Area Forecast Discussion
Issued by NWS Raleigh/Durham, NC

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000 FXUS62 KRAH 280803 AFDRAH Area Forecast Discussion National Weather Service Raleigh NC 403 AM EDT SUN AUG 28 2016 .SYNOPSIS... High pressure will persist over the region through today. An upper level disturbance over the Atlantic will then drift west along the Carolina coast Monday and Tuesday && .NEAR TERM /THROUGH TONIGHT/... As of 1018 PM Saturday... Convection continues to wane with lingering isolated storms drifting slowly westward over the central/western piedmont before diminishing all together as low-level surge of lower theta-e air and increasing CIN advects into the area behind a weak surface front moving in from the ne. This nely low-level flow could also result in the development of some low stratus and/or fog across the NC Coastal Plain during the predawn hours, possibly spreading westward into the Central Piedmont/Triangle area aoa daybreak. Lows tonight 70 to 75, coolest across the ne. && .SHORT TERM /SUNDAY THROUGH SUNDAY NIGHT/... As of 350 PM Saturday... Surface high pressure centered over southern New England will strengthen and nose southward into the Carolinas Sunday. This sfc feature will extend across our Piedmont counties. Associated subsidence should initially limit mixing which may allow low clouds to linger until late morning/mid day. Otherwise, presence of sfc ridge should inhibit convective development in the afternoon hours. Over the southern coastal plain and the sandhills, modest moisture advection courtesy of an upper level low off the SC coast coupled with afternoon heating should trigger scattered convection. Expect the greatest concentration to occur immediately se of our region though 30-40 percent coverage still possible over parts of our se counties. Anticipated cloud cover Sunday morning will limit sunshine. this should to afternoon temps not quite as hot/oppressive as the past couple of afternoon. High temps upper 80s-lower 90s. Again, most of the convection will dissipate with loss of heating. Could see another round of overnight low clouds, though it may be limited to the se half of the forecast area. Low temps upper 60s nw to the low/mid 70s se. && .LONG TERM /TUESDAY THROUGH SATURDAY/... As of 355 AM Sunday... WV imagery this morning depicts an increasingly well-defined mid to upper level low off the SERN U.S coast. The forecast models continue to indicate this feature will drift W --around the SRN periphery of the initially strong sub-tropical ridge centered over the Middle Atlantic states-- and stall along the SERN U.S. coast early this week, before shearing out and lifting away from the region through the middle of the week. The presence of this mid-upper low, and a NRN stream trough forecast to migrate across the NERN U.S through early week, will cause the preceding sub-tropical ridge to succumb over the Middle Atlantic states and ultimately split, with one center expected to retrogress into the central U.S. and the other retreat into the central N. Atlantic Ocean. A broad trough will develop between the two /over ERN U.S./ through the end of the week. This pattern aloft will play an important role in what becomes of the now well-advertised tropical wave along the NRN coast of Cuba this morning, which the models now generally agree will enter the ERN Gulf of Mexico early to mid-week. Significant model spread regarding the track and timing of the associated low develops thereafter, though it seems reasonable that low will eventually be influenced by the aforementioned ERN CONUS trough aloft and be drawn NEWD through or along the SERN U.S coast, with an associated increased probability of rain, through the end of the forecast period. Of greater predictability will likely be a NRN stream cold front forecast to settle through the SRN Middle Atlantic states and Carolinas Thu-Fri, with an accompanying chance of convection maximized in central NC Thu-Thu night. Cooler and drier conditions in post-frontal high pressure ridging across the Middle Atlantic region would follow, though the duration of this post-frontal regime will hinge upon what happens with the tropical low and associated moisture potentially approaching from the south later Fri and Sat. && .AVIATION /06Z SUNDAY THROUGH THURSDAY/... As of 200 AM Sunday... Early showers and storms have pushes west through the southern Piedmont and conditions are mostly VFR across the area at 06Z. Skies have mostly cleared across eastern NC, which may lead to some fog after 08z, though northeasterly flow may favor more low clouds than fog, possibly as low as LIFR. Confidence is pretty high that RWI and FAY will see IFR or LIFR conditions by 09z. To the west, RDU may end up right on the end of the low clouds, but sub-VFR vsbys will still be possible at RDU, GSO, and INT given earlier rainfall. If stratus does indeed develop over the coastal plain, models suggest it will be slow to lift through the morning hours, with a period of MVFR ceilings as far west as RDU between 12z and 15z. Scattered storms will likely develop later this afternoon, mainly from FAY to RWI and to the east. Outlook: VFR conditions are expected to prevail across central NC through most of the upcoming work week. There will be a good chance for early morning IFR/low end MVFR conditions each day due to low clouds and/or fog. In addition, there will be scattered showers and storms each afternoon, with the highest concentration expected in the vicinity of KFAY. && .RAH WATCHES/WARNINGS/ADVISORIES... None. && $$ SYNOPSIS...PWB NEAR TERM...CBL SHORT TERM...WSS LONG TERM...MWS AVIATION...PWB/BS is the U.S. government's official web portal to all federal, state and local government web resources and services.