Warm vs Cold
For the western half of the country, you may want to keep those summer shorts out, while sweater weather filters in the east. These flip in temperatures are as a result of the changes in the jet stream. As the jet stream dips over the east, cool, Canadian will usher into the east. However, as the jet stream bulges in the west, warn air will build over the west.
Much of the Twin Tiers will remain in the upper 50s on Friday and lows are likely to dip into the uppers 30s to low 40s. These high temperatures are about 10-15 degrees below the long term average. As we move into next week, below average temperatures will persist.