|Dew Point:||39.0°F (3.9°C)|
|Sea Level Pressure:||25.98" (879.7 mb)|
Heavy Rain then Chance Rain And SnowLow: 28
Areas Of Blowing SnowHigh: 31 Low: 8
M.L. King Jr. Day
SunnyHigh: 27 Low: 16
SunnyHigh: 34 Low: 28
Chance Light SnowHigh: 46 Low: 35
Rain and patchy fog before 1am, then rain showers likely between 1am and 4am, then a chance of rain between 4am and 5am, then a chance of rain and snow. Cloudy. Low around 28, with temperatures rising to around 35 overnight. Southwest wind 9 to 24 mph, with gusts as high as 41 mph. Chance of precipitation is 100%. New rainfall amounts between 1 and 2 inches possible.
A chance of snow before 7am, then areas of blowing snow and a chance of snow showers. Partly sunny. High near 31, with temperatures falling to around 18 in the afternoon. Wind chill values as low as -2. Northwest wind 30 to 39 mph, with gusts as high as 67 mph. Chance of precipitation is 30%. New snow accumulation of less than one inch possible.
Areas of blowing snow and a slight chance of snow showers before 10pm. Mostly clear. Low around 8, with temperatures rising to around 14 overnight. Wind chill values as low as -4. Northwest wind 18 to 28 mph, with gusts as high as 45 mph. Chance of precipitation is 20%.
Sunny, with a high near 27. Wind chill values as low as -8. Northwest wind 7 to 16 mph, with gusts as high as 26 mph.
Mostly clear, with a low around 16. Southwest wind 2 to 6 mph.
Sunny, with a high near 34.
A chance of snow after 1am. Mostly cloudy, with a low around 28. Chance of precipitation is 40%.
A chance of snow before 10am, then a chance of rain and snow. Cloudy, with a high near 46. Chance of precipitation is 50%.
Rain. Cloudy, with a low around 35. Chance of precipitation is 90%.
... A strong low pressure system will move towards the eastern seaboard tonight, dragging a cold front and plentiful rainfall (snow in the northeast) across the eastern U.S. A rush of cold air and strong northerly wind on Sunday will make temperatures feel exceptionally cold, perhaps some of the coldest this season. The wind will gradually diminish Sunday night with a clearing sky. Another wet low pressure system will impact the region on Wednesday and Thursday.
NEAR TERM /THROUGH SUNDAY/... Expansive area of precip associated with intensifying southerly flow in advance of blockbuster storm system/strong cold front will overspread the remainder of the forecast area over the next couple of hours, with widespread rain expected to continue well into the evening across much of the forecast area, warranting 100 pops.
Meanwhile, across the TN Valley, we are beginning to see some linear convective features developing within the precip region across northern Alabama. This is to be expected in light of the very strong/deep meridionally-oriented forcing depicted along surging cold front. This combined with very strong (50+ kts) 0-1 km shear would be a red flag for high shear/low CAPE severe convective potential IF there was even a modicum of instability present. However, short term guidance remains insistent in shunting ribbon of very low sbCAPE south of the forecast area this evening. Nevertheless, there will probably be plenty of interesting convective features within the frontal band that will need close monitoring late this afternoon/evening. Also could not rule out some isolated damaging winds from showers bringing down the 60kt+ momentum air from aloft via plain old convective mixing.
The bulk of the precip should be pushing to our east around midnight, or shortly thereafter, with total qpf through that time expected to range from 1 to 2 inches across much of the area, with the highest totals expected across the high terrain of southwest NC. Locally higher amounts of 2.5 to 3 inches will be possible, especially along the southern escarpment of the Blue Ridge. This could be enough to tip the scales toward some minor flooding along the usual tributaries of the upper French Broad River, but this is far from a certainty, and even if it were to occur, the threat would be too localized to warrant a Flood Watch.
Cold front will begin surging through the area during the pre-dawn hours, with very strong cold advection on stout northwest flow overspreading the NC mtns, which will send temps plummeting to and below freezing in fairly quick fashion. This will likely result in development of black ice, possibly a "flash freeze" scenario in some areas. Meanwhile, ingredients will come together for an accumulating northwest flow snow event Sunday morning, albeit over a fairly brief (i.e., 6-ish hours) window. While Winter Wx Advisory-level accumulations are expected to primarily impact the higher elevations along the TN border, a dusting up to an inch will also be possible in the lower French Broad Valley as well as the other valleys near the state line, which combined with the black ice likelihood should create enough of an impact to warrant an Advisory for the TN border counties.
Finally, wind will be a major concern within the cold advection tomorrow, as guidance features a robust gradient (8-9 mb) across the high terrain, a very potent isallobaric gradient, with a 30 mb gradient in 6-hour pressure change between the Appalachians and New England, and H8 winds as high as 60 kts in association with developing mountain wave activity. This usually equates to a good high wind scenario, and a High Wind Warning will be issued for zones from Henderson-NC north along the Blue Ridge to Avery-NC and the high elevations of the northern foothills zones. Otherwise, Sunday will be a raw day, with max temps forecast to be 10-15 degrees below climo across the Piedmont/foothills, and more like 20 degrees below across the mtns.
SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY/... As of 255 PM EST Saturday: Though a few lingering snowflakes could not be entirely ruled out along the TN border Sunday night, latest guidance continues to support an overall dry, yet cold, forecast period. With upper troughing pushing eastward through the Carolinas Sunday night into Monday morning, upper ridging will continue to propagate into the central plains, allowing for the pressure gradient over the FA to relax and for gusty NW winds across the mountains at the start of the forecast period to diminish into Monday morning. With clearing skies, the main concern will be the cold temperatures as Arctic high pressure infiltrates into the region - the coldest temperatures of the season thus far. With NW winds in place and cold temperatures across the NC mountains (teens to single digits), expect wind chill values Sunday night into Monday morning to fall to around -5 F in many mountain locations (ie Wind Chill Advisory criteria for the mountains, likely to be addressed in hazard headlines in future fcst packages). Elsewhere across the Upstate and NW Piedmont, wind chill values will bottom out in the low to mid teens Monday morning, with low temperatures ranging in the mid teens to mid 20s.
Though skies will be clear as high pressure moves towards the Carolinas later in the day, the plenty of sunshine in place won't be much of any assistance to warm temperatures on Monday with downsloping flow. Attm, expect areas across the Upstate to break the 40 degree mark, while areas across the NW Piedmont will remain in the mid to upper 30s, and colder across the mountains. On Tuesday, quiet conditions continue as high pressure moves overhead and towards the Carolina coast, though with the return of SW flow, do expect gradually increasing cloud cover into the later afternoon/evening hours ahead of the next approaching system. Though warmer than on Monday, temperatures on Tuesday will remain below normal.
LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... As of 200 PM EST Saturday: The medium range picks up 00Z Wednesday as the first hints of upslope precip make an appearance in our forecast area, supported by a weak wedge of surface high pressure centered near the Outer Banks. The transient surface high progresses quickly off the Mid-Atlantic coast By Wednesday night as the main frontal boundary associated with the low pressure system approaches. Low-level flow will also become southerly on Wednesday, weakening the upslope forcing component as the wedge of high pressure retreats. An upper shortwave will swing through the stout H5 trough closing in on the eastern CONUS late Wednesday night and Thursday, however, increasing rainfall rates as a train of secondary weak lows lifts northeastward from the Gulf and crosses the FA. Timing remains an important question with this system, as global models differ considerably and range from having the main front clear the area early Thursday to lingering through Friday. By Friday night, though, only high elevation NW flow snow will linger. Instability seems insignificant at this time, and any ptype concerns (especially at precip onset and wind down) will be highly dependent on the timing of the system. The vast majority of the precip will likely fall as rain if current guidance is correct anyways, and there is plenty of time to refine and sort out any ptype issues.
Temperatures will be above normal Wednesday and Thursday before a large upper trough deepens over the eastern CONUS Friday and drops temperatures to well below normal over the weekend.