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The '1996 Lake Huron cyclone' (commonly known as 'Hurricane Huron') was a strong cyclonic storm system that developed over Lake Huron in September 1996. It had some characteristics of a tropical cyclone.

Contents

Storm history

Impact

See also

References

External links

References

Storm history

On September 11, 1996, a weak cyclone was situated close to Lake Superior.^[1] Near the surface, a 1012 mbar low existed over Lake Michigan. There was also a 500 mbar shortwave over Ontario. The northwest tilt of the low indicated that the surface center was in a stage of baroclinic development. In addition to this, analysis concluded that the cyclone had a cold core in the mid-troposphere. Analysis at the 700 and 850 millibar levels indicated that the cyclone also had a cold core in the lower troposphere, though a more dense observation would be needed.
The overall windspeed that the cyclone had increased rapidly from 5 mps to 30 mps along with its height. Also at the time, positive vorticity and thermal advection were
causing moderate rain showers occurring over Ontario, while a broken area of thunderstorms was present in a warm portion of an advancing cold front. By September 12, the cyclone moved southward so it was positioned over Lake Huron, with the upper portions centered over Michigan. The cyclone had also dropped in pressure slightly during a 24-hour period from 1012 millibars to 1006. After 1200 UTC September 12, the low moved southeastward and became vertically stacked atop the cyclone from the surface to 500 millibars.
For a brief time, the 300 and 200 mbar levels moved southeastward with the 300 moving over Lake Huron. Excepting the 200 mbar level, the other levels fell to mandatory levels. This height falls spawned the greatest intensification below the 500 mbar level. In addition to that, the cyclone's tilt was neutral, meaning that the storm was in the occlusions stage of baroclinic development. As the cyclone proceeded through this stage, the cold front, which was attendant to the surface low, became an occluded front that extended from Lake Huron to Pennsylvania on September 13. A 250 kilometer swath of showers and thunderstorms was positioned across the occlusion front whereas an area of showers laid along a lacking trough. Also at this time, a third area of showers was centered near the occluded low.
Between 1200 UTC September 13 and 0000 UTC September 14, a shortwave rotated throughout the area of the occluded low. This caused the 500, 700 and 850 millibar levels to move eastward, centering themselves just east of Lake Huron. In just the twelve hours alone, the same levels dropped 20 meters, whereas the 200 millibar level had raised 20 meters. During the same period, the surface low moved slowly over Lake Huron and fell five more millibars to 999 mbar. In response to this change, the maximum sustained winds increased as well. After 0000 UTC September 14, the lower and mid-tropospheric portions of the cyclone moved westward, becoming stacked atop one another again, but this time at the 200 mbar level. In contrast to the earlier developments, the baroclinicity of the system diminished rapidly. However, the lower tropospheric area continued to intensify, dropping to 993 millibars, with major height falls. The lowered baroclicity determined that the heat fluxes may have spawned the intensification.
Between 1200 UTC September 14 and 0000 UTC September 15, visible satillite imagery of the vortex revealed that it had a resemblance of a tropical cyclone. The vortex had an eye-like feature about 30 kilometers wide. In addition to the eye, convective clouds had also formed creating an eyewall of a tropical cyclone. Furthermore, feeder bands of convective showers continued extending westward to about 500 kilometers. Soon after the cyclone passed buoy 45008, winds turned to the east-northeast and rapidly increased. In contrast to earlier in the storm's life, which had more energy to the high levels, now it was near the surface. Surface analysis indicated that a weaker cyclonic circulation perisisted over the eastern shore of Lake Huron with another center existing north of Lake Ontario. During this 12-hour period, the cyclone diminished rapidly, mainly in the lower troposphere. Twelve-hour height rises also occurred ranging from 20 - 60 meters. The cyclone decayed and left Lake Huron September 15.

Impact

Excessive rain of over 100 millimeters (4 in) fell over the land surrounding the Great Lakes. This caused flooding in many areas.

See also

★ Subtropical cyclone

★ Extratropical cyclone

References

1. http://ams.allenpress.com/perlserv/?request=get-abstract&doi=10.1175%2F1520-0477(2000)081%3C0223:HH%3E2.3.CO%3B2

External links

★ Storm history

References

1. http://ams.allenpress.com/perlserv/?request=get-abstract&doi=10.1175%2F1520-0477(2000)081%3C0223:HH%3E2.3.CO%3B2