Extratropical
Highlights – January 2022
1.
Northern Hemisphere
The 500-hPa circulation during January favored a positive
PNA- and positive NAO- like pattern with above-average heights over the North
Pacific Ocean, western U.S., and North Atlantic Ocean, and below-average
heights over northeastern Canada, Scandinavia, and western
Europe (Fig. E9). The main land-surface temperature signals
during January included above-average temperatures across most of Eurasia and
parts of western North America, and below-average temperatures in eastern
Canada (Fig. E1). The main precipitation signals were
below-average rainfall for western Europe, the U.S.
Southwest and West Coast states, and above-average rainfall totals in southern
Asia and eastern Siberia (Fig. E3).
a. North America
The 500-hPa circulation over North America in January
featured above-average heights over the western U.S. and Alaska and
below-average heights over eastern Canada and Mid-Atlantic U.S. states (Fig. E9). This anomalous height pattern reflected a
weakly positive PNA pattern (Fig. E7) and typical wintertime La Nina pattern. In the average for the month, temperatures
were slightly above-average in the western portions of the U.S. and Canada and
slightly below-average for eastern Canada (Fig.
E1). The precipitation pattern favored
near-normal conditions for most of the areas and below-normal rainfall for the
Southeast and West Coast states (Fig. E3).
According to the U.S. Drought Monitor, drought conditions improved for
parts of Northern California, Mid-Atlantic states, and
the Northern Rocky Mountains and degraded for the northern, central, and
southern Plains.
b. Europe and Asia
The 500-hPa height pattern featured a dipole pattern for
Europe with above-average heights in the west and below-average heights in the
east and large positive height anomalies in eastern Siberia (Fig. E9). While this pattern led to dry conditions for
much of Europe, the main feature is widespread above-average temperatures
across Eurasia (Fig. E1).
Temperatures widely reached the 70th percentile with many areas
experiencing temperatures in the 90th percentile (Fig. E1). Above-average precipitation was recorded in
localized areas near India and Eastern Siberia (Fig. E3).
2.
Southern Hemisphere
The 500-hPa height pattern during January featured
above-average heights south of Australia, west of Chile, and south of South
Africa and below-average height anomalies over the Ross Sea and southern
Atlantic Ocean (Fig. E15).
Moderately above-average temperatures were observed for Australia and
central South America (Fig. E1). Rainfall
totals exceeding the 70th and 90th percentiles were
observed in southern regions of Africa and central Australia and below-average
rainfall totals were observed in central and northern South America, with some
areas seeing rainfall in the 10th percentile of occurrences (Fig. E3). The South African monsoon season runs from
October to April. This area has recorded modestly above-average precipitation
during January with totals reaching the 60th percentile of occurrences (Fig. E4).
www.nws.noaa.gov
