Carry an AM Radio to Detect Lightning from Approaching Storms

Another round of potentially strong thunderstorms is possible this afternoon as an approaching cold front plows into a very warm and humid air mass over southwestern Connecticut. In fact, daybreak temperatures were in the upper 70s, and the dew point was close to 70 degrees making it downright tropical outside.

If you're going to be outside later this afternoon and especially this evening, you'll need to keep an eye to the Western sky. Lightning can be a killer. However, if you don't have access to the latest radar, one of the easiest ways to detect nearby lightning is with an AM radio. Ever since I was a child, I have been fascinated by the sound of static on AM radio during thunderstorms.

Each stroke of lightning sends out an electromagnetic radio wave that creates a "static crash" on your AM radio receiver. When you hear these static crashes on the radio, you are actually listening to the lightning in real time. In addition, when you hear thunder outside, you are listening to the time-delayed sound of the lightning.

When I was a child, I was glued to the AM radio. It was the only source of popular music, live sporting events, and local newscasts "back in the day." We didn't have any of the modern technology of today. I quickly learned that I could hear many powerful stations East of the Mississippi River late at night. That's when I'd listen to baseball games from Cleveland, Atlanta, and Pittsburgh.

What struck me as bizarre was that I could hear static from lightning in other parts of the country even though the weather was clear where I lived. That's because lightning is propagated as radio waves by the Earth's ionosphere. So, when I heard static on KDKA in Pittsburgh, I instantly knew why the Pirates' game was being delayed by rain and thunderstorms.

When thunderstorms arrive later this afternoon, why not give it a try. You can hear the sounds of lightning best on the lower frequencies of the AM radio band. Try to find a clear spot on the dial where you can't hear any signals from any radio stations. They will interfere with your listening for static on the radio.

Then, listen for the sounds of static. Radio scientists and engineers call these sounds "static crashes." They are actually the sounds of the lightning. Watch for lightning outside. You will notice that you hear lightning on your AM radio at the exact same time you see the lightning flashes. This is because radio waves and light both travel at the speed of light, which is about 186,000 miles per second.

Fortunately, we won't hear any static on the AM radio this weekend, at least locally. It will be mostly sunny, hot, and moderately humid tomorrow and Sunday with daytime highs in the upper 80s to close to 90 degrees and nighttime lows near 70. Believe it or not, I'll still have my AM radio with me when I take my daily walks. Some habits are hard to break.

Have a good weekend.

Paul

Viewer's Photos Tell the Weather Story

A powerful cold front, as expected, pushed through southwestern Connecticut late yesterday bringing two rounds of intense thunderstorms. The storms delivered locally heavy rain and gusty winds. Nearly one inch (0.80") of rain fell at Sikorsky Memorial Airport in Stratford, bringing the monthly total close to two inches (1.81").

The high temperature climbed to 89 degrees at 3:14 p.m. before the storms brought gusty Northwest winds of 25 to 30 miles an hour and a peak wind gust of 36 miles an hour. As a result, the temperature dropped nearly 20 degrees in five hours. One of our viewers, Lori, took this photo of a rainbow in the Black Rock section of Bridgeport following the first thunderstorm.

The second round of thunderstorms brought heavier rain during the late-eveing hours. Once the storm exited, skies cleared and a Northwest wind delivered much drier air. Dew points dropped into the upper 50s at daybreak this morning, and it was certainly more comfortable. Another viewer sent this photo of a beatuful sunrise behind the sparkling water fountain at Commons Park at Harbor Point in Stamford.

Today will be the best day of the week. We will enjoy mostly sunny skies, lower humidity, and a warm afternoon with daytime highs in the low-to-mid 80s. Tonight will be clear to partly cloudy and mild with a low in the 60s. Tomorrow will become partly sunny and a little more humid with a high in the mid 80s. Thunderstorms are likely tomorrow night and early Friday in advance of hotter air which will arrive by the end of the week.

Paul

A Summer Reality Check

It finally hit me last night while taking a walk around the neighborhood. The Sun was setting a little earlier and slightly closer to due West. Yes, the days are getting shorter. Last Thursday marked one month since the Summer Solstice, and you've probably already begun to notice the subtle changes across southwestern Connecticut.

Here's another point to ponder. This Thursday marks the midway point of Summer vacation for schoolchildren across southwestern Connecticut. How is that possible? It seems like only yesterday we were helping them celebrate the last day of school. That was five weeks ago Thursday. In just a little more than five short weeks, the students and teachers will be heading back to the classroom once again.

The days are indeed getting "shorter." In fact, we have lost over a half-hour (35 minutes) of daylight since the first day of Summer. Sunrise on June 21st happened at 5:19. This morning's Sunrise was at 5:41, 22 minutes later. Sunset is now at 8:17, 13 minutes before the latest Sunset, at 8:30, on the Solstice.

By the end of the month, Sunrise occurs at 5:47, while the Sun sets at 8:10. Two weeks later, by mid-August, the shorter days become even more pronounced, with Sunrise and Sunset times at 6:02 and 7:51, respectively. The "shorter" days have to do with the Earth's revolution around the Sun, and the 23.5 degree tilt on its axis. By the end of September, the Autumnal Equinox begins a six-month period of longer nights and shorter days in the Northern Hemisphere.

Need further proof that we're moving through Summer rather quickly? NFL owners and players agreed early today to the terms of a deal to end the lockout. If players sign off on the agreement, NFL clubs would be able to start signing 2011 draft picks and rookie free agents tomorrow, and training camps would open for 10 of the 32 teams this Wednesday.

Today's weather will be quite different from last week's heat wave. Some showers and a possible thunderstorm are likely today as an East wind keeps the temperature in the 70s. More showers and a thunderstorm are possible tonight with lows of 62 to 68. Tomorrow will be partly sunny and warmer with a high near 85 degrees. The heat and humidity will build before the end of the week. Remember, it's still Summer!

Paul

Excessive Heat Warning in Effect for Entire Region

An Excessive Heat Warning and an Air Quality Alert are in effect through this evening. Today will be the hottest day of the year with high temperatures expected to climb between 94 and 100 degrees this afternoon. The heat index, or the measure of what it actually feels like, may reach or exceed 105 degrees. Use extreme caution if you have to be outside.

Heat is the number one weather-related killer in the United States, resulting in hundreds of fatalities each year. In fact, on average, excessive heat claims more lives each year than floods, lightning, tornadoes and hurricanes combined. Heat disorders generally have to do with a reduction or collapse of the body's ability to shed heat by circulatory changes and sweating or a chemical imbalance caused by too much sweating.

When the body heats too quickly to cool itself safely, or when someone loses too much fluid or salt through dehydration or sweating, his or her body temperature rises and heat-related illness may develop. Studies indicate that the severity of heat disorders tends to increase with age. Conditions that cause heat cramps in a 17-year-old may result in heat exhaustion in someone 40 and heat stroke in a person over 60.

More than 1,250 people died in a disastrous heat wave in 1980. In the heat wave of 1995, more than 700 deaths in the Chicago area were attributed to heat. Between 1999 and 2003, heat-related deaths increased by 54 percent across the United States. During this time, 3,442 deaths resulting in exposure to extreme heat were reported for an average of about 688 deaths a year.

There are several risk factors to take into account. People who have access to three hours of air conditioning a day are less likely to die. Poor health, obesity, diabetes, and cardiovascular disease are all factors for heat-related deaths. Older people need to be careful since changes in physiology affect how a person responds to heat as he or she ages, and older people don't sweat as much as younger people.

Take it easy today and tomorrow. Children, seniors, and anyone with health problems should stay in the coolest available place. Certainly dress for Summer by wearing lightweight, light-colored clothing to reflect heat and sunlight. Drink plenty of water or other non-alcohol or decaffeinated fluids. Your body needs water to keep cool.

Some relief is expected by the latter half of the weekend when daytime temperatures reach the mid 80s, and Monday will feature a high temperature close to 80 degrees, which is more in line with this time of the year. However, look for the mercury to climb back to the upper 80s by the middle of next week. It's still July!

Paul

Summer's First Trimester Report Card

Summer officially began one month ago today. Now, the first heat wave of the season is upon southwestern Connecticut as temperatures soar into the lower 90s and the heat index approaches 100 degrees this afternoon. The hot and humid weather is expected to last through Saturday before some relief arrives by the end of the weekend.

Today's weather video and photos come from Ralph Fato in Norwalk. He wrote, "Many times this year the Sun is failing to burn through the layers. I took some pictures and video this morning with my Kodak Z990." You can almost feel the heat and humidity looking at these. The video can also be found on my Facebook page at facebook.com/piorek12.

So, how have we fared weatherwise since the Summer Solstice 30 days ago? The start of Summer was slightly cooler-than-normal with four of the first five days of the season featuring below normal average temperatures. In fact, the daytime high June 24 was 67 degrees, and the the mercury didn't reach 80 degrees the first five days of Summer.

This month has been a different story, however. Daytime highs reached 91 and 95 degrees, respectively, June 11 and 12, marking the only time we've hit the 90s this year. All but four days this month have been warmer-than-normal, and that trend will certainly continue over the next three days, boosting the 77.4-degree average temperature this month.

The last 30 days have been especially dry. In fact, only seven of the days brought more than one-hundredth of an inch of rain to the region. There was no measured rain over an eight-day stretch from June 30 through July 7, and there have been just two days in the last 12 with more than one-hundredth of an inch of rain.

July and August are traditionally the hottest months of the season with average daily temperatures of 74 and 73.1 degrees, respectively. We experienced a heat wave at the end of August last year. Both months average about three-and-a-quarter inches of rain, but we're nowhere near that this month. Let's see how the final two months of Summer play out.

Paul

First Official Heat Wave of Summer is Forecast for Region

The first official heat wave of the season will affect southwestern Connecticut tomorrow through Saturday as temperatures climb well into the 90s. Technically, a heat wave happens when the temperature reaches 90 degrees or more for three consecutive days. However, as dew points climb into the 70s by tomorrow afternoon, the heat and oppressive humidity will make it feel like 100 degrees or hotter each of the next three days.

An Excessive Heat Watch has been issued for Northern Fairfield and New Haven counties from Thursday afternoon through Friday evening. You'll need to take extra precautions if you're going to be outside for any length of time. You may want to reschedule certain activities to the early-morning or evening hours. Know the signs of heat exhaustion and heat stroke, and wear lightweight and loose-fitting clothing when possible. Drink plenty of water, too.

The mercury has topped the 90-degree mark only twice this Summer at Sikorsky Memorial Airport in Stratford, the official recording station for the National Weather Service. Daytime highs of 91 and 95 degrees were recorded July 11 and July 12, respectively. The temperature reached 88 degrees July 13, just two degrees shy of an official heat wave.

The last heat wave to hit southwestern Connecticut happened over a four-day stretch from late August through early September last year. The high temperatures for August 29 through September 1, 2010, were 91, 91, 94, and 93 degrees, respectively. The mercury topped 90 degrees four times last August, helping to push the average daily temperature for the month to 75.1 degrees, two degrees above normal.

Thus far this month, the average temperature is 76.4 degrees, which is 3.1 degrees warmer than normal. That's just two degrees shy of the hottest July on record (78.4 degrees), which happened in 1994. All but four days this month have delivered warmer-than-normal temperatures. The average daytime high temperature is 85.1 degrees, and the average nighttime low temperature is 67.7 degrees. The coolest temperature was 59 degrees on July 1.

In case you're wondering, the average temperature last July was 78 degrees, less than a degree shy of the monthly record. July of 2010 featured an unforgettable Independence Day weekend heat wave which featured high temperatures of 97, 93, 98, and 95 degrees from July 4 through July 7, respectively. In fact, there were seven days with high temperatures in the 90s.

Today will be mostly sunny with some puffy clouds and a high temperature in the mid 80s. Tonight will be mild and muggy with patchy fog developing and a low of 66 to 71 degrees. The heat wave begins tomorrow and will continue through the start of the weekend. Daytime highs will be in the 90s and nighttime lows will hold in the lower 70s. Stay cool.

Paul