Prof. John Gyakum

John  Gyakum

Synoptic and Dynamic Meteorology

Office: Burnside Hall 715
Tel.: (514) 398-6076
Fax.: (514) 398-6115
john [dot] gyakum [at] mcgill [dot] ca (E-mail)
Group Photo

Research interests

Extratropical transformations and extratropical cyclones

Current research focuses on the dynamical processes associated with tropical cyclones that ultimately affect the Atlantic Canada provinces (Milrad et al 2009a). These cases typically transform from a warm core convectively driven disturbance into a cold core extratropical system. During this latter phase, however, these and other extratropical weather systems are often responsible for copious amounts of rainfall in the Atlantic provinces (Milrad et al 2009b). Work is in progress investigating the processes by which the cyclones transform from tropical to extratropical systems. Additional research is being conducted on the roles that surface fluxes of heat and moisture play in the evolution of these extratropical transformations.

Heavy precipitation events and water vapour transport to extratropical latitudes

We are studying the roles that especially strong poleward moisture transports (Roberge et al. 2009) play in the dynamics of precipitating high-latitude weather systems. One example of a tropical moisture source playing an important role in precipitation is that of the recent Ice Storm that devastated portions of the eastern Canadian Provinces and the northeastern United States. We are using high-resolution atmospheric models to study the evolution of precipitating systems within the Saint Lawrence River valley surrounding Montreal. Such precipitation events are often strongly influenced by the orographically-channeled flow (Carrera et al. 2009) in the region.

Some recent publications

Gervais, M., E. Atallah, J. R. Gyakum, and L. B. Tremblay, 2016: Arctic air masses in a warming world. J. Climate, 29, 2359-2373.

Grotjahn, R., R. Black, R. Leung, M. F. Weaver, M. Barlow, M. Bosilovich, A. Gershunov, W. J. Gutowski, J. R. Gyakum, R. W. Katz, Y.-Y. Lee, Y.-K. Lim, and Prabhat, 2016: North American Extreme Temperature Events and Related Large Scale Meteorological Patterns: A Review of Statistical Methods, Dynamics, Modeling, and Trends. Climate Dynamics, 45, 1-34.

Kushner, P. J., P. Gauthier, J. R. Gyakum, P. Myers, K. Strong, R. Stull, and P. Taylor, 2015: Report on a workshop of the working group on Atmosphere-Related Research in Canadian Universities. CMOS Bulletin, 43, 142-147.

Milrad, S., J. R. Gyakum, and E. H. Atallah, 2015: A meteorological analysis of the 2013 Alberta Flood: Antecedent large-scale flow pattern and synoptic-dynamic characteristics. Mon. Wea. Rev., 143, 2817-2841.

Plante, M., S.-W. Son, E. Atallah, J. R. Gyakum, and K. Grise, 2015: Extratropical cyclone climatology across eastern Canada. International Journal of Climatology, 35, 2759-2776.

Gervais, M., J. R. Gyakum, E. Atallah, and B. Tremblay, 2014: How well are the distribution and extreme values of daily precipitation represented in the Community Climate System Model? A comparison to reanalysis, satellite, and gridded station data. J. Climate, 27, 5219-5239.

Milrad, S. M., J. R. Gyakum, E. H. Atallah, and K. Lombardo, 2014: On the dynamics, thermodynamics, and forecast model evaluation of two snow-burst events in southern Alberta. Wea. Forecasting, 29, 725-749.

Gervais, M., L. B. Tremblay, J. R. Gyakum, and E. H. Atallah, 2014: Representing extremes in a daily gridded precipitation analysis over the United States: impacts of station density, resolution, and gridding methods. J. Climate, 27, 5201-5218.

Small, D., E. H. Atallah, and J. R. Gyakum, 2014: An objectively determined blocking index and its northern hemisphere climatology. J. Climate, 27, 2948-2970.

Milrad, S. M., E. H. Atallah, J. R. Gyakum, and G. Dookhie, 2014: Synoptic typing and precursors of heavy warm-season precipitation events at Montreal, Quebec. Wea. Forecasting, 29, 419-444.

Grise, K. M., S.-W. Son, and J. R. Gyakum, 2013: Intraseasonal and interannual variability in North American storm tracks and its relationship to equatorial Pacific variability. Mon. Wea. Rev., 141, 3610-3625.

Hryciw, L. M., E. H. Atallah, S. M. Milrad, and J. R. Gyakum, 2013: A meteorological analysis of important contributors to the 1999-2005 Canadian Prairie drought. Mon. Wea. Rev., 141, 3593-3609.

Milrad, S. M., E. H. Atallah, and J. R. Gyakum, 2013: Precipitation modulation by the Saint Lawrence Valley in association with transitioning tropical cyclones. Wea. Forecasting, 28, 331-352.

Turner, J. K., J. R. Gyakum, and S. M. Milrad, 2013: A thermodynamic analysis of an intense North American arctic air mass. Mon. Wea. Rev., 141, 166-181.

Splawinski, S., J. R. Gyakum, and E. H. Atallah, 2012: The role of anticyclones in replenishing surface cold air and modulating freezing rain duration. McGill Science Undergraduate Research Journal, 7, 54-60.

Ressler, G. M., S. M. Milrad, E. H. Atallah, and J. R. Gyakum, 2012: Synoptic-scale analysis of freezing rain events in Montreal, Quebec. Wea. Forecasting, 27, 362-378.

Razy, A., S. M. Milrad, E. H. Atallah, J. R. Gyakum, 2012: Synoptic-scale environments conducive to orographic impacts on cold-season surface wind regimes at Montreal, Quebec. J. Climatology and Appl. Meteorology, 51, 598-616.

Hanesiak, J. M., R. E. Stewart, B. R. Bonsal. P. Harder, R. Lawford, R. Aider, B. D. Amiro, E. Atallah, A. G. Barr, T. A. Black, P.Bullock, J. C. Brimelow, R. Brown, H. Carmichael, C. Derkson, L. B. Flanagan, P. Gachon, H. Greene, J. R. Gyakum, W. Henson, E. H. Hogg, B. Kochtubajda, H. Leighton, C. Lin, Y. Luo, J. H. McCaughey, A. Meinert, A. Shabbar, K. Snelgrove, K. Szeto, A. Trishchenko, G. van der Kamp, S. Wang, L. Wen, E. Wheaton, C. Wielki, Y. Yang, S. Yirdaw, and T. Zha, 2011: Characterization and summary of the 1999-2005 Canadian Prairie Drought. Atmos.-Ocean, 49, 421-452.

Splawinski, S., J. R. Gyakum, and E. H. Atallah, 2011: Atmospheric circulation structures associated with freezing rain in Quebec City, Quebec. McGill Science Undergraduate Research Journal, 6, 50-55.

Milrad, S. M., J. R. Gyakum, E. H. Atallah, and J. F. Smith, 2011: A diagnostic examination of the eastern Ontario and western Quebec wintertime convection event of 28 January 2010. Wea. Forecasting, 26, 301-318.

Turner, J. K., and J. R. Gyakum, 2011: The development of Arctic air masses in Northwest Canada and their behavior in a warming climate. J. Climate, 24, 4618-4633.

Small, D., E. Atallah, and J. R. Gyakum, 2011: Wind Regimes along the Beaufort Sea Coast Favorable for Strong Wind Events at Tuktoyaktuk. J. Climatology and Appl. Meteorology, 50, 1291-1306.

Milrad, S. M., E. H. Atallah, and J. R. Gyakum, 2010: A diagnostic examination of consecutive extreme cool-season precipitation events at St. John’s, Newfoundland in December 2008. Wea. Forecasting, 25, 997–1026.

Knowland, K. E., J. R. Gyakum, and C. A. Lin, 2010: A study of the meteorological conditions associated with anomalously early and late openings of a Northwest Territories winter road. Arctic, 63, 227-239.

Danielson, R. E., and J. R. Gyakum, 2010: A composite look at short-time-scale sea-surface temperature changes in the western North Pacific based on ships and buoys. Quart. J. Roy. Meteor. Soc, 136, 319-332.

Turner, J., and J. R. Gyakum, 2010: Trends in Canadian surface temperature variability in the context of climate change. Atmos.-Ocean, 48, 147-162.

Milrad, S., E Atallah, and J. R. Gyakum, 2010: Synoptic typing of extreme cool-season precipitation events at St. John’s, Newfoundland, 1979-2005. Wea. Forecasting, 25, 562-586.