El Nino Winters in the Baltimore Area

Compiled by Barbara McNaught Watson for the Baltimore-Washington Forecast Office

Storms during moderate or strong La Niña events - There were none.
Storms during weak La Niña Events - are noted in blue
Storms during moderate or strong El Niño events - are noted in red
Storms during weak El Niño events - are noted in orange
Years that were neither - are noted in black

Since 1950, there have been 16 winters with significant snowstorms (in this case, defined as 8 or more inches of snow). Hence, based on 50 years of data, the average risk of an 8+ inch snow storm in the Baltimore area is about  1 in 3 chance.  During a La Niña event, the risk drops significantly to about...1 in 7. See the page on LaNiña for more details. During an El Niño event, the risk increases. See the details below.

Of the 9 El Niño winters, there were 5 winters with significant snowstorms (8+ inches) and 4 winters without. That is an increased risk to near 1 in 2 chance of a significant snow event.

El Niño winters tend to be all or nothing. Either you get hardly any snow, as in the case of the last few El Niño events, or you get 150% above normal snowfall with one or in many cases, two or three significant storms.

When looking at the 9 winters that had either a weak El Niño event (4 cases) or an event that only effected a portion of the winter season (5 cases), the same pattern generally held though there was less a tendency toward significant snow events. Three winters had significant storms and above normal snowfall totals for the season and 6 winters had no storms and below normal seasonal totals.

Summary of Table findings:

November   =   5 out 9 were cooler than normal ;  no bias on precipitation totals, though
                        snowfall is not likely with only 2 occurrences in 9. However, one of those
                           events was the Veteran's Day Storm (Nov. 11, 1987).
December   =   ALL were warmer than normal (by an average of 3°); Same as November
                           on precipitation and snowfall. 7 out of 9 Decembers had little or no snow.
January       =   7 out of 9 were warmer than normal; No bias on precipitation totals and 6 out
                           of 9 had below normal snowfall. But the 3 years that did have snow, had
                           significant snow storms.
February     =   6 out of 9 were cooler than normal;  No bias on precipitation totals and 5 out
                           of 9 had below normal snowfall. Four year had above normal and 2 of those
                           had significant snowstorms.
March         =   5 out of 8 were warmer than normal ;  No bias on precipitation totals, but 8
                           out of 9 had below normal snowfall. One year had a significant storm.

El Niño winters in the Baltimore Region mean a milder than normal December. They also tend to be all or nothing when it comes to snowfall. Either there are no significant snow storms and season snow totals average less than 5 inches or there is a tendency toward multiple snow storms with seasonal totals above 30 inches.  These storms usually occur in January and February. November, December, and March often see little or no snow.