Highlights –August 2022
1. Northern Hemisphere
The 500-hPa circulation during
August featured above-average heights for most of the hemisphere with the
largest above-average height anomalies centered over Eurasia and the Bering
Sea, and moderate below-average heights anomalies over central Russia (Fig. E9). The
main land-surface temperature signals included above-average temperatures in
Europe, China, and across much of North America (Fig. E1). The main precipitation signals
included above-average totals across eastern Asia and the southern states across
the United States, and below-average totals in north-central Europe (Fig. E3).
a. North America
Other than a slight tilt toward
below-average height anomalies for the western half of Alaska, much of North
America had near-normal to moderately above-average height anomalies for the
month of August (Fig. E9). The above-average height anomalies were
centered over the Pacific Northwest and surrounding regions in the U.S., as
well as New England and the Newfoundland area (Fig. E9).
This pattern contributed to the moderate and strong above-average
temperature anomalies recorded for much of the U.S. and Canada. Most regions recorded temperatures in the
70th and 90th percentile (Fig. E1).
The main precipitation signals were
a slight tilt toward below-average rainfall for the Pacific Northwest and the
Central Plains, and moderate to strongly above-average rainfall for the
southern U.S. states where some areas recorded rainfall in the 90th percentile
or greater (Figs. E3,
Alaska Panhandle also recorded above-average rainfall (Fig. E3).
b. Europe and Asia
The 500-hPa height pattern featured
strongly above-average heights across northern Eurasia and strongly
below-average heights across most of Russia (Fig. E9). This pattern contributed to
large above-average surface temperature anomalies across Europe, western
Russia, and Asia, with the largest departures ( >
5.0C) observed north of the Black and Caspian Seas (Fig. E1).
A tilt toward slightly below-average temperatures were recorded for
central Russia (Fig. E1). The main
precipitation signals included above-average rainfall for central Russia and
eastern Asia with vast areas exceeding the 70th and 90th percentile (Fig. E3). Drier than average conditions were recorded
for eastern Europe and western Russia (Fig. E3).
c. West African
African monsoon extends from June through September, with a peak during
July-September. During August 2022, the west African
monsoon system was enhanced (Fig. E3) with area-average rainfall totals reaching near
the 100th percentile of occurrences (see Sahel region, Fig. E4).
2. Southern Hemisphere
The 500-hPa height field during
August broadly featured above-average height anomalies with the strongest
departures located in the South Pacific Ocean, and strongly below-average
heights located over the Bellingshausen Sea (Fig. E15). For much of Australia and
southern Africa, the temperature and precipitation signals for the month of
August were largely near-normal, with drier than average conditions recorded
across Patagonia (Fig. E3).
The Antarctic ozone hole typically
develops during August and reaches peak size in September. The ozone hole then
gradually decreases during October and November, and dissipates on average in
early December (Fig. S8). By the end of August 2022, the size of the
ozone hole approached approximately 17 million square kilometers, which is near
the 2012-2021 average size of the ozone hole. Associated with the ozone hole
during August was a strongly above-average polar vortex area and slightly
above-average polar stratospheric cloud coverage (Fig. S8).