textproduct: Raleigh

SYNOPSIS

Arctic high pressure will build across the region today. The high will settle across the Southeast ahead of a strong, clipper low pressure system that swing across the Great Lakes Tuesday night and Wednesday. A moisture-starved cold front trailing the clipper low will move across NC Wednesday night.

NEAR TERM /TODAY AND TONIGHT/

As of 320 AM Tuesday...

* Sub-freezing temperatures will allow any snow or moisture on area roads and sidewalks to freeze, producing hazardous travel through mid to late morning.

* Cold today with highs 15 to 20 degrees below normal

In the wake of exiting shortwave trough, a migratory Arctic high pressure will weaken while building over the area today before shifting offshore tonight.

Light snow/flurries have ended across the area, leaving behind widespread low clouds early this morning. However, dry low-level air advection from the north, combined with increasing subsidence aloft, should lead to NE to SW clearing/partial clearing through mid to late morning.

Across the area that received 1-2 inches of snow across the northern Piedmont and northern coastal plain, morning lows in the lower to mid 20s will support slick spots and patchy black ice, especially on shaded secondary roads, bridges and overpasses. Temperatures should rise above freezing by late morning along with increasing solar radiation, the risk for slippery conditions will diminish.

Temperatures will be unseasonably cold for early December, with highs ranging from mid/upper 30s north to lower 40s south --about 15 to 20 degrees below normal. After the low stratus scatters out, expect periods of broken/overcast cirrus and cirrostratus, some of which may become orographically-enhanced, through tonight. Lows tonight will fall into the 20s area-wide.

SHORT TERM /WEDNESDAY AND WEDNESDAY NIGHT/

As of 320 AM Tuesday...

* Windy conditions will develop ahead of a dry cold front.

The large-scale mid/upper trough over the central and eastern US will be reinforced by several digging shortwave troughs, including a clipper-type perturbation and it's accompanying dry cold front that will sweep through the mid-Atlantic states late Wednesday and Wednesday night.

The primary weather impact will be the development of windy conditions within the pre-frontal regime. SWLY winds will increase after daybreak and peak during the afternoon/max heat, with sustained winds of 15 to 20 mph and frequent gusts between 25 to 35 mph, occasionally reaching 35 to 40 mph at times. Residents should secure outside items and holiday decorations.

Expect considerable cloud cover, consisting of mid and high level clouds, ahead of the cold front. Temperatures will moderate closer to normal for early December, with highs ranging from near 50 north to mid 50s south.

Following the dry cold frontal passage Wednesday night, CAA will ensue. Skies will clear and gusts will diminish. Overnight lows will fall into the lower 30s north to mid 30s south.

LONG TERM /WEDNESDAY THROUGH MONDAY/

As of 320 AM Tuesday...

Behind Wednesday's cold front, the wind should ease off through the rest of the forecast. While a weak boundary should move through on Saturday, a lack of moisture will keep the weather dry. The only chance for precipitation, which is minimal at best, will be late Saturday night into Sunday morning with another cold front moving through the region.

However, the bigger impact with the frontal passage will be a change in temperatures. Temperatures will be below normal Thursday and Friday before moderating to near normal on Saturday, but once Sunday's cold front moves through, much colder air will arrive for the beginning of next week. Sunday night's lows will range from the mid teens to the mid 20s, and most locations on Monday will not manage to reach 40 degrees.

AVIATION /06Z TUESDAY THROUGH SATURDAY/

As of 100 AM Tuesday...

Light snow/flurries have largely ended across the area, leaving behind widespread MVFR ceilings across the area. However, dry low- level air advection from the north and increasing subsidence aloft should support a return to VFR condition from NE to SW between 08 to 14z. Thereafter, expect periods of broken/overcast cirrus clouds, especially across the northern terminals.

Northerly gustiness will diminish will overnight with winds becoming light and variable before shifting to SWLY late Tuesday morning into the afternoon.

Outlook: A 45-50 kt LLJ will result in a period of LLWS Tuesday night into early Wednesday, followed by turbulent conditions Wednesday with frequent SWLY gusts of 30 to 40 mph. Otherwise, predominately VFR is expected through late week.

RAH WATCHES/WARNINGS/ADVISORIES

Winter Weather Advisory from 7 AM Monday to noon EST Tuesday for NCZ007>011-021>028-041>043.