Good Tuesday to everyone across the foothills of Western NC. We have broke the chains it feels like but the cold will return tomorrow but not to where we have been earlier in 2018.
Arctic high pressure is lifting East away from our area returning our coverage area to zonal flow for the day. A short wave will move through the Northeast this evening and early tonight. Behind it high pressure will start to ridge down the eastern slopes of the Blue Ridge. This will develop and in-situ CAD event. Some light drizzle will likely develop after 3am Wednesday Morning and clouds will lock in. The good news is temps will remain above freezing, only dropping back into the upper 30’s. On the flip side though, Wednesday will return to cooler than normal conditions with clouds and drizzle around. Temps only make it back up into the low and mid 40’s for your Wednesday Highs. This CAD looks to lock in and will keep temps in the low 40’s Wednesday Night into Thursday. The CAD event should start to weaken Thursday as high pressure moves East and out to sea off the New England Coast but by that time we are in a strengthening SE flow ahead of our next cold front. Heavy rain will likely develop Thursday Afternoon and continue into Friday. Temps steadily climb as warm air adverts North from The Gulf Of Mexico. Heavy rainfall with the slight risk of some excessive rainfall continue into Friday.
By 1:00pm Friday low pressure moves to a position near Tuscaloosa Alabama and a QLCS (quasi-linear convective system) develops out ahead of it. Ahead of this line low level sheer will increase as the winds turn with height from Southeast to Southwest. Aloft a low level jet develops introducing speed sheer as mid levels winds increase to 50-70k. This would indicate the chance for a supercell thunderstorm or two to develop along the convective band and race Northeast, likely arriving in our area predawn hours Saturday. While straight line winds would be of primary concern, isolated tornadoes could also be possible. This is something that we will watch and update over the next couple of days. Additionally torrential rainfall could last over a 12 hour period. By this time the ground will have started to thaw at the surface but still could be frozen a little deeper. One thing working in our favor is that when the ground freezes and thaws it also take some of the moisture with it through evaporation. We will watch this as flash flooding could also be a concern going into Friday Night.
Behind this the trough enters the region for Saturday and Sunday. Some of the global models want to ring out a little moisture behind this system, and if so, temp profiles would likely support the frozen variety of precipitation on Saturday Night. Behind the lifting low pressure winds will shift back to the NW, bringing back the chance of a decent NW flow snow event in the mountains. That’s something we will continue to watch. Temps Saturday and Sunday will drop 15-20° below normal again.