This is my latest interpretation of the European model (ECMWF) weekly long-range forecast output for North America.
Blocking pattern...when will it end?
The persistent blocking pattern across the far north (-Arctic Oscillation/-North Atlantic Oscillation) is predicted to weaken as we go into the first half of April, but it will be a slow process.
The CPC ensemble forecast (red line) for the Arctic Oscillation (AO) below continues to show a trend toward neutral by the middle of the month, though there is still some uncertainty.
You can also look back and see how low (in the negative) the AO (black line) was from late February through March. The AO was about as low as it ever gets back on March 19 and 20.
For a nice, brief explanation of the different phases of the AO and the NAO you can look at this presentation from the state climate office of North Carolina.
Latest clues to the long range into October.
Some needed rainfall for southern Ontario this week.
Mild air masses likely to outnumber the chilly air masses for a good part of October.
Jet stream pattern across North America will become amplified across North America into next week, which means more extremes in weather.
Warm weather will dominate in the eastern half of the country for the next week. Pattern change possible during the last week of September.
The jet stream will strengthen from the Pacific across southern Canada over the next 1-2 weeks which will keep any sustained chilly/cold air masses up across western Alaska and eastern Siberia.