Past IEM Features tagged: christmas
The weather was quite atypical of what one would expect for Christmas. A round of storms with occasional thunder lifted north over the state during the morning. A cold front with more rain moved west to east over Iowa during the evening. Warm air surged into the state ahead of the front with some locations over 50 degrees. For Sioux Falls Airport, over an inch of precipitation was reported, which easily made for a record for the date. The featured chart displays daily Christmas precipitation for the site. The record setting precipitation was double the previous record set in 2009.
The featured chart looks at snowfall totals before and after Christmas Day for Des Moines. This year's total (5.1) is slightly less than average (8.6) and does not appear to be a predictor of how much snow we get for the rest of the season. The largest accumulation for the later period (1911-1912) shown on the chart occurred after a below average first period. There is only a little hope for picking up snowfall this year to make for a White Christmas Day.
Just over a week left until Christmas and our current landscape is mostly brown. Is there still hope for a White Christmas? The featured chart looks at two metrics of when White Christmas arrives (blue bars) and the frequency of snow on the ground at a certain date surviving until at least Christmas Day (red bars). For this date, about 75% of the time that there is snow on the ground for this date it survives until Christmas. Also when there is snowcover for Christmas, about 40% of the time that snow was already on the ground for today. So there is time yet and some hope!
Much of Iowa looks to be in line to experience a white Thanksgiving (having snow cover). The featured chart presents the observed frequencies of white Thanksgiving, Christmas, and years with both days having snow cover based on long term data for Des Moines. Please note that the Thanksgiving total is for the fourth Thursday of November for each year since 1893, but the actual thanksgiving was on a different date some years prior to 1941. Having snow cover on Thanksgiving does slightly elevate your chances for snow cover on Christmas, but its not an absolute.
Tags: thanksgiving christmas
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Warnings for the United States shown
While Christmas will be white and very cold for Iowa, it is already severe for the deep south and a severe thunderstorm watch is in effect this morning. The featured chart presents the number of tornado and severe thunderstorm warnings per year since 1986 for Christmas. Having severe weather on Christmas is certainly not common with only three years having at least one warning since 1986.
With Christmas a mere eight days away and a brown landscape over most of Iowa, one may wonder if there is still a chance we could have a White Christmas. The featured chart presents the frequency of when the snowfall arrived in time to make for a White Christmas. The chart would indicate that there is still plenty of time as well over 50% of the White Christmas events were established after today's date. The forecast does have some hope for snow later this week with cold temperatures afterwards!
After a very warm Thanksgiving, Christmas does not disappoint with high temperatures well into the 40s. The featured chart presents the daily high and low temperatures on Christmas Day. Having a day with a high temperature above 45 is rather rare as shown by the red bars on the chart. High temperatures look to continue in the 40s for the rest of the year with no snow in sight.
The featured chart presents the observed daily frequency of snowcover partitioned by if there was snow cover on Christmas and the overall average is shown. The highlighted area shows the period were these three lines show visual differences, which is a way to show the memory of having a white or brown Christmas. In other words, by mid February the frequency of having snow cover does not relate to if we had snow cover on Christmas. Back to the matter at hand of our snow state for this Christmas, well it will be brown with very warm temperatures in the 40s!
Tags: snowcover christmas
The featured chart looks at the daily frequency of having snowcover around the dates when there was an inch or more of snowcover on Christmas Day. Just as people wait until the last minute to complete shopping, sometimes Mother Nature waits till the last moment to make the Christmas white. The chart would indicate that roughly 20% of the white Christmas events occur due to a snowfall within 3 days of the 25th.
Tags: christmas snowcover