Climate Impact Company Wind/Solar Verification Report Valid for February 2023 Tuesday March 14, 2023 Discussion: An astounding observation with an uncertain explanation occurred during February. The Central/East-central U.S. observed sharply below normal relative humidity at 850 MB (5,000 feet) while this entire zone was wetter than normal for the final month of meteorological winter (Fig. 1). In fact, Iowa and Michigan were in the top 10 wettest on record while Wisconsin was 5th wettest on record. Despite the late month return of the “atmospheric river” pattern to California, only Southern California observed above normal relative humidity at 5,000 feet. As a review, most rain and snow is generated by cloud cover near or just below the 5,000 foot level. Therefore, the February below normal RH for such a large area is astounding. In the high-level atmosphere near the jet stream axis, above normal RH was observed from the Tennessee Valley to the Mid-Atlantic coastline (Fig. 2). Beneath this zone, Virginia observed their warmest February on record. Fig. 1-2: February 2023 observed 850 MB and 300 MB relative humidity anomalies. The Climate Impact Company 850 MB RH anomaly forecast correctly identified the likely wetter than normal Midwest/Northeast U.S. pattern by forecasting above normal RH (Fig. 3). Despite the correct impression left by this forecast, the RH prediction failed. At 300 MB, the February outlook was very dry (Fig. 4). The observations revealed a normally cloudy month of February except above normal cloudiness in the Mid-Atlantic region. Fig. 3-4: February 2023 forecast of 850 MB and 300 MB relative humidity anomalies. Fig. 5-6: February 2023 observed zonal and meridional wind anomalies. Anomalous wind was barely present in the west-east zonal direction during February (Fig. 5). Exceptions are downslope the northwestern Montana Rockies and parts of the southwest Great Plains. However, the north-south meridional flow produced above normal wind speed anomalies across much of the eastern half of the U.S. while wind speeds were somewhat below normal just-off the U.S. West Coast (Fig. 6). Given the very warm East U.S. regime during February, most of the anomalous wind was from the southerly direction. Fig. 7-8: February 2023 forecast of zonal and meridional wind anomalies. The Climate Impact Company forecast for February 2023 indicated much of the Far West would observe above normal west-east zonal wind (Fig. 7). The verification indicated zonal wind averaged near normal. The forecast produced below normal zonal wind downslope the Rocky Mountains. Similarly, the wind speeds were near normal in this location. The west-east zonal wind forecast was below normal across New England. Observed wind speeds in the zonal vectors for New England was marginally lighter than normal. The meridional wind direction forecast was lighter than normal for the West Coast and Upper Midwest States (Fig. 8). The lighter than normal north-south meridional wind forecast on the West Coast verified. However, stronger than normal southerlies into the Midwest U.S. were un-forecast.