Summer weather goes on spring break, here's what June brings
Thursday, May 31, 2018, 12:14 PM - After an April that could be charitably described as "miserable" across Canada, the month of May has featured an abrupt pattern change and the arrival of widespread summer-like heat. With the beginning of Meteorological Summer rapidly approaching, many are wondering if this balmy weather is here to stay, or if the month of June has any surprises in store.
Read on for a look at what to expect across the country during the weeks ahead.
(Visit our COMPLETE GUIDE TO SUMMER 2018 for an in depth look at the Summer Forecast, tips to plan for it and much more)
MAY ROUNDS OUT AS HOT FOR SOME, VOLATILE FOR OTHERS
May has been a very warm month across nearly all of southern Canada. This is highlighted in the temperature anomaly (departure from normal) map above. Areas in red and orange have experienced a warmer than normal May, with the most persistent heat centred in the west. Parts of British Columbia and Alberta have averaged more than 5ºC warmer than normal for the month.
May has also brought summer-like temperatures to the Great Lakes through southern Quebec. The Maritimes have been warm at times, but the month has been more volatile for Atlantic Canada, especially across Newfoundland. Meanwhile, May has been a cold month for most of Northern Canada, especially for Nunavut, northern Quebec, and Labrador.
MORE ACTIVE AND CHANGEABLE START TO JUNE
Although most Canadians have already found opportunities to break out the sunscreen and light up the barbecue in the past few weeks, we are still in a transitional season and our summer pattern is not locked in quite yet.
The anomaly map below highlights how the pattern will change for the first week of June. The jet stream will become more amplified and shift south over the next several days, with a series of troughs tracking across North America. This will bring a more active, changeable, and spring-like weather pattern compared to the summer-like pattern of the past few weeks.
FOCUS OF COOLEST WEATHER SHIFTS EAST
Shots of cooler air will affect much of the country, with the chilliest temperatures relative to normal centred on the Prairies -- the same areas that have been among the warmest in May. However, temperatures much more typical of spring than early summer will be felt across much of the country in early June, from British Columbia to Newfoundland. As we head towards the second week of June, the focus of the coolest weather will shift east to the Great Lakes region.
Along with cooler temperatures in the west will come a more active weather pattern, and the potential for widespread beneficial rainfall in areas where drought conditions have developed. The precipitation anomaly map below highlights areas where wetter than normal conditions are expected for the first week of June (areas in green and blue). Parts of this region could see 50 to 100 mm of rain during the next seven days.
JUNE ENDS ON A HOT NOTE
This active pattern will delay the arrival of truly persistent, summer-like heat for a while, but as we move into mid-June we expect another pattern change with warmer weather returning first to western Canada and then spreading east.
During the second half of June we expect that we return to a pattern that will resemble what we have seen during the month of May. Warmer than normal temperatures should once again dominate across southern Canada, but this time more warmth should also spread into Atlantic Canada.