The Climate Prediction Center (CPC) recently updated its forecast for this month. It is calling for colder and wetter than average weather in the Northwest, warmer than normal temperatures in the East and South, and above average precipitation in the Southeast.
Our updated January forecast is out. Early #cold expected to overwhelm any potential late warmth in the Northwest. https://t.co/ZojpnS5Ja5 pic.twitter.com/kMyRhMXESR
— NWSCPC (@NWSCPC) December 31, 2016
The CPC says the major climate factors have not changed over the last few weeks, with a weak La Nina continuing in the Pacific Ocean. La Nina is expected to continue through the month, although it is not as strong as observed in the past. This may result in less than robust seasonal impacts. La Nina was discussed and forecast previously by the Climate Prediction Center in the November and Fall/Winter long range forecasts.
La Nina occurs when the waters of the Pacific Ocean show a general trend of cooling, the opposite of an El Nino. During La Nina periods, the Jet Stream is less active in the Southern U.S. This usually leads to less storms systems and below average precipitation. Cooler than normal weather typically occurs across the northern tier of the country and occasionally wetter periods as well.
Widespread colder than normal temperatures expected for days 8-14 outside the northeast, south, and parts of Alaska https://t.co/ShcAG0RWYb pic.twitter.com/wbkWKG3xIj
— NWSCPC (@NWSCPC) December 30, 2016
One of the more noticeable changes in the outlook compared to the previous forecast issued for January was the shift to above normal precipitation in the Southeast. The first couple of weeks of the month are expect to be wetter than average in that area of the country.
High confidence in much above-normal temperatures across the East in early January https://t.co/GLrUcpze6h pic.twitter.com/uJcHVMqTId
— NWSCPC (@NWSCPC) December 16, 2016
For WeatherNation: Meteorologist Mace Michaels
Good to see the CPC change in guidance based on what is really happening. You can thank the weak Polar Vortex allowing cold air to overwhelm the La Nina effect.