07/07/2022, 8:19 am EDT

Intense Negative Multivariate ENSO Index Indicates Robust La Nina Climate Continues

The MEI value for MAY/JUN 2022 was -1.9 which is the strongest negative index in the MEI 1979-2022 climatology with the exception of the second half of 2010 La Nina regime. The difference between the borderline La Nina Nino34 SSTA and intense La Nina MEI is the largest on record.
07/06/2022, 8:03 pm EDT

May/June 2022 Wind and Solar Report

May and June 2022 U.S. Verification Report Fig. 1: May 2022 observed zonal wind anomalies for the U.S. May 2022 wind discussion: The prevailing upper air pattern during May featured two well-structured pressure systems: 1.) A robust semi-permanent upper-level low-pressure trough over the Northwest U.S. and 2.) a compensating semi-permanent high-pressure upper-ridge ridge positioned over New England. As a result, the Central and East U.S. were very warm while Northwest States were unusually chilly. The Northwest was wet during May due to the upper trough while the Southeast States were wet due to an abundance of subtropical moisture. The upper air pattern forced stronger-than-normal wind speeds across the Interior West and across Montana during May (Fig. 1). The stronger westerlies were present due to a stronger-than-normal Pacific jet stream extending inland in-between the Northwest trough and high-pressure ridge west of California. Zonal wind speeds were also stronger than normal helping to inspire an early fire season across New Mexico. Beneath high-pressure, the Northeast observed lighter than normal zonal wind speeds during May. Meridional wind anomalies were stronger-than-normal across the northwest Gulf States, East-central U.S. and Upper Midwest States due to southerly flow around the semi-permanent high-pressure cell over New England (Fig. 2). Otherwise, regions of anomalous meridional wind speeds were limited. Fig. 2: May 2022 observed meridional wind anomalies for the U.S. Fig. 3: June 2022 observed zonal wind anomalies for the U.S. June 2022 wind discussion: During June 2022 an upper-level semi-permanent high-pressure ridge was centered over the Missouri Valley. The high-pressure ridge inspired anomalous heat and dryness for the Great Plains into the Southeast U.S. and also an emerging East-central U.S. drought concern added to the vast drought already in-place for the West U.S., western Great Plains and Texas. Although smaller in aerial coverage but just as intense an upper trough resided over Western Ontario for the first month of meteorological summer. The pressure systems described were causal to the dominant anomalous zonal wind pattern across the U.S. in June. An area of stronger-than-normal west wind stretched across the northern Great Plains to the Great Lakes region with strongest intensity in northeast Minnesota (Fig. 3). The only other area experiencing stronger-than-normal zonal wind was along the upper Texas Coast where easterlies around the high-pressure to the north were intact. Elsewhere, zonal wind was below normal speeds. The Southwest U.S. into California observed lighter zonal wind compared to normal. Most of the Mid-south States to the Interior Southeast U.S. also observed below normal zonal wind speeds primarily due to the presence of high-pressure. Meridional wind anomalies were mixed in June 2022. Stronger-than-normal wind speeds were observed across the Northwest States but with both south (ahead of cold fronts) and north (after fronts passed) catalysts (Fig. 4). For a similar reason, north and south component wind speeds were stronger than normal due to vigorous cold fronts moving across the Upper Midwest States. Once again, due to presence of high-pressure, Southern U.S. meridional wind speed anomalies were near to lighter than normal. Fig. 4: June 2022 observed meridional wind anomalies for the U.S. Please note: Verification of Climate Impact Company forecasts begin with the August report. Fig. 5: May 2022 observed 850 MB (relative humidity) anomalies for the U.S. May 2022 solar discussion: During the warm season (MAY-SEP) interest is primarily with low clouds (5,000 feet) and high clouds (30,000 feet). The mandatory levels of the atmosphere to evaluate relative humidity at these altitudes is 850 and 300 MB. At 850 MB, all low clouds (except stratus) are accounted for by RH at this level. Stratus is more common during the cold season when actual precipitation is added to the solar analysis. At 300 MB the cirrus cloud type is evaluated. Of course, low clouds at 850 MB parallel where precipitation was most buoyant in May…the Northwest States (Fig. 5). Where high-pressure was more dominant atmospheric subsidence ruled and below normal low clouds were observed across the Southwest U.S. and New England during May. The storm track was energetic along the U.S./Canada border in May. Consequently, above normal high clouds were present lowering sunlight potential (Fig. 6). However, high-pressure dominated the Southern States where high clouds were absent leading to above normal sunlight strength. Overall, sunlight intensity was above normal across the southern 2/3 of California to the southern Continental Divide and across Texas to Louisiana during May 2022. Fig. 6: May 2022 observed 300 MB (relative humidity) anomalies for the U.S. Fig. 7: June 2022 observed 850 MB (relative humidity) anomalies for the U.S. June 2022 solar discussion: During early meteorological summer, high-pressure caused widespread low relative humidity at the 850 MB level for the Central and East U.S. (Fig. 7). Precipitation was well below normal and sunlight intensity much above normal in this region. Cloudiness on occasion caused by the early wet monsoon brought showers/thundershowers to the Southwest U.S. causing June sunlight intensity to register below normal for this sector (important to Clearway Energy). The Southwest U.S. monsoon is convective in character and also leads to above normal high cloudiness mostly centered on New Mexico to Nebraska during June (Fig. 8). Conversely, an upper-level ridge pattern in the East yielded limited cirrus and therefore above normal sunlight intensity. Overall, sunlight intensity during June was above normal for most of the eastern half of the nation but below normal in the Southwest States. Fig. 8: June 2022 observed 300 MB (relative humidity) anomalies for the U.S. Please note: Verification of Climate Impact Company forecasts begin with the August report.
07/06/2022, 6:10 am EDT

Flooding/Excessive Heat Continue Across U.S. Crop Areas

A collision of extremes in the Midwest U.S. this morning. Extreme rainfall leads to flash flooding in Indiana and Ohio overnight. A flood watch extends from Indiana to West Virginia. Just south of the heavy rain belt, an Excessive Heat Warning is issued for the Missouri to Tennessee Valley(s).
07/06/2022, 4:54 am EDT

Taking A Look at the Europe/North America Ridge Pattern Forecast for Mid-Summer 2022

Based on ECMWF, Europe has a drought problem for upcoming summer. Dry-to-drought soil conditions are already developing. ECMWF shifts an amplified upper ridge over Western Europe into mid-July eastward to Central/East Europe for late July into August. In the U.S., the upper ridge is suppressed by an emerging eastern North America upper trough the next 2 weeks. However, the Central/Midwest U.S. ridge re-emerges in August.