Highlight: Preliminary look at monthly CDD anomalies for the 2022 warm season. 12Z GFS is wetter Great Plains days 6-10, colder into East days 11-15.
Fig. 1: The U.S. population weight CDD anomaly forecast for summer 2022 compared to the last 3 seasons.
Discussion: The preliminary population weight CDD anomaly forecast by month for April to October 2022 is made without considering influence of the soil moisture regime (Fig. 1). Consequently, considering drought potential in the U.S. a warmer adjustment to an already warmer than normal summer forecast is possible. The initial forecast has a similar structure to each of the last 3 seasons whereas the season starts marginally warm, becomes quite hot during mid-to-late summer and eases back toward normal by October.
At midday, the 12Z GFS is warmer for the West-central and Central U.S. adding to an already warm forecast (Fig. 3). The midday 12Z GFS brought what the central/south Great Plains are looking for…a wetter forecast (Fig. 4). Yesterday, ECMWF introduced a potential colder scenario in 10 days. Today the 12Z GFS generates arctic air in East Canada (Fig. 5). Part of the air mass shifts south into the East U.S. modifying south of snow cover. Support for the colder change is better than yesterday but still not that great. In the 11-15-day period the 12Z GFS is dry again in the Great plains (Fig. 6). The U.S. gas population weight HDD forecast adjustments based on the 12Z GFS were 5-6 HDD colder for next week and the last week of March compared to 24 hours ago (Table 1).
Fig. 3-4: The 12Z GFS 6-10-day temperature anomalies and precipitation amount forecasts.
Fig. 5-6: The 12Z GFS 11-15-day temperature anomalies and precipitation amount forecasts.
|Dates||HDD Forecast||12-Hr Change||24 Hours Ago||10-Year NML||30-Year NML|
Table 1: The 12Z GFS U.S. population weight HDD forecast compared to 12 and 24 hours ago.