Winter 2014-2015

Climate Update: Maine’s 2014-2015 Winter Season

By Sean D. Birkel, Maine State Climatologist, April 2015

The 2014-2015 winter season will be remembered as one of the harshest in Maine in recent decades. Defining elements of the season include a damaging blizzard in the first week of November, record-breaking cold in the month of February (indeed, February ranks the coldest month on record since 1895), and numerous storms with record and near-record snowfall totals. Although overshadowed by events of November and February, December was exceptionally mild, ranking sixth warmest on average statewide.

Early November Blizzard

Winter weather began in the first week of November when a strong storm system tracked up the East Coast, and behind it drew in a cold air mass from Canada (Figure 1). This early season storm brought cold temperatures and a mix of sleet, freezing rain and snow to the Northeast region. The storm hit Maine hard, rendering more than 130,000 homes without electricity for a day or longer after wind and heavy, wet snow accumulation (12 inches in Bangor) downed trees and damaged infrastructure (Figure 2) (Related Resources, 1. November Blizzard). Trees may have been particularly vulnerable to effects of this strong winter storm because root systems had yet to freeze into the ground.

Map of North America showing the daily average of precipitation (rain, mixed, and snow) for Sunday, November 2, 2014; Climate Reanalyzer.org, Climate Change Institute, University of Maine
Figure 1. Weather map of North America for November 2, 2014. The blizzard across Maine was part of a large low-pressure system that traveled northward along the East Coast. Data Source: NCEP Climate Forecast System Reanalysis.

December Warm Wave

By the second week of December, warm circulation developed that would persist for the rest of the month. Warmth peaked on December 25, Christmas Day when temperatures rose into the 50s °F across much of the state (Figure 3). A record high of 54 °F was observed in Bangor; and a record high of 48 °F in Caribou (Figure 4). These warm temperatures caused widespread snowmelt and ice loss on some lakes and rivers that had started to freeze at the beginning of the month. The ice broke on the St. John and Allagash rivers, rare occurrences for late December (Related Resources, 2. December Warm Wave). Very little snow fell in December (Figure 5).

Map of daily temperature departure from average (or anomaly) across North America for Thursday, December 25, 2014.
Figure 3. Map of temperature departure from average (or anomaly) across North America for December 25th, 2014. Warm conditions developed from disturbances off of the North Pacific and the Gulf of Mexico and prevailed across much of the continent for nearly all of December. Data Source: NCEP Climate Forecast System Reanalysis.

 

November 2014 – March 2015 daily temperature data recorded at Bangor International Airport.
Figure 4. November 2014 – March 2015 daily temperature data recorded at Bangor International Airport. The plot includes daily maximum (red) and minimum (blue) temperatures, daily maximum (orange) and minimum (purple) temperature records (1950-present), and the mean daily temperature departure from normal. Warm and cold record temperature measurements (or ties with previous records) for the 2014-2015 winter season are marked by red and blue dots. The prominent December warm wave and February cold wave are labeled. The Summer-In-March event of 2012 is also labeled, given the conspicuousness in the record high-temperature time series (Related Resources, 3. Summer-in-March 2012). An all-time March high temperature of 85°F was measured in Bangor during this exceptional early season heat wave, besting the previous high-temperature record by almost 15°F. Data Source: NOAA Regional Climate Centers.

January, Cold and Snowy

Cold and snow typical of a Maine winter soon arrived, however, with an impressive uptick of snow accumulation leading into February (Figure 6). A blizzard on January 27 dropped more than a foot of snow across much of the state. Repeated southward-tracking storms both began and ended with below freezing temperatures, providing ideal powder-like snow conditions for outdoor recreation, the best in years.

February Snowstorms and Record Cold

February saw several significant snowfall events, including on February 2, a blizzard that dropped another foot of snow (Figure 7). But the real story was the record-breaking cold. Not only did February register as the coldest on record statewide since 1895, but it also registered as the coldest month on record, besting even the cold January of 1994 (Figure 8). Nevertheless, the December-February average winter temperature falls well short of records set during the early part of the 20th century (Figure 9).

Chart showing Temperature anomaly (difference from the 1901-2000 climate average) timeseries averaged statewide for the months of January (top) and February (bottom).
Figure 8. Temperature anomaly (difference from the 1901-2000 climate average) time series averaged statewide for the months of January (top) and February (bottom). February 2015 registers as the coldest month on record in Maine with a temperature anomaly of -10.8 °F below the 1901-2000 February average baseline. Data Source: PRISM Climate Group; images made from Climate Reanalyzer.

 

Temperature anomaly timeseries averaged statewide for December-January-February (DJF).
Figure 9. Temperature anomaly time series averaged statewide for December-January-February (DJF). The 2014-2015 DJF winter season registers as slightly below the 1901-2000 average baseline temperature but falls well short of DJF cold records set in previous decades, particularly those prior to 1935. Data Source: PRISM Climate Group; images made from Climate Reanalyzer.

March Continued Cold and Snow

Climatological winter spans December-February, but Maine often experiences winter conditions from November-March. March 2015 indeed felt like winter, registering below normal temperature for most of the month, and four record low daily temperatures in Bangor (Figure 4). March also saw additional snowfall, including one significant storm on the 15 (Figure 10). In Bangor, 132 inches, or 11 ft., of snow fell between November 1 and March 31. Despite a snowfall deficit and unusual warmth in December, the 2014-2015 winter season ranks one of the snowiest on record (Related Resources, 5. Record Cold and Snowfall).

Meanwhile, in the Rest of the U.S. …

Although Maine experienced a harsh and snowy winter, conditions elsewhere in the nation were far different, particularly across the West where most regions saw record warmth for much of the winter. Record Californian drought continued unabated. The annual March snow survey in the Sierra Nevada measured an astonishing 9% normal snowpack (Related Resource, 6. California Severe Snow Deficit). Winter extremes across the continent developed from a persistent warm-air ridge over the west (linked to above normal sea-surface temperatures across the eastern Pacific), and a likewise persistent cold-air trough downstream to the east (Figures 11, 12). The abundant snowfall in Maine and across the Northeast this winter was fueled by moisture evaporated over the North Pacific and North Atlantic where surface waters were warmer than normal (Figure 13). The development of blizzards and other storms of intense snowfall likely resulted from very cold circulation from the Arctic interacting with warm, moist air mass to the south, facilitation the formation of deep atmospheric low-pressure systems.

Map showing typical ridge-trough wave pattern of the jetstream from east to west across North America for the 2014-2015 winter season, exemplified here in a February 18th forecast.
Figure 11. The typical ridge-trough wave pattern of the jet stream from east to west across North America for the 2014-2015 winter season exemplified here in a February 18th forecast. Persistent ridging over the west brought record warmth and a northward displaced storm track (sending moisture to Alaska and the Pacific Northwest, while leaving California drought-stricken), whereas the trough downstream brought repeated incursions of cold Arctic air. Data Source: NCEP Climate Forecast System Reanalysis.

 

Temperature anomaly map for the U.S. for February 2015 relative to a 1901-2000 climate baseline.
Figure 12. Temperature anomaly map for the U.S. for February 2015 relative to a 1901-2000 climate baseline. The warm-air ridge, cold-air trough pattern evident in Figure 11 is clearly identifiable. Data Source: PRISM Climate Group; images made from Climate Reanalyzer.

 

Map of the world showing sea-surface temperature anomalies for February 2nd, 2015.
Figure 13. Sea-surface temperature anomalies for February 2, 2015. Evaporation above warm surface waters across the North Atlantic and North Pacific yielded plentiful moisture for the intense snowstorms of this winter season. Note the regional average temperature anomalies in the bottom section of the figure. All register above the 1979-2000 reanalysis baseline. Data Source: NCEP Climate Forecast System Reanalysis.

Related Resources

  1. November Blizzard: Strong, early storm cuts 
power to 137,000 homes (November 3, 2014, Portland Press Herald)
  2. December Warm Wave: So long, December thaw: Seasonal low temperatures returning to Maine (December 29, 2014, Bangor Daily News)
  3. Summer-In-March 2012: (March 23, 2012, WunderBlog Archive)
  4. January 27 Blizzard: Live coverage of Maine’s Jan. 27 snowstorm (January 27, 2018, Portland Press Herald)
  5. Record Cold and Snowfall: Weekend snow secures winter records for Maine, New England (February 22, 2015, Bangor Daily News)
  6. California Severe Snow Deficit: California Statewide Snowpack Now Below Record Low Benchmark (March 24, 2015, The Weather Channel)