The August heat may not be as intense or widespread this month as previously thought. The revised August forecast from NOAA’s Climate Prediction Center has significant changes when compared to the outlook issued less than two weeks ago. Cooler than normal readings are now expected over most of the Plains. The above average temperatures that were in the earlier forecast across most of the nation have been pushed back into the West, New England and South Florida.
Some changes have also been made to the precipitation forecast. The wetter than normal forecast has been extended into the Southeast. Drier than normal weather is now in the forecast for the Pacific Northwest. Below is the outlook issued on July 20th.
— NWSCPC (@NWSCPC) July 20, 2017
The Climate Prediction Center states that the changed was based on forecast model guidance, especially for the first half of the month. Current soil moisture conditions were also considered. EL Nino or La Nina will not be a factor since Pacific Ocean water temperatures are in a neutral state and are expected to remain neutral this month.
A shift in the Jet Stream position at the beginning of the month is one the main reasons for the temperature forecast change. An upper level trough will sink down from Canada over the Central U.S., bringing cooler readings for at least the first part of the month. A ridge in the atmosphere will push the Jet Stream northward over the West, creating warmer temperatures. Soil moisture content in the High Plains is well below average, which often produces warmer weather during this time of the year. Model forecasts heavily influenced the precipitation forecast.
For WeatherNation: Meteorologist Mace Michaels