March 5-6, 2013 Snowstorm Summary

A powerful and complex late system winter storm system crossed the southern Appalachians from the northwest late on March 5th and then headed northeast off the mid-Atlantic Coast during the day on March 6th. Partly due to an atypical forecast track, the tricky timing between most significant precipitation and arrival of deeper cold air, as well as late season mild low level air, especially during daytime hours, made this a challenging forecast for many parts of the area. Confidence was high that there would be significant snowfall (8-12 inches or more) across northern portions of the Blacksburg NWS forecast area, with even higher amounts likely farther north into northern Virginia. However, closer to the track of the secondary surface low, and in lower elevations of the Piedmont, forecasting final snow accumulation amounts was much harder.

Snowfall began in some of the higher elevations during the evening of March 5th, but also in the Roanoke Valley and points northward overnight, while many areas southwest of Roanoke, even at higher elevations remained mostly rain or rain/snow mix during the heavier precipitation overnight and could not accumulate much. By the time colder air moved in behind the newly developing low pressure across northeast NC and southeast VA, lingering precipitation bands were confined to far northern and northeastern portions of our area. Colder air was delayed somewhat longer than expected due to the primary low over the Ohio Valley being slow to lose it's influence of advecting warmer air to the east of it, while the secondary low mentioned earlier was trying to pull this cold air in from the northwest. It was not until early on the morning of the 6th before this happened. You can see the evolution of these competing low pressure centers in the animated satellite and surface pressure composite map below (Fig 1).

When all was said and done, there were indeed very significant accumulations of heavy, wet snow across northern portions of the area, including 10" in Clifton Forge and Lexington, 12-17" in Bath County, 12" in extreme northern Rockbridge County and even Buckingham County as well. 6-8" were common in parts of Greenbrier Co WV. These areas experienced widespread power outages due to the heavy snow on limbs and power lines (see photos below), which were also exasperated by wind gusts of 30-40 mph in some places. However many areas also saw large differences across small distances, dependent in part by elevation but also from heavier bands of snow developing in northwesterly flow through much of the day on the 6th. Some Virginia Piedmont locations saw snow falling most of the day, but because of warming daytime temperatures and warm ground conditions, the snow struggled to add up to much. Locations north of our area, especially along the Blue Ridge, picked up 20" or more.

For more details on the final tallies, see the snowfall map and text summary below.

 


Figure 1. Infra-red satellite and surface analysis evolution, showing the complex double structure to the low pressure system, and the primary low moving over the Ohio Valley and only slowly dissipating, while eventually the secondary low takes over to the east to finally bring colder air in behind it, and then slows down temporarily (keeping snow bands across much of northern VA), before finally shifting out eastward off the coast. Notice also the deeper clouds (with heavier precipitation) move through much of NC and SW VA fairly early (by late evening on the 5th), leaving very little left of the precipitation in those areas by the time the cold air arrived.

 

 

Here is a radar loop showing the initial precipitation wave pushing through, followed by wrap-around bands across northern VA (snow by this time) that pivot in place mainly just to the north of our area resulting in the heaviest accumulations across far northwestern VA.

Radar Loop of the Snow Event of March 5-6th

 

 

 

Forecasts of snowfall leading up to the event were better in some places than in others, with confidence the highest across the northern parts of VA, and less confidence farther south and east where it was expected to be a close call between how much precipitation would be left when cold air arrived, and how warm the ground would be. Below is a NWS snowfall forecast provided on a national scale, which local offices adjust as needed, which was issued during the day on the 5th.


Figure 2. Preliminary snowfall forecasts from the NWS Weather Prediction Center, issued midday on March 5th.

 

 

These photos, courtesy of Michele Fletcher in Rockbridge County, show the damage caused by heavy wet snow, with power lines downed by trees, and a power pole, with transformer lying in the ditch.

Photo taken of snow and power lines down in Rockbridge County, courtesy of Michele Fletcher

Photo of snow and transformer down in Rockbridge County, courtesy of Michele Fletcher

 

 

The final snowfall accumulation map for the counties covered by the Blacksburg NWS office is shown below.

 

List of final snowfall reports received at the NWS Blacksburg office:

PUBLIC INFORMATION STATEMENT
SPOTTER REPORTS
NATIONAL WEATHER SERVICE BLACKSBURG VA
1239 PM EST THU MAR 07 2013

THE FOLLOWING ARE UNOFFICIAL OBSERVATIONS TAKEN DURING THE PAST 48
HOURS FOR THE STORM THAT AFFECTED OUR REGION. APPRECIATION IS
EXTENDED TO THOSE WHO PROVIDED REPORTS. THIS SUMMARY IS ALSO
AVAILABLE ON OUR HOME PAGE AT WEATHER.GOV/BLACKSBURG.

********************STORM TOTAL SNOWFALL********************

LOCATION          STORM TOTAL     TIME/DATE   COMMENTS                   
                     SNOWFALL           OF 
                     /INCHES/   MEASUREMENT

NORTH CAROLINA

...ASHE COUNTY...
   3 SW CRESTON           3.1   900 AM  3/07  COCORAHS                
   6 NW LANSING           2.5   730 AM  3/07  COCORAHS                
   WEST JEFFERSON         1.6   743 AM  3/06  VIA FACEBOOK            
   1 NE WEST JEFFERSON    1.1   700 AM  3/06  COCORAHS                
   TROUT                  1.0  1230 AM  3/06  PUBLIC                  

...WATAUGA COUNTY...
   1 SE BEECH MOUNTAIN    5.5   530 AM  3/07  COCORAHS                
   BEECH MOUNTAIN         5.0   903 AM  3/06  LAW ENFORCEMENT         
   BLOWING ROCK           3.0  1049 AM  3/06  TRAINED SPOTTER         
   BOONE                  2.6   700 AM  3/07  CO-OP OBSERVER          
   1 SSE VALLE CRUCIS     2.0   800 AM  3/06  COCORAHS                
   VALLE CRUCIS           1.8   635 AM  3/06  TRAINED SPOTTER         
   5 ESE BANNER ELK       1.5   800 AM  3/06  COCORAHS                
   1 N BOONE              1.5   855 AM  3/06  COCORAHS                
   SUGAR GROVE            1.0   515 AM  3/06  FIRE DEPT/RESCUE        

VIRGINIA

...ALLEGHANY COUNTY...
   CLIFTON FORGE CITY    10.0   602 AM  3/06  LAW ENFORCEMENT         
   RICH PATCH             9.0   745 AM  3/06  VIA TWITTER             
   1 W NATURAL WELL       5.8   700 AM  3/06  CO-OP OBSERVER          
   4 E COVINGTON          5.1   700 AM  3/07  COCORAHS                
   4 E COVINGTON CITY     3.2   100 AM  3/06  2 IN THE PAST 2 HOURS   
   POTTS CREEK            2.0  1051 PM  3/05  LAW ENFORCEMENT         
   CALLAGHAN              2.0  1053 PM  3/05  LAW ENFORCEMENT         

...AMHERST COUNTY...
   4 NW NAOLA             7.0   100 PM  3/06  TRAINED SPOTTER         
   4 N PLEASANT VIEW      7.0   409 PM  3/06  TRAINED SPOTTER         
   AMHERST                4.0   831 AM  3/06  911 CALL CENTER         
   1 NNE BUFFALO HILL     3.5   840 AM  3/06  PUBLIC                  
   5 W FORKS OF BUFFALO   3.5   700 AM  3/07  CO-OP OBSERVER          
   PLEASANT VIEW          2.2  1141 PM  3/05  TRAINED SPOTTER         
   1 N GIDSVILLE          2.0   852 AM  3/06  TRAINED SPOTTER         
   MADISON HEIGHTS        1.0   846 AM  3/06  TRAINED SPOTTER         
   1 W SANDIDGES          1.0   835 AM  3/06  PUBLIC                  

...APPOMATTOX COUNTY...
   2 S STONEWALL          4.3   915 AM  3/06  VIA FACEBOOK            
   2 S APPOMATTOX         4.0   700 AM  3/07  CO-OP OBSERVER          
   APPOMATTOX             2.0   750 AM  3/06  PUBLIC                  

...BATH COUNTY...
   BOLAR                 17.0  1200 PM  3/07  911 CALL CENTER         
   WARM SPRINGS          14.0  1200 PM  3/07  911 CALL CENTER         
   HOT SPRINGS           12.0  1200 PM  3/07  911 CALL CENTER         

...BEDFORD COUNTY...
   PEAKS OF OTTER SUMMI   7.0  1125 AM  3/06  BROADCAST MEDIA         
   3 WNW BIG ISLAND       6.0   700 AM  3/07  COCORAHS                
   4 NW BEDFORD CITY      4.5   700 AM  3/06  CO-OP OBSERVER          
   1 NE POWELLS STORE     4.0   912 AM  3/06  PUBLIC                  
   5 NW LYNCHBURG AIRPO   3.5  1122 AM  3/06  WSET VIA TWITTER        
   1 N BEDFORD            1.3   700 AM  3/06  COCORAHS                
   4 SW HUDDLESTON        1.0   700 AM  3/06  CO-OP OBSERVER          

...BOTETOURT COUNTY...
   2 N DALEVILLE          4.8  1215 PM  3/06  PUBLIC                  
   FINCASTLE              4.5   506 AM  3/06  LAW ENFORCEMENT         
   5 W FINCASTLE          4.0  1230 PM  3/06  PUBLIC                  
   2 NNW FINCASTLE        3.0   700 AM  3/06  COCORAHS                
   BUCHANAN               3.0   700 AM  3/06  CO-OP OBSERVER          
   4 WNW TROUTVILLE       2.5   700 AM  3/06  COCORAHS                
   LAYMANTOWN             1.0   938 AM  3/06  VIA FACEBOOK            

...BUCKINGHAM COUNTY...
   2 NNE BENT CREEK      12.0  1035 PM  3/06  TRAINED SPOTTER         
   GOLD HILL              7.5  1112 AM  3/06  TRAINED SPOTTER         
   3 NE ANDERSONVILLE     6.5   700 AM  3/07  CO-OP OBSERVER          
   3 SW NEW CANTON        6.3  1151 AM  3/06  EMERGENCY MNGR          
   BUCKINGHAM             2.0   730 AM  3/06  LAW ENFORCEMENT         

...CAMPBELL COUNTY...
   ALTAVISTA              3.0   615 AM  3/06  LAW ENFORCEMENT         
   CONCORD                3.0   900 AM  3/06  PUBLIC                  
   LYNCHBURG AIRPORT      3.0  1200 AM  3/07  ASOS                    
   6 SSW LYNCHBURG        2.8   700 AM  3/06  COCORAHS                
   1 S GLADYS             1.6   700 AM  3/07  COCORAHS                
   2 E LYNCHBURG AIRPOR   1.5   537 AM  3/06  COUNTY OFFICIAL         
   3 E BROOKNEAL          1.3   800 AM  3/06  COCORAHS                

...CHARLOTTE COUNTY...
   PHENIX                 3.0   735 AM  3/06  PUBLIC                  
   1 W CHARLOTTE COURT    2.0   700 AM  3/07  CO-OP OBSERVER          

...CITY OF BEDFORD...
   BEDFORD CITY           2.0   725 AM  3/06  LAW ENFORCEMENT         

...CITY OF BUENA VISTA...
   BUENA VISTA CITY       4.5   700 AM  3/07  CO-OP OBSERVER          

...CITY OF COVINGTON...
   COVINGTON              4.0   700 AM  3/06  PUBLIC                  

...CITY OF LEXINGTON...
   1 ESE LEXINGTON CITY  10.4   700 AM  3/07  CO-OP OBSERVER          

...CITY OF LYNCHBURG...
   2 NW LYNCHBURG AIRPO   3.3  1000 AM  3/06  WSET...VIA TWITTER.     
   1 WSW LYNCHBURG CITY   3.0  1139 AM  3/06  BROADCAST MEDIA         
   LYNCHBURG CITY         2.6  1036 AM  3/06  BROADCAST MEDIA         
   LYNCHBURG              2.0   746 AM  3/06  EMERGENCY MNGR          

...CITY OF ROANOKE...
   ROANOKE                3.0   800 AM  3/06  1450FT ELEVATION        
   1 ESE ROANOKE AIRPOR   2.5  1200 AM  3/07  ASOS                    

...CITY OF SALEM...
   SALEM CITY             3.8   843 AM  3/06  DEPT OF HIGHWAYS        

...CRAIG COUNTY...
   SIMMONSVILLE           3.0  1048 AM  3/06  TRAINED SPOTTER         
   PAINT BANK             2.0   709 AM  3/06  FISH HATCHERY           
   NEW CASTLE             1.5   455 AM  3/06  3 INCHES POTTS MTN      

...FLOYD COUNTY...
   6 S COPPER HILL        2.5   700 AM  3/06  COCORAHS                
   COPPER HILL            2.2   700 AM  3/06  CO-OP OBSERVER          
   5 N FLOYD              1.5   921 AM  3/06  VIA TWITTER             

...FRANKLIN COUNTY...
   4 W ROCKY MOUNT        1.2   700 AM  3/06  COCORAHS                

...GRAYSON COUNTY...
   TROUT DALE             3.2   700 AM  3/07  CO-OP OBSERVER          
   3 SSW ELK CREEK        2.5   340 PM  3/06  TRAINED SPOTTER         

...MONTGOMERY COUNTY...
   4 N BLACKSBURG         2.0   830 AM  3/06  VIA FACEBOOK            
   5 NNE BLACKSBURG       2.0   804 AM  3/06  NWS EMPLOYEE            
   CHRISTIANSBURG         1.0   437 AM  3/06  SOCIAL MEDIA            

...ROANOKE COUNTY...
   CAVE SPRING            2.3   736 AM  3/06  PUBLIC                  
   2 W CAVE SPRING        2.0  1145 PM  3/05  PUBLIC                  
   1 NNW HOLLINS          2.0   700 AM  3/06  CO-OP OBSERVER          
   5 NE ROANOKE           2.0   830 AM  3/06  PUBLIC                  
   3 N BOONES MILL        1.7   700 AM  3/06  COCORAHS                
   6 SW ROANOKE           1.5   630 AM  3/06  COCORAHS                
   5 SW ROANOKE           1.5   700 AM  3/06  COCORAHS                
   4 SW ROANOKE           1.3   815 AM  3/06  COCORAHS                

...ROCKBRIDGE COUNTY...
   3 NNE ROCKBRIDGE BAT  13.0  1200 PM  3/06  TRAINED SPOTTER         
   3 NNW VESUVIUS        11.5   650 AM  3/06  11.5 IN RAPHINE         
   7 NNE BUENA VISTA CI  10.0   900 AM  3/06  NEAR MT PLEASANT        
   3 SW ROCKBRIDGE BATH  10.0   335 PM  3/06  TRAINED SPOTTER         
   2 WNW LEXINGTON CITY   7.5   800 AM  3/06  PUBLIC                  
   1 SE GLASGOW           5.0   700 AM  3/07  CO-OP OBSERVER          
   COLLIERSTOWN           4.0  1213 AM  3/06  SOCIAL MEDIA            
   ROCKBRIDGE BATHS       2.0  1142 PM  3/05  TRAINED SPOTTER         
   NATURAL BRIDGE         2.0  1024 PM  3/05  EMERGENCY MNGR          

...SMYTH COUNTY...
   2 N MARION             1.8   326 PM  3/06  TRAINED SPOTTER         
   4 WSW MARION           1.0   700 AM  3/06  COCORAHS                
   2 ENE MARION           1.0   800 AM  3/06  COCORAHS                

WEST VIRGINIA

...GREENBRIER COUNTY...
   QUINWOOD               8.0  1144 PM  3/06  DEPT OF HIGHWAYS        
   CRAWLEY                8.0   530 AM  3/06  EMERGENCY MNGR          
   RENICK                 8.0  1038 AM  3/06  EMERGENCY MNGR          
   ALTA                   7.0  1230 AM  3/06  DEPT OF HIGHWAYS        
   SMOOT                  7.0   232 PM  3/06  TRAINED SPOTTER         
   RUPERT                 6.0   245 AM  3/06  DEPT OF HIGHWAYS        
   RONCEVERTE             6.0   230 AM  3/06  DEPT OF HIGHWAYS        
   AUTO                   6.0   737 AM  3/06  NO POWER                
   LEWISBURG              6.0   230 AM  3/06  DEPT OF HIGHWAYS        
   KESSLER                5.0   345 AM  3/06  PUBLIC                  
   MCROSS                 4.6   700 AM  3/07  CO-OP OBSERVER          
   4 SE RONCEVERTE        3.7   700 AM  3/06  COCORAHS                
   CALDWELL               3.5   530 AM  3/06  EMERGENCY MNGR          
   DROOP MOUNTAIN         3.0   943 PM  3/05  DEPT OF HIGHWAYS        
   FAIRLEA                2.5   530 AM  3/06  EMERGENCY MNGR          
   WHITE SULPHUR SPRING   2.0   530 AM  3/06  EMERGENCY MNGR          
   CLINTONVILLE           2.0  1031 PM  3/05  EMERGENCY MNGR          
   ALDERSON               1.4   700 AM  3/06  CO-OP OBSERVER          
   CHARMCO                1.0  1108 PM  3/05  PUBLIC                  

...MERCER COUNTY...
   FLAT TOP               5.0   500 AM  3/06  DEPT OF HIGHWAYS        
   BLUEFIELD              3.0   500 AM  3/06  DEPT OF HIGHWAYS        
   PRINCETON              2.0   500 AM  3/06  DEPT OF HIGHWAYS        
   1 NE MERCER CO AIRPO   1.7  1200 AM  3/07  ASOS                    
   1 SSE BLUEFIELD        1.5  1026 AM  3/06  VIA FACEBOOK            

...MONROE COUNTY...
   GLACE                  5.5   648 AM  3/06  COUNTY OFFICIAL         
   GAP MILLS              4.0   648 AM  3/06  COUNTY OFFICIAL         
   2 N WAITEVILLE         3.0   445 AM  3/06  DEPT OF HIGHWAYS        
   SWEET SPRINGS          3.0   445 AM  3/06  DEPT OF HIGHWAYS        
   PICKAWAY               2.0   649 AM  3/06  COUNTY OFFICIAL         
   UNION                  1.5   644 AM  3/06  COUNTY OFFICIAL         

...SUMMERS COUNTY...
   1 NNW HIX              5.5   430 AM  3/06  DEPT OF HIGHWAYS        
   3 N CLAYTON            4.5   430 AM  3/06  DEPT OF HIGHWAYS        
   PIPESTEM               4.5   430 AM  3/06  DEPT OF HIGHWAYS        
   FOREST HILL            1.5   430 AM  3/06  DEPT OF HIGHWAYS        
   HINTON                 1.5   430 AM  3/06  DEPT OF HIGHWAYS