Fig. 1-2: The 15-day MAX/MIN Calgary forecast indicates sharp cold. The colder pattern is driven by fast-emerging snow cover.
Fig. 3-4: Heavy rainfall episodes in New England Friday night and the 6-10 day period in the Midwest U.S.
Fig. 5: Latest collection of NOAA/NWS weather watch, warming and advisory areas.
Discussion: It’s only mid-October but an exceptionally cold air mass source region will develop the next 10 days in west/southwest Canada as snow cover develops and builds causing temperatures to dip to >30F below normal. In Calgary the high temperatures are mostly in the 20’s beginning this weekend and the ECMWF indicates risk of low temperatures <0F next week (Fig. 1). The snow cover widens/deepens in west/southwest Canada and into the northern U.S. the next 10 days (Fig. 2). Meanwhile sneaky wet weather events affect the eastern half of the nation including New England where drought is in-place tomorrow night (Fig. 3) and a large part of the Midwest to Mid-South caused by 2 events in the 6-10 day period (Fig. 4). NOAA/NWS issues freeze warnings for parts of the U.S. Corn Belt and western Great Plains (Fig. 5). The California extreme fire risk due to hot, windy and dry weather continues through tomorrow.
U.S. population weight HDD forecast: The consensus forecast trends colder for late October respecting the possible influence on the U.S. by cold air amassing in southwest Canada (Fig. 6).
Fig. 6: U.S. gas population weight HDD forecast utilizing all models and compared to 24 hours ago.