A Winter Weather History Tool
Posted January 17, 2011
With this winter already featuring several brushes with wintry weather, lots of people come to us with questions about historical storms that brought snow, ice or sleet to parts of our state through the years. The State Climate Office of North Carolina has added a searchable database of winter storm impacts to its already informative winter weather section, which also includes a nice collection of information about winter weather impacts, climatology for our regions, and explanations of the synoptic scenarios and weather patterns that most frequently bring wintry weather our way.
The database simply requires that you choose a county and select the particular impacts your interested in, and it will return a list of storms that had some impact of that sort on the county in question. The overview that results includes a brief synopsis of the storm and its effects statewide, and a "details" link where you can get more info on how many injuries or deaths were attributed to the storm, and a map with links to daily observations from any weather stations in the selected county with data that pertains to the dates of the storm in question. To see that data, just click on the station in the map, and then click the "daily" button on the bubble that pops up. In addition, for storms in which more detailed snow and/or ice accumulation contour maps are available, they will be displayed with the other detailed information.
The database remains a work in progress (it's inherently a big project to make a comprehensive database of something as large and varied as a history of winter storms) and the State Climate Office points out you have to use a little caution in interpreting it, as it only addresses storms since 1959, and there can be a few quirks in the way data are sometimes reported by cooperative observer sites that may seem to under-report the local impact of certain storms.
As an example, I did a "snow" search on Nash County to see how it handled the huge storm that impacted my home there at the beginning of March in 1980. That storm did indeed turn up in the results, with an informative narrative description and a nicely detailed snow accumulation map. However, while it correctly noted the dates of the storm as March 1-2, the narrative incorrectly states it as March 1-2, 1977. It also showed climate observations from a station in Nashville for those same dates. Because the reports from these type of stations often include 24-hour precipitation data recorded around sunrise, the report for March 1st showed no snowfall (as it began late in the day on the 1st), while the March 2nd report indicated 4 inches. This might lead you to think only 4 inches occurred from the storm at Nashville. However, the March 3rd report, which the database didn't display since the storm was over at that point, showed that 18 inches of snow fell on March 2nd (but was included in the daybreak report taken on the 3rd). So, this storm produced 22 inches of snow for Nashville, which is clearly depicted on the contour map. However, for storms that do not include such a map, you'll have to keep in mind that there may be additional snow or ice that would only have been reported by an observing site a day after the storm ends.
Despite a few such such limitations, this is a great addition to the wealth of information out there on North Carolina's weather history - give it a try!