Rain remains scarce in Maritimes during typical wet month of October

A trough of low pressure brings showery weather to a larger part of the Maritimes on Thursday.

September finished as one of the driest on record for large parts of the Maritimes, and October hasn’t been much better so far.

Drought worsens

Drought conditions worsened through September in the Maritimes.

The latest update from the Canada Drought Monitor as part of Agriculture and Agri-Food Canada analyzed most of the Maritimes as being in severe to extreme drought. Parts of southern New Brunswick and Cumberland and Colchester counties and the Annapolis Valley in Nova Scotia were placed in the exceptional drought category.

Exceptional drought is the most severe category used by the Canada Drought Monitor and is statistically only likely to occur once in a 50-year period.

Impacts listed by the drought monitor included reduced agricultural yields, Saint John’s Loch Lomond watershed falling nearly one metre, strained municipal water supplies and ongoing dry wells.

Amherst, N.S., Greenwood, N.S., Truro, N.S., and Summerside, P.E.I., all reported their driest September on record. Moncton, N.B., Saint John, N.B., and Charlottetown, P.E.I., their second driest on record. Halifax had the third driest September on record.

Little help through mid-October

October is typically a top-three wettest month for the Maritimes. Thirty-year averages for most sites in the region are well over 100 mm. The region is so far falling well short of those averages.

Aside from one decent rain event on Oct. 8, it has been another dry month. Much of the Maritimes sits with less than 28 per cent of the monthly average for rain this month. There are a few locations with less than 10 per cent, including Sydney, Halifax and Yarmouth.

Large scale weather patterns have continued to favour periods of persistent high pressure. The steering winds in the atmosphere are directing moisture from the sub-tropical Atlantic towards the north Atlantic and by-passing the Maritimes.

Tropical storms and hurricanes continued to take a sharp turn to the east after moving north of Bermuda, not coming close enough to the Maritimes to contribute rain.

I expect October will finish well below average for rain in the Maritimes.

Showery weather

A weak trough of low pressure will hang over the Maritimes on Thursday, bringing scattered showers to the region.

Areas most likely to have persistent shower activity include eastern New Brunswick, western Prince Edward Island, and parts of northern/western Nova Scotia. There is a chance of some high localized rain totals that could exceed 10 mm for those areas through early Friday morning. The remainder of the Maritimes will be lucky to pick up a few millimetres in passing showers.

Long-range forecast models indicate that two weather fronts could potentially cross the region next week. The first is on Tuesday and the second is late in the week. It would be beneficial for the region to catch both of those systems and any rain or showers associated with them.