Previous research has shown that thunderstorm development is affected by large-scale flow. The purpose of this study is to investigate how synoptic flow affects the development, intensity, and thermodynamic environment of northern New England convective storms. Convective storms which occurred during the warm-season months (April – September) of 2003 – 2007 were analyzed. Using NEXRAD Level III storm structure data from the Gray/Portland, ME (KGYX) WSR-88D radar and surface METAR observations within 124 nm of the KGYX radar, thunderstorm days were identified when at least one surface METAR observed thunder or lightning, storm structure identified cells had VIL values ≥ 10 kg m-2, and cells had maximum reflectivity ≥ 50 dBz at least once during their lifetime. Individual cells were identified as being convective when VIL ≥ 10 kg m-2, maximum reflectivity ≥ 50 dBz, and range from the KGYX radar site were between 25 and 125 km. Convective cell intensity, movement, and duration were monitored.

Large-scale flow and stability indices present prior to the initiation of convection were found for each convective cell. Proximity soundings before the first volume scan of each convective cell were generated using the North American Regional Reanalysis (NARR) dataset.

Convective cells were stratified by wind direction at various levels of the atmosphere. Each flow regime and the location of its corresponding convective cells were plotted using ESRI ArcGIS. These plots were created to show the affects of large-scale flow and local terrain on convective development. Stability indices were also stratified by wind direction to discover whether specific indice values were associated with various flow regimes.