Charleston has a humid subtropical climate (Köppen climate classification Cfa), with mild winters, hot, humid summers, and significant rainfall all year long. Summer is the wettest season; almost half of the annual rainfall occurs from June to September in the form of thundershowers. Fall remains relatively warm through November. Winter is short and mild, and is characterized by occasional rain. Measurable snow (≥0.1 in or 0.25 cm) only occurs several times per decade at the most, with the last such event occurring December 26, 2010. However, 6.0 in (15 cm) fell at the airport on December 23, 1989, the largest single-day fall on record, contributing to a single-storm and seasonal record of 8.0 in (20 cm) snowfall.
In what form does half of Charleston's annual rainfall occur?
thundershowers

A number of theories have been proposed regarding Avicenna's madhab (school of thought within Islamic jurisprudence). Medieval historian Ẓahīr al-dīn al-Bayhaqī (d. 1169) considered Avicenna to be a follower of the Brethren of Purity. On the other hand, Dimitri Gutas along with Aisha Khan and Jules J. Janssens demonstrated that Avicenna was a Sunni Hanafi. However, the 14th cenutry Shia faqih Nurullah Shushtari according to Seyyed Hossein Nasr, maintained that he was most likely a Twelver Shia. Conversely, Sharaf Khorasani, citing a rejection of an invitation of the Sunni Governor Sultan Mahmoud Ghazanavi by Avicenna to his court, believes that Avicenna was an Ismaili. Similar disagreements exist on the background of Avicenna's family, whereas some writers considered them Sunni, some more recent writers contested that they were Shia.
What secret society was Avicenna considered to be a follower of?
the Brethren of Purity

Opera debuted in 1996; it has never achieved widespread use, having less than 2% browser usage share as of February 2012 according to Net Applications. Its Opera-mini version has an additive share, in April 2011 amounting to 1.1% of overall browser use, but focused on the fast-growing mobile phone web browser market, being preinstalled on over 40 million phones. It is also available on several other embedded systems, including Nintendo's Wii video game console.
Opera was introduced in what year?
1996