The environment and characteristics of convective events over Niamey, Niger:

1. The environment and characteristics of convective events over Niamey, Niger: AMMA SOP2 observations and climatological context Matthew A. Janiga1, Chris D. Thorncroft, and Earle Williams1 University at Albany1 Thermodynamically Aided Development SOP2 Convection Overview Climatological Context Solid lines indicating tracks of 233K centroids of MCSs passing over the radar. Colored based on time J5 J4 J3 Background J2 J1 West Africa topographic map Fig. 1 The hour (UTC) of maximum <233K pixel frequency in 10.8 μm IR imagery during JJAS 2004-2008. J1 J2 Jos Plateau Convection Jos Plateau Convection Speed Rain fall Some lit. review stuff J3 J5 Jos Plateau Convection Environment of SOP2 Convection Niamey Convection Dynamically Aided Development 850 and 500 hPa Tv’ 900 hPa Wind Arrows Fig. 2 The fraction of time pixels are <233K pixel in 10.8 μm IR imagery during JJAS 2004-2008 at each 30 min interval (UTC). • (-5 to 10 lon) Lat (5-17.5)-time (JJAS) Hovmöller of MCS track density and 900-650 hPa shear. 850 QVC 650 Stream Function 650 PV AEW Centers (Lift or Moisture) Acknowledgements and References This work is supported by NSF grant ATM0507976. Based on an French initiative, AMMA was built by an international scientific group and is currently funded by a large number of agencies, especially from France, UK, US and Africa. It has been the beneficiary of a major financial contribution from the European Community's Sixth Framework Research Program. Detailed information on scientific coordination and funding is available on the AMMA International web site http://www.amma-international.org. We would also like to acknowledge the U.S. Department of Energy as part of the Atmospheric Radiation Measurement (ARM) Program Climate Research Facility. Special thanks to Doug Parker for the his work on the high resolution special observing period radiosonde data at the Niamey Airport as well as to Luc Descroix and Thierry Lebel for their contributions to the Niamey mesosite raingauge data. Lastly we would like to extend thanks to Brian Russell for his work organizing the radar data and helpful discussions. Berry, G., C. Thorncroft, and T. Hewson, 2007: African easterly waves during 2004—Analysis using objective techniques. Mon. Wea. Rev., 135, 1251–1267. Liebmann, B., and C. A. Smith, 1996: Description of a complete (interpolated) OLR dataset. Bull. Amer. Meteor. Soc., 77, 1275-1277. Nettleton L. S., S. Daud, R. Neitzel, C. Burghart, W.-C. Lee, and P. Hildebrand, 1993: SOLO: A program to peruse and edit radar data. Preprints, 26th Conf. on Radar Meteorology, Norman, OK, Amer. Meteor. Soc., 338–339. Relative number of dynamically and thermodynamically forced events and properties of each