Arctic Impact on Southern U.S. Increasing
01/09/2024, 6:56 am ESTAll 50 States Have Weather Hazards; Northeast U.S. Snowstorm Next Tuesday
01/12/2024, 9:00 am EST
Fig. 1-2: The midday 12Z GFS medium-range temperature forecast.
Discussion: The 12Z GFS projects a cold medium-range forecast that is stronger and longer than the FEB-21 “Uri” event. Support for the cold is singularly generated by the GFS model. The 6-10-day forecast frigid forecast trends much colder into Texas (Fig. 1). The 11-15-day forecast is expected to moderate due to mild Pacific influence. However, the GFS doubts that possibility and generates a much colder 11-15-day forecast at midday (Fig. 2). The 12Z GFS generates a whopping 281.5 HDD for Jan. 19-25 (Table 1) which is about 10 HDD colder than the “Uri” event Feb. 12-18, 2021.
| Dates | HDD Forecast | 12-Hr Change | 24-Hr Change | 30-Year NML | 10-Year NML |
| Jan. 5-11
| 191.5 | -0.4 | -0.2 | 209.4 | 201.2 |
| Jan. 12-18
| 273.5 | +12.6 | +10.8 | 211.9 | 205.3 |
| Jan. 19-25
| 281.5 | +26.1 | +52.3 | 212.5 | 207.0 |
Table 1: The 12Z GFS U.S. gas population weight HDD forecast compared to 12 and 24 hours ago.