Search Results

You are looking at 1 - 6 of 6 items for

  • Author or Editor: Thomas A. Niziol x
  • Refine by Access: All Content x
Clear All Modify Search
Thomas A. Niziol

Abstract

Lake effect snowstorms frequently produce heavy snow in western and central New York State during the late fall and winter months when the waters of Lakes Erie and Ontario are relatively ice free. Mesoscale snowbands account for most of the snow. The depth of the snowfall can vary as much as 100 cm in 50 km. An Overview is presented of some of the procedures that the National Weather Service Office in Buffalo uses to forecast lake effect snow. Forecasters at the office developed a computer program for the Automation of Field Operations and Services (AFOS) that provides guidance for forecasting lake effect snow. The program includes the compilation of forecasts for wind direction and temperature in the lower troposphere at Buffalo. It also calculates the fetch across each lake, and the change in wind direction through the lower troposphere. The program requires input parameters that are computed from one of the two operational numerical models of the National Meteorological Center, and the average surface temperature of each lake. The output is used as guidance by the forecasters to determine the potential for lake effect snow and the most likely location of the snowbands.

Full access
Thomas A. Niziol, Warren R. Snyder, and Jeff S. Waldstreicher

Abstract

This article is the final installment of a four-part series that examines the challenge of forecasting winter weather throughout the eastern United States. This paper examines the problems and challenges of forecasting lake effect snows. The climatology of lake-induced snowfall is reviewed, and an overview of the characteristics and evolution of these mesoscale precipitation bands is presented. The atmospheric conditions associated with five different types of lake snow bands are discussed. The abilities of remote sensors to resolve, and dynamical models to simulate, these mesoscale events are also explored. Finally, several techniques designed to improve operational forecasts of lake effect snow are described in detail, along with representative case studies.

Full access
Rodger A. Brown, Thomas A. Niziol, Norman R. Donaldson, Paul I. Joe, and Vincent T. Wood

Abstract

During the winter, lake-effect snowstorms that form over Lake Ontario represent a significant weather hazard for the populace around the lake. These storms, which typically are only 2 km deep, frequently can produce narrow swaths (20–50 km wide) of heavy snowfall (2–5 cm h−1 or more) that extend 50–75 km inland over populated areas. Subtle changes in the low-altitude flow direction can mean the difference between accumulations that last for 1–2 h and accumulations that last 24 h or more at a given location. Therefore, it is vital that radars surrounding the lake are able to detect the presence and strength of these shallow storms. Starting in 2002, the Canadian operational radars on the northern side of the lake at King City, Ontario, and Franktown, Ontario, began using elevation angles of as low as −0.1° and 0.0°, respectively, during the winter to more accurately estimate snowfall rates at the surface. Meanwhile, Weather Surveillance Radars-1988 Doppler in New York State on the southern and eastern sides of the lake—Buffalo (KBUF), Binghamton (KBGM), and Montague (KTYX)—all operate at 0.5° and above. KTYX is located on a plateau that overlooks the lake from the east at a height of 0.5 km. With its upward-pointing radar beams, KTYX’s detection of shallow lake-effect snowstorms is limited to the eastern quarter of the lake and surrounding terrain. The purpose of this paper is to show—through simulations—the dramatic increase in snowstorm coverage that would be possible if KTYX were able to scan downward toward the lake’s surface. Furthermore, if KBUF and KBGM were to scan as low as 0.2°, detection of at least the upper portions of lake-effect storms over Lake Ontario and all of the surrounding land area by the five radars would be complete. Overlake coverage in the lower half (0–1 km) of the typical lake-effect snowstorm would increase from about 40% to about 85%, resulting in better estimates of snowfall rates in landfalling snowbands over a much broader area.

Full access
Brooks E. Martner, Jack B. Snider, Robert J. Zamora, Gregory P. Byrd, Thomas A. Niziol, and Paul I. Joe

Abstract

A destructive freezing-rain storm on 15 February 1990 was observed intensively with advanced ground-based remote sensors and conventional instruments by the Lake Ontario Winter Storms (LOWS) project in upstate New York. A deep layer of warm, moist, southwesterly flow overran a shallower layer of subfreezing, easterly flow ahead of a surface warm front. Precipitation at the surface changed from snowfall to ice pellets, to freezing rain, and, finally, to ordinary rain as an elevated layer of above-freezing air moved into the region and eventually extended to the ground. Measurements from a scanning Doppler radar, wind profilers, a microwave radiometer, and mobile rawinsondes provided detailed information on the storm's kinematic and thermodynamic structure and evolution, and allowed its basic microphysical structure to be inferred. The remote sensors detected signatures of the melting aloft that may be useful for improving detection and forecasts of freezing-rain hazards.

Full access
Laurence G. Lee, Rodney F. Gonski, Eugene P. Auciello, James R. Poirier, Robert A. Marine, Steven Businger, Kenneth D. Lapenta, Robert W. Kelly, and Thomas A. NizioL

Abstract

No abstract available

Full access
Roger F. Reinking, Roger Caiazza, Robert A. Kropfli, Brad W. Orr, Brooks E. Martner, Thomas A. Niziol, Gregory P. Byrd, Richard S. Penc, Robert J. Zamora, Jack B. Snider, Robert J. Ballentine, Alfred J. Stamm, Christopher D. Bedford, Paul Joe, and Albert J. Koscielny

Snowstorms generated over the Great Lakes bring localized heavy precipitation, blizzard conditions, and whiteouts to downwind shores. Hazardous freezing rain often affects the same region in winter. Conventional observations and numerical models generally are resolved too coarsely to allow detection or accurate prediction of these mesoscale severe weather phenomena. The Lake Ontario Winter Storms (LOWS) project was conducted to demonstrate and evaluate the potential for real-time mesoscale monitoring and location-specific prediction of lake-effect storms and freezing rain, using the newest of available technologies. LOWS employed an array of specialized atmospheric remote sensors (a dual-polarization short wavelength radar, microwave radiometer, radio acoustic sounding system, and three wind profilers) with supporting observing systems and mesoscale numerical models. An overview of LOWS and its initial accomplishments is presented.

Full access