SECTION 1: PROJECT OBJECTIVES AND ACCOMPLISHMENTS
Partners project entitled “Linking synoptic climatology to hydrologic
responses in upstate New York and western New England” concluded successfully
December 2002. The objective of the project in the project proposal was to link synoptic-scale flow regimes across upstate New York and western New England to snowpack evolution. This objective arose from a key NWS priority, improving flood forecasting capabilities.
In the course of the research, the focus of the project was narrowed to assessing 6-day snow depth loss with respect to the 200 hPa 6-day mean wind direction. The focus arose from the discoveries that 1) the prevailing wind direction at 200 hPa had a steady state of about 6 days; and 2) continuous days of snow depth loss were typically 6-days or less, correlating with the shifts in the wind direction at 200 hPa. Papers on snow in the western U.S. showed that snow depth gain/loss is best correlated with 700 hPa geopotential heights. Hence, the research from this project reveals that a different forecasting methodology must be adopted for the Northeast to determine cold season flooding potential from snowpack ablation.
Graduate student David Thomas performed the research under the supervision of his advisor, Prof. Mohr, and with the assistance of the other partners in the proposal but particularly with Timothy Scrom of the NWSFO-Albany. Mr. Thomas’ research concluded with the development of a climatology relating significant snow depth losses to four 200 hPa wind directions that occur during the cold season (November-April) in the study area. The climatology exists both as Geographic Information Systems (GIS) based theme maps and as images for presentation in PowerPoint. The theme maps can be linked to other GIS-based data maps of (for example) elevation or land cover, and the PowerPoint presentation can be used for reference and training. Mr. Thomas enhanced the usefulness of his work to NWSFO-Albany by creating a separate set of maps that consider snow depth losses due specifically to rain on snowpack events.
Lessons Learned: Generally, the project encountered very few difficulties and was able to adhere closely to the proposed work and time schedule. In the original proposal, the project was to involve the simulation of snow depth loss across the area of interest. Section 4.1 explains why this portion of the proposed work was abandoned. For projects with small budgets and tight time schedules, data analysis is a preferable course of action compared to modeling. Using GIS and spreadsheet software produced excellent results. Together, it was possible to conveniently organize, display, and interpolate data. It also made possible the smooth incorporation of the research into NWSFO-Albany’s forecasting program.
SECTION 2: SUMMARY OF UNIVERSITY/ NWS EXCHANGES
Timothy Scrom presented the preliminary results of Mr. Thomas’ work at the NWS Cold Regions Hydrology Workshop in Kansas City (November 4-8, 2002). Mr. Thomas, with assistance from Mr. Scrom, assembled a PowerPoint presentation using the GIS maps. A brief selection of the final results of Mr. Thomas’ work will be presented at the Northeast Storms Conference in Saratoga Springs, NY (March 8-9, 2003).
Mr. Thomas continues to work with Mr. Scrom to integrate his GIS-based maps for operational use in flood forecasting by NWSFO-Albany, for example, the Spring flood drill for the hydrometeorological staff.
SECTION 3: PRESENTATIONS AND PUBLICATIONS
Thomas, D.R., T.E. Scrom, and K.I. Mohr, 2002: Linking synoptic climatology to hydrologic responses in upstate New York and western New England. NWS Cold Regions Hydrology Workshop, National Weather Service, Kansas City, MO.
be presented in March 2003:
Thomas, D.R. and K.I. Mohr, 2003: Linking synoptic climatology to hydrologic responses in upstate New York and western New England. 28th Northeast Storms Conference, sponsored by Lyndon State College, Saratoga Springs, NY.
Mr. Thomas is currently working on a thesis of his research to complete the Master of Science degree requirements. He plans to finish the thesis in time for May 2003 graduation. The PowerPoint presentation format used in the presentations will be adapted for future publication in the on-line journal, Earth Interactions.
Included with the electronic copy of this report is a PowerPoint presentation compiled by Mr. Thomas from his final results for use as a training and reference aid for forecasters at NWSFO-Albany.
Project results have also been used in NWSFO-Albany’s hydrologic public outreach and briefing efforts on the spring flood potential. These briefings include or will include:
SECTION 4: SUMMARY OF BENEFITS AND PROBLEMS ENCOUNTERED
4.1 Benefits to the Academic Partner
This project was the first COMET-sponsored collaboration between the University at Albany and NWSFO-Albany in the area of hydrology/hydrometeorology. Despite the importance of snow and snowmelt to the water cycle in the northeastern U.S., there is very little literature relating atmospheric circulation patterns to snowpack evolution. Thus, this project has contributed to both an operational need to improve cold season flood forecasting and an academically underserved topic area.
The research used the long archive of COOP data from New York and border counties of surrounding states. Mr. Thomas did attempt to obtain and implement the NWS-supported SNOW-17 model to simulate snowpack evolution but found that using it would not be easy. Documentation on SNOW-17 is limited and time consuming to track down, and running the model requires numerous tuneable parameters. Prof. Mohr advised him that setting up the model to run would take far more time and effort than fully exploiting the data and GIS software he already had. The density and history of observations and GIS software made it possible to accomplish the project objectives without modeling. The NWSFO-Albany office is integrating GIS-based forecasting aids into their hydrometeorological training and operations programs. By using GIS for his research, Mr. Thomas insured that his work could be easily integrated such programs as the WHFS (WFO Hydrologic Forecast System) and WES (Weather Event Simulator).
The project represented a new area of research (snow hydrology) using new tools (GIS) for the University at Albany’s Department of Earth and Atmospheric Sciences, which has long been known for excellence in synoptic and dynamic meteorology. As the title of the project indicates, it also drew upon the historical strengths of the Department. The success of this effort is encouraging other research projects in hydrometeorology involving NWSFO-Albany and the Department of Earth and Atmospheric Sciences to go forward. Formal refereed publication of Mr. Thomas’ work is planned. The new on-line journal Earth Interactions, jointly sponsored by the American Meteorological Society and the American Geophysical Union, is the best forum for Mr. Thomas’ extensive series of full color GIS maps of snow depth loss.
4.2 Benefits to the NWS Partner
NWSFO-Albany has had a long and fruitful research collaboration with the University at Albany, and it has looked to extend that relationship to the area of hydrology/hydrometeorology. Improving the forecasting of cold season flooding is a top priority for NWSFOs in the Northeast. Cold season floods in the NWSFO-Albany area of responsibility are often caused by rain on snow events and river ice jam events. The project directly addressed the needs and concerns of the NWSFO-Albany and will be integrated into flood forecasting decision trees.
Mr. Thomas’ GIS maps are being linked to FFMP (Flash Flood Monitoring Program) watershed maps already in service at the NWSFO-Albany. For a given 200- hPa flow pattern, forecasters can then identify those watersheds at high risk for flooding whenever rapid ablation of a deep snowpack is possible. The high-risk watersheds will then be intensively monitored. Given the hundreds of small watersheds in the complex terrain of the Albany area of responsibility, this will both simply and focus the monitoring of vulnerable areas.
At Mr. Scrom’s direction, Mr. Thomas supplemented his PowerPoint presentation with Excel spreadsheet databases of significant snow loss cases (indexed by NWS Office, location, and 200 hPa wind direction) from all causes and significant losses from rain on snow only. The presentation and the databases are being used as a training aid and reference climatology for forecasters. The PowerPoint presentation can be downloaded here.
The research involved with this project filled the entire year 2002. Incorporating as much information as was produced by the research into the NWSFO-Albany forecasting program will take longer than the project year. Since Mr. Thomas will be graduating in May 2003 and possibly leaving the area, he is instructing office interns in working with the GIS-based data so that assimilation of the project data can continue smoothly despite personnel changes. The internship program at NWSFO-Albany is a collaborative effort between the NWS and atmospheric science departments at local SUNY schools, particularly University at Albany. Involving students in existing research programs has often encouraged interested students to propose new research projects. Ideally this will include the area of hydrometeorology.