This week’s pattern featuring resurgent mild weather across central & eastern regions and a stormy disposition along the west coast will degrade by day 7 as upper troughiness eases upstream in the Pacific.

This is characterized by the rising PNA which signals an evolving ridge and a warmer-than-average temp profile developing for the west through at least a portion of next week and perhaps beyond.

Downstream a trough should dig into SK, MB & ON with associated unsettled and cooler conditions following another notable warm spell through the mid-range. This cooldown could face resistance into the Atlantic Provinces and instead discharge S/SE through the USA.

Pacific North American (PNA) pattern:


A rundown of temperature departures through the medium and extended range displaying this prospective shift.

12z EPS 2m temp anomalies, days 0-5:


Days 5-10:


12z GEFS 2m temp anomalies, days 10-15:


12z NAEFS temp probabilities, days 8-14:


Also the ‘big 3’ global deterministic models are in general agreement in their respective takes on the mid-term layout, albeit with some differences in amplitude.

12z  ECMWF / GFS / CMC 500mb height anomalies, days 8-10:


A fresh run of the Euro weeklies will be useful to work out the long range.