textproduct: Blacksburg

SYNOPSIS

High pressure will push off the Atlantic coast tonight. A quick moving system follows tonight with some wintry weather at the onset, mainly freezing rain, that chances to rain Sunday. High pressure passes across the region on Monday. Low pressure moving across the Southeast will bring the next chance for a wintry mix during Monday night and Tuesday.

NEAR TERM /THROUGH SUNDAY/

As of 710 PM EST Saturday...

Not much change in the forecast this evening with the only difference being a slightly earlier arrival time of precipitation. Some returns have already begun to fill in on the radar, but the 00Z RAOB indicates this is likely just virga at the moment due to a very stout dry layer between 900mb and 800mb. Light precipitation could begin as early as midnight in the far west and then spread east before sunrise. Based off the RAOB, plenty of room to wet bulb the column below freezing, so could see some light snow briefly, but then a transition to sleet/freezing rain likely once warm advection quickly takes over.

As of 1240 PM EST Saturday...

Key Messages:

1) Added Buckingham, Appomattox and Campbell including Lynchburg to the Winter Weather Advisory for late tonight-Sunday morning

2) Mainly a light icing event that is quick moving, changing to rain Sunday.

Will see increasing high clouds this evening and question will be how cold it gets before the clouds lower and blanket the area. Forecast soundings indicate very dry airmass, so precip likely to be somewhat delayed til pre-dawn in the west. This will be a quick winter event and not much precip, but given how cold its been, it only takes a trace of ice to cause travel issues. The high retreats offshore Sunday morning followed by a cold front which will turn winds back to the southwest changing any wintry precip to rain Sunday morning. Some sleet/snow at the onset also expected, but not a lot, no more than a tenth of an inch or so.

Rain will taper off Sunday afternoon as the front heads toward the coast.

Temperatures tonight to drop into the mid 20s to around 30, then rise into the 40s Sunday.

Forecast confidence is high on some light icing, but lower on snow/sleet. Some areas in the advisory like the Mountain Empire may not see any icing.

SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY NIGHT/

As of 1232 PM EST Saturday...

Key Message:

1) Wintry Weather returns Monday night.

Another round of winter weather is likely by Monday night. While a mid-level trough moves eastward from the upper Mid-West, a surface low in the southern United States gets dragged northeastward by it and creates a battlefield of temperatures between the two. The 540 thickness line will be across our region late Monday night into Tuesday. While specifics are still being ironed out, confidence is increasing in freezing rain as the dominant precipitation type. The surface low will bring in warm and moist air from the south, but cold air damming means surface temperatures are likely to be around or below freezing Monday night into Tuesday morning. The freezing rain will most likely be for areas west of the Blue Ridge, but currently cannot be ruled out east of the Blue Ridge. Total ice accumulations are also likely to be between 0.05-0.20". Snow may be mixed in with the freezing rain for the West Virginia counties but Western Greenbrier may be the only location to see accumulation of 1-2". The freezing rain will transition to just rain as temperatures break above freezing Tuesday afternoon before the system moves out of the area by Tuesday evening. Total rainfall amounts are difficult to project considering much is dependent on how much falls as snow or ice. This system will be closely monitored in the coming days.

LONG TERM /WEDNESDAY THROUGH SATURDAY/

As of 1230 PM EST Saturday...

Key Messages:

1. Wintry mix possible early Friday, and into Saturday.

2. Dry Wednesday and Thursday.

3. Below normal temperatures through the period.

The long term forecast period starts with a period of dry and quiet weather on Wednesday and Thursday, with high pressure at the surface following the frontal passage on Tuesday. A cold front looks to dive south from Canada into the northern Mid Atlantic, with a reinforcing shot of cooler air to the Mid Atlantic and Northeast. This may bring some upslope snow showers to parts of southeast WV, but confidence is low given the relative lack of moisture. Most likely would just be snow flurries. A low pressure system develops along the Gulf coast late in the work week, as a surface high tracks eastward across New England. The low will bring a surge of moisture northward from the Gulf, reaching the area around Friday morning. This could result more wintry precipitation for the area during the Friday morning commute and Saturday morning. The primary precipitation type will depend on how long the cold air lingers while the moisture moves in, but there does look to be a change over to mainly rain by Friday afternoon. That being said, still a lot of uncertainty in the evolution of the low and upper level pattern, which all plays a role in the precip type.

High temperatures will be in the upper 30s to low 40s in the west, and mid to upper 40s in the east. With lighter winds overnight, temperatures will fall into the 20s for most, but then rise into the low 30s by Saturday morning.

EXTENDED AVIATION OUTLOOK

Expect MVFR, possibly IFR from ROA west Monday, with VFR east. Most sites except possibly BLF return to VFR Monday evening, with VFR for all Monday morning. Another system arrives with more wintry weather Monday night so expect sub-VFR cigs/vsbys late Monday night into Tuesday. Return to VFR for most by Wednesday-Thursday, slower at BLF Wed.

RNK WATCHES/WARNINGS/ADVISORIES

VA...Winter Weather Advisory from 2 AM to noon EST Sunday for VAZ007-009>020-022>024-032>035. Winter Weather Advisory from 4 AM to noon EST Sunday for VAZ045>047. NC...Winter Weather Advisory from 2 AM to noon EST Sunday for NCZ001-002-018. WV...Winter Weather Advisory from 2 AM to noon EST Sunday for WVZ042>044-507-508.