December began fairly mild with temperatures reaching into the mid-70s at times. Although there were some weak frontal systems, they failed to significantly affect the temperature or even bring any heavy rains.
The first major storm of the season struck on the weekend of the 17-18th of December with thunderstorms, gales, and a significant cool down. This same system rapidly deepened in the Bermuda marine area and brought storm force wind gusts across the island along with hail showers and very high seas. Pressures fell to nearly 1007mb on the island in association with this storm; the lowest of the month.
Behind the associated front, temperatures took a dive into the low 50s, particularly in the frequent post-frontal showers that contained hail. However, they quickly recovered as high pressure built back in over the western Atlantic peaking in pressure on the 22nd at around 1029mb.
A second powerful and complex storm struck on the 26th with winds again reaching storm force in gusts. However, the system failed to generate significant post-frontal convection behind it and a series of weak troughs brought light showers that did not contain hail to the island. Temperatures were only able to bottom out in the mid/upper 50s.
The remained of December saw a warming trend with Bermuda firmly entrenched on the western flanks of the Bermuda-Azores high pressure and a southerly wind dominating the pattern. The new year began in between showers and thunderstorms along with very muggy conditions. The high reached 73.4F on the 31st; very warm for late December.
The month ended with 1.39inches of rain, an average high temperature of 71F, and an average low temperature of 62.6F. December 2011’s dryness and mildness couldn’t compare to the record cold and storminess of December 2010.
2011 ended with only 34.55″ of rain, Bermuda Weather Service recorded 40.57″ of rain, a full 16″ below average for the year. 2011 was one of the driest years in Bermuda history.