“The Ice Storm of 2009”
January 26-27, 2009
The ice storm of 2009 became the worst ice storm in at least 9 years in the state of Arkansas. According to the National Weather Service this storm may have been the worst in over 76 years in northwest Arkansas, or in other words the worst of a lifetime. It will be a storm that children grow up and tell their grandchildren about a couple generations from now. Forecast models did a good job hinting at a classic ice storm set up several days in advance. All of the television stations and National Weather Service products were very similar indicating a major icing event was likely on late Monday and Tuesday during the last week of January of 2009. An easterly to northeasterly surface flow was taking place as a nearly stationary high pressure was located to the north in northern Missouri. Aloft a very strong and significant warm air advection was setting up, causing the classic overrunning. At 300 mb there was significant divergence and a 180 knot jet over the southwest. At 500 mb the vorticity fields were very high pushing 45, the air was saturated at 700 mb, and the warm air advection was dominant at 850 mb. The main upper level low was moving very slow out of the southwest which allowed a training effect to develop. On Monday night the first batch of freezing rain moved through the area putting down a coating of ice between 0.25-0.50” across the entire viewing area. Early in the morning there was a break in the action and then by daybreak on Tuesday the second more powerful wave moved in to the area. Elevated instability allowed thunder freezing rain to develop by Tuesday morning. In the river valley temperatures warmed up around 33 to 34 degrees changing over the freezing rain to just rain. In northwest Arkansas the freezing rain became heavy. This trend continued all the way through Tuesday night with no let up. After 6 pm, the freezing rain changed over to sleet in northwest Arkansas and the rain began to change over to freezing rain in the river valley. Around 10pm the worst of the winter weather had moved through the area and by midnight the storm had finally come to an end. The storm put down another 0.10-0.20” of ice accumulation with less than 1” of sleet accumulation in the river valley. However the worst impact from the storm in the river valley was the heavy rainfall, nearly 3.5”, freezing on the roadways as temperatures dropped into the low 20s quickly after the storm exited the area. In northwest Arkansas the area picked up on another 0.75” to 1.5” of freezing rain on average with 1-2” of sleet and snow accumulation. This added up to ice accumulations in between 1-2” for most locations in northwest Arkansas with localized areas up to 3” of ice with another 1-2” of snow and sleet accumulation on top of that. In the river valley ice accumulations were in between 0.25-0.50”, which melted and less than 0.25” fell later on that night with less than 1” of sleet and snow accumulation. The area was immediately declared a disaster area by President Obama and FEMA moved in to the area. About 150,000 customers were without power in northwest Arkansas and 12,000 people in the river valley. After 1 week there were still 25,000 customers without power in northwest Arkansas and a quarter of those without power after a week were estimated to remain without power for at least another 2 weeks. Statewide there were over 300,000 customers without power. The storm also impacted Kentucky significantly. This storm was considered to be the worst natural disaster for the state ever. Nationwide there were over 1 million utility customers without power. Up to this point the Ice Storm of 2009 will go down in my book as the biggest single weather event I have ever witnessed in my life.