Operations at the Reagan Test Site were disrupted due to the nearby formation of Tropical Storm Zelda.

The Ronald Reagan Ballistic Missile Defense Test Site, commonly referred to as the Reagan Test Site, is a missile test range in Marshall Islands. It covers about 750,000 square miles (1,900,000 km²) and includes rocket launch sites at the Kwajalein Atoll, Wake Island, and Aur Atoll. It primarily functions as a test facility for U.S. missile defense and space research programs. The Reagan Test Site is under the command of the US Army Kwajalein Atoll, or USAKA.

Severe Tropical Storm Zelda was the last tropical cyclone of the 1991 Pacific typhoon season; it struck the Marshall Islands on November 28. The area of low pressure that eventually became Zelda formed near the International Date Line, and strengthened into a tropical depression on November 27. The Joint Typhoon Warning Center (JTWC) reported that the depression had reached tropical storm intensity near the Marshall Islands on November 28, thus naming it Zelda. On November 29, the storm quickly strengthened to 65 knots according to the JTWC, equivalent to a Category 1 typhoon on the Saffir–Simpson hurricane wind scale. It reached a peak of 80 kn according to the JTWC, and 60 kn according to the Japanese Meteorological Agency (JMA), with a barometric pressure of 975 hectopascals (28.8 inHg). Zelda weakened into a tropical storm on December 2, and then a tropical depression two days later. The JTWC discontinued warnings late on December 4, while the JMA declared the storm to be extratropical the next day and continued to track until it crossed the International Date Line again on December 7.