After a fairly nice day with temperatures in the 30’s, things will be warming up into the weekend. Highs on Thursday will range from the lower 30’s across northeast Iowa to the upper 30’s across southwest Iowa.
Southerly flow will continue to allow our temperatures to warm up on Friday. Highs on Friday will be in the upper 30’s to lower 40’s. We might see a few temperature readings into the mid 40’s across southwest Iowa by Friday afternoon.
The question that some of you have been asking is how long will this warm up last, and will we have snow in time for Christmas? In the updated 8 to 14 day temperatures outlook released by the Climate Prediction Center, most of the country will be seeing these above average temperatures. The best chance for above average temperatures will be across the western half of the country. This means that temperatures will still be above average through the 17th of December, so that is cutting it close to Christmas. What is average for this time of year here in the state of Iowa? Average temperatures should be in the mid to upper 30’s.
Will things be cooling off anytime after the 17th? One of the things that we look at is the Madden-Julian Oscillation or also refereed to as the MJO. What is the MJO? As defined by the Climate Prediction Center “The Madden-Julian Oscillation (MJO) is a tropical disturbance that propagates eastward around the global tropics with a cycle on the order of 30-60 days. The MJO has wide ranging impacts on the patterns of tropical and extratropical precipitation, atmospheric circulation, and surface temperature around the global tropics and subtropics. There is evidence that the MJO influences the ENSO cycle. It does not cause El Niño or La Niña, but can contribute to the speed of development and intensity of El Niño and La Niña episodes.”
From the current GFS ensemble MJO forecast, as of December 2nd, we are in phase 5. By the weekend, it is forecasted to then enter phase 6. Referencing the chart above, you can see most of the country in phase 6 is above average. Continuing forward with the MJO forecast, it then has us entering into phase 7 and then briefly entering into phase 8. This would then mean a cool down would then be on the way into mid December.
Looking at the GFS ensemble mean temperature average anomaly for December 13th through December 18th, it has the state in near 20 degrees above average for this period of time. As you can image, this is not a good sign for snow lovers, or those of you that are hoping for a white Christmas. Christmas is still 22 days away so there is still plenty of time for the forecast to change and hopefully provide us with a white Christmas. But for the time being, it is not looking good. I guess we should consider ourselves lucky that we aren’t having to deal with bone chilling temperatures.