July 2014 featured all the typical facets one expects in a summer month including severe weather, a few hot and humid days and even the season’s first tropical cyclone. The first half of the month included most of the month’s typical summer heat and severe weather in addition to a Fourth of July visit by Hurricane Arthur. Going into the second half, the Northeast saw drier conditions and a September like cool down, with even an anomalous EF-2 tornado touch down just outside of Boston. Read on to learn more about the highlights of July 2014.
During the initial days of July, the Northeast experienced one of only a few strings of hot and humid weather for the entire month with both New York City and Boston hitting the 90 degree mark for the first time on July 2nd. This was the latest first 90 degree day for both cities since 1985. Of course, attention quickly turned to Hurricane Arthur as we neared Fourth of July. After making landfall in the Outer Banks of North Carolina on July 3rd as a Category 2 hurricane (the earliest landfall ever for the state), Hurricane Arthur traveled northward, paralleling the coast and staying less than 100 miles off shore, just in time for the national holiday. Although most of the Mid Atlantic was left unscathed with just clouds, breezy conditions and a few showers for July 4th, New England did no fair as well. The hurricane passed just 75 miles east Chatham, MA dumping 4 – 8 inches of rain across eastern Massachusetts with wind gusts to 50 – 65 mph recorded on Nantucket and Cape Cod. New Bedord, MA was especially hard hit with 6 - 8 inches of heavy rain, resulting in flash flooding as seen in the image below.
.jpg)
Considering the still cool ocean waters in early July, it is unusual for a tropical cyclone to maintain hurricane strength while off the Northeast coast this early in the season. In fact, it was the first tropical cyclone ever to impact the Northeast on July 4th and was also the first July tropical cyclone to affect the Northeast since Tropical Storm Beryl in 2006.
Luckily, the days following Arthur were beautiful, enabling many to enjoy the Fourth of July weekend. By the 7th - 9th, temperatures soared back into the upper 80s and 90s giving way to a round of severe weather. First, storms on the 7th in New England brought a funnel cloud within view of Fenway Park in Boston and damaging winds to the Hudson Valley. Then, a very strong squall line (see image below) plowed through the Mid Atlantic on July 8th. Here, high winds up to 50 – 70 mph knocked down trees and power lines for many locations, especially across Maryland where over 130,000 people were left in the dark.
On the 9th, a cold front stalled over the region causing severe storms in western Connecticut and the Hudson Valley. The front stayed stationary into the 10th and with continued southerly flow aided by the lift of the boundary, storms dumped heavy rain in parts of New Jersey. Morning storms on the 10th inundated Cape May and Atlantic County in 2 – 3 inches of rain with evening storms flooding parts of Morris County in over 2 inches of rain. The stalled boundary finally crossed the region late on the 10th leaving ideal summer weather in its wake for the 11th and 12th.
By the 3rd week of July, an anomalously strong upper level disturbance slowly pushed out of Canada and into the Northeast, fueling numerous severe thunderstorm and heavy rain events from the 13th - 16th. First, a line of thunderstorms overnight on the 13th brought multiple trees down in Maryland and eastern Pennsylvania which was followed by very humid days on the 14th and 15th. With such a moist air mass in place, evening storms both days flooded areas of central New Jersey with rainfall amounts typically seen over the entire month of July.
After training storms dumped an impressive 5 – 6 inches of rain along the Monmouth and Ocean County border on the 14th, a second round of storms on the 15th dumped an additional 1 – 3 inches of rain pushing the month to date rainfall total to over 7 – 9 inches for this region. Other parts of central New Jersey were also hit hard by the heavy rain during this two day period with 2 – 5 inches of rain across Mercer and Middlesex County. The system’s cold front finally crossed the area on the 16th with showers gradually ending from west to east during the day.
As we entered the second half of the month, the Northeast transitioned into a much cooler and drier pattern. Temperatures from the 18th – 20th topped out in the upper 70s to near 80 with overnight lows falling into the 50s outside of the major cities. There were even a few rural locations that cooled into the upper 40s for lows on the 18th. Temperatures rebounded back to summer like levels for the 22 – 23rd ahead of an approaching cold front with widespread 90s on the 23rd. After storms passed on the 23rd, pleasant, dry and cooler conditions returned through the 27th with overnight lows on the 27th reaching record cold levels in Baltimore of 57 degrees (the previous record was 59 degrees set in 2008). Severe weather then developed on the 27th as a strong low pressure system swung through New England which included an EF-0 tornado in Wolcott, CT and excessive lightning in parts of New Jersey from overnight storms. Unfortunately, additional severe weather hit eastern New England on the 28th with an impressive EF-2 tornado touching down in Revere, MA. For more information on this unusually strong tornado, click here.
The final days of July were dry and continued the cool spell as highs failed to get out of the 70s on the 29th and overnight lows bottomed out at record cold levels in the Mid Atlantic the morning of July 30th. Temperatures more common for late September than late July were widespread across the region which included a chilly 48 degrees in Dulles, VA shattering the previous record of 51 degrees set in 1981. Temperatures warmed for the last day of the month with highs well into the 80s along the I - 95 corridor.
Considering folks in the Northeast experienced record breaking warm Julys over the previous four years, many equated the lack of similar anomalous heat this year with a much cooler than normal July. The table below shows that the number of 90 degree days this month (which mainly occurred during the first 15 days) was much lower than that of recent years which also aided in the conclusion of a cooler July.
In addition, folks heading to the shore swam in very cool ocean waters through the month as southerly winds led to plenty of upwelling resulting in temperatures nearly 10 – 15 degrees cooler than normal. However, in retrospect we see the warm start balanced the cool finish and the monthly temperatures actually finished near normal in most spots, with only the Mid Atlantic finishing 1 – 2 degrees below normal. Dulles, VA and Baltimore, MD ranked July 2014 9th and 12th coolest on record, respectively with high temperatures in Dulles staying below normal on most days through the month as seen in the graph below. Interestingly, this is the first July since 2009 that did not finish within the top ten warmest on record for the Northeast.
In the precipitation department, most finished near to above normal. Due to episodes of training thunderstorms, parts of the Jersey Shore measured 8 - 10 inches of rain over the month which is over double the normal rainfall for July. Thanks to Hurricane Arthur early in the month, areas of southeast Massachusetts including New Bedford, MA topped out between 6 – 10 inches or nearly triple the normal July rainfall.
