Real Time High-Resolution NWP @ McGill University

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Real Time High-Resolution NWP _at_ McGill University

• J. Gyakum1, R. McTaggart-Cowan1, P. Sisson2

1 McGill University
2 National Weather Service
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Objectives

• Implementation of a real time MC2 system
• Data collection for stat-istical analysis and
  case studies
• Investigate impacts of high-resolution modelling
  on QPF and near-surface winds

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Outline

• Need for mesoscale modelling
• Description of NWP system
• Validation case study
• (27 September 2002)
• Project timeline and ongoing upgrades

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High Resolution (3km)

• Accurate topography
• Improved wind fields and fluxes
• Model terrain-induced confluence

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Mesoscale Orography
High resolution (6 km)
Degraded resolution (100 km)
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Model Description

• MC2 version 4.9.5
• Non-hydrostatic, semi-implicit time step,
  semi-Lagrangian advection
• Full physics version 3.72
• Three one-way nest domains

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Nesting Strategy
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Computational Platform

• NEC SX-6/8M10 super-computer maintained by
  RPN/CMC
• 10x8 PE nodes
• Theoretical peak performance 10x64 GFlop

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Performance Timeline
Domain 1 (36km)
Domain 2 (12km)
Domain 3 (3km)
0000 UTC
0300 UTC
0600 UTC
0900 UTC
CMC Regional Forecast
McGill Real Time Mesoscale Cascade
All runs completed by 0330 Eastern Standard Time
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Production Suite

• Synoptic

• Mesoscale

Traditional upper-level forcings and QG dynamics
Visualization of processes and forcings occurring
at small scales
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Production Suite

• Synoptic

Traditional upper-level forcings and QG dynamics
dynamic tropopause potential temperature
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Production Suite

• dynamic tropopause ?

• Synoptic

Traditional upper-level forcings and QG dynamics
isentropic potential vorticity
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Production Suite

• dynamic tropopause ?
• isentropic potential vorticity

• Synoptic

Traditional upper-level forcings and QG dynamics
coupling index ?dt - ?e(bl)
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Production Suite

• dynamic tropopause ?
• isentropic potential vorticity
• coupling index

• Synoptic

Traditional upper-level forcings and QG dynamics
moisture transport
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Production Suite

• dynamic tropopause ?
• isentropic potential vorticity
• coupling index
• moisture transport

• Synoptic

Traditional upper-level forcings and QG dynamics
moisture flux divergence
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Production Suite

• dynamic tropopause ?
• isentropic potential vorticity
• coupling index
• moisture transport
• moisture flux divergence

• Synoptic

Traditional upper-level forcings and QG dynamics
Non-standard synoptic output available on 36 and
12 km domains (1 2)
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Production Suite

• Mesoscale

Visualization of processes and forcings occurring
at small scales
frontogenesis function and terms
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Production Suite

• frontogenesis function

• Mesoscale

Visualization of processes and forcings occurring
at small scales
high-resolution convective and explicit
precip-itation
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Production Suite

• frontogenesis function
• high resolution precipitation

• Mesoscale

Visualization of processes and forcings occurring
at small scales
high resolution vertical motion fields
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Production Suite

• frontogenesis function
• high resolution precipitation
• high resolution vertical motion

• Mesoscale

Visualization of processes and forcings occurring
at small scales
cross-sectional plots of various thermodynamic
variables
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Production Suite

• frontogenesis function
• high resolution precipitation
• high resolution vertical motion
• thermodynamic cross-sections

• Mesoscale

Visualization of processes and forcings occurring
at small scales
cross-sectional plots of frontal circulations
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Production Suite

• frontogenesis function
• high resolution precipitation
• high resolution vertical motion
• thermodynamic cross-sections
• frontal circulations

• Mesoscale

Visualization of processes and forcings occurring
at small scales
Mesoscale visualization tools available on 12 and
3 km domains (2 3)
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Case Study (2 May)
GOES-East Water vapour 0000UTC 2 May
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Precipitation Structure
Radar Observations
Model Rain Rate
0900 UTC 2 May 2002 (initialized 0000 1 May)
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Precipitation Structure
Radar Observations
Model Rain Rate
1200 UTC 2 May 2002 (initialized 0000 1 May)
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Project Timeline
model implementation
McGill-side storage structure
analysis tool construction
visualization design
web interface construction
gridded data transfers
AWIPS implementation
real time modelling
completed
in progress
planned
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Case Study (27 Sept)
GOES-East Water vapour (0000 UTC 27 Sept)
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Precipitation
Domain 1 (36km) total 24 hour rainfall ending
1200 UTC 28 Sept
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Precipitation
Observed total 24 hour rainfall ending 1200 UTC
28 Sept
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Precipitation
Domain 2 (12km) total 24 hour rainfall ending
1200 UTC 28 Sept
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Precipitation
Domain 3 (3km) total 24 hour rainfall ending 1200
UTC 28 Sept
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Precipitation
Domain 3 (3km) total 24 hour rainfall ending 1200
UTC 28 Sept
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500mb Height/Vorticity
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325K Potential Vorticity
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Dynamic Tropopause
McGill 24h forecast
RUC analysis 00Z 28
Potential Temperature
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Project Timeline
model implementation
McGill-side storage structure
analysis tool construction
web interface construction
visualization design
real time modelling
March
June
September
December
2002
2003
completed
in progress
planned
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Case Study (30 March 03)
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Dynamic Tropopause
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Dynamic Tropopause
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Coupling Index
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Radar Imagery
0814 UTC 31 March
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Precipitation Bands
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IBL Development
YUL
BTV
Lake Champlain
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Summary

• Implementation of real time mesoscale NWP is
  under way at McGill
• High resolution (3 km) will enhance mesoscale
  flow and QPF forecasts for the St. Lawrence / NE
  states region

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Data Access

• http//132.206.43.1515080
• Grib files available to ftp servers upon request
  to
• rmctc_at_zephyr.meteo.mcgill.ca