Area Forecast Discussion
Issued by NWS Raleigh/Durham, NC

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942 FXUS62 KRAH 232319 AFDRAH Area Forecast Discussion National Weather Service Raleigh NC 619 PM EST Mon Jan 23 2017 .SYNOPSIS... A stacked low pressure system overhead will track east- northeast away from the Carolinas today, then track off the Mid- Atlantic coast on Tuesday. Highs pressure will then influence the region through midweek. && .NEAR TERM /THROUGH TONIGHT/... As of 250 PM Monday... Stacked low pressure system is essentially overhead this afternoon and will depart to the northeast tonight. there are two main areas of precip that may impact central NC tonight; 1) low-topped convection currently southeast of FAY associated with a vort max within the upper low and a -22C cold pool at H5, which has resulting in a couple hundred J/KG of MLCAPE nudging into the southern Coastal Plain, and 2) deformation band moisture over the Foothills and Blue Ridge. the area of convection should rotate north and may reach Clinton/Goldsboro areas before being shunted toward the coast this evening. Still can`t rule out some small hail or graupel given a freezing level down to around 7k ft, but the convection does not look very robust so far. The deformation band to the west will slide east across the CWA between 00Z and 09Z, and hi-res guidance suggests some light rain will be possible over the western Piedmont before a northwest wind (that may gusts to 15-20kt as cold advection kicks in) scours the remaining moisture. The coldest air behind the low may stay west of the mountains tonight and lows should end up on the warmer side of guidance, such as the MAV. 42-46. && .SHORT TERM /TUESDAY THROUGH TUESDAY NIGHT/... As of 250 PM Monday... Ridging aloft will develop behind the departing low on Tuesday, with cold advection easing up through the day. Skies will have generally cleared, but forecast soundings suggest some scattered cu during the afternoon and wind gusts to near 20kt. prefer a blend of MOS for highs, 59-62 and coolest northeast where cold advection lasts longest. Relatively mild high pressure will nose in from the south Tuesday night before quickly retreating ahead of the next cold front. Lows 38-42 && .LONG TERM /WEDNESDAY THROUGH MONDAY/... As of 210 PM Monday... A transition from mild conditions to more seasonable, but generally dry ones, will occur during the medium range. Ridging aloft will crest over the Ern U.S. on Wed, then move offshore in advance of a broad, positive tilt longwave trough that will migrate Ewd and encompass the Ern two thirds of Ern North America by the weekend. A surface cold front --one related to the lead shortwave trough that will initiate the Ewd progression of the longwave trough, and which will trail a parent surface cyclone that will migrate NEwd across the Great Lakes-- will settle across NC late Wed night-Thu. Both moisture and lift are forecast to be limited, as the parent forcing lifts to our NW, so rainfall chances and amounts are likewise expected to be limited. Behind this lead front, temperatures will cool to more seasonable/ average levels for the end of the week and weekend. The positive tilt configuration of the trough aloft will cause surface high pressure to sprawl into the SErn U.S. and suppress any additional precipitation chances until Sun-Mon, at which time a Nrn stream shortwave trough in NW flow aloft will amplify into the Middle Atlantic region and possibly support some degree of cyclogenesis over the Wrn Atlantic. At this time, it appears that a generally dry reinforcing cold frontal passage will result for our region, though the prospects of nearby coastal cyclogenesis will be worth watching in the coming days. && .AVIATION /00Z TUESDAY THROUGH SATURDAY/... As of 618 PM Monday... 24-Hour TAF period: The surface low will move northeast away from Central NC, however lingering low level moisture will result in continued or redevelopment of MVFR/IFR conditions across northern portions (KINT/KGSO/KRDU/KRWI) of the area through the night. Confidence is not high on how log the sub-vfr cigs and visbys will last, but expect gradual improvement to begin between 04Z and 09Z. Northwesterly winds will continue to be strong and/or gusty through the TAF period and should help scour out cloud cover early Tuesday. Periods of light rain are possible over the next several hours, however additional impacts should be minimal. -KC Looking ahead: VFR conditions are expected through Wednesday. A cold front will cross the region late Wednesday night/early Thursday, bringing with a chance of showers and sub-VFR ceilings to the area. VFR conditions should return late Thursday afternoon/evening. -Smith && .RAH WATCHES/WARNINGS/ADVISORIES... None. && $$ SYNOPSIS...SMITH NEAR TERM...SMITH SHORT TERM...SMITH LONG TERM...MWS AVIATION...KC/SMITH is the U.S. government's official web portal to all federal, state and local government web resources and services.