Today Marks Fifth Anniversary of Greenwich Tornado

A Heat Advisory is in effect from 12 noon through 9 o'clock this evening for heat index values of 100 degrees or better. The hot and humid weather will continue for one more day before much less humid air arrives by tomorrow. This time of the year is ripe for severe weather. In fact, one of the most unforgettable storms occurred late in the day on Wednesday, July 12, through early Thursday, July 13, 2006.

A "tornadic-like" thunderstorm roared through the region late in the afternoon, delivering strong winds, heavy rains, and violent lightning. Meteorologists from the National Weather service confirmed that a tornado touched down in Greenwich. The photos below show the damage produced by the storm in "The Gateway to New England."

The most severe damage in southwestern Connecticut occurred on John Street in Old Greenwich. That's where residents said they saw a tornado touch down. Trees and utility poles were toppled, blocking access to John Street and several other roads, including Round Hill Road.

One witness says she looked out her window and saw a funnel cloud tearing its way through Riversville Road. The fallen trees created quite a mess in the area, forcing some residents to leave their cars on the roads and walk home. Crews remained on the scene for quite some time attempting to clear out the fallen trees.

Although a thunderstorm is possible later this afternoon as a cold front approaches from the West, it shouldn't be too severe. The front will usher much less humid air into southwestern Connecticut. The rest of the week and the beginning of the weekend will be just about perfect for this time of the year. It could be a lot worse, though. Just think back five years ago today.

Paul

Heat Wave Hit Region One Year Ago Today

An Air Quality Alert has been posted from 2 p.m. to 10 p.m. today by the Connecticut Department of Environmental Protection for ozone levels which may approach or exceed unhealthy levels. The temperature may top 90 degrees inland this afternoon with increasing levels of humidity. The mercury has reached 85 degrees each of the last two days, but it won't be as hot as the scorching heat wave exactly one year ago.

The official high temperature at Sikorsky Memorial Airport in Stratford one year ago today reached 98 degrees, marking the first heat wave across southwestern Connecticut in nearly two years. The last time the mercury climbed to 90 degrees or better three consecutive days was July 18 to July 20, 2008. A month earlier, an unusual late-Spring heat wave surprised the region from June 8 to June 10, with high temperatures of 90, 97, and 96 degrees, respectively.

Some local communities topped 100 degrees a year ago today. Viewer Robert Marshall of Stamford wrote, "Tuesday (July 6, 2010) was a rough day here on the east side of Stamford. My backyard thermometer registered a high temperature of 104 degrees at around 3:00 P.M. About an hour later we lost our power, but fortunately it was restored about two hours later. (I) drove to Darien for a truly good iced coffee."

He added, "Driving back through Noroton, I saw News 12 cameraman preparing to do a video spot on the Post Road. Driving through Stamford's east side to pick up, uh, some other adult beverages, I saw Frank Recchia on Cove Road, talking with residents about the power outage. I recorded my thermometer's reading with a photo."

A 103-degree scorcher set a record at the Stamford Museum and Nature Center, according to Pat Standaert, who works in the nature center's education department and operates the weather station. The nature center has kept weather records for 60 years. The previous record was 102 degrees, which was established June 26, 1952, and July 15, 1995. The next-hottest July 6 in Stamford was in 1999, when the mercury hit 100 degrees.

The temperature reached 95 degrees one day later, Wednesday, July 7, 2010, marking the fourth straight day of temperatures well into the 90s. After carefully reviewing my record book, I could not find a four-day stretch of 90-degree-plus weather over the previous five years! Sure, it will be a hot and moderately humid day across southwestern Connecticut, but it won't be quite as bad as one year ago today.

Stay cool.

Paul

Despite Heat, Sun Farthest From Earth on Independence Day

Independence Day was sunny and hot with an afternoon high temperature of 85 degrees at Sikorsky Memorial Airport. That's four degrees above the normal high temperature for the date. I took my two sons and their friends to Rye Playland yesterday, and we certainly felt the heat. It was a typical Summerlike day.

Believe it or not, despite the hot weather Monday, the Sun was at its farthest point from the Earth than at any time during the year. If you looked indirectly at the Sun yesterday, it might have appeared a little smaller than usual. That's because the Earth reached a point called Aphelion during its annual orbit around the Sun.

Earth at Aphelion is farthest to Sun, while it is closest to Sun at a point called Perihelion. Though our planet typically reaches Aphelion and Perihelion in July and January respectively, the actual dates vary from year to year. Aphelion happened yesterday when the Earth was 94,511,923 miles away from the Sun. Perihelion was on January 3, when Earth was 92,955,807 miles from the Sun.

Sunlight is roughly about seven percent less intense in July than it is at our closest approach to the Sun in January. You may be left wondering why we still feel the intense Summer heat in July if we're actually farther away from our nearest star. That’s because Earth’s seasons are determined by the tilt on its axis and not by its distance from the Sun.

All planets in our solar system travel around the Sun in elliptical orbits, and that causes the four seasons and the length of daylight. Our days are actually getting shorter now that we've reached the first week of July. In fact, since June 21, the Summer Solstice, we've lost seven minutes of daylight. Sunrise was at 5:25 this morning, as opoosed to 5:19 on the first day of Summer.

Another sunny and quite warm day is in store as the mercury climbs into the mid and upper 80s this afternoon. Tomorrow will be mostly sunny, hot, and more humid with a high of 85 to 90. A front will arrive Thursday bringing scattered showers and thunderstorms, and they will linger into Friday with highs in the low-to-mid 80s. The weekend, though, should be mostly sunny and warm.

Paul

Wet & Warm June Draws to a Close

Wet and warm. That's the best way to describe our June weather. The official statistics were tabulated just after midnight, and last month was a soaker, to be sure. Over a half-foot of rain (6.54") fell across southwestern Connecticut, which was more than double the norm, and the average temperature was one-and-a-half degrees above normal.

June was punctuated by two pronounced wet streaks. The first featured a stretch of seven wet days out of nine from June 9 through June 17. Three of the days --- June 17 (0.89"), June 11 (0.85"), and June 9 (0.66") --- delivered more than a half-inch of rain. Just about three inches of rain (2.99") drenched the rain gauge from June 22 through June 24, with the June 23 deluge (2.41") resulting in serious flooding problems on Naugatuck Avenue in Milford.

Last month's average temperature was 69.5 degrees, which was warmer than the 68-degree normal average for June. The hottest stretch happened from June 7 through June 10 when the daytime highs reached 86, 89, 87, and 83 degrees, respectively. Only nine of the 30 days (30%) were cooler-than-normal, including a three-day streak from June 23 through June 25.

The warmest temperature recorded last month at Sikorsky Memorial Airport in Stratford was 89 degrees on June 8, while the coolest temperature (53 degrees) happened on the mornings of June 3 and June 5. Fourteen days featured daytime high temperatures in the 80s, while there were only five days when the high temperature stayed in the 60s.

July will begin under mostly sunny skies, warm temperatures, and fairly low humidity. A weak system will pass just to our East this afternoon, and then warmer and more humid weather is expected tomorrow and Sunday. A cold front will likely tigger thunderstorms Sunday, but Independence Day will be partly-to-mostly sunny, warm, and slightly less humid with a high near 85.

Have a happy and safe holiday weekend.

Paul

Looking Ahead to July

Half the year is nearly over. July arrives at midnight, and it’s time to look ahead at what the month brings climatologically to southwestern Connecticut. Not surprisingly, July is the warmest month of the year with a mean temperature of 74 degrees. The hottest temperature ever recorded at Sikorsky Memorial Airport in Stratford was 103 degrees on July 22, 1957.

The mercury reached the century mark two other times — July 2, 1966 and July 5, 1999. In fact, the average daily temperature climbs from 72 degrees at the start of the month to 75 by July 31. The warmest July on record happened 17 years ago, in 1994, with an average temperature of 78.4 degrees.

Last July was one of the hottest on record. You may recall the heat wave over the Independence Day holiday weekend. The high temperatures from July 4 through July 7 were 97, 93, 98, and 95 degrees, respectively. In fact, record high temperatures were established July 6 and 7. The mercury also reached 95 degrees July 24. The average temperature for the month was 78 degrees, just shy of the all-time record.

Many people have asked me why the hottest time of the year happens over a month after the first day of Summer. Well, it takes the Earth awhile to absorb the heat. As the Sun’s angle gets higher in the sky and the days grow longer in May and June, the Northern Hemisphere slowly starts to warm.

It’s much like warming your home. When you turn your thermostat up to 72 degrees after being away all day in the Winter, it will take awhile for the house to warm up. It doesn’t happen instantly. That’s why our hottest days are typically in July and early August.

On the flip side, the coolest temperature ever recorded in these parts in July was 49 degrees on July 1, 1988. Aside from that, every record low for the month is in the 50s. Believe it or not, according to the National Weather Service record book, a trace of snow fell at the airport on July 4, 1950. I find that too hard to believe.

As far as precipitation is concerned, the wettest July on record happened in 1971 when over a foot of rain (12.84″) fell. The average monthly rainfall is 3.77 inches. There have been several memorable rainstorms in July. For example, nearly a half-foot (5.95″) of rain fell on July 19, 1971, and nearly four inches (3.93″) was recorded on July 29, 1990. Two other days delivered well over three inches of rain — July 30, 1960 (3.57″) and July 23, 1953 (3.45″).

The length of daylight decreases next month. For example, on July 1, the Sun rises at 5:23 and sets at 8:30. By the middle of the month, on July 15, the Sun rises at 5:32 and sets at 8:24. However, at the end of the month, it rises at 5:47 and sets at 8:10, meaning we lose 44 minutes of daylight. Remember, the “longest” day of the year happened at the Summer Solstice in late June.

Our weather will begin to heat up over the holiday weekend with daytime highs in the 80s to close to 90 degrees inland by Sunday afternoon. A threat of a few scattered showers or a thunderstorm will be with us Sunday, but most of the three-day weekend should be fine.

Paul

The "Dog Days" of Summer Officially Start This Sunday

Summer officially began one week ago today, but our weather has been anything but hot and humid recently. The mercury has not reached 90 degrees at all this month, although there were four straight days with daytime highs well into the 80s from June 7 through 10, including an 89-degree reading June 8.

In case you're wondering, the "dog days" of Summer officially begin this Sunday, July 3, and run through August 11 in the Northern Hemisphere. It all has to do with the star Sirius, known as "the dog star." Sirius is the brightest star in the Northern Hemisphere other than the Sun, and it is found in the constellation Canis Major, thus the name "dog star."

In the Summer, Sirius rises and sets with the Sun. During late July, Sirius is in "conjunction" with the Sun. The ancients believed that its heat added to the heat of the Sun, creating a stretch of hot and sultry weather. They named this period of time, from 20 days before the conjunction to 20 days after, the "dog days," in honor of the dog star.

In ancient times, when the night sky was unobscured by artificial lights and smog, different groups of peoples in different parts of the world drew images in the sky by "connecting the dots" of stars. The images drawn were dependent upon the culture.

The Chinese saw different images than the Native Americans, who saw different pictures than the Europeans. These star pictures are now called constellations, and the constellations that are now mapped out in the sky come from our European ancestors.

They saw images of bears (Ursa Major and Ursa Minor), twins (Gemini), a bull (Taurus), and others, including dogs (Canis Major and Canis Minor). The brightest of the stars in Canis Major (the big dog) is Sirius. The star can be seen prominently in the Winter in the Northern Hemisphere, adjacent to Orion the Hunter.

The conjunction of Sirius with the Sun varies somewhat with latitude. Also, the constellations today are not in exactly the same place in the sky as they were in ancient Rome. The Summer heat is not due to the added radiation from a far-away star, regardless of its brightness. The hot weather is a direct result of the earth's 23.5 degree tilt on its axis, meaning the Northern Hemisphere is tilted toward the Sun during the Summer.

Some showers and a possible thunderstorm are possible later this evening and tonight before much better weather arrives tomorrow through the end of the week. We can expected plenty of sunshine, low humidity, and warm temperatures the next three days. The holiday weekend should be fair, too, with a slight chance of scattered thunderstorms Saturday and Sunday.

Paul