What’s Ahead for this Winter
Brent Bower Ted Buehner Senior Service Hydrologist Warning Coordination Meteorologist NWS Seattle/Tacoma NWS Seattle/Tacoma Winter Season Outlook for the Pacific Northwest: Winter 2017 / 2018
NWS Climate Prediction Center www.cpc.noaa.gov
El Nino vs La Nina
‘Neutral’ Conditions are around average SSTs Historical Trends
1997-98 2015-16 1972-73 1982-83 1991-92 1957-58 1965-66
1988-89 1998-00 1973-75 2007-08 1955-56
El Nino or La Nina (negative) - Weak: 0.5 - 0.9C - Moderate: 1.0 – 1.4 C - Strong: > 1.5 C ENSO Occurrence
El- La- Niño Niña 35% 37% Niño Indices: Recent Evolution Tropical Pacific Status
• Neutral conditions are in place at this time across the eastern equatorial Pacific • Sea surface temperatures (SST) have recently trended cooler again • La Nina Watch – La Nina conditions are anticipated for this fall/winter • Jet stream – tends to spend more time at our latitude with more Pacific storms What’s Ahead – This Winter?
• Still Early
• ~55% Chance of El Niño Neutral Conditions for this coming winter
ENSO-neutral • Less than 25% chance for El Nino or La Nina La Niña • Stay Tuned
Source: http://iri.columbia.edu/our-expertise/climate/forecasts/enso/current/?enso-sst_table What’s Ahead – This Winter?
• Oh how things evolved!
El Niño • ~65% Chance of La Nina for this winter
ENSO-neutral • 30-40% Chance for Neutral Conditions La Niña • Less than 10% Chance for El Nino
Source: http://iri.columbia.edu/our-expertise/climate/forecasts/enso/current/?enso-sst_table U. S. Seasonal Outlooks November 2017 – January 2018
Temperature Precipitation
33% 4033%-50% U. S. Seasonal Outlooks January – March 2018
Temperature Precipitation
60%33% 55-60% Significant Winter Weather Breakdown by ENSO Phase
• Major floods
1. ENSO neutral 2. La Niña (e.g.: 1964-65, 1995-96 and 2007-08) 3. El Niño • Major wind storms
1. La Niña (e.g.: 1995-96, 1998-99, 2007-08) 2. ENSO neutral 3. El Niño • Lowland snow events
1. La Niña (e.g.: 1949-50, 1955-56, 1964-65, 2010-11) 2. ENSO neutral 3. El Niño
Not all winters produce significant weather, yet our history shows…. In Summary
• La Nina Watch in Effect • Current seasonal outlook – Temperature: Odds tipped to warmer than average this fall, then no trend this winter – Precipitation: Odds tipped to wetter than average – Mountain Snowpack: Likely healthy, above average • CPC Seasonal Outlook Charts updated on 3rd Thursday of each month In Summary
• Can always expect some significant winter weather in the Pacific Northwest no matter if El Nino, La Nina or Neutral!
– On the event scale (based on history):
• Good Potential for Cold Air Outbreaks/Lowland Snow across the state
• Odds in Favor:
– One or more major flooding events
– One or more major wind storms
• Stay tuned to the latest this fall/winter season Stay Tuned Decision Support Services
• NWS Web Site
– www.weather.gov/seattle/ • NWS Social Media
– Twitter, Facebook Partnered Missions • Four Phases of National Weather Emergency Mgmt Service Mission Provide Weather, Hydrologic, and Climate Forecasts and Warnings for the United States, its Territories, Adjacent Waters and Ocean Areas, for the Protection of Life and Property and Enhancement of the National Economy. NWS Decision Support Services • Four Phases of Preparedness Emergency Mgmt Internal All-hazard warning receipt tools Exercises External Community Education//Awareness NWS Decision Support Services • Four Phases of Response Emergency Mgmt Event-driven Weather Briefings Web Sites NOAA Weather Radio/EAS NWSChat iNWS Spot Forecasts Phone NWS Decision Support Services • Four Phases of Recovery Emergency Mgmt All-Hazards Weather Support Spot Forecasts Weather Briefings Storm Surveys Determine Potential Mitigative Efforts NWS Decision Support Services • Four Phases of Mitigation Emergency Mgmt After-Action Reports Lessons Learned Enhance Resilience Storm/TsunamiReady Weather-Ready Nation Ambassadors Exercises Partners = Relationships • Know and Work with Each Other • Needs and Requirements, Limitations • Examples – Exercises (tabletops, functional, full scale) – FEMA Integrated Emerg Mgmt Course (IEMC)
– Significant Events/Issues (e.g. – Howard Hanson Dam, SR-530 Slide, Large Public Events) – Workshops, Conferences, Meetings – Real Events Decision Support Services
“What is a Good Forecast? An Essay on the Nature of Goodness in Weather Forecasting”
By Allan H. Murphy; Weather and Forecasting (June 1993)
“First, it should be understood that forecasts possess no intrinsic value. They acquire value through their ability to influence the decisions made by users of the forecast.” Stay Tuned Decision Support Services
• NWS Seattle Web Site
– www.weather.gov/seattle/ • NWS Social Media
– Twitter, Facebook National Weather Service Deployments
• What?
– Deployment of NWS Staff to Your Event
• On-Scene Weather Support
– Briefings, One-on-One Guidance, Tailored Information
– Local Expertise
• To EOCs, ECCs, ICPs, and More
• Trained – ICS, Media National Weather Service Deployments
• When? High Impact Events
– Examples in Washington State
• Howard Hanson Dam (2009-10), SR-530 Slide
• Weather – Major Wind Storms, Floods, Wildfires, Snow/Ice Storms, Landslides
• All-Hazards – EQ/Tsunami, Volcano, Hazmat
• Major Events – Major Sporting, VIP Visits, and More – Example – Hurricane Harvey/Irma Deployments
• State EOC, FEMA Region, Aviation Center
• NWS – Affected WFOs, River Forecast Center National Weather Service Deployments • Practice - Exercises
– Local Examples
• Cascadia Rising - 2016
• Tabletops
– University of Washington – Husky Stadium
– Several Dam, Oil Spill Exercises
– Thurston County School Districts – NWS Staff Conducting More Training Nationwide
• Enhance Consistent Skills, More Staff to Deploy – NWS Staff Can Participate in your Exercises Tabletop Exercises
• Weather Scenarios
– Wind Storm, Flood
– Snow/Ice, Wildfire • All-Hazard Scenarios
– EQ/Tsunami, Hazmat • NWS Seattle Staff
– Come to you
– Walk through scenario
– Levels of Uncertainty • Win – Win ! Exercises
• Functional
– Weather
– All-Hazard • Full-Scale
– Air Disaster
– Earthquake
– Oil Train National Weather Service Deployments
• How?
– Got an Exercise Scheduled or Planned?
– A Real Event?
• Let us Help, Contact us
• Make Arrangements
• We Are Here to Support You
• We Are All In It Together – NWS Seattle
• 206-526-6095 Hazard Simplification
• Simplify NWS • Goals Products – Improve Warning – Better Meet Partner Clarity and Public Needs – Impact Focused – Based on Feedback – Consistent • Emergency Message Managers • What, Where, When, • Public Actions • Media – Enhance Warning • Social Scientists Effectiveness First Changes – Oct 1, 2017 – Winter Weather Products
Hazard Simplification
• Flood Products
– Spring 2018
• Consolidate Flash Flood Watch into Flood Watch
• Reformat all Flood Products
– What, Where, When
– Precautionary/Preparedness Actions Event – Driven Products Outlook Outlook (Heads Up!)
Severe weather conditions are possible in a few days. Consider options – start planning!
2-5 day lead time (long fuse): High Wind, Flood, Winter Storm
12-48 hours lead time (short-fuse): Flash Flood, Severe Thunderstorm, Tornado Event – Driven Products Watch / Warning / Advisory Watch (Get Prepared!) Severe weather conditions are possible, but not yet certain. Prepare now!
Up to 48 hours lead time (long-fuse): High Wind Watch, Coastal Flood Watch
Up to 12 hours lead time (short-fuse): Flash Flood Watch
Up to 6 hours lead time (short-fuse): Severe Thunderstorm Watch, Tornado Watch Event – Driven Products Watch / Warning / Advisory Warning (Take Action!) Severe weather conditions are imminent or have begun in your area. Take immediate action !!
Long-fused warnings: High Wind Warning, Winter Storm Warning, Coastal Flood Warning, Flood Warning
Short-fused warnings: Flash Flood Warning, Tornado Warning, Severe Thunderstorm Warning Event – Driven Products Watch / Warning / Advisory Advisory Weather conditions are expected to cause significant inconvenience and may be hazardous. The greatest hazard is to motorists. Winter Weather Advisory High Surf Advisory Small Craft Advisory Urban and Small Stream Flood Advisory Wind Advisory Heat Advisory Important Terminology NWS Weather and Flood Bulletins Also Impact-Based
Weather/Flood Weather/Flood Weather/Flood Outlook Watch Warning/ Advisory
Time to onset of event (hours)
96-72 48 24 0
Increasing confidence that event will occur Example - FLOOD WARNING TIMING
Forecast Flood Flood Flood Discussion Outlook Watch Warning 19
17
15
13 Extended 11 Briefings Stage (FT) Stage Briefings 9
7
5 8/ 12:00 9/ 12:00 10/ 12:00 11/ 12:00 12/ 12:00 13/ 12:00 14/ 12:00 15/ 12:00 Date/Time
GLBW1 Flood Stage I-5, Chehalis, Dec 2007 AHPS
Flood Categories - Minor - Moderate - Major (EAS)
Observed Forecast AHPS Rivers Web Page
A H P S AHPS – Advanced Hydrologic Prediction Services
Flood Categories - Minor - Moderate - Major (EAS)
Observed Forecast “High Wind” Criteria
• High Wind Warning - Also Impact-Based • 40 MPH or more Sustained and/or Gusts of 58 MPH or greater • Wind Advisory – Also Impact-Based • 30-39 MPH Sustained and/or Gusts 45-57 MPH
Marine Warnings and Advisories
Hurricane Force Storm - 64 knots or greater
Storm Warning - 48 to 63 knots
Gale Warning - 34 to 47 knots
Small Craft Advisory - 21 to 33 knots (plus heavy coastal swells and rough bars) Winter Weather Criteria Also Impact-Based
Winter Storm Warning Winter Weather • Can combine with Ice and/or Strong Winds Advisory • Lowlands – 4 inches or more 1 to 3 inches • Mountains – 12 inches or more 6 to 11 inches
Blizzard Warning • Snow Combined with Strong Winds of 35 MPH or more and visibility less than 1/4 mile
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• What? WRN Ambassadors:
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Ted Buehner Warning Coordination Meteorologist NWS Seattle/Tacoma Any Questions? Flood Warning Program
Brent Bower
Senior Service Hydrologist
National Weather Service – Seattle/Tacoma NWS Hydrology Program
Weather and precipitation forecasts and data Flood warnings and river forecasts Heavy rainfall-induced landslide threat information and alerts Drought information dissemination, tracking support to Washington State Decision support regarding weather (rain) and river flows Hydrologic Outlook
Neutral or Weak La Nina winter Can not predict specific floods or that there will be Strength of La Nina/El Nino no relation to strength of storms Historical large floods in western Washington relative to ENSO Generally occur more frequently in Neutral years Occur next most frequently in La Nina years Not true of all basins AHPS Rivers Web Page
A H P S AHPS
Flood Categories - Major (EAS)
- Moderate
- Minor
Observed Forecast NWM Water.noaa.gov/map Decision Support Services
Impact-Based Decision Support Services Looking for ways to make NWS information fit your needs, aid your weather-dependent decisions
Especially important for unique, atypical situations
SR 530 Landslide I-5 Skagit River bridge collapse Flood Inundation Mapping Vulnerabilities during levee work Elwha dam removal in-stream work NWS SEATTLE WEB SITE
www.wrh.noaa.gov/seattle or… weather.gov/seattle . Tabs – Rivers and Lakes River Observations (or forecasts) Hydrology information . Map (color coded watches/warnings/advisories) Read watches, warnings & advisories “Latest Text Products” drop-down box Questions ? NWS Products and Services Your Weather Support Partner
Serving America Since 1870
Helping Protect Lives and Property and Enhancing Our Economy
Ted Buehner Warning Coordination Meteorologist Brent Bower Senior Service Hydrologist NWS – Seattle/Tacoma