Ice Storms in the St. Lawrence Valley Region

• Main Author: Jones, Kathleen F.
• Other Authors: ENGINEER RESEARCH AND DEVELOPMENT CENTER HANOVER NH COLD REGIONS RESEARCH AND ENGINEERING LAB
• Format: Text
• Language: English
• Published: 2003
• Subjects: Snow; Ice and Permafrost; *DAMAGE ASSESSMENT; *ICE FORMATION; *FREEZING; *CLIMATOLOGY; VELOCITY; DAMAGE; PHYSICAL PROPERTIES; REPORTS; TRANSMISSION LINES; METEOROLOGICAL DATA; ESTIMATES; RAIN; TREES; HISTORY; GUSTS; STORMS; ELECTRIC POWER; WEATHER STATIONS; PHOTOGRAPHS; NEWSPAPERS; EAST(DIRECTION); QUEBEC; Ice; permafrost
• Online Access: http://www.dtic.mil/docs/citations/ADA412652; http://oai.dtic.mil/oai/oai?&verb=getRecord&metadataPrefix=html&identifier=ADA412652

The severe ice storm in January 1998 in Quebec, eastern Ontario, northern New York, and New England disrupted the lives of millions of people. The ice that accreted on trees and wires damaged electrical transmission and distribution lines, causing power outages that lasted many weeks in some areas. In this report, ice storms in the St. Lawrence Valley region of Quebec, eastern Ontario, and northern New York and Vermont are analyzed, focusing on the amount of ice on power lines. Although there are many photographs of ice-covered wires from this storm, only rough estimates of the equivalent radial thickness of ice on the wires can be obtained from these photos. The analysis in this report relies on historical weather data and ice accretion models to estimate the equivalent ice thickness on wires both in this storm and in past freezing-rain storms. The CRREL and Simple ice accretion models incorporate a physical model of the process of ice accretion with empirically determined parameters. Qualitative information from newspapers, Storm Data, and other reports on damaging storms supplement the model results to provide a better understanding of the climatology of ice storms in the region. Ultimately, all this Information is used to calculate equivalent ice thicknesses from freezing rain for long return periods. For the St. Lawrence Valley region in the vicinity of Montreal, Ice thicknesses on wires 10 m above ground and perpendicular to the for 50 and 200 year return periods are estimated to be 33 mm and 52 mm, respectively. Gust speeds concurrent with these ice thicknesses are about 20 m/s. Ice thickness estimates for the 1998 storm at the three weather stations in the Montreal area range from 48 to 55 mm. The original document contains color images.