This week’s bitter cold produces about 265 U.S. gas population weight heating degree days (HDD). By comparison, this week is second coldest compared to recent memorable cold weeks including Cold Weather Event “Uri” from the week of 2/13/21 (260) and 2/20/21 (271), “Elliot” 12/24/22 (254), and polar vortex events from January 2024 (249) and 2015 (258).

The morning low temperature forecast for Houston is adjusted for colder readings to 17F making the cold peak for next week’s arctic outbreak rival previous cold events Uri and Elliot from earlier this decade.

Great Lakes ice is emerging and should spread rapidly given the long duration cold pattern ahead. Open water moderates arctic air. However, once ice is sufficiently expansive the moderating effects cease.

High focus on ERCOT (and everywhere else) for next week’s arctic outbreak. In Texas, the outbreak lasts January 19-24 and peaks on January 21. Texas will add snow and ice storm concern during that time. Note the ECM ENS 6-10-day forecast of <0F risk!