Extratropical Highlights �June 2016

 

1. Northern Hemisphere

The 500-hPa circulation during June featured above-average heights over the high latitudes of the North Pacific, the western half of the United States, the high latitudes of the North Atlantic, and central Siberia (Fig. E9). At 200-hPa, the circulation across the Pacific Ocean showed no lingering El Ni�o signal (Fig. T22).

The main land-surface temperature signals during June included above-average temperatures across Alaska, western Canada, much of the continental U.S., and eastern Europe (Fig. E1). The main precipitation signals included above-average totals in central Europe, and below-average totals in the north-central U.S. (Fig. E3).

 

a. North Pacific/ North America

The 500-hPa circulation during June featured above-average heights over the high latitudes of the North Pacific and the western half of the United States (Fig. E9). Overall, surface temperatures remained well above average in Alaska and western Canada. Surface temperatures were also well above average across much of the continental U.S., with many areas recording departures above the 90^th percentile of occurrences. Precipitation was below average across the north-central U.S., which was situated immediately downstream of the anomalous ridge axis (Fig. E3).

According to the U.S. Drought Monitor, exceptional or extreme drought continued across central and southern California during June, while severe drought persisted in western Nevada and developed in northern Georgia. Moderate drought was evident in scattered areas around the U.S., including eastern Oregon, the southern half of New Mexico, western Arizona, portions of western South Dakota, eastern Iowa, northern Mississippi, northern Alabama, portions of south-central and southeastern Tennessee, and portions of New England.

 

2. Southern Hemisphere

The mean 500-hPa circulation during June featured generally above-average heights in the middle latitudes, and below-average heights across the polar region and the high latitudes of the South Pacific (Fig. E15). At 200-hPa, the circulation across the Pacific Ocean showed no lingering El Ni�o signal (Fig. T22).

The main surface temperature signals during June included above-average temperatures in northern and eastern Australia and in South Africa, and below-average temperatures in central South America (Fig. E1). The main precipitation signals included above-average totals in both western and eastern Australia, with departures in eastern Australia exceeding the upper 90^th percentile of occurrences (Fig. E3).