textproduct: Raleigh

WHAT HAS CHANGED

* Patchy light rain/sprinkles will be possible over the Piedmont through this evening and again early Mon.

* Patchy dense fog will be possible Tue and Wed morning, especially over the ne Piedmont and nrn-cntl Coastal Plain.

KEY MESSAGES

As of 200 PM Sunday...

1) Temperatures will remain seasonable and slightly above average, with considerable mid and high-level clouds and patchy light rain/sprinkles over the Piedmont, through Mon.

2) Patchy dense fog will be possible Tue and Wed morning, especially over the ne Piedmont and nrn-cntl Coastal Plain.

3) Chance of showers from late Wednesday night through Friday night or early Saturday. Above-normal temperatures expected through the week.

DISCUSSION

As of 200 PM Sunday...

KEY MESSAGE 1... Temperatures will remain seasonable and slightly above average, with considerable mid and high-level clouds and patchy light rain/sprinkles over the Piedmont, through Mon.

A shortwave perturbation, evident in regional radar and GOES-E satellite data over the TN Valley and embedded within an elongated synoptic trough from the upr Great Lakes to the ern Gulf, will progress ewd and across and offshore the Middle Atlantic and Carolinas through Mon. It will be accompanied by considerable mid and high-level cloudiness and virga. Some of the precipitation may reach the surface in the form of patchy, very light measurable rain of a hundredth or two, or non-measurable sprinkles. Those occurrences will be favored along the track of the shortwave disturbance and strongest ascent from s-cntl VA to n-cntl NC Mon morning.

KEY MESSAGE 2... Patchy dense fog will be possible Tue and Wed morning, especially over the ne Piedmont and nrn-cntl Coastal Plain.

Skies will clear from west to east with the passage of the aforementioned shortwave perturbation late Mon-Mon early night, then remain generally so until deep moisture increases ahead of the next trough aloft late Wed and Wed night. Related mainly clear, and calm to light nely to ely stirring within the lingering presence of a surface ridge axis, will favor good radiational cooling both Mon and Tue night. As the related airmass gradually modifies and low-levels moisten through that time, the risk of morning fog will increase. Some may become dense over the ne Piedmont and nrn and cntl Coastal Plain, where the greatest overlap of calm and moisture recovery is anticipated.

KEY MESSAGE 3... Chance of showers from late Wednesday night through Friday night or early Saturday. Above-normal temperatures expected through the week.

A frontal system approaching the Mississippi Valley Wednesday morning will lift a warm front north across the Mid-Atlantic on Thursday ahead of an approaching cold front. The primary boundary will cross the region Thursday into Friday before pushing offshore Friday evening, followed by a weak, dry reinforcing boundary early Saturday.

Showers are expected to develop over the western Piedmont late Wednesday night before spreading eastward Thursday and Thursday night. Behind the initial boundary, drier air will begin filtering into the region Friday night. Model guidance has trended drier over recent runs, cutting back both PoPs and QPF; consequently, confidence in widespread precipitation remains low. For now, the highest PoPs are focused Thursday afternoon, where enough instability may develop to support a few isolated rumbles of thunder.

Temperatures will run 10 to 14 degrees above climatological normal throughout the period. Highs will consistently reach the mid 70s to lower 80s, with mild overnight lows generally in the mid 50s to lower 60s.

AVIATION /00Z MONDAY THROUGH FRIDAY/

As of 735 PM Sunday...

24 hour TAF period: VFR conditions, with overcast mid and high-level clouds, should prevail through the 24 hour TAF period. Periods of cigs in the 5-7 kft range will be possible, accompanied by some virga or very light rain, favored across the Piedmont through mid- day Mon. Calm to light nely winds should prevail.

Outlook: Areas of fog and low stratus are expected to develop Tue and Wed morning, probably with greatest coverage from e-cntl VA through n-cntl NC and with highest probability of occurrence and lowest restrictions at RWI and RDU. A moist axis, and a couple of bands of showers and possible flight restrictions, will precede a slow-moving cold front across the region Thu and Fri.

RAH WATCHES/WARNINGS/ADVISORIES

None.