Realities (NDFD, NDGD, IFPS) David Ruth Meteorological Development Laboratory National Weather Service, NOAA 3rd NCEP/NWS Ensemble User Workshop November 1, 2006

The National Academies - 2003

National Digital Forecast Database (NDFD) Contains a seamless mosaic of NWS digital forecasts Is available to all users and partners – public and private Allows users and partners to create wide range of text, graphic, and image products

How is NDFD Produced? Detailed Interactive Collaborative National Centers Model Guidance Detailed Interactive Collaborative Grids Local Digital Forecast Database Field Offices National Centers Collaborate Data and Science Focus NWS Automated Products User-Generated Products National Digital Forecast Database TODAY...RAIN LIKELY. SNOW LIKELY ABOVE 2500 FEET. SNOW ACCUMULATION BY LATE AFTERNOON 1 TO 2 INCHES ABOVE 2500 FEET. COLDER WITH HIGHS 35 TO 40. SOUTHEAST WIND 5 TO 10 MPH SHIFTING TO THE SOUTHWESTEARLY THIS AFTERNOON. CHANCE OF PRECIPITATION 70%. Digital Text Graphic Voice

Spatial Detail Evident in the NDFD

Availability of NDFD Grids via FTP XML web service WMO GRIB v2 format CONUS, 16 CONUS sectors, Hawaii, Guam, and Puerto Rico GIS output available via downloadable GRIB decoder XML web service NDFD points in Extensible Markup Language (XML) Element, forecast time, and point location requested by user application Access via Simple Object Access Protocol Web graphics at weather.gov/forecasts/graphical

Who downloads NDFD grids? M2M User

Commercial NDFD graphics The Weather Underground

Commercial NDFD graphics Ham Weather

Commercial NDFD graphics AccuWeather Pro (by subscription)

NDFD in commercial software WeatherBug Plus ($19.95)

NDFD GIS display ESRI ArcMap-ArcInfo

NDFD point forecast via Google Maps Weather Mole

NDFD point forecast via Google Maps Weather Bonk

Route Forecast from NDFD Weather Bonk

Interactive NDFD Airport Forecasts Weather Meister

Observed Weather at 3/22 00z

7 days of forecasts valid 3/22 00z

NDFD Forecast Elements - original dozen - Status Probabilistic Range Source Maximum Temperature operational no 7 days WFO Minimum Temperature PoP12 yes Hourly Temperature Hourly Dewpoint Predominant Weather Wind Direction Wind Speed Sky Cover experimental Precipitation Amount 3 days Snow Amount 2 days Significant Wave Height 5 days

NDFD Forecast Elements - latest additions - Status Probabilistic Range Source Apparent Temperature operational no 7 days WFO Relative Humidity Trop. Cyclone Winds >34kt experimental yes 5 days TPC Trop. Cyclone Winds >50kt Trop. Cyclone Winds >64kt Wind Gust

NDFD Forecast Elements - contribution from SPC - Status Probabilistic Range Source Tornadoes planned yes 1 day SPC Hail Damaging Tstorm Winds Extreme Tornadoes Extreme Hail Extreme Tstorm Winds Total Severe Tstorm 3 days Total Extreme Tstorm

NDFD Forecast Elements - contribution from CPC - Status Probabilistic Range Source Temp. Above Normal planned yes 8-14 day CPC Temp. Below Normal Precip Above Normal Precip Below Normal 30 day 90 day

NDFD Forecast Elements - proposed and deferred - Status Probabilistic Range Source Prob. of Frozen Precip deferred yes 7 days WFO Prob. of Freezing Precip Prob. of Thunderstorms Probabilistic QPF 3 days Floating PoPs PoP06

NDFD Forecast Elements - next in line from WFOs - Status Probabilistic Range Source Weather Hazards 2007 no TBD WFO 20 ft Winds Max/min Relative Humidity Lightning Activity Level Mixing Height Transport Winds Haines Index Ceiling Height Visibility Ice Coverage Swell Height Swell Direction

The Digital Forecast Process Numerical Modeling Observations Output Model Interpret. Sensible Weather Forecast Editing Digital Product Generation User Products

Interactive Forecast Preparation 4D Field Modification Matrix Editing Observations Threshold Adjustment Numerical Modeling Object Editing Grid Editing Model Interpret. Numerical Output Forecast Editing Sensible Weather Product Generation Digital Forecast User Products

Proposed Course of Action 2003 MDL Science Review Phase out software as an external MDL product line Establish MDL as world leader in the Probabilistic Real-time Interpretation of Models and Forecasts Make MDL interpretative products available in database that provides interoperability with NDFD

PRIMF Digital Flow Climatology PRIMF Server Current Observation Numerical Output NDGD NDFD NWS Forecast Offices and Centers NWS Customers and Partners

PRIMF Components High-resolution MOS and updates to MOS (i.e., LAMP) Statistical interpretation of NDFD highlighting forecast uncertainty (NUANCE) Real-time forecast monitoring and feedback Probabilistic coastal hazards Verification of NDFD and NDGD

NUANCE NUANCE = Numerical Uncertainty Assessment of NDFD via Climatology and Ensembles Given the single value NDFD forecast for a weather element, recent NDFD performance, and related guidance (e.g., ensemble spread), quantify the expected variability of observations for that weather element. http://ams.confex.com/ams/WAFNWP34BC/techprogram/paper_94464.htm

Personal Views on Reality Forecasters at 120+ WFOs neither have the time, expertise, or tools to quantify uncertainty for all NDFD elements. Information about forecast uncertainty can be derived from NDFD single value forecasts, climatology, and ensemble spread. NDFD and NDGD provide an ideal avenue to convey uncertainty information to those who can use it in digital form. Complex decision support applications and displays should be developed by private weather providers for specific user communities. Uncertainty information can be added to NWS end-user products created from NDFD and NDGD