lj0109

31.6 and freezing rain

Currently sitting at 32.9/27.7 at 15:30 in Saint Matthews, SC (Calhoun County)

CAE's latest thoughts: Area Forecast Discussion National Weather Service Columbia SC 335 PM EST Tue Jan 18 2022 .SYNOPSIS... High pressure and a dry airmass will remain over the region through Wednesday, producing more typical January weather. A cold front moves into the area Thursday bringing a good chance of rain. Friday into the weekend look very unsettled with a mix of wintry weather expected through Saturday. Conditions improve Sunday into the first part of next week. .SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/... Wednesday looks to be the primary transition day as the surface high pressure center will slowly shift offshore. Southwest surface and 850mb flow will ramp up throughout the day as the high exits and central CONUS shortwave approaches allowing modest moisture into the area with dew points climbing into the upper 30`s and low 40`s. Cloud cover is expected to persist throughout the day given the overrunning and moisture return at low-mid levels. High temperatures will finally jump above average for the first time in several days, generally in the low 60`s across the area. Southwest flow will continue ahead of the front associated with the shortwave off to the west into Wednesday night. There is good consensus across guidance on the overall timing of the front, entering the forecast area from the northwest around 12z Thursday and progressively sliding southeast through the area by 18z. Overall precip totals will be fairly low given the mountain interaction and general lack of synoptic lift. The arctic airmass begins filling in behind this front and this is where things start to get more uncertain. The front is expected to slow and stall as a weak area of low pressure develops along the Gulf coast and northern Florida. Guidance is somewhat consistent is showing PoPs continuing into late Thursday as the front stalls but the interaction with the diving cold air is the primary uncertainty. Regardless of model solution, the surface layer air should remain too warm for any frozen precip until early Friday morning. Some wintry PoPs begin across our extreme northern counties between 06z and 12z Friday. .LONG TERM /FRIDAY THROUGH TUESDAY/... While a somewhat clearer picture has developed in the last few model suites, there is still relatively high uncertainty in the Friday-weekend system will play out. The mid-upper level flow is inherently chaotic and unstable for run to run consistency with numerous shortwaves embedded across the general southwest flow across the CONUS. So this type of uncertainty is annoyingly expected given the pattern. Each global operational model and its corresponding ensemble are depicting somewhat unique solutions on how both the upper level pattern will develop over the northeast and southwest CONUS, and how the low pressure center will develop along the stalling cold front. Friday appears to be coming into clearer focus, albeit slowly, with NAM, ECMWF, and GFS all developing a broad shield of overrunning over top the southward rushing arctic airmass as strong south- southwest flow ramps up. Associated ensembles are still quite scattered in timing and intensity of this precip, but at least there is a decent signal compared to 24 hours ago. Obviously this interaction between a thin cold layer, sharp mid level trough, strong upper level jet, and weakly developing low pressure is tricky and guidance likely not get a good handle on it for another day or so. So current thinking on Friday wintry precip is increasing slightly in confidence but intensity remains a big question mark as does spatial extent. All wintry precip types are possible at this time across the fa, particularly sleet and freezing rain. We should start to see better agreement in the next suite or two over the specifics of the Friday event. More uncertainty develops for how the shortwave over the southwest CONUS and western Gulf will track east and then interact with stalled front. The GFS and associated ensembles are more aggressive with pushing the shortwave east and spinning up the stalled front in the Gulf. This then swings another batch of wintry precip into the fa Saturday and would dramatically increase impacts. The EC and Canadian ensembles and operational are much more suppressed with this second shortwave, so impacts would be minimal or none. Again with the complexity of the 500 mb pattern, this will be inherently unstable run to run so not expecting consistency for another run or two. In general, there is a large spread of possible outcomes with this event ranging from mild inconvenience to highly impactful winter storm across the Midlands and CSRA. Cold temps fill in behind this regardless of what plays out and the long term is expected to remain well below average.

CAE issues Winter Storm Watch for northern tier of CWA: URGENT - WINTER WEATHER MESSAGE National Weather Service Columbia SC 338 PM EST Thu Jan 13 2022 Chesterfield-Newberry-Fairfield-Kershaw-Northern Lancaster- Southern Lancaster- Including the cities of Cheraw, Pageland, Newberry, Winnsboro, Winnsboro Mills, Camden, Lugoff, Indian Land, Lancaster, Elgin, and Lancaster Mill 338 PM EST Thu Jan 13 2022 ...WINTER STORM WATCH IN EFFECT FROM LATE SATURDAY NIGHT THROUGH LATE SUNDAY NIGHT... * WHAT...Heavy mixed precipitation possible. Total snow accumulations of up to two inches and ice accumulations of one tenth to one quarter of an inch possible. * WHERE...Portions of central South Carolina. * WHEN...From late Saturday night through late Sunday night. * IMPACTS...Power outages and tree damage are likely due to the ice. Travel could be nearly impossible.

Agree with this 100%. Precipitation usually over performs compared to the regular NAM's output.

A few of the discrete cells across E-Central GA are trying to get their act together:

That was my report. I was on the way back to Columbia from Nashville via ATL and was monitoring that cell as I was approaching CAE. Wish I had a dash cam for the footage, it was pretty incredible to see the sky light up as crossed I-20 about 3M to my East.

@Lookout FFC starting to chime in on the FZRA threat around the Athens/Gainesville area that you have been discussing over the last few days:

Several Tornado Warnings already issued in the bands setting up across southern and central SC

I wouldn't be surprised if ILM went with a few inland Tropical Storm Watches/Warnings especially around the SC/NC border. CAE just issued a Tropical Storm Watch for the eastern tier of its CWA as of 11AM.

12Z Euro up to Hour 102:

12Z Euro makes landfall west of PCB near Seaside/Rosemary Beach

12Z Euro rolling now....A lot faster vs 00Z.

12Z GFS:

Yep! The 06Z Euro EPS Mean is pretty dang close to the 00Z UK OP with regards to the track over the Carolinas. Will be interesting to see what the 12Z UK and Euro show in the next few hours...

06Z Euro EPS:

12Z Euro EPS

A stronger ridge over the Atlantic to the N/NE of Florence coupled with another ridge in the Great Lakes Region evolving into the OH Valley are the culprits to the further South and West trajectory.

Then crawls west across Central SC. Brutal for NE SC and Eastern NC

12Z FV3-GFS now more southwest as well. Landfall at MYR then crawling west across Central SC:

Yep Florence, meet Florence

At 120 Florence is pretty much centered over....Florence, SC:

After making landfall near Holden Beach, still stalled at 102 near the NC/SC border...

00Z Euro makes landfall just SW of ILM near Holden Beach

Maybe for the extreme southern coast, but say a shift of 50-100 miles in a southward direction of the projected Euro track were to occur with only hours to spare...that would bring a large portion of SC into some pretty rough stuff, especially Charleston north and east... Way better to play it safe imho.