§ 1.6.2.1 Winter v. NRDC, Inc. On October 8, 2008, the United States Supreme Court rendered its decision in Winter v. Natural Resources Defense Counsel, Inc., 555 U.S. 7, 129 S.Ct. 365 (2008). Although IB Property Holdings, LLC v. Rancho Del Mar, 228 Ariz. 61, 64, 263 P.3d 69, 72 (Ct. App. 2011) expressly rejected application of “the more stringent [preliminary injunction] standard that Winter announced, an understanding of Winter is critical to the applicability of any pre-October 2008 federal authorities in two principal respects.
“The relevant difference between the Winter and Shoen [v. Shoen, 167 Ariz. 58, 63, 804 P.2d 787, 792 (App. 1990) ] standards is that Winter requires the parties seeking an injunction to demonstrate that irreparable injury is likely, rather than merely possible.” IB Property Holdings, LLC, 228 Ariz. at 64, 263 P.3d at 72 . Accordingly, as more fully discussed below, pre-October 2008 federal cases discussing application of preliminary injunction factors should still be persuasive regarding Arizona preliminary injunction applications. However, to the extent pre-October 2008 federal authorities hold that the strength of other preliminary injunction factors diminishes the applicant’s obligation to demonstrate that his probability of suffering irreparable harm is less than “likely,” they are no longer authoritative in federal preliminary injunction proceedings.2
Winter arose out of an extreme factual setting. The United States Navy required sonar testing in order to develop appropriate...
