Area Forecast Discussion
Issued by NWS Raleigh/Durham, NC

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000 FXUS62 KRAH 271403 AFDRAH Area Forecast Discussion National Weather Service Raleigh NC 1000 AM EDT THU OCT 27 2016 .SYNOPSIS... A cold front will approach from the west today, crossing central NC late tonight. High pressure will build into the region Friday, and persist over the area through the weekend. && .NEAR TERM /through Tonight/...
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As of 1000 AM Thursday... Weak DCVA between shortwaves over the Great lakes and Southern Plains will impact this area late this afternoon, with the associated cold front lagging until after midnight. Ahead of the trough axis, some patchy stratus in the Piedmont is scattering and we should see a fair amount of sun as periods of high clouds drifting overhead from the southwest. Statistical guidance is in good agreement on highs in the low to mid 70s, which with dewpoints in the mid 50s this afternoon doesn`t suggest much instability. However, mid-level lapse rates are actually in the 6-7 C/km range, so with moistening there could be weak instability develop from southwest to northeast. This could help some of the showers that trigger ahead of the aforementioned trough to move east into the Piedmont late this afternoon, and an isolated thunderstorm is possible. Deep layer shear will likely increase to 30-40kt given ~35kt flow at 500mb in upstream raobs this morning, but the lack of instability will limit updraft strength and should preclude any real strong storms. Hi-res guidance offers quite a variety of solutions when it comes to coverage, but most at least hint at a stronger convective cell or two in the western Piedmont by 20z. -BS Tonight, sfc cold front will advance east across central NC between 06Z-12Z. Northwest flow behind the front will advect a drier air mass into the region. This arrival of the drier coupled with the downslope component of the low level wind will aid to decrease cloudiness nw-se toward daybreak. Expect the clearing to initiate in the Triad around 06Z, reaching our eastern periphery shortly after daybreak. Min temps on the mild side due to the low level mixing and extensive cloudiness. Min temps lower 50s nw to the mid- upper 50s se.
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&& .SHORT TERM /Friday and Friday night/... As of 338 AM Thursday... High pressure will build into central NC Friday and Friday night in the wake of the exiting cold front. Low level cold air advection brief as core of the cold air will slide to our north, just brushing our far north-northeast counties. Where clouds are still prevalent early Friday will depart by mid day with sunny skies expected areawide Friday afternoon. Clear skies and near calm winds Friday night will lead to excellent nocturnal cooling conditions. High temperatures near 70 far north to the mid-upper 70s south. Min temps Friday night upper 40s northeast to near 50-lower 50s south. && .LONG TERM /Saturday through Wednesday/... As of 304 AM Thursday... Dry and warm conditions on Saturday as high pressure sinks south across the region. Shortwave will cross the Mid Atlantic on Sunday bringing a weak dry cold front through NC late Sunday/early Monday. Expect a dry passage with upper level westerly winds and limited moisture return. Ahead of the front, southwesterly flow and increasing low level thicknesses will support temperatures near 80 degrees. Surface high pressure will move in to the region Monday through Wednesday, as upper level ridging will builds over the Southeast. This will support continuing dry conditions and above average temperatures through midweek. && .AVIATION /12Z Thursday through Monday/... As of 740 AM Thursday... Increasing southerly low level flow will advect a moderately moist air mass into central NC today. This has aided in the development of pockets fog and low clouds, though bulk of the region still experiencing VFR conditions. The fog and/or low clouds will lift and dissipate by 14Z. Otherwise, expect a veil of mid-high level clouds throughout the day. An approaching surface cold front will result in breezy southerly winds with gusts near 20kts probable. This surface front will cross central NC late tonight, primarily between 06Z-12Z Friday. Enough moisture and lift will exist to support a few showers though VFR conditions are expected to persist. High pressure will build into our region in the wake of the departing front Friday. This weather system will maintain control of our weather through the weekend. && .RAH WATCHES/WARNINGS/ADVISORIES... None. && $$ SYNOPSIS...WSS NEAR TERM...WSS/BS SHORT TERM...WSS LONG TERM...30 AVIATION...WSS is the U.S. government's official web portal to all federal, state and local government web resources and services.