As most of you remember, last December was one of our coldest on record, with temperatures below freezing for almost 90% of the month. Temperatures last December hit rock bottom with several subzero nights and days that did not make it above 20 degrees. We also had quite a bit of snow last December (even though we could have had more). Even with a warm and rainy ending last year, temperatures still averaged nearly 6 degrees below normal for the entire month. This year, we can't even to seem to get a nighttime low below freezing rather than a daytime high. So far this December, temperatures have averaged 1.5 degrees above normal (it would be much higher if it weren't for those rare cold days.). Another thing different from last December was snowfall and snow cover. This year, only about 10-20% of the United States is covered by snow, while a year ago, nearly 60% of the United States. This really does show how warm it has been since November. There are two bad things that have been happening because of this warmth. One, well above normal precipitation, creating major river flooding all over Northern Indiana and Ohio. Two, this warm air has locked all of the cold air in Canada, and it has been building for several months. If any kind of slight stratospheric warming occurs in the next several weeks, then expect all of this cold air to rush southward, enhancing the stratospheric warming process. When this happens, that's when I expect the worst of winter to arrive.
As for my white Christmas forecast, I expect that we do have a better chance than I thought a week ago. The Monday/Wednesday storm of next week has shifted southward on most if not all computer models. Current indications show a mix event with some periods of rain, changing over to all snow for a good chunk of Tuesday night. This could mean several inches of snow depending on the track of the system. If the storm tracks farther northward, and pulls in the cold air faster, expect heavier precipitation with higher snowfall totals. If it tracks northward without pulling the cold air in faster, I would expect very heavy rainfall amounts, with widespread flooding possible by Wednesday. If the storm decides to head south, expect a brief changeover to snow, with not as much precipitation as a result. Current indications are that the ridge will once again become moderate in strength next week, allowing the storm to take a farther northward track (through southern Indiana and Ohio), but at the same time a major trough develops in the Midwest, helping to bring more cold air into the back side of the storm than during the last several storms. This would be the scenario to bring a mix event with heavy rain, then rapidly falling temperatures causing a changeover to snow. These all look to be a possibility by Tuesday. If we end up not getting any snowfall Tuesday night, we have yet another chance on Friday. According to the GFS and CMC models, a rather strong Alberta Clipper will move through possibly moving far enough south to tap into the Gulf of Mexico moisture, which could a major storm in the area. If it does tap into enough moisture, and with the amount of cold air that the GFS and CMC are expecting in the area, I believe that this could a rather potent snowstorm. Right now, it looks it will be snowing throughout the day Friday, with the possibility of a couple of inches of snow. Whether or not this comes to fruition, I'm not sure, but one thing I do know is that more than likely very cold weather and cloudy weather will be in place Christmas Day, with the possibility of snow showers. At this time, I think that indications show a pretty good chance of a white christmas, it just all depends on if that cold air in Canada decides to shift southward. Stay tuned for further updates.
As for my white Christmas forecast, I expect that we do have a better chance than I thought a week ago. The Monday/Wednesday storm of next week has shifted southward on most if not all computer models. Current indications show a mix event with some periods of rain, changing over to all snow for a good chunk of Tuesday night. This could mean several inches of snow depending on the track of the system. If the storm tracks farther northward, and pulls in the cold air faster, expect heavier precipitation with higher snowfall totals. If it tracks northward without pulling the cold air in faster, I would expect very heavy rainfall amounts, with widespread flooding possible by Wednesday. If the storm decides to head south, expect a brief changeover to snow, with not as much precipitation as a result. Current indications are that the ridge will once again become moderate in strength next week, allowing the storm to take a farther northward track (through southern Indiana and Ohio), but at the same time a major trough develops in the Midwest, helping to bring more cold air into the back side of the storm than during the last several storms. This would be the scenario to bring a mix event with heavy rain, then rapidly falling temperatures causing a changeover to snow. These all look to be a possibility by Tuesday. If we end up not getting any snowfall Tuesday night, we have yet another chance on Friday. According to the GFS and CMC models, a rather strong Alberta Clipper will move through possibly moving far enough south to tap into the Gulf of Mexico moisture, which could a major storm in the area. If it does tap into enough moisture, and with the amount of cold air that the GFS and CMC are expecting in the area, I believe that this could a rather potent snowstorm. Right now, it looks it will be snowing throughout the day Friday, with the possibility of a couple of inches of snow. Whether or not this comes to fruition, I'm not sure, but one thing I do know is that more than likely very cold weather and cloudy weather will be in place Christmas Day, with the possibility of snow showers. At this time, I think that indications show a pretty good chance of a white christmas, it just all depends on if that cold air in Canada decides to shift southward. Stay tuned for further updates.
No comments:
Post a Comment