textproduct: Raleigh

WHAT HAS CHANGED

As of 200 AM Sunday...

Snowfall slowly coming to an end into early Sunday.

A fast moving system will bring a chance of precipitation Tuesday night through Wednesday night, falling mostly as rain, though a few snowflakes could mix in late Wednesday night.

KEY MESSAGES

As of 200 AM Sunday...

1) Bitter Cold temperatures today under fresh snow cover. Black ice will be a threat tonight

2) Well below normal temperatures will persist through next weekend as Arctic air remains in place across the region.

3) A fast moving system will bring a chance of precip to the area Tuesday night through Wednesday night. Precip should be light, fall mostly as rain, although a few snowflakes could mix in late Wednesday night.

DISCUSSION

As of 200 AM Sunday...

KEY MESSAGE 1... Bitter Cold temperatures today under fresh snow cover. Black ice will be a threat tonight

Latest satellite imagery reveals the deep and vigorous upper-level trough off the SC coast. The system will continue to track ENE into daybreak Sun morning. As it does so, the system will start to shear out, which will lead to the deep lift and 850-700 mb FGEN to weaken with time. Radar returns combined with webcams showed the northern Piedmont and northern Coastal Plain starting to clear out in terms of snow, with just isolated reports of lingering light snow. Light to moderate snow was persistent south of US-64 and especially over the Sandhills and into the Central Coastal Plain along I-95.

Snow should taper off by sunrise, but a few lingering light snow or flurries may exist over southern Sampson until 8 am. As a result, the Winter Storm Warning will likely be allowed to expire by 7 am for most, if not all, of central NC.

Bitter cold temperatures and dangerous wind chills will persist even after the snow has ended. The Extreme Cold Warning persists until 10 AM, where wind chills into mid-morning will range from zero to 5 below with NW winds in the 20 to 30 mph range and temps in the low/mid teens. Skies should clear out today with plentiful sunshine. But fresh snow cover will limit our highs. We undercut highs, despite NW downslope winds of 20 to 30 mph, in the mid 20s to near 30 degrees. Wind chills this afternoon will hover in the teens. Tonight, weak ridging at mid-levels spreads east from the TN valley and that should favor winds going light or calm overnight into Mon morning. With a fresh blanket of snow, excellent radiational cooling suggests lows in the single digits to low teens, in line with the colder EC MOS guidance. A Cold Weather Advisory may be needed tonight with wind chills in the single digits to near zero. Although there won't be much melting today, the sun will help somewhat. Refreezing of slush will warrant the threat of black ice across central NC. A Winter Weather Advisory or SPS may be issued later today as a result.

KEY MESSAGE 2... Well below normal temperatures will persist through next weekend as Arctic air remains in place across the region.

In the wake of the coastal low, surface high pressure will settle over the area Monday into Tuesday. While winds will turn out of the south and temperatures will moderate slightly into the low/mid 40s, these readings will remain well below normal for early February. Temperatures will retreat into the 40s and upper 30s by the middle of the week as a weak wave passes through the area, then rebound slightly into the mid/upper 40s to close out the week. Overnight lows this week will also remain well below normal with teens and 20s to start the week, mid 30s on Wednesday, then back into the teens and 20s Thursday and Friday.

KEY MESSAGE 3... A fast moving system will bring a chance of precip to the area Tuesday night through Wednesday night. Precip should be light, fall mostly as rain, although a few snowflakes could mix in late Wednesday night.

Once again, there is good ensemble agreement on a fast moving shortwave trough digging through the area late Tuesday night/Wednesday morning, exiting the area late Wednesday night/Thursday morning. Timing among the GFS/GEFS/EC/ECENS is much more consistent with today's 12Z suite of guidance showing precip moving in from west to east late Tuesday night. Weak WAA ahead of the trough could result in some snowflakes mixed in at precip onset, but this should quickly turn to rain as the boundary layer rises above freezing. Precip continuing at times through the day although ensemble mean QPF is only a few hundredths of an inch. Even the 90th percentile QPF is less than a quarter of an inch based on this morning's guidance. As the trough moves off the coast and post- frontal cold advection takes hold, the entire thermal profile should slip below freezing. There could be a few snowflakes that mix in as precip is exiting the area but dry air chasing the precip would suggest a limited threat of snow accumulation.

AVIATION /06Z SUNDAY THROUGH THURSDAY/

As of 145 AM Sunday...

24 hour TAF period: Widespread snow across central NC on Saturday and Saturday evening is gradually diminishing from west to east early this morning. The snow has ended across the Northwest Piedmont and Triad areas, intensities have decreased across the remainder of the Piedmont and Triangle area with bands of heavier snow across the Sandhills and Coastal Plain beginning to fade. Snow should end in the Triangle area between 07Z and 09Z with the snow ending a little later between 08Z and 10Z at KFAY and KRWI. Expect VFR conditions to return by daybreak at all locations. Winds will be gusty at times in the Triad overnight, briefly relax toward daybreak and then pick up with mixing and cold advection during the day. Gusty winds will continue through the overnight and during the day today at KRDU, KFAY, and KRWI. As winds intermittently weaken, there could be some LLWS concerns, with 35-40 kts at 2kft (up to 50 kts at 2kft over KRWI for a few hours). Winds and wind gusts decrease this afternoon with a general light west-northwest wind overnight.

Outlook: VFR conditions and fair weather is expected through Tuesday. The next weather system will bring a chance for sub-VFR conditions and precipitation Tuesday night through Wednesday night. Fair weather should return for Thursday.

CLIMATE

Record Low Temperatures:

February 1: KGSO:-4/1936, KRDU: 8/1981, KFAY: 1/1936

Record Low Maximum Temperatures:

February 1: KGSO: 27/1971, KRDU: 28/1900, KFAY: 32/1981 February 2: KGSO: 30/1951, KRDU: 31/1994, KFAY: 31/1948

RAH WATCHES/WARNINGS/ADVISORIES

Winter Storm Warning until 7 AM EST this morning for NCZ007>010-021>026-038>041-073>076-083-084. Extreme Cold Warning until 10 AM EST this morning for NCZ007>011-021>028-038>043-073>078-083>086-088-089. Winter Storm Warning until 1 PM EST this afternoon for NCZ011- 027-028-042-043-077-078-085-086-088-089.