While the weather looks warmer than normal for this week and probably the first part of the weekend (as it has been for most of this month), there is no guarantee this trend will continue into the Fall.
To give us an inkling of how things might change we turn to the latest edition of the Climate Prediction Center’s (CPC) monthly outlooks - released over the weekend. In this latest model run we see the un-exciting “EC” category over Wisconsin for September. “EC” means the computer models are predicting an equal chance of temperatures being above normal or below normal (same goes for the September precipitation).
The weather could end up warm and dry or cold and wet – but we get no definitive guidance from the climate models.
For September, the one part of the country with more than equal chances of a temperature trend is in the south and southwest, including Texas. The CPC outlook is for a higher chance of above normal temps than below normal temps – just the thing Texans do not want to hear. They have already had their fill of heat (and drought) so far this year.
Looking a little further into the future, the three month outlook (September, October, November) indicates a greater chance of above normal temps for our part of the country, which would mean a very nice Fall period. Since the computer models are indicating EC for September alone, then that might mean the warmer weather will be concentrated in October and November, prolonging our “warm” season a bit. Keep your fingers crossed.
What about for all the winter enthusiasts? Well, there might be some good news for you as well. The CPC three month outlook for the winter (December, January, February) indicates a little better chance of below normal temps than above normal temps.
The climate models also indicate a greater chance of above normal precipitation around the central Great Lakes region, including southeastern Wisconsin. Much will hinge on the El Nino/La Nina (ENSO) trend in the Pacific ocean. Right now the southcentral Pacific ocean surface temps are in a neutral range and they are expected to stay that way through the Fall. Some ENSO computer models are hinting at the formation of another, albeit weak La Nina. If La Nina forms, recent history indicates it will increase our chances of having real Wisconsin Winter weather (cold and snow).