early and late northeast snow storms
DESCRIPTION
Hali Castleman , Chris Kasprak , VJ Vesnaver , John Kerr. Early and late northeast snow storms. October 3-4 1987. November 6-7 1953. Record setting snowfall in Virginia, Maryland, Delaware, Pennsylvania, and Western New York - PowerPoint PPT PresentationTRANSCRIPT
EARLY AND LATE NORTHEAST SNOW
STORMSHali Castleman, Chris Kasprak, VJ Vesnaver, John Kerr
•Record setting snowfall in Virginia, Maryland, Delaware, Pennsylvania, and Western New York
•The greatest snow total occurred in central Pennsylvania where 29.8 inches fell at Lock Haven
November 6-7 1953
April 18-19 1983•Stalled vehicles and hazardous driving conditions resulted in the closure of many major highways
•Heaviest snowfall in Pennsylvania and New York up to 19.6 inches reported
May 9-10 1977
Latest Recorded Snow in Boston
500,000 People Without Power in MA
12.7 Inches in Worcester
10-20 Inches in the Berkshires
Winchester CT 1977
Start With What We Know…
These early/late season snow storms are all familiar in some ways Strong Low Pressure Systems Combination of Lows
Characteristic Differences They occur outside of the typical
snowstorm season (December-March) Nature of the low pressure systems Where’s the High? How does it get so cold?
500-hPa map
250-hPa map
Cutoff Low
Cutoff Low
Cut Off Lows
Meeting of the low pressure system and the
anticyclone
Where is the High Pressure?
With no anticyclones to the north bringing in the cold air, these early and late storms need to make their own.
Cooling by Melting- The Bergeron Process
Cooling by Melting
Cut Off Low
No sourceOf Canadian Arctic air
April 9-10 1996 The significant
snowstorm of the long winter of 1995\1996
A few locations in Massachusetts, northern Rhode Island, and southern New Hampshire reported over 20 inches of snow
500-hPamaps
250-hPa maps
Cut off low
Surface maps
850-hPamaps
Valid only: September and May