12/15/2022, 8:11 am EST

Major East U.S. Snowfall Days 6-10 Followed by Vigorous Cold Days 11-15

Forecast confidence is increasing for a significant snowstorm in the East later next week. ECM has an incredible amount of snow across the entire northeast quadrant of the U.S. while GFS focuses heavy snow on Virginia. With snow on the ground and following arctic air, the East will be super cold for Christmas Day and for a few days that follow.
12/14/2022, 8:31 pm EST

Clearway Energy January/February 2023 Wind/Solar Outlook

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.  
12/11/2022, 9:13 am EST

Feared “Ridge Bridge” Pattern Ahead for North America…Triggers Siberian Express Cold Outbreak!

The character of the -AO regime is about to change. The high-latitude high-pressure ridge shifts from Greenland to Alaska and gradually an Alaska “ridge bridge” toward Siberia develops. The result is increasing risk of a cross-polar arctic air surge from Siberia into North America in 7-10 days. The pattern described is often referred to as the “Siberian Express” and the Alaska “ridge bridge” phrase became popular after the North America “polar vortex” winter of 2013-14.
12/09/2022, 4:09 pm EST

U.S. November/Autumn 2022 Climate Report

November 2022 and SEP/OCT/NOV 2022 Climate Report Discussion: The U.S. November 2022 thermal climate produced two distinct patterns: Cold West and warm East (Fig: 1). The West U.S. finished the month in the top 10 coldest (for November) in the 128-year historical record. Idaho finished 4th coldest all-time. In the East, New England, North Carolina and Florida each finished in the top 10 all-time warmest for November. Nationally, the U.S. ranked 44 of 128 years where 1 is coldest and 128 is warmest. The November 2022 precipitation climate ranked moderately wet. The South and East ranked wetter than normal but not excessive (Fig. 2). Nebraska and the Ohio Valley were marginally wet. Meteorological autumn 2022 was (nationally) warmer than normal ranking 24th warmest in the 128-year historical record. The West and North U.S. ranked warmer than normal including Washington and New England which ranked in the top-10 warmest autumn seasons on record (Fig. 3). Maine observed their 4th warmest autumn season on record. Uniquely, only Tennessee and Alabama observed a cooler than normal autumn season. The autumn season was dry, ranking 23rd all-time in the 128-year historical record where 1 is driest. Motivating the dry climate pattern for meteorological autumn were top-10 driest all-time rankings for Nebraska, South Dakota, Minnesota, Indiana, and Kentucky (Fig. 4). The West Coast was moderately drier than normal during autumn. The wet regions were New England and Florida. Fig: 1: NOAA state rankings for temperature during November 2022. Fig: 2: NOAA state rankings for precipitation during November 2022. Fig: 3: NOAA state rankings for temperature during SEP/OCT/NOV 2022. Fig: 4: NOAA state rankings for precipitation during SEP/OCT/NOV 2022.