Winter Weather Warning Decision Making Weather Workshop

1. Winter WeatherWarning Decision Making Weather Workshop October 8, 2002 Jim Lee Chief, Fire and Public Weather Services Branch Office of Climate, Water, and Weather Services

2. Introduction • Welcome • Achieving better winter weather forecasting performance, through: • Training • Better science & technology • Experience • Agenda • Brief review of what’s new in policy • NWS Directives System • Future Plans

3. NWS Directives System • NWS is at the end of transitioning from the WSOM to the NWS Directives System • NWS Directives System Vision: • NWS policy development is efficient and effective • NWS policies are easily understood and accessed • NWS Directives System basic building blocks: • Policy Directives • Procedural Directives (Instructions and Manuals) • Regional Supplements

4. Winter Weather Directives • NWS Policy Directive (NWSPD) 10-5, Public Weather Services • Defines the mission critical, high level public weather policy • NWS Instruction (NWSI) 10-513, WFO Winter Weather Products Specification • Describes winter weather products issued by WFOs • NWSI 10-514, National Winter Weather Products Specification • Describes winter weather products issued by HPC • NWS Directives Web Page: http://www.nws.noaa.gov/directives/

5. NWSI 10-513: Issuance Criteria Defined • Winter Storm Outlook: • > 30% chance of a hazardous winter weather event exceeding local warning criteria in the next 3-to-5 days • Winter Storm Watch: • > 50% chance of a hazardous winter weather event meeting or exceeding local warning criteria in the next 12 to 48 hours • Winter Weather Warning and Advisories: • > 80% chance of a hazardous winter weather event meeting or exceeding local warning criteria in the next 36 hours

6. Comfort and Growth • Commensurate with science & technology, we need to go beyond our “comfort zone” to grow • Yes, there will be failure; however, anticipate learning from failure

7. Winter Weather Warnings Blizzard Warning Heavy Snow Warning Ice Storm Warning Heavy Sleet Warning Lake Effect Snow Warning Winter Storm Warning Winter Weather Advisories Snow and Blowing Snow Advisory Snow Advisory Freezing Rain Advisory Sleet Advisory Lake Effect Snow Advisory Winter Weather Advisory Catalog of Event SpecificProducts

8. Winter Storm Warning Issuance Criteria • “Winter Storm Warning”: A winter weather event having: • More than one predominant hazard: • Snow and sleet • Sleet and ice • Snow, sleet and ice • Heavy snow and blowing snow - New • At least one of the precipitation elements meets or exceeds locally defined 12 and/or 24 hour warning criteria • When the precipitation type cannot be determined

9. Minimum Forecast Snowfall Criteria • Issuance criteria based on the average value of the forecast snowfall range and not high endpoints

10. Future Plans • AMS Policy Statement issued January 2002 • “Enhancing Weather Information with Probability Forecasts” • Local Winter Weather Warning/Advisory Criteria Program, based on: • Snowfall rate, and/or • Time of occurence

11. Winter WeatherScience and Technology Infusion PlanTeam Composition • Sam Contorno – NWS/OST • Mark Tew – NWS/OCCWS • Marty Ralph – OAR/ETL • Jack Dostalek – NESDIS/CIRA • John Cortinas – OAR/NSSL/CIMMS • Andy Edman – NWS/WR SSD • Paul Sisson – NWS/WFO BTV • Jeff Waldstreicher – NWS/ER • Peter Manousos – NWS/NCEP/HPC • Allen White – OAR/ETL • Paul Neiman – OAR/ETL • Paul Stokols – NWS/OCCWS

12. Winter WeatherDRAFT Expected Results/Outcomes High Level National Benefits Accuracy On Track Low Risk High Risk

13. Observations Targeted Observations Dual Polarization 8km WRF AdvancedEnsembles Forecast Techniques Meso Snowband Technique Deployment Dissemination OTE Enabling Technologies DTE Weather Event Simulator Training R&D 10 01 02 05 06 07 08 04 09 11 12 03 Winter Weather DRAFT Key S&T Solutions DA/NWP

14. Future Plans (cont.) • Winter Weather Experiment (WWE) II • Coordinated by OCWWS, NCEP, Eastern and Central Region Headquarters • Goal: Improve winter weather products and services provided for the public • Evaluate HPC’s role in facilitating a collaborative set of guidance products • Evaluate the performance of EMC’s SREF during winter events • HPC is striving to be the coordination leader or National Center for Winter Storms (e.g., SPC, TPC)

15. Future Plans (cont.) • WWE II (winter 2002-2003) • All 23 ER WFOs and 8 CR WFOs will work with HPC to test and evaluate the concept this winter • HPC will prepare three graphical products • Verification statistics of pre vs. post chat sessions

16. Summary • Issuing watches, warnings, advisories and statements is the core mission of the NWS • Go back to your WFO and use these materials to train • Take time for the course evaluations • Thanks for taking the time to attend! • James.E.Lee@noaa.gov • 301-713-1867x107