3 Big Weather Changes

There will be a configuration in the northern branch of the jet stream. This will bring weather changes by the end of the week such as warmer temperatures and less storms in the south. 

A southward dip in the jet stream across the West and the Plains to start the week will be replaced by an upper-level ridge by midweek. The end result is that temperatures will be on an upward swing across these regions. In fact, highs in the 100s are not out of the question in the Desert Southwest, while upper 70s and low 80s return to the northern Plains. Unfortunately, weather conditions in the Northeast will start out gloomy with below-average temperatures and scattered showers expected on Monday, particularly across the interior. This follows a cool finish to last week in the region with many cities experiencing below-average temperatures.

An area of low pressure in the upper atmosphere centered near Nova Scotia on Monday will shift east by midweek. This should allow warmer temperatures to take shape by Wednesday in the Northeast. Another dip in the jet stream may nudge temperatures downward a few degrees Thursday into Friday. However, temperatures this week will be within a few degrees of late-April averages.

http://www.weather.com/forecast/national/news/three-big-weather-changes-this-week