Subsidence/Low Relative Humidity Squash North Atlantic Tropics July to Mid-August
08/19/2022, 10:40 am EDTThe China Drought Catalyst
08/22/2022, 4:50 am EDTHighlights: New U.S. drought concern for autumn is the Mid-south States, beneficial autumn rains for Europe while China drought persists.
Fig. 1-3: Daily soil moisture anomaly analysis for North America, Europe/Western Russia and Asia.
U.S., Europe/Russia and Asia discussion: An update on global soil moisture conditions, recent trend and outlook is provided. We begin with the U.S. which is currently experiencing drought in California, much of the Great Plains and Northeast Corridor (Fig. 1). The seasonal trend has been wetter across the Southwest U.S. and drier in the Central and Northeast States and most recently in the Northwest U.S. Short-term outlooks indicate major changes. The remainder of August is super-wet across Texas and the southern Great Plains and to a lesser extent, the remainder of the South and East U.S. while dryness is increasing in the North-central/western Midwest States. The SEP/OCT/NOV 2022 outlook indicates high impact dryness for the Mid-south U.S. including Texas where heavy rains occur in late August. The dryness reaches northward into the Midwest States.
Historic drought has blasted Europe during summer 2022 (Fig. 2). Across Greenland/Iceland a super intense upper trough formed in May and has persistent since that time. To compensate for this upper trough, an amplified ridge developed over Europe to produce rapidly developing drought with attendant hot weather. However, similar to the Southern U.S., short-term weather changes are occurring including flooding rains in France and that rainfall is forecast to shift to Southeast Europe this week. There may be more rainfall in France to Poland in the 6-10-day period. There is some minor benefit to the Rhine River levels by this rainfall. The seasonal soil moisture trend has been much drier across all but Northern Europe and the dry trend has also included the western Black Sea region. The SEP/OCT/NOV 2022 outlook is beneficial rainfall for Europe while Western Russia to the Black Sea region is dry.
China has shifted into a hostile drought pattern at amazing speed since early summer (Fig. 3). The culprit? High-pressure ridging associated with dramatic warm SSTA off the East Asia Coast. Operational models are mostly dry the next 10 days but some beneficial rainfall is possible according to all models in the 11-15-day period. The SEP/OCT/NOV 2022 outlook favors a mostly drier than normal climate and worsening drought.
Fig. 4-6: Daily soil moisture anomaly analysis for South America, Australia and Africa.
South America, Australia and Africa discussion: Soil moisture deficits are widespread across north/east Argentina and central to east-central Brazil while the long-term Chilean drought rages on (Fig. 4). The seasonal trend is drier in all of these zones especially the past 30-45 days. The wet exceptions are Southeast Brazil and north/northeast coast of South America. The outlook into early September across drought areas is mostly dry. The SEP/OCT/NOV 2022 outlook stresses dryness in Brazil while the Argentina regime is less certain.
In Australia, sneaky dryness has developed over parts of the northwest and southwest/south continent (Fig. 5). Other zones, particularly in the East are soaking wet. The 15-day precipitation outlooks are wetter than normal across East Australia. Most of the western half of Australia is dry. The SEP/OCT/NOV 2022 precipitation outlooks are confidently wet across East Australia while western sections could be drier than normal to promote drought.
Africa is observing hostile dry conditions in northwest continent, parts of tropical Africa and also the southwest coast (Fig. 6). Into early September, tropical Africa looks very wet while the southern third of the continent is arid. During SEP/OCT/NOV 2022, dryness is forecast to expand across Southern Africa.