UpstateSCGamecock

GSP For the rest of the forecast period, all eyes and interests remain on the potential for snow across the area Thursday and Thursday night. The general consensus of the latest model guidance continues to place the recently passed cold front well south of the area, with cyclogenesis progged to develop somewhere along this feature just off the Carolina/GA coast. However, in regards to available moisture and supportive upper dynamics, guidance just isn`t in agreement. This has been a trend for the past few days, with models coming in wetter one run, then drier the next. With this latest run, the 00Z ECMWF comes in slightly drier than before. With that said, collaborating with neighbors, have kept with the bulk of the moisture coming in Thursday afternoon into Thursday night (at or less than a quarter of an inch QPF), as colder temperatures infiltrate in. However, per latest guidance and fcst soundings, anticipate precipitation to begin as early as Thursday morning across the southern mountains, where a rain, snow, rain/snow mix is expected at the onset of precip. As the precipitation expands northeastward into the area, areas along and south of the I-85 corridor look to remain warm enough for all rain through the afternoon and evening hours, as max temperatures climb into the lower 40s. While areas over the NW Piedmont could see a few snowflakes mixed in. A transition to a rain/snow mix is expected into Thursday night as any lingering precipitation tapers off and temperatures drop. Given the warmer temperatures during the day, do not anticipate any travel concerns at this time across the Upstate and NW Piedmont. As for the mountains, max temperatures on Thursday will struggle to warm as much as the Upstate and NW Piedmont, with many areas progged to remain around freezing. Thus, snow accumulations will be possible, mainly a dusting to below an inch in some locations, with up to 2 inches possible across the higher elevations. With this said, any slight changes in the coming model runs will easily change the outcome of this event. Thus, best to keep close attention as we draw closer in time. .

Brad P Charlotte Met .

While the pattern is not optimal, I must point out that areas of NE GA got 7 inches and parts of SC 3+ in one of the most hostile patterns on 2.8.20. .

Discussion from GSP .LONG TERM /WEDNESDAY NIGHT THROUGH SATURDAY/... As of 315 am Sunday: The medium range will begin with chilly/drying high pressure building south through the forecast in the wake of the increasingly E/W oriented frontal zone. Global guidance suggests we are by no means out of the woods regarding the potential for resurgent moisture into the cool air mass in the Wed night/Thu time frame, as the 00Z GFS now redevelops precip (albeit primarily a very cold rain) across roughly the southern half of the area Thu morning. While the ECMWF remains considerably drier than the GFS, it nevertheless is trending in a wetter direction, with qpf response now depicted into the southern half of the forecast area Thu morning. Needless to say, small pops are retained in the forecast through the day Thursday, with mainly a mountain snow/Piedmont rain forecast, although the chance of wintry weather developing east of the mtns is certainly there if post-frontal precip does indeed develop. The remainder of the medium range looks dry and colder than normal. .

We know the faults of the GFS but it’s shown this storm signal for this date multiple times. Can we finally score? .

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Euro Feb 2 WNC Bomb .

Agree. I just wanted to point out how both the GFS and Euro ENS match closely for 28th/29th storm threat. Yes, over 300 hours so it’s just eye candy. .

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.LONG TERM /WEDNESDAY THROUGH SATURDAY/... As of 230 AM EST Sunday: Upper level heights begin to rise as a ridge axis develops west of the fcst area Wed. A stg subs zone will encompass the region beginning Wed afternoon...which will allow a 1028 mb sfc high to transit the se/rn states into Fri. This setup will return clearing skies and cooler max/min temps...altho near or just below normal levels each day. By Fri night...a developing h5 trof will dig across the ern CONUS which will be a weather maker for the FA into the weekend. Much uncertainty exists during this time frame as the GFS and ECMWF models are at odds with the details of the trof config. The GFS is developing a closed low within the trof and diving it across GA/SC and off the Atl coast thru Sat...while the ECMWF keeps a faster non/closed trof axis crossing the area with limited coastal sfc low development. The GFS scenario would bring a decent amt of wintry precip to the FA as colder air would have more time to be advected south as the low deepens off the coast. The latest ECMWF on the other hand keeps the better moisture axis over the ern zones with a limited freezing sfc-layer potential. Its interesting that the 00z ECMWF has trended more inline with the colder and moister GFS soln...however this system will be monitored over the upcoming week and much can change with the sensible weather fcst. So for now...have a low-end chance sn or -ra/sn mix over the northern zones Fri night with limited/nil snow accums. .

Well... .

NAM much colder than GFS .

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Could you just as easily say the very inconsistent Gfs is the stupid one? FV3 and Euro haven’t changed H5 every run like GFS and have shown a storm for much of the board the past 2 days. .

“Light wintry precipitation across the midlands” vs “rain in the piedmont”. Lots of time for GSP to watch models. Just feels good having a potential board wide storm to track. Upstate counties south of 85 have basically faired the same way of Columbia, lately. .

I actually felt your areas discussion sounded more bullish than Upstate’s discussion. .

Since the Midlands discussion was posted, I thought I’d share GSP. LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/... As of 227 PM EST Sunday: The rest of the fcst just looks like good old-fashioned winter across the western Carolinas...as a broad long-wave upper trof grips the eastern half of North America. It seems likely that we will have to deal with at least some wintry precip next weekend, given the fairly good confidence that temps will remain below normal for the period. The main question will be...one system or two? Or, perhaps, more succinctly, will we see any effect from a clipper-type low passing by to the north Thursday night and Friday morning? The GFS says yes...there will be enough low level moisture far enough south to wring out snow showers near the TN border thru most of Friday...but the new ECMWF says no...the moisture will stay well to the north. Have split the difference, which keeps the precip chances down in the slight chance range for the time being. The bigger issue will be the second system diving down into the upper trof Saturday and lingering into Sunday. Model guidance has been all over the place with little run-to-run consistency. Will it be another fast-moving clipper like the GFS indicates, or will the short wave dive farther south, close off a small upper low, induce cyclogenesis along the southeast coast, and precipitate a potential winter storm for parts of the Carolinas next Sunday? The forecast remains conservative at this time, with nearly climo 30/20 precip prob and a mountain snow/Piedmont rain arrangement. Perhaps this is something of a cop-out, but we need better run-to-run consistency before we get carried away. Stay tuned. .

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ICON, like the FV3, has the 27th/28th system. Southern slider. .

It’s snowing in Clinton, SC. Thanks ULL. .

Will precip begin before sunrise or is this an afternoon event for the ULL in SC? .

While it’s still 33 in Clinton. We did get 1/2 of sleet from the storm. .

GSP’s discussion page doesn’t give much hope for snow south of 85 and they are not sure if frozen gets to advisory criteria. Your post gives me hope. Thanks for the informative posts for your neck of the words. That would bode well for me in S of 85 in SC. .

Any one care to discuss the cold air and dew points aligning up with reality as compared to modeling? Are we still on track? .