As you requested, we have investigated the weather conditions in the vicinity of 500 Main Street, Trenton, New Jersey on June 14, 2011, with particular attention to the amount of rain that fell, especially between 6:00 PM and 9:00 PM on that date. The results of our investigation are presented in the following paragraphs.
Our research shows that the weather in the Trenton area was quite warm and relatively dry during the first 13 days of June 2011. During that period, most places in the Trenton area received less than 0.50 inches of rain. Between the 1st and the 13th, daytime highs ranged from the middle eighties to the upper nineties and early morning lows were in the sixties and seventies.
During the pre-sunrise hours of June 14, 2011, the sky was mostly clear, the temperature was in the seventies, and the wind was light and variable. As the morning progressed, the sky became partly to mostly cloudy and the temperature rose into the eighties. From the time of sunrise through 12:00 Noon, the wind blew mainly from the south and southeast at an average speed of 5 to 10 MPH. At 12:00 Noon, the temperature was between 85 and 88 degrees.
During the first two hours of the afternoon on June 14, 2011, the sky was partly to mostly cloudy and the wind blew mainly from the south and southeast at an average speed of 6 to 12 MPH. The early afternoon high temperature was within a couple of degrees of 90. From 2:00 PM through the end of the day, the sky was cloudy. Thunderstorms moved into the Trenton area between 2:45 and 3:00 PM. During the next seven to seven and a half hours, rain fell much of the time. From 6:00 to 8:00 PM, the rainfall rate was extremely heavy. Most of the Trenton area received between 4.35 and 5.00 inches of rain during the afternoon and evening of June 14, 2011. However, in a few spots as much as 5.50 or 6.00 inches of rain fell. Not only was the total amount of rain that fell large, there was also an unusually large amount of rain that fell during a relatively short period of time. At the site in question, at least 3.50 and possibly as much as 4.00 inches of rain fell during the two-hour period from 6:00 to 8:00 PM. By 9:00 PM, the intensity of rain had decreased. Around 10:00 PM, the rain ended. During most of the time that rain was falling, the temperature was in the seventies and the wind blew from the east and the northeast at an average speed of 8 to 16 MPH. However, there were a few wind gusts as high as 30 or 35 MPH. From the time that the rain ended through 12:00 Midnight, the temperature was in the middle seventies and the wind was variable in direction with an average speed of less than 10 MPH.
Specifically, in the vicinity of 500 Main Street, Trenton, New Jersey on June 14, 2011, between 6:00 and 9:00 PM, the sky was cloudy, the temperature was between 72 and 76 degrees, and the wind was blowing mainly from the east and northeast at an average speed of 8 to 16 MPH with gusts as high as 30 or 35 MPH. Rain fell throughout the period in question and it had rained much of the time since between 2:15 and 3:00 PM. Thunderstorms dumped copious amounts of rain on the Trenton area between 5:00 and 9:00 PM. In the vicinity of 510 Main Street, at least 4.35 to 5.00 inches of rain fell during the afternoon and evening of June 14, 2011, although it is possible that the rainfall total was as high as 5.50 or 6.00 inches. The heaviest rain fell from 6:00 to 8:00 PM. During those two hours, between 3.50 and 4.00 inches of rain fell in the vicinity of 500 Main Street. A rainfall of 3.50 inches or more in two hours in Trenton is expected to occur on the average of only once in 100 years. It is certainly no surprise that the heavy rain that fell in Trenton on June 14, 2011, caused major problems. Because most drainage systems were not built to withstand that much rain during such a short period of time, many streets were flooded. There was also considerable flooding of basements and creeks. In summary, the rain event in Trenton during the afternoon and evening of June 14, 2011 was very unusual, considering both the total amount of rain that fell and the short duration rain intensity. As would be expected, the rain caused considerable flooding of streets, creeks, basements and other areas.
The information in this report has been determined from the best sources of weather information available to us at this time and is the result of interpretation by our staff of professional meteorologists and represents our opinions to a reasonable degree of scientific certainty.
Note: All time references in this report are expressed in Eastern Daylight Time (EDT).Note: Dates, times, names, and locations may have been changed to protect client confidentiality.
Additional Reports Are Available Upon Request.