textproduct: Raleigh

SYNOPSIS

A cold front will move southwestward across NC this morning, followed by cold high pressure that will ridge across the Middle Atlantic today. The front will then waver across the Carolinas ahead of a stronger cold front that will sweep across the region on Monday.

NEAR TERM /THROUGH TONIGHT/

As of 1215 PM Thursday...

A fickle front is in the process of wavering back and forth across the forecast area. The front is currently in the process of lifting north across North Carolina and should spend much of the afternoon in Virginia before retreating to the south, moving south of the entire forecast area by sunrise on Friday. The front, and associated clouds, are also wrecking havoc on predicting the temperatures. As of 12pm, it was 50 and cloudy in Henderson, but 70 at several sites with clear skies near the South Carolina border. With the front pushing north, clouds beginning to clear out, and southerly wind, temperatures should really ramp up during the beginning of the afternoon. Current forecast ranges from the mid 60s in the north near the Virginia border to mid 70s across the southeast.

Cloud cover will increase overnight with the return of the front, primarily between 3 and 5 thousand feet, but with drier air closer to the surface, there isn't a threat of rain. Overnight lows will be similar to last night's values, ranging from the mid 30s in the northeast to the upper 40s in the southwest. While the temperature gradient last night was primarily related to cloud cover, tonight's lows should be more connected to the amount of time spent on the cold side of the front and the development of the wind from the northeast.

SHORT TERM /FRIDAY AND FRIDAY NIGHT/

As of 1215 PM Thursday...

The front should extend from Blacksburg down towards Charlotte and arcing southeast across South Carolina. Meanwhile, high pressure will be centered just east of Hudson Bay with ridging extending into eastern North Carolina. The front appears likely to remain nearly stationary through the daytime hours before sliding slightly farther to the south Friday night. Clouds should become rather thick with a low level inversion setting up around 5000 ft, and the wind will veer from northeast to southeast through the day. Considering the northerly component of the wind will disappear, it may not be a true cold-air damming case, but the cloud cover will certainly keep highs much cooler than today. Have blended in NBM 10th percentile guidance with the NBM, and this gives highs ranging from the mid 40s across the northeast to upper 50s across the southwest.

Despite the front being south of the area Friday night, the wind should slowly veer to the south. As drier air begins to move into the area, this should slowly erode the cloud cover from south to north overnight. As a result, temperatures Friday night will generally be steady state through the night. Although temperatures in the southwest will drop a few degrees early in the evening where clearing occurs first, lows should mostly be in the 40s.

LONG TERM /SATURDAY THROUGH THURSDAY/

As of 1215 PM Thursday...

* The frontal zone will waver across the Carolinas through Sun, with rollercoaster swings in temperatures

* Rain chances increasing with the cold front Mon, along with gust winds along and immediately behind it

The wavering front from Fri will likely start out over central to southern VA during the early part of the day on Sat. The front is yet again forecast to sag back south, reaching the SC border by early Sun. Ahead of that, we should warm back up well above average Sat with mid/upper 60s NE to mid 70s SW. The frontal passage Sun will favor another seesaw in highs with mid 50s NE to low 60s S. This is still some 5 to 10 degrees above seasonal normals.

The cold front Mon was noted in the prior shift to be slowing, and that trend has continued today, with its passage centered on Mon evening. Guidance appears to be trending somewhat wetter along and ahead of the front, with PW values some 150-180 percent of normal and good moisture transport. Deep lift, however, does appear to be situated across our north so there is a lack of forcing overall. The low/high end varies from a few hundredths of an inch of rain to two tenths of an inch. It looks gusty ahead and behind the front, with gusts upwards of 30 mph at times, along with another rollercoaster ride with highs back in the 60s and 70s.

A much cooler airmass is favored Tue-Wed with temps back below normal in the mid/upper 40s for highs and lows in the 20s. A warming trend may return late in the week with possible low 50s Thu. Guidance is mixed on a possible secondary cold front Thu. Some AI models are more aggressive with the NW flow, while other ensembles keep zonal flow. For now, expect near to slightly below normal temps to start the New Year.

AVIATION /06Z FRIDAY THROUGH TUESDAY/

As of 125 AM Friday...

A backdoor cold front and related gusty wind shift to nely, which has already passed RWI and RDU as of 06Z, will continue to move swwd across cntl NC this morning. A band of post-frontal, mostly 3500- 5000 ft stratocumulus ceilings will also accompany the front, beneath continued 6-10 thousand ft altocumulus that will continue to stream across the region. Those stratocumulus ceilings will probably lower into upr end MVFR range from south to north this afternoon through evening, as "overrunning" lift strengthens.

Outlook: A frontal zone will continue to waver across NC through the weekend, with related periods of mostly MVFR ceilings and also a risk of low-level wind shear Sat and Mon mornings. A stronger cold front will sweep across the region with a chance of rain and additional flight restrictions on Mon.

RAH WATCHES/WARNINGS/ADVISORIES

None.