10/10/2022, 12:04 pm EDT

If El Nino Appears Later 2023, How Will Global Precipitation Patterns Change?

La Nina 2020-22 is likely to produce a 3rd peak in November followed by a steady demise in early 2023. Most analog and dynamic model forecasts agree with this scenario. Neutral ENSO evolves by FEB/MAR 2023 and El Nino may follow for the second half of 2023. If El Nino generates later in 2023, a much different climate pattern emerges. Included wet risk for the Southern U.S. and northern Argentina/southern Brazil and a dry climate for India, Southeast Asia, Indonesia, and Australia.
10/09/2022, 11:41 am EDT

Clearway Energy September 2022 Wind and Solar Verification Report

Discussion: The September 2022 climate across the U.S. was characterized by anomalous warmth dominating the West alongside a stronger than normal Southwest wet monsoon while the East-central/Mid-south U.S. observed very dry conditions. The zonal wind anomalies observed in September were lighter than normal across the Southwest U.S. and Continental Divide region while slightly above normal in Pennsylvania (Fig. 1). In the East, meridional wind was lighter than normal (Fig. 2). There was an area of stronger than normal meridional wind across Southern California. The September forecast anticipated a much stronger zonal wind across the Southeast U.S. (Fig. 3). That result is surprising as the projected upper air pattern (high pressure West/low pressure Northeast) verified. The forecast indicated above normal west-to-east flow south of the Northeast low-pressure area, but observation reveal the wind was lighter than normal (from the west). The meridional wind anomaly forecast indicated light wind across the Central U.S. (Fig. 4). However, observations reveal wind speeds in the north and/or south direction were near normal during the late warm season. Fig. 1-2: September 2022 observed zonal and meridional wind anomalies. Fig. 3-4: Original Climate Impact Company zonal and meridional wind anomaly forecast for September 2022. In September 2022, the above normal strength of the wet Southwest U.S. Monsoon was dominant. Heavy convection leads to well above normal moisture at 850 MB (Fig. 5) extending westward to California (at times). In opposition to that pattern was generally clear skies across the expanding drought zone in the Mid-south U.S. The high cloud regime (at 300 MB) also followed the low cloud pattern closely (Fig. 6). The September forecast completely understood the expanding dryness and drought risk to the Central/Mid-south U.S. (Fig. 7-8). However, the low specific humidity (SH) forecast at low and high levels of the atmosphere in that zone were too strong due to the under forecast SH in the Southwest States. Fig. 5-6: September 2022 observed 850 and 300 MB specific humidity anomalies. Fig. 7-8: Original Climate Impact Company 850 and 300 MB specific humidity anomaly forecast for September 2022.  
10/09/2022, 11:34 am EDT

Clearway Energy NOV/DEC 2022 Wind and Solar Climate Forecast

November/December 2022 Outlook Methodology discussion: As a reminder, the November/December 2022 zonal/meridional wind and solar forecast is based on a constructed analog. 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 are used to project the most likely climate scenarios going forward from the next few months out to several seasons. The month 1 and 2 ahead projections are in this report. 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. This product is experimental – likely to be enhanced for improved reliability.    Climate discussion: Vividly indicated in the North America multi-model Ensemble (NMME) Q4/2022 global sea surface temperature anomaly (SSTA) forecast in the persistence of La Nina in the equatorial central and eastern Pacific Ocean (Fig. 1). The influence of La Nina on global climate is made more dramatic by the opposite SSTA regime in the far western Pacific Ocean tropics where a negative Indian Ocean dipole (-IOD) pattern has evolved. As important to North America climate is the large areas of warm SSTA either side of the continent represented by marine heat wave NEP22A and the warm phase of the multi-decadal oscillation (+AMO). The large areas of warm SSTA in the middle latitudes are well-correlated to increased strength of the subtropical high-pressure centers during mid-to-late summer. When these high-pressure areas expand over the continent, drought can emerge quickly. The process identified were major contributors to China, U.S. and Europe drought patterns during the past several months. However, during the northern hemisphere cold season, the upper-level high-pressure ridge areas tends to consolidate to the warm ocean regions and in-between cold low-pressure areas (polar vortex) convene over the northern land masses. The pattern described is likely to evolve as northern hemisphere winter 2022-23 arrives (Fig. 2-3). Fig. 1: The Q4/2022 global SSTA forecast by the North America Multi-model Ensemble and regions of influence for North America climate. Fig. 2-3: The Climate Impact Company constructed analog upper air forecast projected for November and December 2022 across North America. November/December 2022 wind forecast: The upper air pattern projected for November is very instructive explaining the prevailing wind anomaly pattern. The stronger-than-normal jet stream pattern between an evolving polar vortex in Western Canada and lingering high-pressure across the Southern U.S. explains the positive zonal wind anomalies across the Northern U.S. (Fig. 4) as westerly flow can be ferocious at times. This westerly wind downslopes the Continental Divide and is a warm air producer across the northern tier of the U.S. during late autumn. Cold fronts moving west-to-east across the U.S. are likely to induce strong southerly flow upon approach leading stronger than normal meridional wind anomalies across the northeast sector of the U.S. (Fig. 5). Primary wind generation areas are likely to receive slightly below normal wind speeds during November in the Southwest. In December, a polar vortex pattern is projected across Central Canada. This pattern looks imposing. However, a “ridge bridge” of high-pressure across Alaska to Siberia allowing arctic air flow pattern cross-polar into the polar vortex is not expected during early winter. The positive zonal anomalies in the Northwest U.S. and western Texas (Fig. 6) have near equal chance of westerly or easterly direction (slightly favoring west). Elsewhere, zonal wind anomalies are limited during early winter. The meridional wind anomaly forecast in December yields moderate positive values for the Gulf States including Texas (favoring eastern Texas) and the East Coast (Fig. 7). The polar vortex pattern should propel strong cold fronts into the South and East with following gusty northerly wind explaining the positive meridional anomalies. Fig. 4-5: Experimental Climate Impact Company constructed analog forecast of zonal and meridional wind anomalies for the U.S. during November 2022. Fig. 6-7: Experimental Climate Impact Company constructed analog forecast of zonal and meridional wind anomalies for the U.S. during December 2022. November/December 2022 solar forecast: Making a DESIREABLE return in this month’s outlook for November and December are relative humidity (RH) anomalies replacing specific humidity (SH) anomalies. RH anomalies were not available in the data set for the past two months. A large U.S. drought covering much of West and Central U.S. during early autumn is forecast to expand eastward (by NOAA) during Q4/2022. Consequently, relative humidity levels at 850 and 300 MB are generally below normal especially for the southern 2/3 of the U.S. (Fig. 8-11). Northern U.S. cloudiness increasing dramatically in lower levels (due to to snowfall) in December. Solar generation areas should receive above normal sunlight during the final two months of 2022. Fig. 8-9: Experimental Climate Impact Company constructed analog forecast of 850 MB (low cloud) and 300 MB (high cloud) relative humidity anomalies for the U.S. during November 2022. Fig. 10-11: Experimental Climate Impact Company constructed analog forecast of 850 MB (low cloud) and 300 MB (high cloud) relative humidity anomalies for the U.S. during December 2022.  
10/07/2022, 10:53 am EDT

Rhine River Water Level Forecasts Improving

Slowly, the European Drought is easing. During the late warm season areas of beneficial rainfall have developed. More recently, rainfall occurred in the proper area to cause water levels of the Rhine River to increase dramatically and out of critically low levels.