Cool analysis, as June rain record nears

With yesterday's showers finding a target in the rain gauge at Philadelphia International Airport, the June rainfall total stands at 8.75 inches officially.

The 142-year record is 10.02, set back in 138, and that mark might be in trouble. Showers are in the forecast every day for the final five days of the month.

For today, the government's mayhem center in Oklahoma has the region under the "slight risk" category for severe weather -- that is, for storms with wind gusts of 58 m.p.h. or better, and-or hail. Heavy rain is possible later in the week.

What will this mean for the rest of the summer?

Having the soil and foliage so wet may bode well for those rooting against strong heat waves. The more energy the sun has to spend on evaporating water, the less it has for heating.

Another arugment against blistering heat is the persistence of the pattern. So far, the hot stuff has been confined to the West, and this current mild heat spell is a walk in the shade compared with some of the bake-a-thons of recent summers.

This morning, WSI Corp., a Massachusetts commercial service, updated its summer outlook and is calling for temperatures to average only slightly above normal in July and August. Again, that would be quite a contrast to recent years.

Three of the last four summers were among the hottest on record in Philadelphia, but none of those Junes matched this one for rainfall.

This so far is the second-wettest on record, and 2003 and 2006 finiished in the top five. We note that in 2003 the heat flared in late July and lapped into August.

It wasn't comparable to the devastating heat wave in Europe that summer, but it was plenty hot.

In 2006, it turned hot at the end of June, and heat persisted into July.

Tony Gigi at the National Weather Service in Mount Holly looked at the other wettest Junes and found that basically wet tends to beget wet and that the odds would favor near-normal temperatures the rest of the way.

Overall, July temperatures after the 10 wettest Junes average slightly below normal, and August, right around normal. Meanwhlle, precipitation stayed above normal.

Here is is his analysis:

Year   July Temp  July Precip  Aug. Temp   Aug. Precip

1887    80.7           7.14            74.0             2.31

1906    75.6           5.33            76.2             9.56

1928    77.3           3.60            77.2             5.47

1938    77.3           6.52            78.3             4.10

1962    72.0           2.30            72.0             6.58

1969    75.1           8.33            75.2             2.66

1973    77.9           2.39            78.7             2.03

1975    76.6           6.32            77.0             2.11

2003    78.7           2.01            78.2             3.26

2006    79.4           4.27            78.1             3.93


AVG    77.1           4.82            76.5             4.20

Norm   78.1           4.35            76.6             3.50