Area Forecast Discussion
Issued by NWS Raleigh/Durham, NC

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000 FXUS62 KRAH 161139 AFDRAH Area Forecast Discussion National Weather Service Raleigh NC 640 AM EST Thu Nov 16 2017 .SYNOPSIS... A fast-moving upper level trough will cross North Carolina early this morning. High pressure will move in from the northwest today through Friday, before moving offshore Friday night. A warm southwest flow will overspread the area Saturday, ahead of a cold front that will cross the region Saturday night. Cool high pressure will return for Sunday through Monday. && .NEAR TERM /today through tonight/... As of 215 AM Thursday... The mid level shortwave trough responsible for the light showers now moving through the NE portion of the forecast area will be moving to our east by daybreak, resulting in a west-to-east clearing trend early this morning. One minor perturbation will cross VA and northern NC early this afternoon, but the lack of any moisture will render this wave benign. Plenty of sunshine is expected today, with neutral vertical motion trending toward subsidence, and high pressure building in at the surface. The arrival of an area of 20-25 kt northwesterly winds at 850 mb will culminate in some gustiness to 15-20 kts, especially late morning into this afternoon. Very little cooling will take place through much of the day, with thicknesses starting out close to normal and rising at a near-climo pace today, so expect highs in the low-mid 60s. Cooler air builds in in earnest tonight, with thicknesses falling to 10-15 m below normal under clear skies and with diminishing winds, prompting good radiational cooling. Lows 30-35. -GIH && .SHORT TERM /Friday through Friday night/... As of 225 AM Thursday... Surface high pressure will build quickly overhead Fri and off the coast Fri night. Heights will continue to rise modestly Fri with a flat to gently anticyclonic mid level flow, and a dry column in place. Increasing high thin clouds are expected Fri evening/night as subtle mid level waves pass overhead (hopefully these will be thin enough so as to not impede viewing of the Leonid meteor shower). With lots of sunshine Fri but a cool start, expect highs of 55-61. Milder lows Fri night of 34-38 under fair skies with the onset of return flow on the back side of the exiting high. -GIH && .LONG TERM /SATURDAY THROUGH WEDNESDAY/... As of 255 AM Thursday... Models show much better consensus concerning the timing of an upper trof rotating across the Great Lakes and its associated surface front which will race east across the Tar Heel state late in the day. Winds will be gusty as the pressure gradient tightens ahead of the front, with low level jetting of 30 knots supportive of southwest gusts of 20 to 25 mph at the surface by afternoon. The window for PoPs will be narrow and largely confined to the immediate vicinity of front concurrent with strongest low level convergence. While this forcing in the frontal zone will be very strong, convection will be limited by a lack of moisture advection and the front`s unfavorable diurnal timing. The low level jetting increases to 50+ knots overnight, with steep mid level lapse rates in the dry air ahead of the front, so stronger showers could produce gusts to 40 mph, but thunder would be unlikely - isolated at best. The front will spill over the mountains in the afternoon, with likely PoPs in the western Piedmont early Saturday night. These likely PoPs will translate quickly across central NC, reaching the Coastal Plain after midnight before ending towards sunrise Sunday. Highs Saturday will be mild, 65 to 70, in strong warm air advection ahead of the front. Mins Saturday night will benefit from delayed cold air advection and mixing, with temperatures at sunrise around 40 in the west to 50 east. Cool and dry high pressure will settle into the area Sunday, with rather low amplitude upper troffing lingering Sunday through midweek. Have low confidence in features capable of producing any precipitation that might impact the area through this latter extended period. Highs Sunday and Monday will be mostly in the 50s, with modest warming to the mid 50s to lower 60s on Tuesday and Wednesday as the airmass modifies. Morning mins will fall to near or a few degrees below freezing Monday and Tuesday mornings, and to mostly mid 30s Wednesday morning. && .AVIATION /12Z Thursday through Monday/...
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As of 640 AM Thursday... Despite the passage of an upper level trough and accompanying light showers through the area early this morning, cloud bases will be high (around 8,000-10,000 ft AGL) with VFR vsbys. Once this system passes to our east this morning, VFR conditions with mostly clear skies and unrestricted vsbys are likely today through tonight as surface high pressure builds into the area. Winds will be mainly from the NW today under 10 kts, becoming light northerly tonight. Looking beyond 12z Fri, VFR conditions are likely through Sat. MVFR conditions are expected Sat evening/Sat night as a cold front moves through with scattered showers. VFR conditions will return Sun through Mon as high pressure builds in. -GIH
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&& .RAH WATCHES/WARNINGS/ADVISORIES... None. && $$ SYNOPSIS...Hartfield NEAR TERM...Hartfield SHORT TERM...Hartfield LONG TERM...mlm AVIATION...Hartfield is the U.S. government's official web portal to all federal, state and local government web resources and services.