Early Season Winter Storm To Bring Ice And Flash Flooding To Western NC Thursday.
A difficult forecast continues for Wednesday Night into Thursday. This will likely be a high impact winter storm for some across Western North Carolina. For others, it could mean a nuisance rain event, and then for some others a heavy liquid rain event that leads to flash flooding.
Its a tough forecast to lay out for sure. Let’s start with our key points
The greatest risk for flash flooding will be in Catawba, Cleveland, Lincoln, and Rutherford. That’s where rain totals Wednesday Night through Thursday Afternoon could reach 2-4 inches. Now, don’t get me wrong, flash flooding is possible in any of the 8 counties we service. Streams and creeks are running in the 90th precentile for this time of year. This is due to a very wet year that really stretches back to November of 2017. If you recall the November prior to that, 2016, we could not buy a drop of rain. For the 2018 calendar year most areas are 6-12, and some places 25, inches above normal. With all areas most likely receiving more than 1.5 inches of additional rainfall Thursday we are expecting flash flooding to occur on a localized basis.
The hard part about this forecast is the amount of cold air, how deep it is, and how far south it comes. Anyway you slice it Thursday is going to be bitter, even for whomever records the highest high temperature in our area Thursday Afternoon. In fact high temps will likely be at midnight Thursday Morning. Recorded high temperatures will likely go down as being around 40°. Temps through Thursday Morning will continue to fall for two reasons. 1 is a cold high pressure over New England forcing a shallow pool of cold air south, down the Easter slopes of the mountains. 2 is heavy precipitation bringing colder air aloft down to the surface. Now number 2 will be more prominent across the mountains. The mountains will be sticking up into the warm nose of air Initially but as precipitation falls it will cool the air down to below freezing and by susnrise Thursday a major ice storm will likely be underway. Down off the mountain in the immediate adjacent foothills we expect the cold, sub freezing, shallow layer of cold air to be more stubborn to erode. So that is the reason for the Winter Storm Watch across Alexander, Burke, Caldwell, and McDowell. Ice accretion up to a quarter inch could be possible. Here is the tricky part. It’s going to be spiratic. You may leave your house Thursday Morning and the temperature be 33°. But you may go 5 or 10 miles up the road and be in a area where ice is continuing to build and bridges And overpasses are frozen. This could cause even worse headaches for motorists than if it was a widespread ice storm because you are driving into the unknown. One minute you are good and the next you could hit ice and be in a major wreck. So travel with care Thursday Morning if you have to travel at all. Travel should improve Thursday Afternoon outside of the mountains. Remember that a Flash Flood Watch remains in effect as well. Sleet will mix in from time to time and the hope is the sleet will help limit the amount of ice that builds up on trees and power lines.
In Catawba, Cleveland, Lincoln, and Rutherford just because you are not in a winter storm watch is not the all clear. You aren’t. Even in these counties a brief period of sleet/freezing rain is possible Thursday around sunrise. While accumulations should be light, if any, in these four counties the morning commute could be impacted by those spuratic bridges and overpasses that have ice. Catawba County could see ice hang on a bit longer than the other three but this should all melt away in these counties between 9 and 11am. With the current forecast flash flooding will be your main concern and you should monitor forecasts through the day on Thursday and be ready to seek higher ground if flash flood warnings are needed, remembering that there could be icy spots on roads during the mornings.
Power outages are very likely in the mountains. We expect widespread issues from the NW sections of Burke, McDowell, and Caldwell on west into the higher elevations. It is there we will see the highest freezing rain totals. See accumulation maps below.
Finally the final tbought I’ll leave you with is that I have never heard anyone complain about being too prepared in a high impact event of anykind. There is an outside,10% chance, that impacts could be greater with ice area wide, but there is also another 10% chance that all of the foothills see zero ice. We are at about 80% confidence in our forecast, which is great, but it never hurts to have that manual can opener and a can of beanie weenes just in case.
Have a great Wednesday.
Foothills Weather Network