Potential future work on NWFS in S outhern Appalachians

1. Potential future work on NWFS in Southern Appalachians • Define categories for pattern recognition, determine if there are important differences in resultant snow amounts/patterns/duration/etc. • Have to clearly define sub-categories • We talk about “hybrids”, but what is a hybrid? Anything that contains larger scale vertical motion not influenced by terrain. • Start with GSP sub-categories:- “Post-frontal”- “Comma-head” or “Wrap-around”- “Cut-off low”- Proposed new one: “Clipper” Separate or part of “Post-frontal”? • Also need to separate upslope enhancements even in larger scale synoptic events containing deep vertical motion (can be done with modeling – removing mountains). Include in classification scheme? • Many events probably evolve from “hybrid” to a more “pure” NW flow upslope. Do we need to separate an event when it becomes “pure” (and how easy would that be, what fcst utility would it serve)? • Once we have clearly defined categories, test out on a year (or two) of past events to see how well it works and refine as necessary (can be automated if criteria are clearly defined). This is similar to NCSU approach with CAD events. • Don’t want to have too many categories. Keep simple.

2. Potential future work on NWFS in Southern Appalachians • Identify specific differences between sub-categories, beyond synoptic patterns and evolutions- trajectories- snow-liquid ratios- microphysics- temp/moisture profiles- seasonal differences- diurnal component (convective modes)- sfc temp ties into above two- amount/duration/pattern of snowfall! • Maybe above physical characteristics are much more important than synoptic categories/patterns (so perhaps we categorize based on these instead (G.L. connection vs none; deep mstrvs shallow, daytime vs nighttime, etc) • Create composites for each category of synoptic maps (which maps/fields?) – will decide these details later

3. Potential future work on NWFS in Southern Appalachians • Model performance- evaluate within different categories?- considervarious WRF physics schemes out there (taking advantage of RENCI and gridded verification tools)?- consider NCEP models and longer fcst ranges (beyond 24 hrs), utilize BOIVerify (for QPF anyway) • When to populate with derived grids (QPF or snow amt) from a model vs. using physical parameters from models to generate the derived grids within GFE (in other words, how to utilize mesoscale model output in current WFO fcst process)

4. Potential future work on NWFS in Southern Appalachians • Create database of events by sub-categories? • What to include?- regional snowfall maps (Greg Dobson help)- various analysis maps (what fields, how much of the evolution?)- mesoscale maps- soundings- satellite/radar • Can get carried away, need to pick most important things • Do we keep adding each year, or focus on what we have already plus maybe next two years of field program? • Create an analog tool similar to the St. Louis CIPS project for winter wxin general (http://www.eas.slu.edu/CIPS/ANALOG/analog.php)?

5. Potential future work on NWFS in Southern Appalachians Other ideas: • Leverage HMT-SE (additional data collection, modeling) -GL • More careful trajectory analysis –GL • Sensitivity of upstream stability/snow cover, and model resolution of these upstream aspects –GL • Froude # relationship to accumulation – GSP • Evolution of convective mode (development of horizontal banding vs cellular convection) – DM, RNK • Extending the climatology and trajectory work that Baker and Chip did with the last 10 years. - BP • Looking at temporal trends of snowfall/snow ratio (may tie in with convective mode) - DM • Larger scale (global) circulation patterns –DM?

6. Other Notes: • Will need to think about funding sources (NSF, CSTAR, COMET, ???) • Need to prioritize, identify top operational needs and marry with research interests; start small? • Smaller break-out groups to begin taking on different projects • Researchers might consider spending a shift or two in a WFO to familiarize with fcst process (likewise, operational folks might consider helping with field work at PogaMtn!) • Need to consider role of models in terms of derived output (i.e., fcst snowfall) vs. better use of base model fields to generate derived output with other tools (such as GFE)