Tropical Storm Chantal was the third named storm of the 2007 Atlantic hurricane season. Chantal developed late on July 30 to the north-northwest of Bermuda. It moved rapidly to the northeast, and quickly became extratropical by August 1. Chantal slightly affected Bermuda, impacted Atlantic Canada as an extratropical cyclone, and then strengthened significantly through baroclinic processes as it approached the United Kingdom.
Chantal caused $5.5 million (2007 USD) in damage, but no fatalities.
|Formation||July 30, 2007|
|Dissipation||August 1, 2007|
|Highest winds||50 mph|
|Lowest pressure||994 mbar|
|Damages||$5.5 million (2007 USD)|
|Areas affected||Bermuda, Atlantic Canada|
|Part of the||2007 Atlantic hurricane season|
On July 21, a front moved off the coasts of South and North Carolina. During the next several days, the front moved southward and southeastward while degenerating into a low-level trough. By July 25, the front had generated an area of cloudiness and showers a few hundred miles east of northeastern Florida. The aforementioned area of cloudiness and showers drifted to the south, and then became quasi-stationary a few hundred miles east of the Bahamas on July 26. During the next two days, deep convection was not persistent with the area of disturbed weather, and it was not until July 28 that the first Dvorak classifications were taken on the system. Over the next couple of days, the convection did not organize significantly as the system moved off to the north. By 1200 UTC July 30, visible satellite imagery show that a surface circulation developed with the area of disturbed weather, although the convection was too far away from the circulation center to justify upgrading the system to a tropical cyclone at that time. However, near 0000 UTC July 31, the convection was involved enough with the low-level circulation center to justify upgrading the system to Tropical Depression Three while located about 210 miles north-northwest of Bermuda, and about 450 miles east of Cape Hatteras, North Carolina. During the next 6 to 12 hours, deep convection increased over the circulation center, and QuikSCAT data suggests that the cyclone strengthened into Tropical Storm Chantal by 0600 UTC July 31. It is estimated via QuikSCAT that Chantal reached its peak intensity of 50 mph at 1200 UTC July 31.
The primary steering mechanism for the cyclone was a mid-level trough centered just south of East Coast of the United States. The flow on the eastern side of the trough caused Chantal to move north-northeast to northeast with an increase in foward speed. By 0000 UTC August 1, a convective band that had been wrapping around the center of the storm started to weaken, and the circulation center became embedded within a frontal zone, indicating that the cyclone was losing its tropical characteristics. By 0600 UTC August 1, Chantal became an extratropical cyclone. Shortly thereafter, Chantal moved across the eastern portion of the Avalon Peninsula in Newfoundland at around 1300 to 1400 UTC that same day. Chantal, as an extratropical cyclone, strengthened to near hurricane force as it accelerated northeastward across the North Atlantic late on August 1 and early on August 2. That same day, however, the cyclone weakened a bit, and its foward speed also slowed. This weakening was short-lived, however, as Chantal re-intensified to near hurricane force early on August 3. By this time, Chantal had turned to the east. Later that day, however, Chantal began its final weakening, and passed a couple hundred miles to the south and southeast of Iceland on August 4. On August 5, Chantal's extratropical remnants turned to the northeast and merged with another extratropical cyclone located several hundred miles east of Iceland.
Tropical Storm Chantal began affecting Bermuda on July 30, in the form of scattered showers, as well as cloud cover. On July 31, as the cyclone passed west of the island, it produced more rainfall, amounting to 2.12 inches at the Bermuda International Airport, accounting for 35% of the monthly rainfall total. In addition to the rain, thunderstorms were reported on the island, and a maximum wind gust of 45 mph was recorded. After the storm passed Bermuda, a ship with the call sign C60Y4 recorded sustained winds of 37 mph over the open waters of the northern Atlantic Ocean. Around 2300 UTC July 31, a buoy located southeast of Nova Scotia recorded a pressure of 995 mb as Chantal passed by the buoy.
Shortly after Chantal became a tropical storm, Canada's Atlantic Storm Prediction Center issued a gale warning for the waters offshore Newfoundland. Later on, the Newfoundland Labrador Weather Office issued heavy rain warnings for southeastern Newfoundland. Offshore, waves reached 20 feet. Onshore, the cyclone produced gusty winds, with an unofficial report of a wind gust of 54 mph reported near the location where the cyclone made landfall. Chantal's extratropical remnants produced rain, with 1.7 inches of rain falling in one hour at St. John's West, the highest hourly rainfall in the country associated with the storm. Across the rest of the country, rainfall totals reached 5.9 inches at Whitbourne. The rainfall caused flooding and also washed out several roads along the Avalon Peninsula, with several communities in the region declared state of emeregencies. In Spaniard's Bay, the resulting flooding caused a bridge to depress about 1.5 feet; a temporary bridge within two months of the storm, and a permenant replacement was scheduled to be released by the summer of 2008. Total insured damage across the country reached $5.5 million (2007 USD).
Lack of Retirement
Because of the minimal damage, the name Chantal was not retired during the Spring of 2008 by the World Meteorological Organization. It is on the list of names to be used for the 2013 Atlantic hurricane season.