1. Scientific Needs for Weather Weather Observations, Forecasts and Warnings Weather Prediction QPF Landfalling Hurricanes Coastal Meteorology Mountain Meteorology Urban Meteorology

2. Weather Observations and Forecasts and Warnings - 1 ( Emanuel et al. 1995 and Dabberdt and Schlatter 1996)  Scientific needs  Convective storms  Deep convective downdraft processes  Cloud microphysical processes  Cloud ice properties  Entrainment  Land-surface-atmosphere interactions  Atmospheric electricity

3. Weather Observations and Forecasts and Warnings - 2 (Emanuel et al. 1995 and Dabberdt and Schlatter 1996)  Scientific needs  Extratropical cyclones  Understand mesoscale phenomena  Gravity waves  Slantwise convection  Development and evolution of frontal cyclones  Potential vorticity  Role of tropopause in atmospheric dynamics  Aviation weather  Better understanding of mesoscale phenomena  Thunderstorms  Fronts  Clear-air turbulence  Wind shear  Icing

4. Weather Observations and Forecasts and Warnings - 3 (Emanuel et al. 1995 and Dabberdt and Schlatter 1996)  Scientific needs  Modeling fire weather  Seasonal climate prediction  Low-frequency oscillations  Influence of hurricanes on low-frequency coupled atmosphere-ocean and atmosphere-land surface  External influences, such as volcanoes and solar output  Data assimilation techniques for operational datasets

5. Weather Observations and Forecasts and Warnings - 4 (Emanuel et al. 1995 and Dabberdt and Schlatter 1996)  Observational needs  Maintain operational rawinsonde network  Improved measurements of temperature, liquid and ice in cloud  Microphysical measurements, particularly within ice clouds  Improved water vapor measurements  WVSS on commercial aircraft  GPS  DIAL  Raman lidars  Radiosondes  Dropsondes  Infrared spectrometers  Microwave radiometers  Unpiloted aircraft  Satellite radiances

6. Weather Observations and Forecasts and Warnings - 5 (Emanuel et al. 1995 and Dabberdt and Schlatter 1996)  Observational needs  Measurements of the maritime atmosphere  Ocean fluxes  Global observing systems  Targeted, adaptive observations  Better observations over the mountainous West  Wind profilers  Wind and temperature profiles upwind  Enhanced mesoscale observations

7. Weather Observations and Forecasts and Warnings - 6 (Emanuel et al. 1995 and Dabberdt and Schlatter 1996)  Observational needs  Better observations over the eastern N. Pacific  Profiles of wind, temperature and humidity  GOES rapid scan  Dropsondes from commercial or military aircraft  Altitude-controlled balloons  Unpiloted aircraft  Buoys  Profilers on buoys  Satellite radiometric measurements  Moisture profiles combined with wind measurements  WVSS on commercial aircraft  GPS techniques  Eye-safe Raman lidars  Fourier transform infrared radiometry (like AERIs)  Wind profilers  WSR-88D radars

8. Weather Observations and Forecasts and Warnings - 7 (Emanuel et al. 1995 and Dabberdt and Schlatter 1996)  Observational needs  Better measurements for initial conditions  Surface temperature and albedo  Soil classification  Soil moisture  Snow distribution  Vegetation  SST  Sea ice distribution  Wave state  Ocean color for tracking currents  Airborne radars for process studies  Aircraft in-situ measurements for downdraft process studies  Polarimetric radars for QPF  Bistatic radars  Joint radar and lightning measurements  Ultimate objective  Benefit to society

9. Weather Prediction (Emanuel et al. 1997)  Scientific needs  Physical mechanisms of rapidly growing weather systems  Observational needs  Observations in data sparse regions  Automated rawinsondes  Ship measurements  Profilers on ships  Moored and drifting buoys  ACARS  Piloted and unpiloted aircraft  Automated floating devices  Passive satellite measurements  Global winds derived from sequential satellite imagery  Sea-surface winds from scatterometers  GPS soundings of temperature and moisture  Lidar wind measurements from satellite  Ultimate objective  Benefit to society

10. QPF - 1 (Fritsch et al. 1998)  Scientific needs  Process and climatological studies  New design for data-gathering strategies for model initialization  Define probabilistic framework for precipitation forecasting and verification  Development of advanced ensemble techniques  Better understanding of storm lifecycle, especially MCCs  Better understanding of cloud microphysics  PV anomalies  Surface boundaries  Orographic influence  Improved precipitation estimates in 4DDA  Assimilate WSR-88D  Forecast validation  Land-surface-atmosphere interactions

11. QPF - 2 (Fritsch et al. 1998)  Observational needs  Improved accuracy and resolution of precipitation observing system  Mobile radiosondes  Portable lidars  Mobile radiometers  Improved moisture measurements  Stability profiles  In situ aircraft observations  Land surface measurements  Polarimetric radars  Satellite estimates  Rain gauges  Ultimate objective  Benefit to citizens, governments, agriculture and businesses  “Precipitation is the most important atmospheric variable to forecast”

12. Landfalling Tropical Cyclones - 1 (Marks and Shay 1998 and Emanuel et al. 1995)  Scientific needs – Improve physical understanding and provide better initial conditions  Hurricane motion – increased skill  Intensity change – poor skill  Atmospheric and oceanic boundary layers  Air-sea coupling mechanisms  Tropical cyclogenesis

13. Landfalling Tropical Cyclones - 2 (Marks and Shay 1998 and Emanuel et al. 1995 and Rotunno et al. 1996)  Observational needs  Mobile observing system in a translating storm-coordinate system, including:  Satellites  Satellite-borne sensors  Sea surface scatterometers  Special Sensor Microwave Imager  Passive water vapor measurements  Active radar  Active lidar  Piloted and unpiloted aircraft from boundary layer to 20 km  Expendables from aircraft  Fixed and mobile coastal platforms  Moored and drifting platforms  Expendable bathythermographs  Ultimate objective  Real-time analyses of storm surge, winds and rain  Improve warnings  Provide local areas with info before, during and after landfall

14. Coastal Meteorology and Oceanography - 1 (Rotunno et al. 1996 and Emanuel et al. 1995)  Scientific needs  Coastal weather prediction  Air-sea fluxes and boundary layer structure in areas of mesoscale variability and at high wind speeds  Improved air-sea models of coastal zones  Understanding sea ice formation  Coastal flash flood forecasting  Polar lows

15. Coastal Meteorology and Oceanography - 2 ( Rotunno et al. 1996 and Emanuel et al. 1995)  Observational needs  Measurements in ABL and upper-ocean mixed layer  Measurements of air-sea fluxes and boundary layers in presence of ice formation  Onshore and offshore profilers  Satellite data of  Special Sensor Microwave Imager (SSMI)  Ocean wave spectra and winds from scatterometers and SARs  Precipitation  Snow cover  Sea ice coverage and thickness  TPW  SST

16. Coastal Meteorology and Oceanography - 3 ( Rotunno et al. 1996 and Emanuel et al. 1995)  Observational needs  Depth of thermocline  UAVs over oceans from boundary layer to upper levels  Moored and drifting buoys measuring ocean fluxes  Radars  Upper ocean current sensors  Minimeteorological drifters  Polar measurements of humidity and radiative fluxes  Ultimate objective  4-D VAR  Improved forecasts for more than 50% of US population

17. Mountain Meteorology - 1 (Smith et al. 1997 and Emanuel et al. 1995 and Dabberdt and Schlatter 1996)  Scientific needs  Modeling topographic circulations  Rocky Mountain lee-side phenomena  Lee-side cyclogenesis  Cold air outbreaks  MCSs  Trapping of cold air in basins and valleys  Orographic precipitation and flash floods  Generation of PV over mountains  Collective and multiscale effects of complex terrain (continuum of scales)

18. Mountain Meteorology - 2 (Smith et al. 1997)  Observational needs  WSR-88Ds  Polarimetric radars  Profilers and RASS  Doppler lidars  3-D, time-varying observations of multiscale orographic flows  Satellite sensors  Special Sensor Microwave/Imager (SSM/I)  Synthetic Aperture Radar (SAR)  Sun-glint observations  Visible imagery  Water vapor imagery  Sounding capabilities  GPS and sounding combinations to get temperature and water vapor profiles  Global wind measurements  Ultimate objective  Benefit to society

19. Urban Weather - 1 (Dabberdt et al. 2000)  Scientific needs  Impacts of visibility and icing on transportation  Winter storms  Convective storms  Lightning  Air quality and toxic releases  Integrate multiple datasets into models  Explicit use of cloud-resolving models  Inadvertant urban convective storm modification  Forecast uncertainty quantification

20. Urban Weather - 2 (Dabberdt et al. 2000)  Observational needs  Detection of low-visibility and icing conditions  Radar precipitation estimates in winter regimes  Location of mixed-phase precipitation  Quantitative forecasts of frozen/freezing precipitation  GPS integrated precipitable water and refractive index profiles  ACARS in-situ measurements  Boundary layer winds, stability and convergence lines  Ultimate objective  Benefit to society living in urban areas