textproduct: Raleigh

WHAT HAS CHANGED

* Rainfall forecast totals for Sunday have continued to trend lower, particularly over the Piedmont.

KEY MESSAGES

As of 220 PM Saturday...

1) A cold front sliding south across central North Carolina will bring the potential for heavy rain, particularly to the south and east of the Triangle, along with much more seasonable temperatures.

2) Periods of light rain and cool temperatures remain possible through the day on Sunday before a reinforcing cold front moves through the region Monday.

DISCUSSION

As of 220 PM Saturday...

KEY MESSAGE 1... A cold front sliding south across central North Carolina will bring the potential for heavy rain, particularly to the south and east of the Triangle, along with much more seasonable temperatures.

Through the day, a cold front has swept south across much of North Carolina. In counties along the Virginia/North Carolina border, 2pm temperatures were only in the 60s, with 70s along and to the south of US-64, and 80s contained to the warm side of the front across the southern part of the state. A line of rain currently extends along much of the US-64 corridor, although there is a gap near the Triad. While this line has been the focus of rain during the late morning and early afternoon hours, high-resolution models suggest that the character of the rain will become more of a cluster late this afternoon into the evening hours, primarily south and east of the Triangle, as a wave of low pressure forms along the front. South of US-64, most locations will have at least a quarter inch of rain this afternoon, with 0.5 to 1 inch of rain east of Raleigh and Fayetteville. There may be a bit of a lull this evening, with rainfall ramping up once again after midnight. While locations to the north of US-64 should generally have less than a half inch of rain through sunrise Sunday, most locations south of US-64 will have at least three quarters of an inch of rain, with some locations receiving 2 inches of rain. Isolated locations with excessive rainfall cannot be ruled out. Overnight lows will range from the mid 50s across the north to the mid 60s across the south.

KEY MESSAGE 2... Periods of light rain and cool temperatures remain possible through the day on Sunday before a reinforcing cold front moves through the region Monday.

Today's cold front will stall to our south tonight, before potentially wavering back north over the region in the south tomorrow. At the same time, cool high pressure will continue to extend southward into central NC through the day on Sunday, allowing for a cool wedge airmass to remain in place. Thus, cloudy skies with periods of light to moderate rain remain possible, especially in the south and east closer to the frontal boundary and the coast. However, CAM guidance is still trending drier in regards to the rainfall amounts possible, especially in the Triad region. Many models suggest that the Triad may remain dry, or only receive minimal rain on Sunday, while the 12Z HREF suggests that the eastern half of the CWA may only receive up to 0.5 inch of rain. However, looking at the LPMM data, it will be possible for a few locations in the east to receive up to an inch of rain.

A reinforcing cold front will move through the region on Monday. This should eliminate any rain chances for the rest of the week as cool and dry high pressure builds back in. Monday may warm up ahead of the frontal passage into the mid to perhaps upper 70s, with Tuesday and Wednesday cooling into the upper 60s to low/mid 70s, with Tuesday looking to be the coolest day. Lows look to drop into the 40s Tuesday night as well. Temperatures will then warm back to slightly above normal to end the week ahead of the next frontal passage next weekend.

AVIATION /18Z SATURDAY THROUGH WEDNESDAY/

As of 145 PM Saturday...

24 hour TAF period: A cold front has moved from north to south across much of the forecast area, having passed all terminals except FAY. FAY is likely to have VFR conditions for the rest of the afternoon, unless scattered showers/thunderstorms develop in advance of the front. Meanwhile, MVFR/IFR ceilings have developed at all other terminals with cooler and more moist air, and ceilings will continue to lower through the afternoon, evening, and overnight hours, eventually dropping to LIFR. As of 1745Z, there is currently a band of showers extending from RWI west to RDU and HBI, although this is not expected to remain the focus of rainfall - the heaviest rain should eventually be south and east of RDU, RWI, and FAY. This area should fill in, not as a line segment, but as a cluster of showers and thunderstorms. FAY appears to be the only location that should have the potential for any thunderstorms - INT/GSO should be too stable at this point, and it appears that RDU/RWI will have minimal instability being on the cool side of the front.

Outlook: Widespread rain and restrictions are expected to continue Sunday afternoon and Sunday night. While INT/GSO may go VFR Sunday night, other terminals will likely keep restrictions until Monday. Dry VFR conditions should then persist into the middle of the week.

RAH WATCHES/WARNINGS/ADVISORIES

None.