Short answers, pulled from the story.
A sirocco is a Mediterranean wind that comes from the Sahara and can reach hurricane speeds in North Africa and Southern Europe, especially in summer. It forms when warm, dry tropical air originating in the Arabian or Sahara deserts is pulled northward by low-pressure cells crossing the Mediterranean Sea.
The name sirocco comes from the Arabic šurūq, a verbal noun of šaraqa related to aš-šarq, the word for the East. Local names for the same wind include scirocco, sciroccu, xaloc, xlokk, jugu or jugo, and Libyan Arabic qibliyy or khamsin.
Sirocco winds can reach speeds of up to 100 km/h. They are most common during autumn and spring, peaking in March and in November.
Blood rain is the local name for rainfall in southern Italy that forms when the sirocco picks up moisture over the Mediterranean Sea and mixes it with red Saharan sand. The red sand mixed into the falling rain gives it its color and its name.
Anchovies from the Gulf of Trieste near Barcola are a prized local delicacy that are caught only during a sirocco. When a cold wind such as the bora blows instead, those anchovies disappear into the Adriatic.
Acqua alta is a flooding phenomenon in the Venetian Lagoon that occurs when a sirocco wind combines with a rising tide. That combination pushes water levels high enough to flood the lagoon.
The Roman poet Horace described the sirocco in his account of a journey to Brundisium in 37 BC, calling it Atabulus while passing through Trevico in Apulia. Atabulus was a Messapic word for the wind.