GFS indicates next week’s arctic outbreak will produce historic cold. Chicago low temperatures to -4 and -5 Mar. 4-5. Minneapolis -23 same days. Boston to 11 Mar. 3-5. GFS is highly changeable (which was the case prior to arctic outbreak early FEB). CIC constructed analog season 1-3 ahead forecast out this afternoon Midday 12Z GFS… Days 6-10: Warmer except colder New England and Montana. Days 11-15: Colder Upper Midwest; warmer Southeast. Dates HDD forecast 12-hr change 24 hours ago NOAA Nml Feb 15-21 211.0 0.0 209.2 191 Feb. 22-28 178.5 -1.6 184.1 175 Mar. 1-7 224.0 -23.0 195.6 163 Table 1: CWG tabulates the 12Z GFS OP gas population weight HDD forecast into early March. The midday GFS and storms/cold… 3-4 in. of rain Tennessee Valley from weekend storm; tornado outbreak Mid-South Saturday. Midday model sees some Alberta Clipper style snows across NY/New England later next week. Midday model highlight is the cold forecast for early March with departures from normal of 35-45F below normal near Calgary to Des Moines March 2 and reaching 20-30F below normal New England March 5. Record breaking cold air mass. Winter 2018-19 looked like La Nina… Preliminary winter 2018-19 temperature anomalies show northern chil and Southeast/Mid-Atlantic warmth. Reminiscent of a La Nina (not El Nino winter climate).