An amplified H5 pattern featuring downstream atmospheric blocking and a continental ridge dividing closed upper lows oriented near the GL and the SW USA will be the catalyst for another round of significant moisture pushing into the east, while warmer air settles through parts of the west.
00z EPS 500mb height anomalies @ hour 120:
The associated surface low will begin to affect ON beginning tomorrow morning before tracking into QC through Friday and Saturday. A wet southerly flow should affect Atlantic Canada on the eastern flank of the storm.
This system won’t be able to briskly progress out of the region due to the downstream block, leading to a spell of lingering cool & disturbed weather into next week.
06z GFS @ hour 48 / 72 / 96 / 120:
Total precip @ hour 144:
Previously waterlogged and flood-prone areas are a concern once more as they have precious little capacity to absorb this additional moisture, aggravating an already ugly situation.
Farther west through the Prairies a burgeoning ridge will lead to a milder and drier temperature profile over the next while.
00z GFS ensembles 2m temp anomalies, days 1-7: