textproduct: Raleigh

WHAT HAS CHANGED

As of 131 PM Sunday...

Winter Weather Advisory is in effect until 10 am Monday morning.

Cold Weather Advisory is in effect from 7 pm this evening to 9 AM Monday morning.

KEY MESSAGES

As of 252 PM Sunday...

1) Bitter Cold temperatures tonight under fresh snow cover. Icy driving conditions will persist through Monday morning.

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

3) A couple of upper disturbances will move through the area from Tuesday night into Wednesday night, but precipitation amounts look fairly light. A brief changeover to snow at the end of the event can't be ruled out, but confidence in that occurring is low and impacts are expected to be minimal at this time.

DISCUSSION

As of 252 PM Sunday...

KEY MESSAGE 1... Bitter Cold temperatures tonight under fresh snow cover. Icy driving conditions will persist through Monday morning.

Sfc analysis this afternoon depicted a 1034 sfc high centered over LA/MS, extending nwly flow across central NC. 15 to 25 mph gusts continue to show across the area, but the gradient between the high and the offshore low should subside this evening. The boundary layer will remain mixed a bit, so can't rule out a bit of wind, but overall wind magnitudes should be far lower than last night/earlier today. While winds will lessen, the arctic air mass in combination with the fresh snowpack and clear skies tonight will drop temperatures into the upper single digits to around 10 degrees (some lower single digits will be possible across the western Piedmont). As such, wind chills will still drop into the lower single digits to near 0 tonight through early Monday morning. To account for this, a Cold Weather Advisory has been issued from 7 pm tonight through 9 am Monday.

Given many roads will likely have lingering snow coverage across much of central NC, in addition to moisture from melting snow today, black ice and hazardous travel will remain a concern the rest of today through mid to late Monday morning.

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

Nwly flow aloft behind the departing low keeps conditions cold Monday as the arctic high transitions across the southeast/Mid- Atlantic. Given the cold airmass, and remnants of lingering snowpack, highs will struggle to reach the mid to upper 30s Monday afternoon. Overnight lows Monday will again be quite cold in the mid teens, however calm winds should preclude the need for cold weather advisories.

Flow aloft turns zonal Tuesday with some moderation in the low-level thicknesses. Daytime highs will reach the lower to mid 40s both Tuesday and Wednesday afternoons. A brief shot of colder air may be possible behind our next potential system Thursday.

KEY MESSAGE 3... A couple of upper disturbances will move through the area from Tuesday night into Wednesday night, but precipitation amounts look fairly light. A brief changeover to snow at the end of the event can't be ruled out, but confidence in that occurring is low and impacts are expected to be minimal at this time.

A series of fast-moving shortwave troughs will move across central NC from Tuesday night through Wednesday night. At the surface, a weak low will pass near or just north of our region along a cold front, followed by another low that passes just south of us on Wednesday. GFS/ECMWF/CMC ensemble guidance is in pretty good agreement that precipitation will move in from west to east on Tuesday night and Wednesday. QPF amounts look light, around a tenth to quarter inch, and boundary layer temperatures look warm enough for many liquid, though a few flakes can't be ruled out at the onset across the far north.

The GFS and CMC then try to give us another round of precipitation on Wednesday night with the second disturbance behind the cold front. The best chance would be in the SE. However, the ECMWF and most of its ensembles give us very little. A changeover to snow at the end can't be ruled out if the GFS and CMC verify as CAA takes over behind the front, but this is a case of cold air "chasing" the precipitation, which typically results in very limited snowfall if any across our area.

AVIATION /18Z SUNDAY THROUGH FRIDAY/

As of 133 PM Sunday...

24 hour TAF period: VFR conditions will continue through the remainder of the TAF period. Gusty winds will continue this afternoon before the gusts subside during the mid to late afternoon. Sustained winds will relax tonight although the boundary layer is likely to remain mixed or much of the overnight.

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

Climate

Record Low Maximum Temperatures:

February 1: KGSO: 27/1971 KRDU: 28/1900 KFAY: 32/1981

February 2: KGSO: 30/1951

Record Low Temperatures:

February 2: KGSO: 6/1971 KRDU: 5/1971 KFAY: 15/1971

RAH WATCHES/WARNINGS/ADVISORIES

Winter Weather Advisory until 10 AM EST Monday for NCZ007>011- 021>028-038>043-073>078-083>086-088-089. Cold Weather Advisory from 7 PM this evening to 9 AM EST Monday for NCZ007>011-021>028-038>043-073>078-083>086-088-089.