Washout Thursday; Sunny & Chilly Friday
Evening Update: 2/17/21 (6:20pm)
Good evening folks! There are only a few adjustments to make to this morning's update for the incoming freezing rain and rain event tonight into Thursday morning. All of SW NC is now in play for a slight glaze (under 0.05") and the Southern Highlands Plateau (Highlands - Cashiers - Lake Toxaway) holds to the previously forecasted amount of 0.10 - 0.15". The hotspots for SW NC will be Haywood and Transylvania counties and their totals have increased over the past few runs, with expected ice accretion totals anywhere from 0.15 - 0.30". One important twist we did not mention earlier is that we will experience snow and sleet at the onset, likely before midnight, and this will kick over to freezing rain shortly thereafter. Locations above 4000' may pick up a quick dusting of snow and sleet before the transition to freezing rain occurs but this will not be as impactful as ice accretion above 0.10".
One silver lining to all of this is that our part of the state will warm up well before our neighbors in the French Broad Valley and the NW NC mountains, with temps reaching the 40's by the late morning - early afternoon hours depending upon location and elevation. With this in mind, your best bet is to check local reports in the morning and plan for a delay that could last for several hours as we wait for temps to reach the upper 30's - low 40's (when melting really takes hold).
Quick Update: 2/17/21 (9:35am)
Good morning folks! I thought it necessary to provide a quick update before tomorrow morning's regularly scheduled post as the threat for freezing rain and ice accretion has increased over the past 24 hours. SW NC is not in the prime area for major ice accretion, however what we previously mentioned as a minimal threat has grown to an impactful event for portions of the region, in particular for the Southern Highlands Plateau (Highlands - Cashiers - Lake Toxaway), with a much higher chance for 0.10" + accretion across Transylvania county. This will all come down to how close to freezing or below freezing the temperature drops down to at your location before precip begins, in tandem with how far away you are located from the Great Balsams and Southern Highlands Plateau.
For those who live in Cherokee, Graham, or Clay counties your threat remains minimal with a glaze up to 0.10" of ice accretion possible by sunrise on Thursday morning. Granted, 0.10" of ice is still disruptive but the chance for that level of accretion is much lower compared to those who live throughout the Southern Highlands Plateau and down into Transylvania county. These two areas will certainly pick up 0.10" of ice accretion and we recommend delaying any travel Thursday morning till everything warms above freezing and melting occurs. Haywood County also is in play for a glaze (0.05") up to 0.10" of ice, in particular for the southern portion of the county including towns such as Cruso. The major buildup of ice will occur further along the blue ridge escarpment toward NW NC and the Piedmont, where amounts could exceed 0.25 - 0.40".
Macon, Swain, and Jackson counties (not including the plateau) will for the most part miss out on this event thanks to the growing warm nose and little CAD influence on the deeper valleys southwest of the Great Balsams. This being said, a degree or two in the wrong direction will bring about freezing rain and higher accretion amounts so be sure to check the car, deck, or railing tomorrow morning before heading out; if there is a glaze perhaps check local weather outlets (feel free to email us directly at firstname.lastname@example.org) before heading to work in the morning.
I will post a discussion tomorrow morning, sometime around 9:30am and of course provide updates beforehand across our social media accounts (see top right of the page for links) if the event is stronger than forecasted. Boiled down, if you can delay an hour or two tomorrow that is preferred, especially if you live in Southern Jackson and throughout all of Haywood and Transylvania counties.
Original Discussion: 2/16/21 (10:50am)
Good morning folks! It sure is nice to see the sun shine again, even if its blustery outside with westerly winds around 10 - 20mph and temps only making it to the mid 20's - low 40's this afternoon. Fair weather will continue into Wednesday morning but clouds are expected to build across the region as the day moves along and although we lose the sunshine, we'll make up for it with temps pushing to the upper 30's - low 50's depending upon elevation as southwest flow increases across the area. Showers move in Wednesday night and become widespread during the pre dawn hours as a low pressure system approaches the region, crossing the Carolinas on Thursday, extending widespread rainfall throughout the day. There is no doubt this will be a washout for the region and if you need a day to catch up on sleep, Thursday is your day with cloudy skies and persistent rainfall throughout the day. Regionwide totals will average out to 1.75" Wednesday evening into Friday morning, however the Southern Highlands Plateau and Unicoi Mountains are likely to pick up 2.5" and one or two locations may hit the 3" mark. As the system departs Friday morning we'll be treated to a round of NW flow snow but this should be quick hitting and over with by the early afternoon hours (not as robust as we originally thought this past Sunday). Temps will be similar to today and sunshine will take over before midday for a majority of the area. The weekend ahead looks gorgeous with sunny skies overhead both days, however we'll start out Saturday morning in the teens across the region and will push into the 40's Saturday and 50's on Sunday. Our next rain event is showing up on the models late Sunday night - Monday morning, with some possible high elevation snow (not set in stone this far out).
Windy conditions (NW winds at 10 - 20mph) will persist across the higher elevations tonight, while the valleys calm down to a light breeze, all under mostly clear skies becoming partly cloudy after midnight.
Clouds will increase as the day moves along Wednesday, however temps will make a run at the low 50's for the valleys, while the higher elevations sneak into the upper 30's - low 40's. Isolated showers are likely before sunset but the main event gets underway sometime during the pre dawn hours on Thursday. Cloudy skies and increasing moisture will cap overnight lows to the low - upper 30's across the landscape. There is a chance Haywood County and the Southern Highlands Plateau experience a few hours of freezing rain before sunrise, but as of this morning the threat remains minimal.
Any areas experiencing freezing rain early Thursday morning will quickly give way to a cold rain as warmer temps push back into the region, breaking down the Cold Air Damming influence for our portion of the state, while those in NW NC and the Piedmont deal with the threat for a much longer period of time. Temps Thursday warm to the mid - upper 40's above 4500' for Jackson County and points SW, while the higher elevations around Haywood County sit in the upper 30's - mid 40's a few hours longer. Eventually all of SW NC will see temps in the mid 40's - low 50's Thursday afternoon with widespread rainfall throughout the day and coverage extends into the evening hours but slowly begins to wind down to isolated coverage as we approach midnight. Temps bottom out to the upper teens - upper 20's Thursday night as the low pressure system wraps colder air into the region and this will kick over any lingering rain over to snow, but we do not expect any accumulations outside of the normal NW flow snow locations.
NW flow snow will continue into the late morning hours on Friday, while the rest of SW NC dries out under mostly sunny skies. Even with sunshine overhead, NW flow should keep temps to the mid 20's - low 40's depending upon elevation, alongside NW winds around 10 - 20mph (much like today). Wind speeds calm down and clear skies setup shop Friday night, allowing ideal radiational cooling conditions to take place and temps will likely perform an inversion, with the valleys sitting in the low - mid teens, warming to the upper teens - low 20's along the ridgelines.
Saturday and Sunday keep sunshine overhead and temps warm to the low - mid 40's Saturday, pushing into the low - mid 50's on Sunday! We'll stop here and circle back Thursday morning, taking a deeper look into the rain/snow event for early next week.