Winter Weather National Weather Service Buffalo, NY Average Seasonal Snowfall SNOWFALL = BIG IMPACTS • School / government / business closures • Airport shutdowns/delays • Traffic accidents with injuries/fatalities • Money plowing/treating roads • Lost resources in traffic congestion • Power outages/damage in strong storms 4 Communicating Risk Potential The National Weather Service uses a “Ready, Set, Go” approach Substituting the words “Outlook, Watch, and Warning” This approach is based on the lead-time of the event and forecaster confidence. Hazardous Weather Outlook • Issued each day between 5am and 6am • Updated as necessary throughout the day • Outlines potential weather hazards expected over the next seven days • The potential for major storms beyond two days will be discussed in the HWO WATCH vs. WARNING Watch Conditions are favorable for severe weather in or near the watch area. Watches are issued for winter storms, ice storms and blizzards. Warning The severe weather event is imminent or occurring in the warned area. Warnings are issued for winter storms, ice storms and blizzards. WINTER WEATHER WATCHES • Issued when forecaster confidence in the event occurring is at 50% or greater • Updated at least once every 12 hours or when there is a change in timing, areal extent, or expected conditions. • Generally issued 24 to 48 hours in advance • Types: – Winter Storm (Snow, Blowing Snow, Blizzard, Lake Effect) – Wind Chill WINTER WEATHER WARNINGS • Issued when hazardous winter weather is occurring or is imminent. • Forecaster confidence is at 80% or greater • Warnings can be issued based on significant public impact events • Generally issued 12 to 36 hours in advance Warnings • Issued when forecaster confidence reaches 80% • Types • Blizzard Warning • Ice Storm Warning • Lake Effect Snow Warning • Winter Storm Warning • Wind Chill Warning Blizzard Warning • Wind speeds of 35 mph or greater AND • Visibility of ¼ mile or less in blowing snow AND • Conditions must persist for at least 3 hours • Blizzards may or may not be accompanied by falling snow – When not accompanied by falling snow, it is referred to as a Ground Blizzard • “Severe” blizzard – All of the above except temperatures below 20° F – Wind chills well below zero Ice Storm Warning • Issued when 1/2 inch or more of ice accumulation is expected • An Ice Storm Warning means that freezing rain is expected to be the dominant precipitation type Winter Storm Warning • Issued when a combination of snow, sleet, and/or freezing rain are expected to reach warning criteria • Issued for a general heavy snowfall of: – 7 inches in 12 hours – 9 inches in 24 hours Lake Effect Snow Warning • Issued for a general heavy snowfall of: – 7 inches in 12 hours – 9 inches in 24 hours • Lake effect snow warning implies the localized nature of the heavy snow – In most cases not everyone in a county will receive warning criteria snowfall Wind Chill Warning • Issued for dangerously cold wind chills – Wind speeds generally 5 mph or greater • Issued when wind chills are forecast to fall below -25° F WINTER WEATHER ADVISORIES • Issued when winter weather is expected to cause significant inconveniences. • If caution is not exercised, could lead to life-threatening situations • Advisories: – Winter Weather (Snow, Lake Effect Snow, Blowing Snow, Ice or Sleet) – Wind Chill 17 ALSO NEW THIS WINTER... • Short-fused SNOW SQUALL WARNINGS – Visibilities of ¼ mile or less – Sub-freezing ambient road temperatures or plunging surface temperatures along and behind arctic front sufficient to produce flash freezes – Gusty winds and blowing snow • Beginning December 1st 18 OUR GOAL • To provide more information to – Facilitate improved decision making – Elicit the proper public response during the most life-threatening weather events 19 Weather Forecasts are Inherently Uncertain • Chaotic Nature of the Atmosphere • Deficiencies In Observations • Uncertainties in Computer Simulations of Atmosphere Yet the demand for snowfall forecasts has escalated! 20 Accurate Forecasts Desired Days in Advance But, as Lead Time increases, Certainty decreases • We need to better communicate the range of possibilities – Find a balance between Lead Time and Certainty • NWS constantly striving to provide: – The most accurate weather forecast – Relay our degree of uncertainty 21 Our Websites • www.weather.gov/buf • http://digital.weather.gov • http://preview.weather.gov/edd 23 Enter a Zip Code Or City, State Click Location on the Map www.weather.gov/buf 24 “Point and Click” Forecast Hourly Forecast Graphs For a text forecast for a County Select Text Bulletins then Zone Forecast www.weather.gov/buf 27 http://digital.weather.gov Graphical Forecasts from NWS digital database Zoom-able to Street Level Forecasts of: • Temperature • Wind • Probability of Precipitation • Hazards • Precipitation Amounts – 6-hr and total • Snow amounts – 6-hr and total 28 http://preview.weather.gov/edd • Current Observations: – Radar, Satellite, Hazards, Surface Observations • Forecasts: – Forecast Graphics – Hydrology http://go.usa.gov/hegF 29 Storm Total Forecast 30 Winter Weather Snowfall Rate Threat Buffalo Forecast Office http://www.weather.gov/buf/Snowfall_Rate_Threat_Loop 31 Winter Weather Snowfall Rate Threat Buffalo Forecast Office http://www.weather.gov/buf/SnowfallRateThreatTiles 9/22/2017 32 Winter Weather Snowfall Rate Threat Buffalo Forecast Office http://www.weather.gov/buf/Snowfall_Rate_Threat_Loop 2AM Tuesday 11/18/2014 6AM Tuesday 11/18/2014 33 www.weather.gov/buf NWS Weather Information On Your Mobile Phone Take the weather with you on your mobile phone! Wherever you are, you can get the local weather forecast from the National Weather Service with one click on your home screen. Bookmark mobile.weather.gov to make sure that you have the latest weather news and information on the go. 9/22/2017 35 Weather Ready Nation Ambassadors • Partners commit to working with NOAA and other Ambassadors to strengthen national resilience against extreme weather. • Unifies efforts across government, non-profits, academia, and private industry toward making the nation more ready, responsive, and resilient against extreme environmental hazards. • Ambassadors serve a pivotal role in affecting societal change — helping to build a nation that is ready, responsive, and resilient to the impacts of extreme weather and water events. 5 Fun Facts about Snow 1. All snowflakes have six sides 2. Snow crystals are translucent, not white. All visible colors are reflected, which together, look white. 3. Most snowflakes fall at a speed of 2 to 5 feet per second, roughly the same speed as a person casually walking through a park 4. Official snowfall and snow depth measurements include snow, sleet and ice pellets – in the summer, hail will also be recorded as a trace of snow if it is on the ground when the observation is taken. 5. A cubic foot of snow may contain between 1 and 2 million individual snowflakes. Fall begins Friday (9/22) at 4:02 PM 38 Any Other Questions?.