New York, being in the northeast , has a rich history of snow & ice cases.  A whole series of rules have arisen which accompany and inform the law of accidents on snow & ice.  As one example, the precipitation must have already ended for a case to be viable. The difference between misfeasance and nonfeasance also applies.  Here in this legal malpractice case Teodorescu v Resnick & Binder, P.C. ,2008 NY Slip Op 07904 ,Appellate Division, Second Department 
 the court lays out a series of rules for snow & ice cases, for legal malpractice and for summary judgment.

Legal Malpractice:  "To prevail in an action to recover damages for legal malpractice, a plaintiff must establish that the defendant attorney failed to exercise the ordinary reasonable skill and knowledge commonly possessed by a member of the legal profession, and that the attorney’s breach of that duty proximately caused the plaintiff to sustain actual and ascertainable damages (see Rudolf v Shayne, Dachs, Stanisci, Corker & Sauer, 8 NY3d 438, 442). To establish causation, a plaintiff must show that he or she would have prevailed in the underlying action, or would not have incurred any damages but for the attorney’s negligence (see Rudolf v Shayne, Dachs, Stanisci, Corker & Sauer, 8 NY3d at 442; Davis v Klein, 88 NY2d 1008, 1009-1010; Lamanna v Pearson & Shapiro, 43 AD3d 1111; Cohen v Wallace & Minchenberg, 39 AD3d 691). A defendant moving for summary judgment in a legal malpractice action must present admissible evidence that the plaintiff cannot prove at least one of the essential elements of a legal malpractice cause of action (see Levy v Greenberg, 19 AD3d 462; Crawford v McBride, 303 AD2d 442). "

Snow & Ice: "To make out a prima facie case of negligence in a slip-and-fall case involving an accumulation of snow and ice, the plaintiff must demonstrate that the defendant created the condition which caused the accident, or that it had actual or constructive notice thereof (see Voss v D & C Parking, 299 AD2d 346). To give rise to constructive notice, a defect must be visible and apparent, and exist for a sufficient length of time prior to the happening of an accident to permit the defendant to discover and remedy it (see Gordon v American Museum of Natural History, 67 NY2d 836; see also Chianese v Meier, 98 NY2d 270, 278). In order to prevail in the underlying action against the NYCHA on a theory of constructive notice, the plaintiff would have had to introduce evidence of the origin of the particular icy condition that caused her to fall (see Simmons v Metropolitan Life Ins Co., 84 NY2d 972; Ciaschi v Taughannock Constr., 204 AD2d 883). General awareness that snow and ice may be present is legally insufficient to constitute notice of the particular condition that caused the plaintiff’s fall (see Piacquadio v Recine Realty Corp., 84 NY2d 967; Gloria v MGM Emerald Enterprs., 298 AD2d 355). "

Summary Judgment: "In the instant case, the defendant established its prima facie entitlement to judgment as a matter of law by demonstrating that the plaintiff would not have been successful in an action against the NYCHA on a theory of constructive notice. The defendant relied on the plaintiff’s deposition testimony, which was insufficient to support her claim that the icy patch where she slipped existed when she traversed that sidewalk the previous evening. The plaintiff could not point out the exact location of her fall other than that it was in the middle of the block in front of the George Washington Housing Project. In opposition to the defendant’s motion, the plaintiff failed to raise a triable issue of fact as to whether she could have prevailed against the NYCHA on a theory of constructive notice. The plaintiff offered only speculation that the ice on which she slipped had to have been a product of the prior snowfalls, which were not properly cleared. "