Back to Back to Back storm systems end March and begin April


For much of the month of March, the weather was stuck in a pattern dominated by high pressure centered over the western Atlantic. This meant that skies remained fair and there was little if any precipitation. However, this did not bode well for Bermuda continues to be in a significant drought with both hydrological and agricultural impacts. March 2012 ended as the driest March in the Bermuda Weather Service Records with only 0.79″ of rain being recorded.  This is the third year in a row that Bermuda has seen unusually dry conditions at least in spring.

However, the pattern shifted as March ended and April began allowing a a series of strong winter-type storms to push into the area. The first storm came March 29th and 30th with gales and brought most of the month’s rain. The cold front associated with this storm did not push all the way through to usher in cooler drier air before the next storm developed and pulled the front northwards as a warm front.

Storm winter storm Exits to the Northeast on the 3rd of April. NOAA GOES-East Infrared Satellite Image.

The second storm was much more significant than the first. It brought strong gales to the island with storm force gusts. In fact, the winds from this storm were stronger than any previous storm this year, and the low pressure recorded in Bermuda with it was lower than with any previous storm this year at 995mb. This is very unusual as this type of storm typically only has the right conditions to develop in mid-late winter; by early spring the upper air patterns do not typically favor the intensification of extra-tropical storms in the Gulf Stream.

The April storm consisted of three parts:

1. Rain and showers for most of the day on the 1st associated with a trough of low pressure ahead of the cold front. There were a few embedded thunderstorms, but for the most part it was moderate to heavy rain. Additionally winds were near gale force for the duration of the day from the south. Most of the rain fell on this day with many stations recording between 0.4" and 0.6" of rain. (Bermuda Weather Service Radar Image April 1st 2012, 9:13pm)
2. A break for most of the day on the 2nd, southerly winds continued. However, by 7:30-8:30pm a line of strong to severe thunderstorms moved across the island in association with the cold front. Bermuda Weather Service recorded wind gusts at 65mph and Magnolia Hill at 70mph with a severe thunderstorm that only affected the eastern parishes. (Bermuda Weather Service Radar Image April 2nd 2012, 7:53pm)
3. Overnight on the 2nd and into the morning of the 3rd, cold air convection started up along a post-frontal trough bringing in some showers and thunderstorms. The Eastern parishes again got hit with a storm that produced 66mph gusts and hail at the Bermuda Weather Service. A record low temperature of 50.2F was also recorded in this hail storm. Lows around the island were in the low 50s. (Bermuda Weather Service Radar Image April 3rd, 7:23am)

However, despite producing severe winds, this second storm did bring some much needed rain to the island. Over an inch of rain was recorded at the Bermuda Weather Service over the first three days of April because of this storm system.

Here are some observations from around Bermuda between April 1st-3rd:

Station Max Wind Gust Precipitation
Magnolia Hall, Smith’s 70mph N/A”
Bermuda Weather Service 66mph 1.19″
Gilbert Hill, Smith’s 55mph 0.78″
Chaingate Hill (Me), Devonshire 46mph 0.29″
Moore’s Lane, Pembroke 44mph 0.83″
George’s Bay, Sandy’s 40mph 0.83″
Knapton Hill, Smith’s 38mph 0.80″

All observations other than the one marked (me) are from the http://www.wunderground.com website, or the Bermuda Weather Service.

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