textproduct: Raleigh

SYNOPSIS

A cold front will move through the area this morning. The front will then settle off the coast of the southeastern United States into the middle of the week as cool high pressure extends into the area from the Mid-Atlantic.

NEAR TERM /TODAY AND TONIGHT/

As of 155 AM Sunday...

* Much cooler today with below normal highs, warmest in the early part of the day * Cloud cover slow to erode with a moist post-frontal NE flow * A few patchy showers around into midday, but storms should mainly reside east of the area

The surface cold front is still tucked west of the Appalachians of NC and VA. The majority of the shower activity has waned considerably in the last few hours as the effective front has pushed well east of the area and stabilized the atmosphere. Plenty of low and mid-layer clouds will continue to overspread the area as the upper-trough is still to our west and the 850/700 mb frontal position will be slow to move through until late tonight to early Mon.

The cold front will edge south and through the area this morning across the north, to early afternoon in the far SE, eventually reaching the coast this evening. The front will then settle offshore of the SE US later tonight as cool 1027 mb high pressure edges southward from the OH valley.

It will be a much cooler day today compared to yesterday, by some 15- 20 degrees in the upper 60s to near 70 in the north to the low 80s in the SE. Our warmest temperatures should be felt this morning just along and south of the front. As the front moves through, temperatures could drop into the 60s along/north of US-64 as suggested by some high-res models. Otherwise, expect plenty of low stratus with a moist post-frontal NE flow, at times gusting to 15-20 mph in the SE. The low clouds will be slow to erode, earliest to lift in the NW Piedmont and slowest in the southeast. As for rain chances, isolated to scattered rain/showers are possible this morning and early afternoon mainly along/north of US-64 with the 850/700 mb front and trough overhead. This afternoon, instability largely focuses east of the area. The latest HREF shows the best chance of storms along and just inland of the immediate coast. We have kept 30-percent PoPs in the Sandhills and Coastal Plain, however.

Low and high clouds should finally clear out tonight with high pressure building into the area. Overnight lows will dip into the low/mid 50s in the north and near 60 in the south. Some spots in the far north could dip into the upper 40s.

SHORT TERM /MONDAY THROUGH MONDAY NIGHT/

As of 155 AM Sunday...

* Dry, Breezy, and Cool

Underneath broad upper troughing, parent surface high centered over the Northeast US and New England will be the dominate weather feature as it extends southward along much of the Eastern Seaboard. While some cloud cover may linger across the far eastern zones, highs Monday afternoon will range from 75 to 80, about 4-8 degrees below normal for early September. A modestly pinched gradient between the high and a stalled offshore front will support NELY gusts of 15 to 25 mph, with comfortable humidity levels as BL dewpoints mix out into the upper 40s and 50s. Lows Monday night will generally fall into the 50s, though some lower 60s are possible across the SE counties where increasing/thickening cirrus spreads in from the east.

LONG TERM /TUESDAY THROUGH SATURDAY/

As of 155 AM Sunday...

* Cooler Than Normal, Mainly Dry

Overview: Broad upper troughing will persist across the Eastern US through the period. At the surface, high pressure will extend southward along the Eastern Seaboard and into the Carolinas through mid to late week, while a frontal zone wavers offshore.

Temperatures: A prolonged period of NELY low-level flow will support below-normal temperatures with gradual moderation back toward seasonable normals by the end of the work week as the high weakens and begins to break down. A dry back-door cold front will approach late-week, followed by renewed high pressure next weekend.

Precip chances: Shortwave energy embedded within the long wave trough may temporarily force the offshore frontal zone to retrograde westward towards the immediate coast Tuesday-Wedneday, potentially resulting in some light rain across the far eastern zones. The front will then shift back offshore Thursday, reinforcing dry conditions. Otherwise, the extended period will remain mostly dry.

AVIATION /12Z SUNDAY THROUGH THURSDAY/

As of 608 AM Sunday...

Areas of LIFR-IFR stratus and patchy low visibilities will start the TAF period. The cold front will be moving through this morning, with a gradual erosion of the LIFR-IFR ceilings. The moist NE flow behind the front will favor a prolonged period of MVFR stratus across the terminals today, with lifting to VFR earliest at GSO/INT around 16- 19z and latest at FAY/RWI around 00z. The latest forecast may be somewhat on the pessimistic side, but is a blend of several high-res models. More optimistic solutions suggest lifting to VFR between 15 and 21z over central NC, while slower solutions do not lift out MVFR in the east until 03-05z Mon. High pressure building in tonight should otherwise favor VFR to return at all terminals. Northeast winds will prevail today, with some brief gusts to 18 kt, most favored at the eastern sites. While there is the chance of a few isolated showers or a storm, most activity should reside closer to the coast. If any storm were to occur later today, it would be most favored at FAY.

Outlook: Largely VFR conditions should prevail into much of the upcoming week, however a stalled front offshore of the SE US could favor a chance of sub-VFR conditions in showers Tue and Wed.

RAH WATCHES/WARNINGS/ADVISORIES

None.