One final surge of cold Canadian air of the extended September series draining into the Midwest (7°-10° below average) this past weekend ensures a cool and wet 1^st half of the week across the Northeast.  However, at the same time colder and wetter pattern change starting in the West is certain to shift summer-like heat out of the Pacific Northwest (mid 80s-mid 90s) eastward in a modifying (weakening) form; warming Midwestern temperatures near 80° by midweek, and the Northeast to the mid 70s by the end of the workweek. Similar level modest warmth (3°-6° above average) is forecast to return to the central and southern Plains early this week (low-mid 90s in most of Texas). Meanwhile slightly below average temperatures in most of the Southeast to mid Atlantic region this week appear slowest to recover near seasonal levels (low-mid 80s)late in the 6-10 day period. Precipitation is far less certain amongst models and from run to run of the same model but longer range forecasts maintain relatively mild temperatures east of the Rockies into mid October, and even the cooler West recovers to seasonal temperatures starting late next weekend (Sep 24). At this point there is no substantially cold air in sight building across North America suggesting temperatures across most of the U.S. will remain slightly – moderately above average through most if not all of the latter half of fall.