Tools to Enable Forecasters to Communicate Winter Storm Impacts across the Sierra and Western Nevada

Winter storms pose several forecast challenges across the Sierra and western Nevada, with impacts to a wide range of end users in public safety, transportation, recreation, and water supply. While the predictability of winter storms has increased in recent years, critical details such as the axis of heaviest precipitation and snow level variations have a lower predictability even just 1-2 days in advance.

Over the past two winters NWS Reno has been enhancing tools to assist forecasters in messaging the context of a winter storms to end users. One specific action we’ve started is to provide partner agencies in the Sierra and western Nevada with feasible rain, snowfall, and wind scenarios ahead of winter storms. The key is to provide a readily digestible amount of information on top of the NWS official deterministic forecast - so we’ve focused on just three: “most likely”, “low”, and “high” scenarios. Even without probability of occurrence forecasts, these scenarios provide useful guidance to agencies for planning staffing, emergency response, and adjusting schedules for community events and travel. While partners still heavily weight their decisions on the “most likely” or official NWS forecast, the alternate scenarios give them enhanced situational awareness of where the forecast may bust.

This presentation will cover the tools and messaging graphics used at NWS Reno to brief partner agencies using the scenario approach, focusing on precipitation and snowfall forecasts from the Winter Storm of January 29th to February 1st, 2016. The presentation will also highlight how our messaging assisted the pre-event preparations of the Reno-Tahoe Airport Authority and impacts to flight operations during the storm.