(Des Moines) The weather forecast this week is for more seasonal temperatures with a chance of rain beginning Wednesday. This is a welcome relief after nearly three-months of unusually cold and wet weather. State Climatologist Harry Hilaker says that persistent weather pattern has been caused by a predominance of what is called “northwest flow” with the jet stream is going from northeast to southwest across the middle part of the country.
“And that basically acts to push to any Arctic air mass in our direction bringing with it cooler than usual temperatures,,” stated Hilaker. This cool pattern has been going on for almost three months now and unfortunately that pattern is not going away, at least for the short term.
“By the end of this week we expect below normal temperatures again,” said Hilaker. “The cooler weather pattern will be with us for awhile, but not to the extreme that we have experienced the last 90-days.”
And generally speaking, Hilaker says the weather pattern does not appear to be as wet as what it has been.
May 6, 2013