Historic Half-Blizzard of 2015
Dr. Ryan Maue -- WeatherBELL January 27, 2014 2:30 PM EST
The authorities acted exactly as they should have considering the information that was provided to them by the National Weather Service and emergency planners responsible for putting the wheels in motion.
The NWS was consistently forecasting worse conditions e.g. higher snowfall amounts and more severe impacts after each successive weather model forecast on Sunday and Monday for NYC, New Jersey. Eventually, the official NWS forecast turned into a historic, worst-case scenario. So, as each update arrived, NWS's adjustments were all in the "more severe"
direction. That's an ominous signal that suggested NWS had a high-level of confidence in their forecast. However, it was clear at the time that the exact opposite was true -- this was a low-confidence solution meaning the chance of a 30-inch snowfall occurring in NYC required everything to "go right" for the Blizzard's track, intensity, and motion. The uncertainty level on this forecast was also considerable for NYC as reliable weather models were giving an enormous range of solutions from 6-inches to 3-feet for NYC.
The NWS produces a deterministic forecast with a certain range e.g. 24-36'' of snowfall but information about confidence is not imparted. Were they expecting 3-feet more than 2-feet or were the values inside that range equally likely? What was the chance of 4-feet or 1-foot? Weather forecasters deal with this question every day when they issue a rain-fall forecast and call for 30% chance of rain or 100% chance of rain. That's more easily understood by the public as they can take action based on their perceived risk of the event. An umbrella would be a good fashion accessory with 90% chance of thunderstorms at rush hour.
This indeed goes back to Hurricane Sandy which was the "worst case scenario". Our weather models were all very confidently saying that all hell would break loose. The same NWS forecasters at Mount Holly were warning at the top of the lungs to take immediate action to save lives and property. In this respect, the public was appropriately warned and should have definitely feared the effects of this extraordinary hurricane.
The same level of media hype and perceived (update: 2:35 PM) government (city, state) overreaction surrounding this blizzard in NYC may cause future complacency with warnings. However, the weather forecasters and authorities will not hesitate to issue the same emergency declarations because a False Alarm in the "safe direction" is hardly the worst possible outcome.
The public should be upset that the forecast was blown for NYC and ask for answers. They will get them and the weather forecasting enterprise at the NWS will benefit from the added experience and lessons learned. But should we be disappointed that NYC wasn't buried in 3-feet of snow? Some say "go big or go home" or "bring it". The historical nature of extreme weather events is exciting -- as evidenced by the sometimes outlandish media coverage -- that drives ratings. In the case of NYC, everyone was able to watch the forecast bust unfold from the warmth and comfort of their homes rather than risk being stuck in traffic or buried on the Thruway.
While private weather forecasters including the Weather Channel were skeptical of the enormous snowfall forecasts for NYC, the risk of publicly challenging NWS and emergency management decisions would have provided "mixed messages" that could have led to the worst possible outcome: public not heeding legitimate and lawful warnings.