A Study of Major Snowstorms for Hickory NC

**Updated 11/8/04**

The 20 dates and there approximate snow accumulations at the airport used for Hickory were: 
Date:                       Snow Amount:
Feb 26-27 2004              7.2 inches 

Jan 23 2003	            9 inches 

Jan 6-7 1996	            8 inches 

Mar 12-14 1993	            10 inches 

Jan 7 1988	            11 inches 

Jan 22, 1987	            16 inches 

Jan 12-14, 1982	            8.5 inches 

Mar 22-23, 1981	            9 inches 

Feb 9-10, 1980	            9 inches 

Feb 18, 1979	            11 inches 

Jan 7-8, 1973	            9 inches 

Dec 3, 1971	            12 inches 

Feb 15-17, 1969	            15.6 inches 

Jan 15-16, 1966	            8.5 inches 

Jan 16-17, 1965	            12.7 inches 

Jan 1, 1962	            8 inches 

March 9, 1960	            9 inches 

March 2-3, 1960	            8.8 inches 

Feb 13, 1960	            9 inches 

Feb 15, 1958	            8 inches

The following are the 10 mean surface maps for the 10 time periods given above.The highest mean pressure ~1030mb was centered over Minnesota with another area of higher pressure across western New England. No closed contoured damming high pressure was noted over the northeast US, but it is obvious that the area of high pressure across the northern US noses into the northeast US, and then down the Appalachians in a cold air damming signature.

  • Mean SLP 12 hours before precip starts
  • Mean SLP 6 hours before precip starts
  • Mean SLP around start of precip
  • Mean SLP between start of precip and peak of precip
  • Mean SLP around peak of precip
  • Mean SLP between peak of precip and end
  • Mean SLP around end of precip
  • Mean SLP 6 hours after end of precip
  • Mean SLP 12 hours after end of precip
  • Mean SLP 18 hours after end of precip

    This map shows the track of the surface low:
  • Track of the mean sea level pressure low

    The mean path of the surface low was from the western Gulf a couple hundred miles south-southeast of Brownsville, TX paralleling the Gulf Coast 100-150 miles offshore of Texas, Louisiana, Alabama, and Mississippi and making landfall around the big bend coastal sections of Florida around Appalachee bay with a northeast heading. The low then tracks across the extreme northern parts of the Florida peninsula to near Savannah, Georgia. It then moves to about 150 miles east of Charleston, SC, the system then takes a more north-northeast track to a position <100 miles east of Cape Hatteras, NC then NNE pretty far off shore of the mid-atlantic and northeast US.

    This track took the heaviest precipitation from northeast Mississippi, northern Alabama and northern Georgia into western North and South Carolina across most of North Carolina and extreme southeast Virginia off shore. So the mean track of the heaviest Hickory, NC snowstorms kept the mean axis of heaviest precip off shore of the mid-atlantic and northeast.
    The following 10 figures are the mean precip maps:
  • Mean precip 12 hours before precip starts
  • Mean precip 6 hours before precip starts
  • Mean precip as precip starts
  • Mean precip between when precip starts and peak
  • Mean precip at peak
  • Mean precip between peak and end of precip
  • Mean precip at end of precip
  • Mean precip 6 hours after end of precip
  • Mean precip 12 hours after precip starts
  • Mean precip 12 hours after precip starts



    The following 10 figures are the mean NH 500mb pattern:
  • NH Mean 500mb 12 hours before precip starts
  • NH Mean 500mb 6 hours before precip starts
  • NH Mean 500mb around start of precip
  • NH Mean 500mb between start of precip and peak of precip
  • NH Mean 500mb around peak of precip
  • NH Mean 500mb between peak of precip and end
  • NH Mean 500mb around end of precip

    The following field is the NH 500mb anomalies. Notice the key features. 1.) Like the Raleigh cases, there is a strong negative anomaly located east of Newfoundland in the 50/50 low position. 2.) Unlike the RDU cases, there is a strong positive anomaly stretching from southern Greenland to the Baffin islands, in the classic negative NAO position. 3.) A strong positive anomaly north of Alaska in the Beaufort Sea in the classic +PNA position. 4.) A negative anomaly just south of the Aleutian Islands.
  • NH 500mb Anomalies

    The following 10 figures are the mean US 500mb pattern:
  • USA Mean 500mb 12 hours before precip starts
  • USA Mean 500mb 6 hours before precip starts
  • USA Mean 500mb around start of precip
  • USA Mean 500mb between start of precip and peak of precip
  • USA Mean 500mb around peak of precip
  • USA Mean 500mb between peak of precip and end
  • USA Mean 500mb around end of precip

    One can see the prevalent 500 mb features. A very strong positive anomaly over Alaska creating cross-polar flow. A 500mb ridge around Greenland and Iceland signifying a -NAO, although since this is a mean plot, the feature is subtle.

    THe following field are the 850mb heights showing us the track of the 850 low.
  • 850mb Heights 12 hours before precip begins
  • 850mb Heights 6 hours before precip begins
  • 850mb Heights around when precip begins
  • 850mb Heights between when precip begins and the peak
  • 850mb Heights around peak of precip
  • 850mb Heights between peak and end of precip
  • 850mb Heights around end of precip

    The following fields are the 300mb winds. The maps show a departing jet streak across the mid-atlantic into the atlantic, very similar to the RDU fields. Putting the gulf coast in the right front entrance region of the jet streak, thus a favorable region for upward motion and low pressure development.
  • 300mb Winds 12 hours before precip begins.
  • 300mb Winds 6 hours before precip begins.
  • 300mb Winds when precip begins.
  • 300mb Winds between when precip begins and peak.
  • 300mb Winds at peak of precip.
  • 300mb Winds between peak and end of precip.
  • 300mb Winds as precip ends.

    Next I plotted 1000mb, 850mb, 700mb, and 500mb heights for NC and attempted to get mean thickness values and heights for this type of weather scenario for Hickory. The following was noted:

    12 hours before precip:
    1000-850mb thickness (m) 1287
    850-700mb thickness (m) 1532
    1000-500mb thickness (m) 5386
    850mb T (C) -3

    6 hours before precip:
    1000-850mb thickness (m) 1290
    850-700mb thickness (m) 1532
    1000-500mb thickness (m) 5395
    850mb T (C) -3

    Precip Begins:
    1000-850mb thickness (m) 1288
    850-700mb thickness (m) 1534
    1000-500mb thickness (m) 5399
    850mb T (C) -2.5

    Between beginning and peak of precip:
    1000-850mb thickness (m) 1293
    850-700mb thickness (m) 1537
    1000-500mb thickness (m) 5413
    850mb T (C) -2

    Peak of precip:
    1000-850mb thickness (m) 1294
    850-700mb thickness (m) 1537
    1000-500mb thickness (m) 5414
    850mb T (C) -2

    Between peak and end of precip:
    1000-850mb thickness (m) 1295
    850-700mb thickness (m) 1536
    1000-500mb thickness (m) 5412
    850mb T (C) -2.5

    End of precip:
    1000-850mb thickness (m) 1291
    850-700mb thickness (m) 1524
    1000-500mb thickness (m) 5373
    850mb T (C) -4.5

    These values will be useful for comparing with potential snow events. If the model is showing something that looks like a threat, you can compare it with these maps and parameters to see if it lines up with climatology.

    Some conclusions for Hickory:
    1. The 500mb pattern most common in these 20 events is one where there is pronounced ridging over and above Alaska and also in western North America leading to cross-polar flow and a +PNA, also there are signatures of 500mb ridging near Iceland and Greenland leading to -NAO.
    2. The mean 500mb height values were in general between 5540-5600m before and during most of the storm.
    3. The mean 1000-500mb thickness values were around 5380-5410m for most of the storm. The mean 1000-850mb thickness values were between 1287-1295m throughout the storm. The mean 850-700mb thickness were around 1532-1537m througout the storm.
    4. The mean track of the surface low as demonstrated above is across the northern Gulf, the northern FL peninsula, and just off the southeast coast.
    5. Most storms that effect western NC with heavy snow, will not effect areas north of southeast VA and the lower Delmarva with heavy precip.