On February 9th, a weak surface trough along with a broad west-southwest, cold cyclonic lower atmospheric flow across Lake Ontario accounted for a single lake effect snow band from Lake Ontario into portions of extreme southern St. Lawrence county.
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.
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.
The episode as NWS BTV wrote it up.
On February 9th, a weak surface trough along with a broad west-southwest, cold cyclonic lower atmospheric flow across Lake Ontario accounted for a single lake effect snow band from Lake Ontario into portions of extreme southern St. Lawrence county.
Snowfall totals were 2 to 6 inches in southern St. Lawrence county with localized reports of a foot at Gouverneur.
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 Burlington, VT wrote its last area forecast discussion before the first event at Feb 9, 6:39 AM EST, 2 hours 21 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BURLINGTON VT 639 AM EST WED FEB 9 2011 .SYNOPSIS... BROAD WEST TO SOUTHWESTERLY FLOW ALONG WITH PERIODIC FLURRY OR LIGHT SNOW SHOWER ACTIVITY WILL BE THE RULE OVER THE NEXT FEW DAYS AS TEMPERATURES REMAIN SEASONALLY COLD. ANY ACCUMULATIONS WILL REMAIN LIGHT THROUGH THE PERIOD...AND BE MOST CONCENTRATED ACROSS THE NORTHERN MOUNTAINS AND TO THE LEE OF LAKE ONTARIO. THE NEXT CHANCE FOR MORE WIDESPREAD LIGHT SNOW APPEARS TO OCCUR BY NEXT WEEKEND AS LOW PRESSURE DROPS SOUTHEAST FROM CENTRAL CANADA. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... AS OF 217 AM EST WEDNESDAY...FAIRLY STRAIGHTFORWARD FORECAST ON TAP FOR TODAY AS SHORT RANGE MODEL SOLUTION REMAIN IN OVERALL GOOD AGREEMENT. THIS WILL FEATURE BROAD AND GUSTY SOUTH TO SOUTHWESTERLY WINDS ALONG WITH SCATTERED FLURRY/SNOW SHOWER ACTIVITY...MAINLY ACROSS THE NRN MOUNTAINS AND TO THE LEE OF LAKE ONTARIO WHERE SOME LAKE EFFECT SHSN WILL BE ONGOING TODAY. THIS IS IN RESPONSE TO ADDITIONAL SHORTWAVE ENERGY AND SECONDARY PUSH OF ARCTIC AIR HEADED SOUTH FROM CENTRAL ONTARIO. MODELS HAVE BACKED OFF SOMEWHAT ON DEGREE OF SOUTHWARD PUSH OF THIS FEATURE TODAY...THOUGH STILL FEEL ENOUGH MOISTURE AND FAVORABLE UPSLOPE COMPONENT TO PERHAPS SQUEEZE OUT A FEW SHSN ACROSS THE FAR NRN MTNS LATER TODAY. IN REGARD TO LAKE EFFECT ACTIVITY...WITH MEAN LAKE ONTARIO WATER TEMPERATURES NEAR MID-WINTER SEASONAL LOW VALUES...OVERALL RESPONSE FAIRLY MARGINAL DESPITE MORE FAVORABLE WIND REGIME AND 925 MB THERMAL PROFILES. THUS WILL OFFER ONLY MINOR ACCUMULATIONS IN THE TRADITIONAL SNOWBELT AREAS OF FAR SRN FRANKLIN/ST LAWRENCE COUNTIES. ONLY OTHER THING WORTH NOTING IS POTENTIAL GUSTY WINDS ACROSS PORTIONS OF THE AREA TODAY. MOMENTUM TRANSFER PROGS OFF THIS MORNING'S FCST SOUNDINGS WOULD SUPPORT DEEP BNDRY LAYER MIXING...WITH GUSTS IN THE 15 TO 25 RANGE ACROSS VERMONT...AND 30 TO AS HIGH AS 40 MPH ACROSS THE WESTERN SLOPES OF THE ADIRONDACKS INTO THE SLV. AS A RESULT...HAVE INTRODUCED AREAS OF BLOWING SNOW IN THESE AREAS ACCORDINGLY. A QUICK LOOK AT MEAN 925-850 MB THERMAL PROGS SUPPORT BLENDED MOS HIGHS GENERALLY IN THE 17 TO 23 DEGREE RANGE AREA WIDE. && .SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY/... AS OF 217 AM EST WEDNESDAY...REMAINDER OF FCST WILL BE ONE OF PERSISTENCE AS BROAD THOUGH FAIRLY FLAT CYCLONIC FLOW PERSISTS ACROSS THE AREA. WEAK BUNDLES OF MOISTURE-STARVED SHORTWAVE ENERGY EMBEDDED WITHIN THIS FLOW WILL TRAVERSE THE AREA EVERY 12-HOURS OR SO WITH MEAN LOW LEVEL FLOW REMAINING SOUTH TO SOUTHWESTERLY. THIS WOULD SUPPORT THE IDEA OF VARIABLY CLOUDY SKIES...AND DAILY CHCS OF LIGHT SNOW SHOWER OR FLURRY ACTIVITY...ESPECIALLY ACROSS THE NRN MTNS AND TO THE LEE OF LAKE ONTARIO. ANY ACCUMULATIONS DURING THIS PERIOD WILL BE LIGHT WITH MANY VALLEY LOCALES REMAINING ESSENTIALLY DRY. TEMPERATURES TO REMAIN SEASONABLY COLD WITH HIGHS IN THE TEENS ON THURSDAY...AND ABOUT 4-5 DEG WARMER BY FRIDAY. OVERNIGHT LOWS A TAD MORE TRICKY SHOULD ANY PARTIAL CLEARING OCCUR...BUT WITH OVERALL DECENT CONSENSUS AMONG GFS/MET MOS SAW NO REASON TO DIVERGE GREATLY FROM A BLENDED SOLN HERE. && .LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... AS OF 400 AM EST WEDNESDAY...OVERALL PATTERN WL FEATURE NW FLW ALOFT WITH SEVERAL EMBEDDED DISTURBANCES...BUT OVERALL AMOUNT OF QPF WL BE LIGHT...WITH AT OR SLIGHTLY BLW NORMAL TEMPS. STILL LOOKING AT PATTERN CHANGE FOR LATE NEXT WEEK...BUT LATEST TRENDS OFF THE GFS/ECMWF AND ENSEMBLES DATA CONTS TO DELAY THIS WARM UP...DUE TO LOCATION OF HUDSON BAY POLAR VORTEX AND THE ASSOCIATED NW FLW ALOFT. EVENTUALLY MID/UPPER LVL TROF WL BREAK DOWN ACRS THE EASTERN CONUS...AS WESTERN STATES BECM MORE ACTIVE AND RIDGE SHIFTS EAST. AN EXTENDED PERIOD OF ABOVE NORMAL TEMPS STILL LOOKS LIKELY BY LATE NEXT WEEK. OTHERWISE...BEST CHCS FOR SNOW SHOWERS ASSOCIATED WITH CLIPPER LIKE SYSTEMS WL BE SUNDAY INTO MONDAY...THEN AGAIN MONDAY NIGHT INTO TUES. BOTH GFS/ECMWF IN GOOD AGREEMENT WITH TAKING FAST CLIPPER SYSTEM TO OUR NORTH ON SUNDAY...WITH A BAND OF ENHANCED MOISTURE AND Q-VECTOR CONVERGENCE EXPECTED TO MOVE ACRS OUR REGION. WITH THE PRIMARY SFC LOW PRES PASSING TO THE NORTH...EXPECT LIMITED QPF/SNOWFALL WITH TEMPS WARMING INTO THE 20S TO NEAR 30. BY LATE MONDAY INTO TUES...SEVERAL RUNS OF THE ECMWF CONTS TO SUPPORT A STRONG MID/UPPER LVL S/W AND DEEPER SFC LOW PRES TRACKING FROM THE GREAT LAKES ACRS SOUTHERN PA...THEN INTO SOUTHERN NEW ENGLAND. THIS TRACK WOULD PLACE OUR FA IN A FAVORABLE REGION TO RECEIVE ANOTHER LIGHT TO MODERATE SNOWFALL EVENT...ALONG WITH ANOTHER SHOT OF COOLER TEMPS ON THE BACKSIDE. IT SHOULD BE NOTED THE GFS IS MUCH FLATTER AND WEAKER WITH TROF DEVELOPMENT AND THE ASSOCIATED SFC LOW PRES...WHICH WOULD SUGGEST LIMITED IMPACT TO OUR CWA. WL CONT TO MENTION CHC POPS ATTM FOR LATE MONDAY INTO TUES WITH TEMPS MAINLY IN THE TEENS AND 20S. GFS CONTS TO BE THE COLDER OF THE SOLUTIONS...WHILE ECMWF IS SLIGHTLY WARMER...BUT WITH THE MEAN PROGGED 85H TEMPS BTWN -12C AND -16C THRU EARLY NEXT WEEK...EXPECT AT OR SLIGHTLY BLW NORMAL TEMPS. MID/UPPER LVL RIDGE AND BUILDING HGHTS ARRIVE BY LATE WEDS INTO THURS...WHEN TEMPS ARE EXPECTED TO REBOUND TO ABOVE NORMAL LVLS. && .AVIATION /12Z WEDNESDAY THROUGH SUNDAY/... THROUGH 12Z THURSDAY...THE BIG AVIATION IMPACT FOR THE NEXT 12 TO 18 HRS WL BE DEVELOPING SOUTHWEST WINDS OF 10 TO 20 KNTS WITH GUSTS TO NEAR 30KNTS POSSIBLE AT BTV/MSS/PBG/SLK TODAY. THE STRONGEST WINDS OF 35 TO 45 KNTS WL BE ACRS THE REGION BTWN 12Z- 14Z THIS MORNING...BUT BEST MIXING OF THE WINDS OCCURS BTWN 14Z- 22Z TODAY...THEREFORE EXPECT STRONGER WINDS FROM MID MORNING THRU MID AFTN TODAY. OTHERWISE...SW FLW WL ADVECT LLVL LAKE MOISTURE ACRS THE NORTHERN/WESTERN DACKS AND PRODUCE SOME SNOW SHOWER ACTIVITY...ESPECIALLY THIS AFTN AT SLK. OCCASIONAL MVFR/IFR CONDITIONS WL BE POSSIBLE AT SLK. IN ADDITION SOME MVFR CONDITIONS WL BE POSSIBLE AT TIMES IN AREAS OF BLSN AT MSS/BTV/MPV. WINDS SHOULD WEAKEN TONIGHT...AS LLVL TEMP INVERSION DEVELOPS...WITH SOME SCATTERED MAINLY MTN SNOW SHOWER ACTIVITY PREVAILING. THIS EVENING...A BRIEF PERIOD OF SNOW SHOWERS WL BE POSSIBLE AT MPV/BTV/PBG/MSS/SLK FROM LAKE MOISTURE INTERACTING WITH POTENT 5H VORT...AND SECONDARY ARCTIC FRNT. THIS COULD PRODUCE A PERIOD OF MVFR/IFR CONDITIONS FOR 20 TO 30 MINUTES. OUTLOOK 12Z THURSDAY THROUGH SUNDAY...MAINLY VFR CONDITIONS WL PREVAIL WITH EXCEPTION OF A FEW MTN SNOW SHOWERS AND THE POTENTIAL FOR OCCASIONAL MVFR CONDITIONS AT MPV/SLK. OTHERWISE...LLVL WAA AND MID LVL MOISTURE WL PRODUCE MORE SNOW SHOWERS ON SATURDAY ACRS NORTHERN NEW YORK INTO VERMONT WITH OCCASIONAL MVFR CONDITIONS POSSIBLE. && .BTV WATCHES/WARNINGS/ADVISORIES... VT...NONE. NY...NONE. && SYNOPSIS...JMG NEAR TERM...JMG SHORT TERM...JMG LONG TERM...TABER AVIATION...TABER
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE BURLINGTON VT 217 AM EST WED FEB 9 2011 NYZ026>031-034-035-087-VTZ001>012-016>019-100730- NORTHERN ST. LAWRENCE-NORTHERN FRANKLIN-EASTERN CLINTON- SOUTHEASTERN ST. LAWRENCE-SOUTHERN FRANKLIN-WESTERN CLINTON- WESTERN ESSEX-EASTERN ESSEX-SOUTHWESTERN ST. LAWRENCE-GRAND ISLE- WESTERN FRANKLIN-ORLEANS-ESSEX-WESTERN CHITTENDEN-LAMOILLE-CALEDONIA- WASHINGTON-WESTERN ADDISON-ORANGE-WESTERN RUTLAND-WINDSOR- EASTERN FRANKLIN-EASTERN CHITTENDEN-EASTERN ADDISON-EASTERN RUTLAND- 217 AM EST WED FEB 9 2011 THIS HAZARDOUS WEATHER OUTLOOK IS FOR NORTHERN NEW YORK...CENTRAL VERMONT...NORTHEAST VERMONT...NORTHWEST VERMONT AND SOUTHERN VERMONT. .DAY ONE...TODAY AND TONIGHT. NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME. .DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY. NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION IS NOT EXPECTED AT THIS TIME. JMG
The national radar mosaic for the moment the first event began.
1 lake-effect snow. Local standard time, as filed.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in New York in 2011Every state in 2011This day in weather historyWarnings in New York, February 2011
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: 279317.