Saturday, September 15, 2012

Forecast for Sunday, September 16, 2012

High pressure will continue to bring pleasant, mostly clear conditions through Monday Morning across our region. Winds will relax later tonight, after breezy conditions early this evening. Once the wind relaxes, it should remain light through Monday.
Clouds should increase ahead of our next system later on Monday. There could be a few showers developing late Monday. By Tuesday, a strong cold front will be to our west and this front will move east. Along that strong frontal boundary will be waves of low pressure enhancing precipitation. At this point, it appears the strongest waves of energy will move northward along the front when it is still positioned to our west. This means that the highest precipitation amounts should be to our west as well. However, we will still get some heavy showers and thunderstorms as the front moves through later on Tuesday and Tuesday Night. Meanwhile, earlier on Tuesday there could be some frequent showers associated with warmer air rushing ahead of the cold front. By early Wednesday Morning, there may be a few leftover showers and at that time the region is expected to have received one to two inches of rain from this event.
This set-up on Tuesday will also favor a period of strong winds as strong winds will reside just above the surface, especially if there is a break in the action and sunshine mixes the winds to the surface or if the heavier rain can bring the stronger winds down to the surface. In addition to the wind, any thunderstorm will have the potential of creating an isolated tornado as the wind shear and helicity increases. It is a question of whether the best instability will coincide with the increasing shear and we have a few more days to watch this set-up closely.  
Then another period of abundant sunshine and low humidity follows the nasty period of weather. Another, weaker cold front may approach next weekend bringing the chance for showers and sprinkles.