Heavy Snow, Lewis
- When
- December 20, 4:15 PM EST
- Where
- Lewis forecast zone
- Property damage
- $5,000
- Reported by
- TRAINED SPOTTER
- Coordinates
- 43.785, -75.449 (the zone’s center; the record gives no point)
Heavy Snow in New York, December 20, 2001
An area of low pressure moving across southern Ontario brought snow to the region. East of Lake Ontario snowfall amounts varied from barely a covering at low elevations to seventeen inches on the Tug Hill plateau.
Where it happened
Every event with a place to put it; 1 filed by county or forecast zone are drawn at its center, in a lighter ring. Tap one for its entry below.
- Tornadoes
- Tropical storms and surge
- Floods
- Wind
- Hail
- Winter weather
- Heat and drought
- Cold
- Fire, smoke and dust
- Marine and coastal
- Other
The toll
- Deaths
- 0
- Injuries
- 0
- Property damage
- $5,000
- Crop damage
- None recorded
- Events
- 1
Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.
What happened
The episode as NWS BUF wrote it up.
An area of low pressure moving across southern Ontario brought snow to the region. East of Lake Ontario snowfall amounts varied from barely a covering at low elevations to seventeen inches on the Tug Hill plateau.
What forecasters said that day
The local office's own words before the first event, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.
NWS Buffalo, NY wrote its last area forecast discussion before the first event at Dec 20, 3:45 PM EST, 30 minutes earlier.
Area forecast discussion, Dec 20, 3:45 PM EST, 30 minutes before
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BUFFALO NY
345 PM EST THU DEC 20 2001
THE TROUGH THAT EXTENDS WEST OF THE SURFACE LOW...LOCATED JUST NORTH
OF NEW YORK STATE...HAS CAUSED THE SURFACE WINDS TO BACK AROUND TO
THE WEST SOUTHWEST ACROSS WESTERN NEW YORK. THE RESULTING WIND SHIFT
HAS GENERATED A LAKE SNOWBAND OVER SOUTHERN ERIE AND WYOMING
COUNTIES. THIS BAND WILL CONTINUE TO PROGRESS STEADILY TO THE SOUTH
AS THE SURFACE LOW MOVES TO THE EAST THIS EVENING.
EARLY THIS AND EVENING AND OVERNIGHT...THE BOUNDARY LAYER WINDS WILL
SWITCH BACK TO THE WEST NORTHWEST...ALLOWING THE SNOWBAND TO BECOME
REORGANIZED ACROSS THE SOUTHERN TIER AND SOUTHEAST OF LAKE ONTARIO.
THE UPSLOPE INFLUENCE ACROSS THE SOUTHERN TIER WILL ENHANCE THE
SNOWFALL ACROSS THAT AREA. THEREFORE WE HAVE DECIDED TO ISSUE A LAKE
EFFECT SNOW WARNING FOR THE COUNTIES OUTLINED BELOW. THE MM5 SHOWS
AN IMPRESSIVE CONNECTION TO LAKE HURON WHICH COULD KEEP STEADIER
LAKE EFFECT SNOWS OVER CHAUTAUQUA THROUGH FRIDAY MORNING.
THE CONNECTION TO GEORGIAN BAY WILL HELP TO GENERATE STEADIER SNOW
SHOWERS ACROSS OUR WESTERN LAKE ONTARIO COUNTIES TONGIGHT.
SOUTHEAST OF LAKE ONTARIO...THE LAKE EFFECT SNOW WILL GET BETTER
ORGANIZED THIS EVENING AFTER THE LOW LEVEL SHEAR DECREASES BEHIND
THE DEPARTING LOW. THE SHORTER NORTHWEST FETCH ACROSS THE LAKE WILL
HELP TO KEEP ACCUMULATIONS DOWN...BUT THE LAKE SNOWS WILL LINGER
THROUGH MOST OF FRIDAY. BECAUSE WE ARE EXPECTING GRADUAL
ACCUMULATIONS OVER A 24 HOUR PERIOD...WE HAVE OPTED FOR A LAKE
EFFECT SNOW ADVISORY FOR THE SOUTHEAST LAKE ONTARIO COUNTIES.
THE SNYOPTIC SNOW ACROSS THE HIGHER ELEVATIONS OF THE NORTH COUNTRY
WILL DIMINISH IN INTENSITY THIS EVENING...BUT THE COMBINATION OF
ABUNDANT LOW LEVEL MOISTURE AND UPSLOPE FLOW WILL KEEP THE SNOW
SHOWERS GOING OVERNIGHT THROUGH FRIDAY AFTERNOON.
THE SNOW SHOWERS WILL WIND DOWN SLOWLY FROM WEST TO EAST FRIDAY
AFTERNOON AS THE RIDGE BUILDS IN FROM THE WEST. THE HIGH WILL BRING
DRY WEATHER TO THE AREA SATURDAY BEFORE THE NEXT SYSTEM BRINGS RAIN
SHOWERS ON SUNDAY.
.BUF...LAKE EFFECT SNOW WARNING TONIGHT INTO FRIDAY MORNING NYZ019.
LAKE EFFECT SNOW WARNING TONIGHT NYZ020.
LAKE EFFECT SNOW ADVISORY TONIGHT AND FRIDAY NYZ004>006.
WINTER WEATHER ADVISORY EARLY THIS EVENING NYZ007-008.
TJPThe radar
The national radar mosaic for the moment the first event began.
Event by event
1 heavy snow. Local standard time, as filed.
What these are
- Heavy Snow
- Snowfall reaching the local warning threshold without the other hazards of a winter storm.
After NWS Directive 10-1605, the rules offices file Storm Data by.
The same day elsewhere
- Tornado and Hail in California, December 20, 2001
- Heavy Snow in California, December 20, 2001
- Heavy Snow in Maine, December 20 to 21, 2001
- Winter Weather in California, December 20 to 21, 2001
- Strong Wind in West Virginia, December 20, 2001
- Winter Storm and High Wind in Alaska, December 20 to 21, 2001
- Heavy Snow and High Wind in Alaska, December 20, 2001
- Blizzard and High Wind in Alaska, December 20 to 21, 2001
- Winter Storm in Maine, December 20 to 21, 2001
- Heavy Snow in Pennsylvania, December 20 to 21, 2001
- High Wind in Alaska, December 20, 2001
- High Wind in Virginia, December 20, 2001
More
Every storm in New York in 2001Every state in 2001This day in weather historyWarnings in New York, December 2001
Sources
NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24. Each event’s entry at NCEI: 5276008.