EXPERIMENTAL Zonal/Meridional Wind Anomaly Forecast EXPERIMENTAL Relative Humidity Anomaly Forecast Valid: January and February 2023 Methodology discussion: The December/January 2022-23 zonal/meridional wind and solar forecast is based on a constructed analog (CA). The constructed analog identifies regional sea surface temperature anomalies (SSTA) that influence North America climate. Past similar SSTA regimes are identified, and their correlating climate patterns calculated and used to project the most likely climate scenarios for the next two months to produce this forecast. The wind speed/relative humidity anomaly forecast is experimental. Zonal (west-east) and meridional (north-south) anomalies are projected for wind generation use. The relative humidity at 850 MB (5,000 feet) is used to project low cloud potential interference with sunlight and similarly at 300 MB (30,000 feet) to project sunlight potential interference from high (cirrus) clouds.    Climate discussion: The Climate Impact Company constructed analog (CIC-CA) forecast is based on a regression for December 2022 using a robust negative phase of the arctic oscillation (-AO) and presence of La Nina. The unique combination of these two climate diagnostics was found in 6 years (in this century). Projecting the following most likely climate for January and February using this methodology accounts for the wind speed and solar forecast in this report. January/February 2023 wind forecast: The ferocious arctic outbreak in December is forecast to dissipate and be replaced by a somewhat milder regime for January. Expect a major weather pattern change to initiate during the first third of the month. Despite the major weather pattern change anticipated, the zonal and meridional wind speed anomalies are not particularly impressive during January (Fig. 1-2). Below normal wind speeds (both zonal and meridional) are forecast across Ontario/Quebec and into New England during mid-winter. Above normal wind speeds are projected across Florida. Western Canada will have above normal northerly wind, most likely the last third of the month. There is lack of significant wind in the primary wind generating areas of the Southwest U.S. to Texas. During February, another pattern change is expected. Likely occurring during the first third of the month is another arctic outbreak possibly similar to the second half of December 2022 episode. The early-to-middle February chill is replaced by a warmer pattern late in the month. The CIC-CA wind speed forecast appears understated given the dramatic weather pattern changes expected. Zonal wind speeds are lighter than normal across Central/East Canada and stronger than normal in Florida (Fig. 3). Meridional wind speeds are stronger than normal across the Canadian Prairies and that set of anomalies could easily extend across the Great Plains especially the first half of the month from the north due to another cold air outbreak from Canada (Fig. 4). The meridional wind speeds across the Northeast are notably lighter than normal. In the primary wind generating areas the CIC-CA forecast yields a lack of anomalous strong wind. Fig. 1-2: The experimental Climate Impact Company constructed analog forecast of zonal and meridional wind anomalies for the U.S. during January 2023. Fig. 3-4: Experimental Climate Impact Company constructed analog forecast of zonal and meridional wind anomalies for the U.S. during February 2023. January/February 2023 solar forecast: As previously indicated, a cold (December) to warm national climate transition is expected in January. The 850 MB relative humidity (RH) forecast yields above normal cloudiness on the West Coast including all of California suggesting above normal precipitation (Fig. 5). Lower clouds hold down the potential sunlight on the West Coas States. Additionally, above normal cloud cover at 850 MB is projected across the Tennessee Valley and southeastern Great Plains. Elsewhere below normal 850 MB RH is expected. High clouds located at 300 MB are projected near to below normal during mid-winter (Fig. 6). Minimal high cloudiness is projected across Florida. In February, above normal cloudiness is projected across California and the Southwest U.S. at both low and high level implying above normal precipitation risk (Fig. 7-8). Low clouds are above normal across the southern Great Plains to the Ohio Valley. At 300 MB, RH is below normal across the Northwest, North-central, Midwest, and Mid-Atlantic States. The Southeast can expect above normal sunlight in February. Fig. 5-6: Experimental Climate Impact Company constructed analog forecast of 850 MB (low cloud) and 300 MB (high cloud) specific humidity anomalies for the U.S. during January 2023. Fig. 7-8: Experimental Climate Impact Company constructed analog forecast of 850 MB (low cloud) and 300 MB (high cloud) specific humidity anomalies for the U.S. during February 2023.  

Discussion: A tale of two regimes dominated the November 2022 U.S. climate pattern. In the West, a semi-permanent upper-level low-pressure trough caused almost the entire West to finish in the top 10 coldest late autumn seasons in the 1895-2022 historical record. Meanwhile, in the East, an upper ridge pattern with axis across the northern Mid-Atlantic States yielded all-time top 10 warm late autumn seasons for New England and Florida. The Southern States turned wetter than normal while the Midwest U.S. autumn dryness continued although less aggressively. In the U.S., cloud cover related to relative humidity (RH) at 5,000 feet (850 MB for “low” clouds) and 30,000 feet (300 MB for “high” clouds) was above normal for both levels in Florida and the Upper Midwest/South-central Canada (Fig. 1-2). Blow normal RH at each level identifying areas of above normal sunlight were observed across the northern half of California and Oregon. The Climate Impact Company forecast for November indicated a large area of below normal RH at 850 MB (Fig. 3). The forecast for below normal low-level cloudiness was too aggressive. Similarly, the low RH forecast at 300 MB for most of the U.S. implied widespread above normal sunlight (Fig. 4). However, only the West Coast observed above normal sunlight while the presence of above normal cirrus clouds to suppress sunlight was observed across the Southwest U.S. and much of Southern Canada. Fig. 1-2: November 2022 observed 850 MB and 300 MB relative humidity anomalies. Fig. 3-4: November 2022 forecast of 850 MB and 300 MB relative humidity anomalies. Areas with above normal zonal and/or meridional wind speeds during November 2022 were in short supply. Zonal wind anomalies were stronger than normal across North Dakota to Iowa and coastal New England during November. Below normal zonal wind speeds were dominant in the Continental Divide region and eastward across the Mid-south States to the Carolinas and Virginia (Fig. 5). Meridional wind speeds were above normal in Wisconsin and New England (Fig. 6). The Climate Impact Company November 2022 zonal wind speed forecast called for above normal across the northern tier of the U.S. (Fig. 7) and only the North-central States validated that claim. The tendency for less than normal zonal wind speed across the southern tier of the U.S. was hinted at by the CIC prediction. The November 2022 meridional wind speed anomaly forecast featured above normal for the Great Plains and Northeast U.S. (Fig. 8). Only parts of this large zone observed above normal meridional wind speeds in November. Fig. 5-6: November 2022 observed zonal and meridional wind anomalies. Fig. 7-8: November 2022 forecast of zonal and meridional wind anomalies.

EXPERIMENTAL Zonal/Meridional Wind Anomaly Forecast EXPERIMENTAL Specific Humidity Anomaly Forecast Valid: December 2022 and January 2023 Methodology discussion: The December/January 2022-23 zonal/meridional wind and solar forecast is based on a constructed analog (CA). The constructed analog identifies regional sea surface temperature anomalies (SSTA) that influence North America climate. Past similar SSTA regimes are accumulated, and their correlating climate patterns are used to project the most likely climate scenarios going forward from the next two months to generate this forecast. The wind/relative humidity anomaly forecast is experimental. Zonal (west-east) and meridional (north-south) anomalies are projected for wind generation use. The relative humidity at 850 MB (5,000 feet) is used to project low cloud potential interference with sunlight and similarly at 300 MB (30,000 feet) to project potential interference from high (cirrus) clouds.    Climate discussion: The CIC-CA forecast presented is based on the projected significant influence on North America climate of a persistent La Nina, Northeast Pacific marine heat wave and the combination of a warmer than normal North Atlantic basin coupled with a large cool pool of ocean water south and southeast of Greenland referred to as the North Atlantic warm hole (NAWH). December/January 2022-23 wind forecast: In December, the projected upper air pattern based on the CIC-CA forecast renders a persistent cold upper trough in Central Canada. However, the attendant cold and snow is likely to stay mostly in Canada while a milder and drier Pacific zonal flow stretches across the U.S. In December, zonal wind speed anomalies are stronger than normal across Western Canada and into the northwest quadrant of the U.S. (Fig. 1). Above normal zonal wind is also likely across wind power generating areas of Western Texas. However, elsewhere zonal wind speed anomalies are generally near normal. The meridional wind speed anomalies are well below normal on the West Coast and Nevada (Fig. 2). However, above normal north-south wind speeds are prevalent across the Southeast and East U.S. In January, above normal zonal wind speed continues across Southwest Canada and the leeward Rocky Mountains southward through Texas (Fig. 3). Below normal zonal wind speed anomalies are indicated for the Southwest and Northeast U.S. The meridional wind speed anomaly forecast for mid-winter indicates mostly below normal values for much of the U.S. (Fig. 4). In summary, the CIC-CA wind speed anomaly forecast for DEC/JAN 2022-23 does not indicate unusually anomalous wind speeds for wind power generation areas with the possible exception of Texas. Fig. 1-2: Experimental Climate Impact Company constructed analog forecast of zonal and meridional wind anomalies for the U.S. during December 2022. Fig. 3-4: Experimental Climate Impact Company constructed analog forecast of zonal and meridional wind anomalies for the U.S. during January 2023. December/January 2022-23 solar forecast: Interestingly, the December outlook features a nationally below normal relative humidity (RH) forecast at 850 MB with strongest anomalies in California and the leeward Southern Rockies (Fig. 5). Implied is below normal cloud cover for much of the U.S. at 5,000 feet where most clouds producing precipitation occur. December could be an unusually dry month for the U.S. At 30,000 feet where cirrus could hinder sunlight intensity, the December 300 MB RH anomaly forecast is below normal across the Southwest U.S. especially California (Fig. 6). Sunlight intensity is at an annual minimum during DEC/JAN although in December sunlight amount is likely much above normal for solar power generation areas across the Southwest U.S. In January, the below normal RH pattern at both the low and high cloud etage continues across much of the U.S. (Fig. 7-8). Fig. 5-6: Experimental Climate Impact Company constructed analog forecast of 850 MB (low cloud) and 300 MB (high cloud) specific humidity anomalies for the U.S. during December 2022. Fig. 7-8: Experimental Climate Impact Company constructed analog forecast of 850 MB (low cloud) and 300 MB (high cloud) specific humidity anomalies for the U.S. during January 2023.  

Remainder of November 2022 Outlook Wind Outlook Discussion: Moderate to high wind is forecast for the next several days across Northern California as strong high pressure extends from southern Canada to the Great Basin and forces gusty north and east wind into northern California (Fig. 1). Mid-to-late this week and into early next week lighter wind is expected. Later this month, arrival of a Pacific upper-level low-pressure trough will spawn a period of increasing westerly wind across northern California. In Southern California, wind power generation is “moderate” today and Wednesday, due to increasing easterlies (Fig. 2). After the short-term events, wind generation is weak for the remainder of November. Wind generation is not a problem across Texas for mid-to-late November as at least moderate risk is present most of the time (Fig. 3). A moderate southerly wind will develop for early this week across Texas followed by chilly northerlies Monday night. A cold burst (with moderate north wind) for mid-to-late week is likely. Return-flow southwesterlies early next week followed by another cool outbreak featuring gusty northerlies around Thanksgiving is expected in Texas. Fig. 1: Wind generation potential using all models through the next 15 days for Northern California. Fig. 2: Wind generation potential using all models through the next 15 days for Southern California. Fig. 3: Wind generation potential using all models through the next 15 days for Texas. Solar Outlook Discussion: Near peak solar generation capability (for November) is forecast across California through the next week as high pressure dominates and skies are generally clear across the state (Fig. 4). However, the last 7-10 days of November feature increased exposure to Pacific westerlies across Northern California therefore increased cloud (and rain/snow) risk is likely. Consequently, state wind average for solar generation capability lowers for the last third of November. In Texas, despite sharp air mass changes, the solar generation potential is moderate through the next 10 days with 2 or 3 days close to ideal (Fig. 5). There may be 2 or 3 days when solar generation is suppressed more so than indicated in the 10-day forecast. In the extended-range, cloud cover may be near or above normal with wet weather risk due to a moisture fetch off the Gulf of Mexico. Fig. 4: Solar generation potential using all models through the next 15 days for CAISO. Fig. 5: Solar generation potential using all models through the next 15 days for ERCOT.