The Madden Julian oscillation (MJO) has been active and a key contributor to climate patterns of the past several months. The MJO trend continues through mid-to-late February. Models indicate a strengthening phase_3 (East Indian Ocean/West Maritime Continent) over the next 10 days shifting east to phase_4 (Eastern Maritime Continent) in the 11-15-day period.

The 06Z GFS 11-15-day forecast returned a wintery look featuring deep arctic air across West and South Canada seeping into the Great Plains and Northeast U.S. The outlook raised the HDD forecast for the week ending February 26th to 194 HDD, up 21 HDD from the previous outlook.

Weather warning, watch, and advisories cover the Northeast and East U.S. this morning for the last blast of arctic air of the winter season. Added are High Wind Warnings for the Mid-Atlantic region which drive wind chill to -10F to -20F shortly after dawn tomorrow once the arctic air arrives. Fresh snow helps to enhance the incoming cold. The cold burst marks the coldest air mass of the season for NEPOOL with the second coldest for PJM-East.

One of the strongest climate signals during DEC/JAN/FEB representing extreme temperature across North America is the Asia/Bering Sea/North America (ABNA) index. The ABNA index 16-day forecast indicates a strong positive phase spike next week and representative of a widening anomalous warm pattern in North America.