RSS Feed
June - A Month of Extremes

By Joe D'Aleo
Monday, July 6, 2009


Last week we wrote about the ring of fire ridge in the south central with heat ringed by thunderstorms west and north and east. The ridge was backing up some towards the intermountain by months end and temperature were cooling in all but the south central.

Around the south central warm ridge, colder than normal temperatures were found in the west, north and east much of the month and ended up well below the normal.

 

The first half of the month was extremely cold and even snowy in south Central Canada and the northern United States. In snowed in North Dakota in early June. It was also unusually cold in southwest – well below the normal in places like Palm Springs, CA (10-20F below normal early in the month). In general, the desert southwest was unusually mild. Phoenix had 15 straight days with highs below 100F, the first time since 1913.

 

The month, especially the second half was very hot in the southern plains and the heat expanded north and east a bit later after mid-month before being suppressed again by months end.

 

In the northeast, the month was unusually cold and wet. In Boston it was 4.7F below normal in a tie for 6th coldest June (with 1982) in 138 years of record keeping, all the other years were 1916 or earlier. It was just short of two standard deviations colder then normal. Here are the top coldest Boston Junes.

Year

June Mean

1903

59.8

1881

61.7

1897

62.2

1916

62.7

1886

63.2

2009/1982

63.3

The NWS spot checked the average maximum temp at Boston for the month and it appears this is the second coldest average high temp since 1872. 1903 is the record. A trace or more of rain fell on 22 days of the month. Measurable (0.01 inches or more) occurred on 16 days just short of the record of 18 set in 1942.

At Blue Hill Observatory in Milton, MA, just southwest of Boston, the month of June had just between 26 and 27% of the possible bright sunshine. Normal for June is 55% and the gloomiest June in 1903 had just 25% of the possible sunshine. Second place had been June, 1998, with 36%. So, this month has taken over 2nd place, not an enviable distinction for vacationers.

New York City Central Park was also cool, cloudy and wet. The month averaged 3.7F below normal and ranked as the 8th coldest since 1869. It rained in 23 days of the month and ended up as the second wettest June ever falling short of 1927.

COLDEST                    WETTEST

June Average

Year

Rainfall

Year

64.2

1903

10.27

2003

65.2

1881

10.05

2009

65.7

1916

9.78

1903

66.8

1926/1902

9.3

1972

67.2

1958

8.79

1989

67.3

1927

8.55

2006

67.4

1928

7.76

1887

67.5

2009/1897

7.58

1975

67.7

1878

7.13

1938


The pattern related to the arctic oscillation which was strongly negative this month.

A negative AO correlates with a cool southwest and north central and northeast but a warm south

It also related to the high latitude volcanoes - Mt Redoubt in the spring and Russia’s Sarychev Peak this June. Also important is the developing weak El Nino seen in the eastern tropical Pacific heat content below. It too favors cool across the north.

The solar minimum also is often cool in the southwestern states and activity though it increased in terms of sunspots, the solar irradiance and flux and geomagnetic activity remained very low. Given the diminishing solar activity and the cooling Pacific (PDO) and Atlantic (AMO), we should see declining temperatures for the next few decades much as we did the last time that happened from the late 1940s to late 1970s.

 

Advertisements