We have been talking about this December thaw coming up this week, and the models continue to show mild, above average temperatures for the week ahead. Monday our highs will range from the mid 40’s across southern Iowa to the mid 30’s to the north. High pressure will then build into the state on Tuesday, and as it does, our warming trend will begin. Temperatures on Tuesday and Wednesday will be in the 30’s. The real warmth will begin on Thursday with highs in the mid 40’s across western and southern Iowa, and the upper 30’s across northeast Iowa.
The graphic above is of the 18z GFS run. The GFS has been fairly consistent with temperatures rising into the 50’s. The ECMWF has been more bullish the past few runs, as it had temperatures soaring into the upper 50’s and lower 60’s across southwest Iowa with the upper 40’s to lower 50’s across northeast Iowa. The 00z run of the ECMWF has since backed off on the warmth and is now in the mid to lower 50’s for much of central, southern, and western Iowa, with the upper 40’s across the northeast. This latest run seems to be a little more reasonable and falls in line with the other long range models like the GFS.
This warm up will be short lived though as a cold front will be moving through the state on Sunday into Monday (December 14th-15th) of next week. The good news is this cold front will not be an arctic cold front, so our temperatures will only fall back into the 30’s and 20’s, and that is where we should be for this time of year. Below is Monday, December 15th at 6pm, and you can see the cold front is moving into eastern Iowa.
After the cold front moves through, highs the following Tuesday will be in the lower to upper 20’s with wind chills in the single digits to lower teens. If you have been missing winter, it shall return. However, the bigger question everyone is wondering is will we see a white Christmas? While the models do not go that far out, there are a few things that we will be watching that could bring us a white Christmas. Right now, the models only go through Tuesday morning of December 23rd. A lot will change between now and then so keep doing your snow dance, and lets hope for a white Christmas. The best shot we will have is around December 22nd. Cutting it close to Christmas, but its worth a shot. Until then, enjoy the warmth as you never know what January will bring!