Abnormal Weather

A strong upper-atmospheric trough will dig into the Plains and Midwest as an upper-atmospheric ridge builds in the West. This will mean chilly temperatures for the northern Rockies to the southern Plains and into the Midwest, while the West Coast will bake in searing heat.

September Snow  Rapid City, South Dakota saw its earliest measurable snowfall (at least 0.1 inch) on record on September 11 with 0.9" reported (previous record was September 13). North Platte, Nebraska also saw its earliest snow with a trace reported on Thursday.

Lake-Effect Rain Showers This first taste of fall will even bring the chance for lake-enhanced rain showers late this week in parts of the Great Lakes region.

Western Heat The heat persists in much of the Pacific Northwest as a strong ridge of high pressure builds into the region again.

Quiet Tropics One of the factors that has limited tropical development this season is wind shear. This year, according to records that date back to 1970, the period from June to August tied for the second-highest average vertical wind shear on record. Wind shear is important because it removes the heat and moisture from the area near a storm's center and causes the convection to be displaced. This makes it more difficult for the system to become organized and develop.

  http://www.weather.com/news/weather-forecast/strange-weather-early-snow-cold-heat-quiet-tropics-20140910