textproduct: Raleigh

SYNOPSIS

Arctic high pressure will weaken and modify over the Carolinas through Wednesday. A warm front will lift north across the region on Thursday. A cold front will sweep across the area late Thursday and Friday.

NEAR TERM /THROUGH TONIGHT/

As of 340 AM Tuesday...

Orographically enhanced cirrus clouds persist across parts of the northern Piedmont and northern Coastal Plain in the fast NW flow aloft behind the departing mid/upper trough over the North Atlantic and Canadian Maritimes. This is having some warming effect on temperatures, which are in the upper-20s there in many spots vs lower-to-mid-20s where skies are clear across the south. Still, with dew points in the single digits to mid teens, along with light winds, low temperatures tonight are expected to drop into the upper- teens and lower-20s.

Sunny skies will prevail today under continued NW flow aloft and an Arctic surface high centered to our south that moves offshore. Light SW return flow and modification of the surface high will help temperatures get warmer than yesterday, albeit still below normal, reaching the mid-40s to 50. High clouds will begin moving in from the west on Tuesday night in advance of the next shortwave moving into the lower/mid MS Valley. This along with continued light SW flow and air mass modification will keep lows from getting as cold as recent nights, generally mid-20s to 30.

SHORT TERM /WEDNESDAY THROUGH THURSDAY/

As of 210 AM Tuesday...

The warming trend will continue on Wednesday with south/southwesterly low level flow, along with dry weather. Afternoon high temperatures are expected to be in the in the 50s. Cloud cover will begin to thicken from the south overnight as lead initial s/w disturbance approaches the area from the southwest. Any precip will hold off until Thursday though. However, the increasing moisture/cloud cover will have an impact on overnight lows. For now will keep lows in the 30s, but we may need to raise lows if the guidance trends faster with this system (40s).

Rain/showers will overspread the area on Thursday as the lead s/w disturbance moves into the region ahead of the deepening trough to the west of the area. Expect we'll see an in-situ CAD boundary develop across the our region with high temps likely ranging from the mid/upper 40s across our far nw Piedmont to the 60s to near 70 across our far southeast. While no flooding is expected this should be a good wetting rain, with rainfall amount of up to 0.50 inch possible, with locally higher amounts (Thursday into Thursday night).

LONG TERM /THURSDAY NIGHT THROUGH MONDAY/

As of 1145 PM Monday...

* Wet Thu night, with areas of fog possible in lingering, in-situ cold air damming over the nw Piedmont * Clouds and a chance of rain/showers linger early Fri, with clearing and otherwise seasonable and dry conditions through Sat * Milder and with just a slight chance of rain Sun into Sun night * Cooler/more seasonable and dry Mon

The models indicate a highly amplified shortwave trough may assume negative tilt while pivoting across and offshore the Middle Atlantic and New England Fri-Fri night, with associated glancing but strong height falls across cntl NC early Fri, when the aforementioned chance of rain will linger. In its wake, continued progressive flow will become quasi-zonal across the mid-latitudes, around a sub- tropical ridge forecast to migrate from the sern Pacific to MX and the srn Plains. Another shortwave trough will then progress across the Great Lakes and Northeast this weekend, but there are larger than average differences in its associated amplitude and degree of influence, if at all, in cntl NC.

At the surface, a pair of fronts will probably be in the process of merging and moving ewd and across cntl NC early Fri. Following, ~1025mb high pressure will migrate quickly ewd and across and offshore the Southeast through Sat. A warm front will develop ewd from the Mid-South to the srn Middle Atlantic Sat night and Sun, where it will linger ahead of a reinforcing cold front that will move across the srn Middle Atlantic Sun night. Rain chances with each appear low at this time, given the weak but still uncertain influence of the aforementioned shortwave trough across the northeast quarter of the nation this weekend. A strong, ~1030-1035 mb high will follow and ridge across the Middle Atlantic Mon, with cooler and dry, nely flow directed across cntl NC.

AVIATION /12Z TUESDAY THROUGH SATURDAY/

As of 645 AM Tuesday...

VFR will prevail across central NC through the next 24 hours. A deck of orographically enhanced cirrus continues across the northern Piedmont and northern/central Coastal Plain, but it will dissipate by mid morning. Otherwise, Arctic high pressure over the Southeast US will move east and offshore today, resulting in sunny skies and light SSW winds. Some high clouds will move in from the west by early Wednesday morning.

Outlook: VFR conditions will prevail through Wednesday. Flight restrictions and rain will accompany a frontal system across the region Thu-Thu night. Additionally, low-level wind shear will be possible Wed morning. VFR and dry weather will return on Friday and Saturday.

RAH WATCHES/WARNINGS/ADVISORIES

None.