Saturday, August 8, 2009

Where Cold Fronts Come to Die

During the summer months, cold fronts usually have trouble moving through our part of the world and many times they stall and dissipate over our region or just south and east of here over the coastal Carolinas. This is due to several factors including the positioning of the jet stream and the strength of the Bermuda High. Also, the cool/dry air masses and their associated high pressure areas are not that forceful at this time of year. That is why the heat and humidity usually win out in Hampton Roads. Every so often though, a cool air mass will have enough of a push to make it here bringing a brief break to the heat and humidity. When the fronts do make it out to the Gulf Stream off the Southeastern Coastline, there is that possibility that a tropical cyclone could spin up if conditions are right. If there is an unusually strong high pressure area to the north, this could increase the possibility of tropical cyclone development. Once we get into September and October, the cool air masses start to become stronger and have more push, so they often begin to make it through our area with no problem. However, it all depends on the weather pattern at the time and the direction that the upper-level winds are blowing. If they are blowing SW to NE or parallel to the cold front, then the front will most likely stall out. If the upper-level winds are blowing NW to SE, the front should be able to push off the coast with no problem. There are times when the jet stream is too far north to push the fronts through the area.