The intended purpose of the real-time analyses and forecasts of the quasi-geostrophic (QG) diagnostic equations web page is to provide an interactive tool that can be used to enhance classroom education and/or weather discussions in both the academic and operational environment by providing visualizations of core QG dynamical equations.
The calculations and visualizations are produced using NCAR Command Language version 6.6.2 on computer resources at the NOAA National Severe Storms Laboratory and the University of Oklahoma. All fields are computed using 12-hourly pressure-level data from the Canadian Meteorological Centre (CMC) Global Deterministic Forecast System forecasts available in GRIB2 format at 0.24×0.24 degree latitude-longitude grid spacing. The raw CMC global forecasts are read using information at every third grid point and then are smoothed using a 9-point local smoother run 80 times to produce cleaner results for the QG diagnostics. A detailed description of the fields displayed on each set of images is provided in the Users’ Guides and as captions on the animations themselves. While every attempt is made to keep the images up-to-date, it is possible that there will be interruptions to the image generation services as system updates occur.
Each animation provided at the links below includes a 20-day analysis archive and the most recent forecast out to 144 hours. Images older than 20 days are not retained.
1. Sutcliffe Development Theory: (click here for Users’ Guide)
2. Petterssen Development Equation: (click here for Users’ Guide)
3. Height Tendency Equation: (click here for Users’ Guide)
4. Omega Equation: (click here for Users’ Guide)
5. QG energetics: [Lackmann (2011) pp. 57-65]
6. References:
Bluestein, H. B., 1992: Principles of Kinematics and Dynamics. Vol. I. Synoptic-Dynamic Meteorology in Midlatitudes. Oxford University Press, 431 pp.
Carlson, T. N., 1998: Mid-Latitude Weather Systems. Amer. Meteor. Soc., 507 pp.
Hakim, G. J., L. F. Bosart, and D. Keyser, 1995: The Ohio Valley wave-merger cyclogenesis event of 25-26 January 1978. Part I: Multiscale case study. Mon. Wea. Rev., 123, 2663-2692.
Hoskins, B. J., I. Draghici, and H. C. Davies, 1978: A new look at the omega equation. Quart. J. Roy. Meteor. Soc., 104, 31-38.
Keyser, D., M. J. Reeder, and R. J. Reed, 1988: A generalization of Petterssen’s frontogenesis function and its relation to the forcing for vertical motion. Mon. Wea. Rev., 116, 762-780.
Keyser, D., B. D. Schmidt, and D. G. Duffy, 1992: Quasigeostrophic vertical motions diagnosed from along- and cross-isentrope components of the Q vector. Mon. Wea. Rev., 120, 731-741.
Martin, J. E., 1999a: Quasigeostrophic forcing of ascent in the occluded sector of cyclones and the Trowal airstream. Mon. Wea. Rev., 127, 70-88.
Martin, J. E., 1999b: The separate roles of geostrophic vorticity and deformation in the midlatitude occlusion process. Mon. Wea. Rev., 127, 2404-2418.
Martin, J. E., 2006: Mid-Latitude Atmospheric Dynamics: A First Course. John Wiley & Sons Ltd., 324 pp.
Lackmann, G., 2011: Midlatitude Synoptic Meteorology: Dynamics, Analysis, and Forecasting. Amer. Meteor. Soc., 345 pp.
Petterssen, S., 1956: Motion and Motion Systems. Vol. I. Weather Analysis and Forecasting. McGraw-Hill, 428 pp.
Sutcliffe, R. C., 1947: A contribution to the problem of development. Quart. J. Roy. Meteor. Soc., 73, 370-383.
Sutcliffe, R. C., and A. G. Forsdyke, 1950: The theory and use of upper air thickness patterns in forecasting. Quart. J. Roy. Meteor. Soc., 76, 189-217.
Trenberth, K. E., 1978: On the interpretation of the diagnostic quasi-geostrophic omega equation. Mon. Wea. Rev., 106, 131-137.