and M.B. Chambers, 2000: The Climatology of Moderate and Heavier Snowfall Events in Northwest Missouri. Part 2: The synoptic and dynamic character of heavy snowfalls.
3. Presentations and preprints (Presenter is underlined where relevant).
Berger, C.L., A.R. Lupo, P. Browning, C.C. Rayburn, M.D. Chambers, M. Bodner, 1999: The Climatology of Heavy Snowfall Events in Northwest Missouri. Preprints of the Eleventh Conference on Applied Climatology, January 10 - 15, Dallas, TX.
Chambers, M.D., and A.R. Lupo, 1999: The climatology of heavy snowfall events in Northwest Missouri: A dynamic perspective. Transactions of the Missouri Academy of Science, 33, in press. April 16 - 17, Cape Girardeau, MO.
Rayburn, C.C., and A.R. Lupo, 1999: A climatology of heavy snowfall events in Northwest Missouri. Transactions of the Missouri Academy of Sciences, 33, in press. April 16 - 17, Cape Girardeau, MO
Berger, C.L., A.R. Lupo, P. Browning, C.C. Rayburn, M.D. Chambers, M. Bodner, 1999: The Interannual Variability of Heavy Snowfalls in Northwest Missouri. Preprints of the Eighth Conference on Climate Variations, September 13 - 17, Denver, CO.
Berger, C.L., A.R. Lupo, P. Browning, C.C. Rayburn, M.D. Chambers, M. Bodner, 1999: The Interannual Variability of Heavy Snowfalls in Northwest Missouri. Program of the 25th Meeting of the National Weather Association, October 18 - 22, Biloxi, MS.
Moderate and heavy snowfalls in Northwest and Central Missouri: A climatological and dynamical perspective. KU - MU workshop 1999. National Weather Service Training Center, Kansas City, Missouri, 10 August, 1999 (Presented by A. R. Lupo)
Moderate and heavy snowfalls in Northwest Missouri: A Climatological and dynamical perspective., The National Weather Service Regional Office, Pleasant Hill, Missouri, 28 September, 1999. (Presented by M. Bodner and A.R. Lupo)
SECTION 4: SUMMARY OF BENEFITS AND PROBLEMS ENCOUNTERED
The benefits to the University are that all participating personnel gained a new understanding of the character and forecasting of heavy snowfalls in the Northwest and Central Missouri region. All participating personnel learned more about operational forecasting and forecasting procedures through our visits to the Pleasant Hill WFO. This includes gaining exposure to new technologies used at the WFO including such products as AWIPS. Through our collaboration with the WFO, classes which expose our students to operational forecasting and procedures (e.g. Synoptic Meteorology I and II, Dynamic Meteorology, Daily Analysis and Forecasting, Weather Briefing, and Introductory Meteorology) will be updated to include what we have learned. The biggest benefit to the University of Missouri Atmospheric Science Program has been to increase our collaboration and develop a smooth working relationship with the personnel at the Pleasant Hill WFO. As our relationship has developed, faculty other than the PI have been brought into this relationship. Future projects and collaborative efforts are planned with the Pleasant Hill WFO.
The main problem on the University side has been our access to computing power. Our department is in the process of seeking to upgrade our computing facilities. Thus, some aspects of the project have been more difficult to complete than if computational resources were ideal. The resolution of this problem has been fairly simple in that the PI does have access to more powerful computing resources at other institutions. A small problem initially dealt with the exchange of information, especially in light of these computer resource problems. Instituting regular meetings resolved this problem. Finally, the last problem has involved finding the proper balance between the amount of work proposed and the timetable we give ourselves to complete the project. Both PI's agreed at our last meeting that we did not provide ourselves with ample time to complete all the work proposed. We also agreed that in our first project together, our list of specific tasks we wished to complete in one year was very ambitious, especially in light of the many directions some of this work enthusiastically took. This project taught us much about balancing our enthusiasm versus a reasonable timetable.
The main benefit to the National Weather Service Forecast Office comes from the research. The collaboration with university and student researchers has produced a winter storm climatology that we can reference on a day to day basis during the cool season. It has been especially useful for forecasters new to the region in understanding the range of possibilities when forecasting winter weather. The research has also disproved a common misconception. It was commonly believed that heavy snow usually occurred from the "southwest low" type flow pattern. The study showed that heavy snow does occur with this pattern, but most heavy snows resulted from the progressive trough pattern. The study also reinforces the synoptic scale forcing and temperature profiles needed for heavy snowfall.
A second benefit for the office was the interaction with the university. Although only one forecaster was directly involved with this research, an interest has spread to a few other forecasters who have inquired about additional research projects that they can become involved in. The forecasters have shown an interest in the results of the study and are anxious to make use of this knowledge this winter season.
A few problems were encountered and resolved. We learned that our proposal was too ambitious for the amount of time we ended up having. Additional activities at the NWS WFO (i.e., AWIPS Operational Test and Evaluation and a shortage of staff) reduced the amount of time that the SOO and forecaster could devote to completing the tasks agreed to be completed by the WFO. Additionally, work on the synoptic climatology was delayed while we acquired the NCEP reanalysis data as they became available and to develop the programming needed for display of derived data fields.