Saturday, June 02, 2007

May 2007 Highlights

..Warm start then cooler and very wet..

Weather conditions started off warm in May over Winnipeg after April’s warm temperatures and below normal rainfall. In fact, the dryness was quickly becoming a concern to area farmers and forestry officials with increasing incidents of grass fires and forest fires. A much need rainfall of 20-30 mm fell on the 4th-6th which helped to quickly green up area vegetation. Temperatures continued to warm up reaching a peak of 31C on the 9th.. a record high for the date. By mid month however, the weather became more variable and unsettled, with very wet conditions in the last 10 days of the month. Frequent showers and locally heavy thunderstorms brought heavy rains to parts of southern Manitoba, especially just south and east of Winnipeg. Officially, 75 mm of rain fell at Winnipeg airport for the month, about 20 mm above average for May. However rainfall was much heavier to the south and east, with 93 mm at the Forks weather station downtown, 120 mm in St Vital and 126 mm in Dugald. Even heavier rains fell across the southern Red River valley and Whiteshell areas with monthly rainfall totals of 165 mm in Morden, 135 mm in Morris, 130 mm in Pinawa, and a whopping 206 mm in Kenora.. thanks in large part to a tremendous one day rainfall of 106 mm on May 29th that caused some road washouts in Pointe Du Bois. By the end of May, farmers had had enough of a good thing.. and were eager for a stretch of warm dry weather once again to continue with planting and spraying operations.

All in all.. a very wet end to a changeable month.


  1. It is intersting to note that in almost all convective precip events...the southeast parts of the city consistently receive more rain than the airport. Seems like St Vital etc are in a different precip regime than Northwest Winnipeg.

    On a different note, very cool, dry has moved into Winnipeg courtesy of yet another arctic high. Dewpoints have crashed to below freezing. With a light northwest flow I can just see the aiport dropping to zero or slightly below.

    Then by midweek we have the potential for more heavy rain and storms. An upper wave/trough moves in with a deep surface low (for this time of year) tapping lots of moisture.


  2. Good observation Dan about the southeast end of the city often getting more convective rainfall than the northwest. It certainly seems that way. I don't know if this is just a fluke, or some actual physical phenomena that takes storms over a certain path through the city. Only good long range climate data from various parts of the city could determine if this was a random occurrence, or a more consistent trend.

    As for tonight.. yes, a chilly one for early June. We could see some patchy frost outside the city, but there's an area of high cloud to our northwest that may save us from a more serious frost threat overnight. Also dewpoints have started to climb above zero tonight.. so we may see more dew than frost.