Thursday Morning High Impact Weather Briefing; Preparations Should Be Nearing Completion.
Good Thursday Morning.
Here is our Thursday Morning update. As the title says, your preparations should be moved toward completion and you should be able to finish those ahead of the storm on Friday. Cutting to the chase.
A major winter storm will affect Western NC over the upcoming weekend, possibly lasting into the first part of next week. Low pressure is about to make landfall over Southern California this morning. This low pressure will phase with a northern stream piece of energy over the middle of the Country before moving East. Saturday low pressure will be near Houston Texas with heavy rain running well out ahead of it. High pressure will ridge down the Eastern slopes of The Blue Ridge through the day on Saturday.
Initial precipitation will likely have a hard time making it up into North Carolina and South Carolina initially because the precipitation will have to overcome some very dry air at the surface. Any precipitation that tries to fall before Noon on Saturday will likely evaporate before reaching the ground. This will take a little while for the low pressure to overcome and therefore we continue to lean toward a start time between 3pm Saturday and 8am Sunday. We will narrow that time down further with each update going forward because model data will get better. Weather balloons will be launched into this storm as it comes on shore out in California today. That data will be loaded into the overnight model runs tonight giving us a clearer picture of what is going to happen.
Going off experience and climatology this type setup should produce snow from roughly I-40 North with just a little sleet mixed in and then a sleet snow mixture between I-40 South to the NC/SC Boarder. This high pressure I feel has been underdeveloped in all the model runs leading up to now leading to that fluctuating boundary layer moving North and South with every other model run. The models will start to handle that pressure level better tonight I beleive and we will likely see the models trend toward a all snow scenario North of I-40, a mainly snow scenario mixing with sleet along I-40, and a snow/sleet/freezing rain mix South of there down into Upstate SC. Although models have shown rainfall for most of the event for the Upstate of SC there too will likely see a period of heavy snow for a while. We will see if Im right about that in future model runs. In the Upstate up into Cleveland and Southeast Rutherford County I think stand the best chance of seeing accumulating freezing rainfall Sunday Evening. This could cause a major disruption of power in those areas from the weight of the heavy wet snow and the freezing rain mixture.
In Northern Cleveland, Lincoln, Northern and Western Rutherford County, and Southern Catawba County this system would likely be a sleet/snow mix for a large part of the event but even here I think a period of freezing rain is possible.
Going North from there in Alexander, Burke, Caldwell, Northern Catawba, and McDowell the snow will fall heavy at times. Sleet will likely mix in from time to time which could compact snow totals a small bit. In these areas I have a concern that weak built structures could collapse under the snowfall. That is an aspect of this storm you should think about as major totals pile up. Building code for areas East of the mountains indicates that homes and buildings are built to withstand around 15 inches of snowfall. Obviously we have had more than that before but my concern is for some of those buildings like you store things in out back. Might not be a bad idea to give them a little more support during this storm.
Up into the higher elevations of NW Burke, NW Caldwell, NW McDowell, and NW Rutherford Counties now and this looks like the area that will be hardest hit. Heavy snow and gusty winds on Sunday will make travel nearly impossible. Winds are indicated to get up near 40mph along the ridge tops in these NW Sections. If wind becomes sustained for 3 hours at 35mph that constitutes a blizzard. We will see how NWS handles this area's watch once it is issued today. This area will see up-slope flow over a 5-8 hour period on Sunday, increasing snowfall totals up there. If you have been around this year you know how wet it has been and how these areas have been bombarded with copious moisture time and time again. Marion has set it's record yearly maximum already this year and we have another 2/3's of a month to go. That is why we think this area will likely have locations that exceed 20 inches.
I caution you with these accumulation maps though. This is early in the game and we will likely make edits to the accumulation maps in future forecasts. This system will become very clear overnight tonight into Friday. By Friday all areas in Western North Carolina should be finishing up those storm preparations.
*A major winter storm will impact the area this weekend
*Timing: Saturday Evening through Monday, possibly extended if upper low becomes more centered over our area.
*Accumulations: Damaging accumulations of snow and ice are expected
*Impacts: Travel will become impossible Sunday across the Foothills. Trees and powerlines will fail across the area leading to widespread power outages.
*Preparations: Emergency Kits, extra batteries for phones and reading devices, books, 3 days worth of food for each individual in the household, 3 days worth of drinking water for each individual in your household (1 gallon per person), flashlights, pet food, pet shelter, neighbors phone numbers, a way to receive warnings if cell phone service becomes disrupted, All-Hazards Weather Radio capable of operating on batteries, toilet paper, alternate means of heat, generators filled with fuel, and a phone that is able to dial 911 in the event of an emergency.