Raleigh, North Carolina:

The region also experiences occasional periods of drought, during which the city sometimes has restricted water use by residents. During the late summer and early fall, Raleigh can experience hurricanes. In 1996, Hurricane Fran caused severe damage in the Raleigh area, mostly from falling trees. The most recent hurricane to have a considerable effect on the area was Isabel in 2003. Tornadoes also have on occasion affected the city of Raleigh most notably the November 28, 1988 tornado which occurred in the early morning hours and rated an F4 on the Fujita Tornado Scale and affected Northwestern portions of the city. Also the April 16, 2011 F3 Tornado which affected portions of downtown and North east Raleigh and the suburb of Holly Springs.

Please answer a question about this article. If the question is unanswerable, say "unanswerable". How big was the tornado in 2011?
F3