880 FXUS61 KRNK 101613 AFDRNK Area Forecast Discussion National Weather Service Blacksburg VA 1113 AM EST Sat Dec 10 2022 .SYNOPSIS... High pressure will remain wedged down the east side of the Appalachians through tonight resulting in abundant cloud cover and potential for light rain, drizzle and fog. A cold front will cross the area on Sunday leading to dry weather for Monday and Tuesday. A low pressure system will bring more precipitation on Wednesday and Thursday, including the possibility of a wintry mix. && .NEAR TERM /THROUGH TONIGHT/... As of 1100 AM EST Saturday... Little change for the rest of the day. Only minor changes in temperatures for the rest of the day. Much of the light rain on radar now gone but have kept drizzle and fog in where satellite and observations were still showing stratus and ridges in the clouds. VDOT sensors have fog along I-77 where it crosses the Blue Ridge in Carroll County. Previous: Just about the entire week was overcast, so only fitting we add another day to the list. The weather pattern has essentially remained the same the entire week with our part of the country falling in a battle zone between cool seasonal air from the north trying to suppress the maritime air from the Atlantic and Gulf coast regions. In between, a large mass of cloud, with occasional disturbances passing along a stationary front between the two airmasses. For today, a shallow wedge of high pressure remains east of the Appalachians, reinforcing the cool airmass, but it is weakening with time. Winds will remain from a northeasterly direction today before going calm tonight as the wedge retreats ahead of an approaching cold front Sunday. Until the winds subside, expect upslope lift along the eastern side of the Appalachians to reinforce the cloud cover which may be associated with light rain or drizzle at times. Fog will also linger along the crest of the Blue Ridge where intersection of the cloud base with the terrain will result in fog and low visibility. Greatest impacts today are still expected along the southern Blue Ridge from Floyd and Carroll Counties into the North Carolina High Country. Visibility along the Parkway and where I-77 drops off the mountain may remain poor through the day. For tonight, expecting southwest winds to develop aloft ahead of an approaching cold front. Surge of moisture, which can be seen on the radar mosaic in the form of rain over the Mid-MS and into the ARKLATEX is forecast to move east on a trajectory to reach the Appalachians during the overnight tonight...the heaviest of the rain passing to our south across the southern Appalachians. Never the less, increased the probability for at least some light measurable rain across our forecast area, especially the mountains. Temperatures today and tonight are not expected to change very much, with readings staying within 5 degrees of current values. && .SHORT TERM /SUNDAY THROUGH TUESDAY NIGHT/... As of 300 AM EST Saturday... Confidence is high for drier weather during Monday and Tuesday. Two shortwave troughs will head eastward on Sunday with one crossing over the New England states and the other passing over the Southeast. Because these troughs should miss the Mid Atlantic to the north and south, drier air will arrive to cause any remaining precipitation to taper during Sunday morning and eventually vanish by Sunday evening. High pressure should build overhead on Sunday night to provide quiet weather through Monday and Tuesday. Colder air should push low temperatures below freezing, especially during Tuesday morning. A low pressure system will organize and intensify across the Plains on Tuesday. The cold front associated with this system should move eastward toward the Ohio River Valley during Tuesday night. The models still show notable timing discrepancies with the arrival of this frontal boundary and its accompanying moisture toward late Tuesday night. The GFS still remains faster than the ECMWF and the Canadian models, but it appears that any precipitation will only reach the western Appalachian Mountains just before daybreak on Wednesday. With a shallow layer of colder air near the surface and milder air arriving aloft in the model soundings, it is possible that this precipitation could begin as a wintry mix. && .LONG TERM /WEDNESDAY THROUGH FRIDAY/... As of 300 AM EST Saturday... Confidence is increasing for a low pressure system to arrive on Wednesday with the potential for mixed precipitation. As a cold front heads toward the Appalachian Mountains on Wednesday, significant moisture should spread across the Mid Atlantic. While there are still model discrepancies regarding the timing, it appears that the precipitation may start as a wintry mix of rain, sleet, and freezing rain. There could be a brief window for snow north of Route 460 during the morning, but those chances diminish considerably as model soundings depict a significant warm nose approaching +5 C that would melt any potential snowflakes before reaching the ground. The wintry mix should transition over to rain by midday for most locations, but there may be pockets of freezing rain where colder air at the surface holds longer across the Alleghany Highlands of Virginia and the southern Shenandoah Valley. Precipitation should continue into Wednesday night. Although most areas will see rain, some mixing with freezing rain is possible further to the north. The precipitation should begin to taper toward Thursday, and colder air will begin to arrive from the northwest. The ECMWF and the Canadian models appear more consistent than the GFS model going forward in time, so the consensus of these two models were favored for the remainder of the week. They depict upslope rain and snow showers developing west of the Blue Ridge by Thursday night as the Piedmont turns dry. Winds could become gusty from the northwest during Friday as the low pressure system heads offshore. Meanwhile, upslope rain or snow showers may continue along and west of a line from Boone to Lewisburg. && .AVIATION /16Z SATURDAY THROUGH WEDNESDAY/... As of 645 AM EST Saturday... Widespread IFR to LIFR in the mountains this morning with potential to linger for most of the day Saturday. Low level easterly wind flow remains persistent and will continue to maintain the cloudy and foggy conditions that have been around for much of the past week. IFR/LIFR level stratus will keep most TAF sites near the mountains in poor flight conditions. Cigs are much improved east of a CHO-LYH-DAN line with MVFR-VFR cloud bases there. Light rain/drizzle are still expected today across the mountains and will continue to complicate the weather for aviation attms. Average confidence for ceiling, visibility and wind. Extended Aviation Discussion... Unsettled weather pattern is expected to persist into Sunday before improvement takes place Sunday night into Monday. A cold front is expected to cross the region Sunday afternoon, winds shifting to the west and northwest. This should scour much of the cloud cover. Monday and Tuesday are expected to be dry, promoting a return to VFR. This will be short lived. A low pressure system will impact the region Wednesday into Thursday with sub-MVFR conditions and the potential for mixed winter precipitation. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...None. NC...None. WV...None. && $$ SYNOPSIS...PM NEAR TERM...AMS SHORT TERM...PW LONG TERM...PW AVIATION...PM