A quick look at a weather map can usually give us a quick idea whether it will produce severe weather. On the left is the scenario for Thursday. A weak cold front will work in from the north. Because of its east-west orientation, there may be just enough convergence at the surface to produce some showers. However, long-lived thunderstorm activity isn’t expected. With east-west cold fronts, the jet stream is almost always parallel to the front. While rain is possible, big thunderstorms aren’t likely.
However, with thunderstorms that sweep in from the west, there is usually more convergence which leads to higher rain and thunderstorm chances. Southerly winds in advance of the front can bring in higher levels of moisture from the Gulf of Mexico. In addition, there’s usually a strong jet stream perpendicular to a north-south front. This leads to higher wind shear…and a higher intensity of thunderstorms! So as we head through the spring season, be on the lookout for the north-south orientation on the weather map.
This post was written by Eric Sorensen on April 8, 2014