textproduct: Blacksburg

SYNOPSIS

High pressure builds in from the Ohio Valley today, and pushes east northeast into the Northeast by this evening. All the while, low pressure develops along the front off the Gulf Coast. This system will advance into our area tonight through Tuesday with another round of wintry weather changing to rain. High pressure returns Tuesday night, with brief upslope snow showers possible across SE West Virginia.

NEAR TERM /THROUGH TONIGHT/

As of 200 AM EST Monday...

Key Messages:

1) New Winter Weather Advisory Goes into Affect tonight.

2) More significant Freezing Rain is expected for locations along and west of the Blue Ridge tonight into Tuesday morning.

Today will be a quick transition between two systems as high pressure skirts quickly north of the region through the Ohio valley and into the Northeast by this evening. As this happens very dry air will advect into the region from the northwest and north as the High pressure moves east. This dry air will eventually help cool the region as precipitation from the southeast moves into the area late Monday evening. Much of the precipitation will likely evaporate as it falls early on; however, as the dry air is eventually worked over, the atmosphere should cool down to below freezing through much of the boundary layer from 850mb to the surface across Mountain locations. Some areas overnight across the Alleghany highlands may initially start as light snow showers before a quick transition to freezing rain develops as a 45 knot southwesterly jet quickly develops a plus 2-3 degree Celsius warm nose around the 800-700mb level. This warm nose and surface temperatures will continue to rise through the early morning hours, with rain taking over as the dominant precipitation across the region during the mid morning hours on Tuesday.

Overall, before the transition to all rain occurs, areas along and west of the Blue Ridge are forecast to see totals ranging from 0.10" to 0.25" of freezing rain, with the Alleghany highlands and Greenbrier river valley potentially seeing up to half an inch of snow prior to a freezing rain transition.

Temperatures today generally look to climb into the low to mid 40s across the region, with lows falling into the upper 20s to low 30s by the early evening as freezing rain starts across the region. Temperatures will only rise throughout the overnight hours as warm air advection from the southeast slowly brings temperatures above freezing through the mid morning hours on Tuesday.

SHORT TERM /TUESDAY THROUGH THURSDAY NIGHT/

As of 200 AM EST Monday...

Key Messages:

1) A Winter Weather Advisory is in effect for areas along/west of the Blue Ridge through noon Tuesday.

2) Mountain upslope snow showers continue into Tuesday night for WV.

3) Below normal temperatures through the period.

A low pressure system across the Carolinas will be moving up the East Coast Tuesday morning. A high pressure system over the Northeastern US will be exiting the region, but enough cold air damming will be in place to allow for wintry precipitation to occur during the early Tuesday morning hours. By daybreak, freezing rain will be the only wintry precipitation occurring, mainly north of I- 64, with a few spots in the higher elevations along the Blue Ridge further south. The wedge fully erodes by late morning, with a miserable cold rain ending by early afternoon as warmer air from the south slowly raises temperatures to above freezing area-wide. Behind the system on the back side, northwest flow increases, with winds gusting 20-25 mph west of the Blue Ridge. This upslope flow will cause snow showers that continues for Tuesday afternoon into Tuesday night for the western mountains in WV as an upper-level trough passes through, but this also fades quickly as high pressure builds in. The high sits over the region through Thursday, when a weak cold front pushes through, possibly bringing a few flurries to Western Greenbrier County in WV Thursday afternoon. Most of the area will remain dry, as the upper-level trough stays to the north. High pressure from the Midwest then builds back in for the late week.

QPF totals will be modest, with around 0.50-0.75" expected area- wide, most falling before daybreak on Tuesday. Snow totals remain light, with a quick dusting possible in the higher elevations along/west of the Blue Ridge, with possibly up to an inch in Western Greenbrier late Tuesday with the upslope flow. Ice accumulations will be low but still impactful, with a glaze across most of the area, except for the southern Piedmont. Along/west of the Blue Ridge is expected to see between 0.10-0.20" of ice, with locally higher amounts possible on the ridgetops. Due to these totals, a Winter Weather Advisory is in effect through noon Tuesday along/west of the Blue Ridge.

Temperatures remain below normal, with highs on Tuesday/Wednesday in the 30s/40s, slightly increasing Thursday across the Piedmont into the low 50s. Overnight lows will mainly be in the 20s, with a few teens in the highest elevations.

LONG TERM /FRIDAY THROUGH SUNDAY/

As of 200 AM EST Monday...

Key Messages:

1) Another round of wintry precipitation possible Friday.

2) Rain chances again late weekend, with milder air, though temperatures remain below normal.

High pressure over the Ohio Valley moves into southern New England on Friday, and causes a weak wedge to form across the Mid-Atlantic area. Another storm system is expected to develop along the southern jet stream and move into the Carolinas, though the strength and path is uncertain. The latest model runs have backed off of the moisture across our area, with some light rain/snow for midday Friday before clearing out Friday night. Due to the variability in the models, confidence in any wintry precipitation is low, but the setup remains favorable if moisture and cold air can combine over our area. PoPs are kept around 50%, but model trends will be worth watching as these could lower. A zonal flow aloft along with surface high pressure again builds into the area for Saturday into early Sunday, before another system moves through during the day Sunday. This system will be to our north across the Great Lakes, keeping all precipitation as rain. The front moves through late Sunday, with a large high pressure settling in for early next week, with quieter weather expected.

Temperatures will continue to remain below normal, particularly on Friday, as highs will only be in the 30s area-wide. Highs then recover into the 40s/50s for the weekend. Lows will remain consistent, in the 20s to around 30 degrees each morning.

EXTENDED AVIATION OUTLOOK

Return to VFR for most by Wednesday-Thursday, slower at BLF Wed. Friday yet another storm system looks to bring wintry weather and poor flying weather to the region.

RNK WATCHES/WARNINGS/ADVISORIES

VA...Winter Weather Advisory from 7 PM this evening to noon EST Tuesday for VAZ007-009>020-022>024-032>035. NC...Winter Weather Advisory from 7 PM this evening to noon EST Tuesday for NCZ001>003-018-019. WV...Winter Weather Advisory from 7 PM this evening to noon EST Tuesday for WVZ042>044-507-508.