April Fools' Snow; COLD Thursday
Good morning folks! We're still on track for a healthy amount of rain starting later tonight as spotty light showers, ramping up throughout the day on Wednesday and peaking with strong thunderstorms later in the evening, wrapping up as snow late Wednesday night for the typical NW flow favored ridgelines. Forecasted rainfall totals have been adjusted upwards and we now expect anywhere from 1.75 - 3" of rain from Tuesday night through Thursday morning. We also have a handle on how much snow may fall for the favored locations and if everything holds together, we expect anywhere from 2 - 3" of snow to fall along the TN line in the GSMNP, with a lower range of a dusting up to an inch for the Cataloochee Divide, Plott Balsams, Great Balsams, and perhaps the Unicoi Mountains. Thursday will feel like February with temps in the 40's for the valleys alongside a stiff NW wind, so pull those jackets back out of the closet and be prepared for subfreezing lows Thursday, Friday, and Saturday nights. Dry weather takes hold on Thursday and the upper level trough will slowly give way to an upper level ridge/high pressure setup Friday into Saturday, setting up a gradual warming trend with sunny skies overhead Thursday through early next week.
Temps warm up nicely this afternoon to the low 70's under sunny skies, although we do expect high clouds to stream overhead before sunset as moisture ramps up across the region. Southwesterly flow ahead of the approaching cold front tonight will help initiate isolated light showers, first along the escarpment (Highlands - Cashiers - Lake Toxaway) during the evening hours, then expanding to all of SW NC by the pre dawn hours. Overnight lows settle into the mid 40's - low 50's under cloudy skies with rainfall totals under a quarter inch by sunrise.
Wednesday will feel very spring-like as we deal with cloudy skies, a strong southerly wind throughout the day alongside temps pushing to the upper 60's - low 70's across the valleys; low - mid 50's for the highest ridgelines. Scattered showers pepper the region during the morning hours and the main event takes place during the afternoon and evening hours, with moderate rainfall before sunset, ramping up to heavy rain as the front approaches the region during the evening hours. This timeline is likely to change but overall the end result will be the same and rainfall totals will range from 1.75 - 3" by sunrise on Thursday; highest amounts along the GA and SC state lines due to upslope. As the cold front crosses the region Wednesday night we will notice a sharp drop in temps by roughly 10 - 14 degrees in a matter of 45 minutes - 1.5 hours, prompting rain to kick over to snow for the higher elevations. Its possible some wet snow falls for the lower elevations, but accumulations will remain confined to the NW flow favored ridgelines (TN line, Cataloochee Divide, Plott Balsams, and Great Balsams) with 1 - 3" of snow by sunrise depending upon location and elevation. Overnight lows bottom out to the low 20's - low 30's and NW winds will be howling around 15 - 25mph as we wake up on Thursday.
Although sunshine takes over by the mid morning hours on Thursday, strong cold air advection will continue and we'll deal with a frigid start to April with temps only reaching the upper 20's - mid 40's depending upon elevation! Add in NW winds around 10 - 20mph, gusting to 35mph, and it will feel downright cold for early April, when temps are normally supposed to the be in the mid - upper 60's across the valleys. Overnight lows plummet to the low teens - low 20's depending upon elevation, under clear skies with NW winds around 5 -10mph. This will ensure a hard freeze across the area by sunrise on Friday.
Friday through Tuesday is much of the same, as dry weather takes hold under a high pressure system that will gradually slide from west to east over the weekend, allowing southerly flow to take over and temps to slowly moderate. We'll remain chilly on Friday as temps only reach the upper 30's - mid 50's and we'll warm to the mid 60's Saturday, upper 60's - low 70's Sunday, and mid 70's by Monday, all under sunny skies! Overnight lows will dip below freezing Friday night for all of SW NC (low - upper 20's), while the valleys climb above freezing Saturday night and the higher elevations above 3500' dip back into the upper 20's - low 30's. Starting Sunday late morning, all of SW NC will be above freezing and remain there through at least middle of next week.
We'll stop here and circle back on Thursday morning with a new discussion. I doubt we'll need a quick update tomorrow morning for the upcoming rain event but if its needed, I'll post one before noon to capture any last minute changes.