Local ground stations in numerous cities reported all-time-record highs on June 27. Seattle reached 104°F (40°C) that day, the city’s hottest temperature ever recorded on any day of the year. All-time records also fell in Oregon, where Portland reached 112°F (44°C). In Canada, the town of Lytton, British Columbia, hit 116°F (47°C)—the highest temperature on record anywhere in the country on any date. The heat tops Canada’s previous record of 113°F (45°C) set in July 1937 in Yellow Grass and Midale, Saskatchewan.
According to blog posts by atmospheric scientist Cliff Mass, the extreme heat is the result of the right combination of unusual conditions. Namely, exceptionally high pressure inland and low pressure near the coast have set up a strong flow of air from east to west, helping to push cool ocean air away from the coast. Also, as warm air flows over the Cascade Range, it becomes even warmer as it descends the range’s western slopes.
Forecasts called for temperatures on June 28 to break even more records, followed by some relief as winds from the south to southwest are expected to carry some cooler air inland. Climate change video
And never to miss out on a weather story the Daily Express is stating that we will have a heat wave in mid-late July (despite their source for this information saying the confidence level is low – but the Met Office long range forecast, again with low level of confidence is ‘Temperatures are likely to be above average for much of this period, with an increased risk of some very warm or hot spells occurring.’