1. A Report to the WWRP Working Group on Nowcasting Research, 9 February Science of Nowcasting Winter Weather for Vancouver 2010 (SNOW-V10) by George Isaac Cloud Physics and Severe Weather Research Section Environment Canada
Nowcasting Winter Weather in Complex Terrain – Experiences from SNOW-V10
Presentation Shortened to Remove Material Still Under Review
Conclusions Remain the Same

2. Acknowledgements
Paul Joe1, Jocelyn Mailhot2, Monika Bailey1, Stephane Bélair2, Faisal Boudala1, Mindy Brugman4, Edwin Campos1, Richard Carpenter3, Stewart Cober1, Bertrand Denis4, Chris Doyle4. Doug Forsyth5, Ismail Gultepe1, Thomas Haiden6,
Ivan Heckman1, Laura Huang1, Jason Milbrandt2, Ruping Mo4, Roy Rasmussen7, Janti Reid1, Trevor Smith4, Ron Stewart 8, and Donghai Wang9
1 Cloud Physics and Severe Weather Research Section, Environment Canada 2 Recherche en prévision numérique, Environment Canada 3Weather Decision Technologies, Oklahoma, USA 4 Meteorological Service of Canada, Environment Canada 5National Severe Storms Laboratory, Norman, Oklahoma, USA 6Central Institute for Meteorology and Geodynamics (ZAMG), Austria 7 National Center for Atmospheric Research, Colorado, USA 8 Department of Environment and Geography, University of Manitoba 9Chinese Academy of Meteorological Science, China

3. Main Goals of SNOW-V10 Related to Nowcasting in Complex Terrain (Developed at March 08 Workshop)
To improve our understanding and ability to forecast/nowcast low cloud, and visibility;
To improve our understanding and ability to forecast precipitation amount and type;
To improve forecasts of wind speed, gusts and direction;
To develop better forecast system production system(s).
Assess and evaluate value to end users;
To increase the capacity of WMO member states (Training component).

4. Participating Groups Observing Systems and Associated Nowcast Systems
EC Region OAN Sites
EC Research Sites
UBC (McKendry) and U. Manitoba (Stewart)
NCAR WSDDM System + (Rasmussen)
BOM STEPS System (Seed)
NSSL Radar (Forsyth)
FMI (Koistinen)
Modeling Systems
EC Research Models
WDT (Carpenter)
China (Donghai Wang)
Austria INCA (Haiden)
Germany (Bott)
Switzerland (Mueller)
Verification
EC Team
NCAR (Brown)
Others:
CSU (Chandra & Vaisala)
U. Washington (House)

5. The Winter Olympic Challenge
Steep topography, highly variable weather elements in space and time
Village Creekside
5 km

6. Cypress Mountain

7. Summary of Instruments
Callaghan scanning C-Band Radar located near Whistler.
NOAA/OU X-Band Dual- Polarization Radar located at Canada/U.S. Border south of Vancouver.
Vertically Pointing X-Band Radars were located at TFT, RND and WWA.
A 915 MHz Boundary Layer Wind Profiler located at Squamish Airport (WSK).
A profiling microwave radiometer located at Timing Flats (TFT)
A rawindsonde system located at Nesters (VOC).
Ceilometers located at YVR, WWA, TFT, WSK, WGP, and VOG,
Recording visibility meters located at VOA, VOL, RND, VOT, VOG and YVR.
Hot Plates located at YVR, VOG, RND, VOA, VOL and TFT
Present weather sensors, either the Vaisala FD12P, Parsivel or POSS located at VOA, VOL, VOD, WWA, WSK, YVR, TFT, VOT, RND, and VOG,
A 3D anemometer located at the ski jump (VOW).
Temperature, relative humidity and GPS sensors were installed on the Whistler Village to Roundhouse Gondola, and the Whistler to Blackcomb gondola.
The Roundhouse site, near the helipad, was instrumented with a significant list of equipment. as an extension of the Fog Remote Sensing and Modeling Project (FRAM) (Gultepe et al., 2009).
Special surface sites measuring temperature and humidity were installed by UBC up Whistler Mountain
Snow Density measurements were made at some selected sites, mainly VOA, VOL RND and VOC after significant snowstorms.
Snow Photographs were made continuously at RND as a special project during some intensive periods and then irregularly outside those periods.

8. Whistler Peak Looking East Towards the Telecomm Tower

9. Roundhouse Helipad Site (RND)
FD12P MRR VRG GEONOR K-Z Solar Radiation Wind LPM Parsivel D Anemometer Sentry Vis
FMD YorkU PC TPU SFC Radiometer X SW IR Radiation/Surface Radiatioin
WXT Aerosol TPU Icing Detector
GCIP
DMIST

10. VOA Three Platforms
SNOW-V10
OAN
Whistler
Maintenance

11. VOA (Pig Alley) Precipitation Occurrence Sensing System (POSS)
X Band, Continuous Wave Radar
Large sample volume
Present weather, precipitation type and intensity
Doppler Spectrum, Drop Size Distribution
Parsivel - Laser-imaging system,particle shadows
- Present weather, precipitation type and intensity
- Doppler Spectrum, Drop Size Distribution
Visibility due to precipitation reported
Hot Plate – heated top/bottom surface
Designed for snowfall precipitation measurements
Wind
Vaisala FD12P – laser scattering system
Visibility
All 1 minute (1 and 1)!

12. VOL Mid-station/Raven’s Nest
Harvey Fellowes

13. VOB
(No Power, 15/1 min data)

14. Timing Flats

16. Timing Flats (VOT) Ceilometer 25K, (also CL31 – aerosol mode)
Radiometer Parsivel OAN (1 min) POSS
MRR
Move in summer

17. Whistler Village Gondola (WVG)
Local Beer Company

18. 1 degree

19. P2P (Peak to Peak)

20. Snow Photography McGill University U Manitoba
Need to help develop higher accuracy radar retrievals.

22. Network Radar Coverage
100 km
NSSL
XBand
DualPol
Whistler Radar

23. Whistler Doppler Weather Radar

24. Blocked flow (downslope winds)
means Intense
precipitation is on the slope and not on mountain peak
Precipitation: the intense precipitation is on the slope.
Doppler velocity: Blue means air is moving to the left or downslope

25. EC OAN Squamish Airport LAP-3000 Wind Profiler co-located with
Full compound autostation.
Site also had Remote Video System
and Automatic Weather Station
EC OAN

26. Wind Profile for 12 hours duration.
Normally, just 1 profile with radiosondes.
Considerable structure within 12 hours.

27. Canadian Models Used in SNOW-V10
Model Name
Organization
Country
Spatial Resolution
Temporal Resolution Available
Times of Day Run (UTC)
Length of Forecst (hours)
General Description
ABOMLAM1km
Environment Canada
Canada
1 Km
15 min
Every 15 min
Max 6 h
Adaptive Blending of Observation and Models using GEM LAM1k
ABOMREG
15 km
Adaptive Blending of Observation and Models using GEM Regional
INTW
1 and 15 km
INTegrated Weighted Model using LAM1k, GEM Regional and Observations
LAM1k
1 km
30 s (Model), 15 min (Tables)
11 and 20 UTC
19 h
Limited-Area version of GEM model
LAM2.5k
2.5 km
1 min (Model), 15 min (Tables)
06 and 15 UTC
33 h
REG
7.5 min (Model), 15 min (Tables)
00, 06, 12, 18 UTC
48 h
Regional version of GEM (Global Environmental Multiscale) model

28. Other Countries Models Used in SNOW-V10
Model Name
Organization
Country
Spatial Resolution
Temporal Resolution Available
Times of Day Run (UTC)
Length of Forecst (hours)
General Description
CMA
Chinese Meteorological Administration
China
15 km & 3 km
1 hour
00 and 12 UTC
48 h & 24 h
CMA GRAPES-Meso NWP model
WDTUSL
Weather Decision Technologies and NanoWeather
USA
pointwise or 100 m grid
02, 08, 14, 20 UTC
48 h
Surface layer model nested in NAM. Works particularly well in quiescent condistions..
WSDDM
National Center for Atmospheric Research (NCAR)
Radar Resolution
10 min (based on radar update)
Every 10 min
2 hours
Nowcast based on storm tracking of radar echo using cross correlation and real-time calibration with surface precipitation gauges.
ZAMGINCA
Central Institute for Meteorology and Geodynamics (ZAMG)
Austria
1 km
Every hour
18 hours
The Integrated Nowcasting Through Comprehensive Analysis (INCA) system uses downscaled ECMWF forecasts as a first guess and applies corrections according to the latest observation.
ZAMGINCARR
15 min
Every 15 min
The precipitation module of INCA combines raingauge and radar data, taking into account intensity-dependant elevation effects. The forecasting mode is based on displacement by INCA motion vectors, merging into the ECMWF model through prescribed weighting.

30. Products During Olympics
Each group produced a Table showing 24 hour forecast of significant variables for main venue sites (hourly intervals and 10 to 15 min intervals in first two hours). Similar to what forecasters produce
A Research Support Desk was run during Olympics and Paralympics (virtual and on-site) providing real time support to forecasters.
A SNOW-V10 Web site was created with many of the products (time series for sites, remote sensing products, area displays, soundings (gondola and others), and a very successful Blog.

31. Research Support Desk (RSD) VANOC
SNOW-V10
Research Support Desk (RSD)
On-Site (3 scientists)
WebEx (at least once per day)
VANOC
Chris Doyle
Central Forecast Office
Trevor Smith et al.
SNOW-V10 Web Site
SNOW-V10 Blog
1 min Data from Research Sites
Whistler Radar
Microwave Radar
MRR
Wind Profiler
Gondola Profiles
Model and Data Charts
Forecast Tables
Nowcasts
etc
Venue Forecasters
Cypress Freestyle
Callaghan Nordic
Callaghan Ski Jump
Whistler Alpine
Whistler Sliding
Pacfic Weather Centre Data
15 Min Data
Soundings
Meteograms
Satellite Data
Other Model Data

32. Harvey’s
Cloud
Equipment on Whistler mountain provided good data for forecasters and help in understanding weather processes
Remote Sensors
Most of SNOW-V10 data from instruments are now being displayed on Web site ( Model data is also being shown.

33. Weather Decision Technologies (WDT) Products for Vancouver 201033 33

34. INCA (Integrated Nowcasting through Comprehensive
Analysis) developed at the Austrian national weather service
Products were available in real time for forecaster use and evaluation 34 34

35. Adaptive Blending of Observations and Model (ABOM): What is it how does it work
Statistical method for generating point forecasts using model and observation data
The current observation + a weighted combination of forecasts from three different methods:
Extrapolation of the current observation trend
The change predicted by a model forecast
Observation persistence
The weights are determined from recent history and are updated every 15 minutes with new observation data (an hour was used in the studies here)

36. Background of INTW INTW refers to integrated weighted model
LAM 1k, LAM 2.5k and REG 15k were selected to generate INTW
Major steps of INTW generation
Data pre-checking - defining the available NWP models and observations
Extracting the available data for specific variable and location
Calculating statistics from NWP model data, e.g. MAE, RMSE
Deriving weights from model variables based on model performance
Defining and performing dynamic and variational bias correction
Generating Integrated Model forecasts (INTW)

38. Summary and Future …1
Many physical processes were well documented during SNOW-V10 such as: diabatic effects due to melting snow, wind flow around and over terrain, diurnal flow reversal in valleys associated with daytime heating, precipitation reductions and increases due to local terrain influences, etc
Weather changes rapidly in complex terrain and it is necessary to get good measurements at time resolutions of at least min. SNOW-V10 attempted to get measurements at 1 min resolution where possible.
Because of the rapidly changing nature of the weather, weather forecasts also must be given at high time resolution.
There are many difficulties in measuring parameters, especially precipitation amount and type in this environment. Special scanning strategies were necessary for the scanning radar placed at Whistler and significant differences were observed with many different types of surface precipitation sensors placed at several locations. 38 38

39. Summary and Future …2
SNOW-V10 has made progress in forecasting “non traditional” variables like ceiling, visibility, wind gusts, etc.
Nowcast schemes are showing skill.
There is value in presenting real-time obs and several models to forecasters doing Nowcasting.
The techniques tested are not yet good enough to issue standalone nowcasts. Significant errors exist of high impact events that require forecaster intervention.
Weather Forecasts, both long and short term, were critical in the conduct of these games, both long term and short term.
Statistical verification of models and nowcasts are continuing.
Papers are being written on SNOW-V10 data.
At the 4th SNOW-V10 Workshop held in Huntsville, north of Toronto, January, with 35 participants, it was decided to prepare a special issue of Pure and Applied Geophysics (Pageoph) with a deadline of 1 October 2011 for submission of papers. 31 tentative titles have been received.
The idea of a forecaster training workshop is being explored. 39 39

40. Questions?