La Nina 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 9 winters with moderate to strong La Niña events and 7 winters with weak events (5 weak through the entire winter and 2 weak at the start and normal from January through March). Of those 16 winters, only two significant event (8 + inches of snowfall) was recorded at Baltimore: January 1996 and January 2000. Both of these events occurred during a weak La Niña. By contrast, there have been 8 significant snow events during moderate to strong El Niño events and 3 more during weak El Niño episodes. See page on El Niño events for more details.

Of the 9 moderate to strong La Niña winters, no significant snowstorms (8+ inches) occurred and all 9 seasons reported below normal seasonal totals. That means that a La Niña winter greatly diminishes the risk of a significant snow event. The lack of a sub-tropical jet across the southern U.S. greatly diminishes the likelihood of coastal storms. Coastal storms (also known as "nor'easters) give the Baltimore area its significant snow storms. Smaller snow storms (not related to coastal storms) can be expected and less than normal snowfall can be expected for the season. Warning: This does not consider ice and the potential for an ice storm.  While rare, it is possible in this region to have a significant storm without a coastal low.

Summary of Table findings:

November   =   5 out 9 were warmer than normal ; 8 out of 9 normal or below normal
                         Snowfall ; 7 out 9 had below normal precipitation
December   =   6 out 9 were within 2° of  normal ; no bias on overall precipitation;
                        7 out 9 had near normal or below normal snowfall
January       =   5 out of 9 were within 1° of normal, but 4 were 3-6° above normal; 7 out of 9 had
                        below normal snowfall ; 7 out of 9 had normal or below normal precipitation
February     =   6 out of 9 were warmer than normal (3 were normal) ; 7 out of 9 were
                         significantly below normal on snowfall (6 to 7") and 2 were normal ;
                         6 out of 9 were normal for precipitation
March         =   8 out of 9 were normal to below normal (0 to 5°) ; 7 out of 9 were normal to
                         above normal on precipitation (0 to 1") ; 5 out of 9 had below normal (2 to 3")
                         snowfall but 4 years had 4-5" above normal.

La Nina winters in the Baltimore Region have less snow than a typical winter. The snow tends to come in smaller doses - not in significant storms. Best chances for snow in a La Nina winter appears to be March. Nor'easters/coastal lows are rare during moderate to strong La Nina events. Since these are a primary source of  large snowstorms in the region, such storms are unlikely during La Nina events. The exception would be a significant snow small-scale event not associated with a coastal low that drops significant snow, but again, this is rare.  Temperature-wise, February shows the strongest trend toward warmer than normal.