Area Forecast Discussion
Issued by NWS Raleigh/Durham, NC

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000 FXUS62 KRAH 171830 AFDRAH Area Forecast Discussion National Weather Service Raleigh NC 130 PM EST Sat Feb 17 2018 .SYNOPSIS... A warm front will gradually lift north into the southern counties of central NC this afternoon then stall. A weak cold front will approach from the west later today and cross our region tonight. High pressure will build into the area Sunday, then quickly drift offshore Sunday night. && .NEAR TERM /THROUGH TONIGHT/... As of 1055 AM Saturday... Just minor tweaks required to the near term forecast, primarily to adjust PoPs down a touch through early afternoon. Low level cold air advection and overcast skies preventing temperatures from rebounding this morning. Most locations have seen temperatures hold steady or fall a degree or two since sunrise. Expect this trend to continue through the afternoon. Per SPC meso- analysis, 850mb flow beginning to increase to our south-southwest. This strengthening isentropic upglide should cause patchy light rain to develop across the southern and western Piedmont through 3 PM, and over the remainder of central NC late this afternoon-early this evening. Should see an increase in coverage toward dusk-early evening as a mid-upper level s/w gets closer to central NC. Still expect overall rainfall totals to be light, with most locations totaling less than a quarter of an inch. The overcast skies, continued low level cold air advection, and patches of light rain will cause temperatures to show very little variation from current levels through this afternoon. Tonight, the mid-upper level s/w will traverse across the region this evening, accompanied by patchy or areas of light rain/drizzle. The bulk of this precip should be diminishing or ending shortly after midnight. NW flow behind the exiting s/w will advect a drier air mass into central NC, possibly leading to partial clearing across the Piedmont very late tonight. Whether the clouds depart by morning will play a role in the minimum temperature forecast across the Piedmont. Current low temp forecast based on partial clearing to occur, allowing temperatures to drop into the mid-upper 30s. If clouds hold on through daybreak, min temps at or slightly above 40 degrees will be more probable. && .SHORT TERM /SUNDAY AND SUNDAY NIGHT/... As of 345 AM Saturday... As continental high pressure moves in on Sunday, expect rain to stop and skies to clear. This will be a fast moving transitory high that will end up moving east of the area and offshore by Sunday night. For all the chilly temperatures on Saturday, Sunday will feature highs in the upper 50s to middle 60s across the area. Winds will begin to swing around to southerly by Sunday evening setting up the beginning of return flow that will exist early next week. Sunday night lows in the 40s with highest temps in the southwest. && .LONG TERM /MONDAY THROUGH SATURDAY/...
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As of 130 PM Saturday... ...Unusually warm temperatures will shatter some records during this week... The daily record highs and record high minimum temperatures are included in the Climate section below for February 20 and 21 (Tuesday and Wednesday). These are the most likely days that will see new records. We will add to this the chance of record warmth continuing Thursday (February 22), and this may be extended in later forecasts due to the slowing of the decay of the strong upper ridging. To start off the warming, a warm front will push northward into the area. Some areas of light rain and showers are expected, with the highest POP in the NW zones into early Monday. Guidance continues to favor the warm front and WAA drying advection to bring clearing into the region Monday afternoon, especially south and west. Highs should moderate back into the 60s, except some upper 50s north. This may be tempered if the cloudiness persists into the afternoon more than currently expected. The main storm track is forecast to remain to the west and north of central NC this week. This occurs as a very strong and unusual subtropical ridge is forecast to set up just off the south Atlantic coast, most likely waxing Tuesday and Wednesday. A battle between arctic air over the northern Rockies into the upper Midwest and the record warmth in the southeastern states will lead to an active storm track, but much of the significant rain is expected to remain just to our NW, or from the Appalachians west and north. One front will likely make a run at us on Thursday, but due to the extensive upper ridge, will likely stall and return north on Friday. Most models now depict the strong ridge to remain in place into next weekend, with the potential for more record warmth depending on the position of the "backdoor" fronts. Sensible weather will be for only a slight chance of lingering light rain or drizzle Monday morning, otherwise increasing warmth and humidity Tue-Wed. leading to highs potentially in the upper 70s NW ranging into the lower 80s elsewhere. Some 83-84 degree readings will be possible from Laurinburg to Fayetteville) Tue-Thu. Lows in the 60s mid to late week will also likely set records. We will back off on highs some Thursday, especially NW given the increasing clouds and chance of showers associated with the slowing front. Otherwise, a return to SSW flow again Thursday night and Friday may extend well into next weekend. Highs again may surge toward records. More on this in later forecasts.
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&& .AVIATION /18Z SATURDAY THROUGH THURSDAY/... As of 1240 PM Saturday... Aviation parameters will gradually deteriorate across central NC through the afternoon as ceilings will lower into the IFR/low end MVFR range while areas of light rain and/or drizzle develop, reducing the visibility into the IFR category. These adverse aviation conditions will persist through the evening. A weak sfc cold front will traverse the region overnight. Nwly winds will usher in a drier air mass, leading to lifting/dissipating ceilings and an end to the spotty light precip. There may be a brief period of IFR/LIFR visibility due to fog between 09-13Z Sunday in proximity of the Triad terminals and possibly KRDU, but forecast confidence is not high enough at this time to mention in the terminal forecast. VFR parameters expected Sunday but this will not last much into Sunday night as another low pressure system will begin to effect our area, leading to MVFR/IFR ceilings and areas of light rain late Sunday night through Monday. While an improvement in aviation conditions expected Tuesday through Thursday with periods of VFR parameters, a moderately moist atmosphere will lead to the probability of sub VFR parameters, primarily during the late night-early morning hours due to low clouds and patchy fog. && .CLIMATE...
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RDU Records: Date | High Year | High Min Year ------------------------------------------ 02/20 75 1939 62 1939 02/21 76 2011 55 1939 02/22 75 1897 60 1897 02/23 79 1980 57 1962 02/24 81 1982 58 1985 GSO Records: Date | High Year | High Min Year ------------------------------------------ 02/20 74 1922 56 1939 02/21 74 2011 50 1954 02/22 74 1925 57 1980 02/23 74 2017 52 1922 02/24 79 1982 55 1985 FAY Records: Date | High Year | High Min Year ------------------------------------------- 02/20 82 2014 60 1939 02/21 80 1991 61 1953 02/22 77 2003 56 1989 02/23 80 1922 55 1922 02/24 83 1930 60 1975
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&& .RAH WATCHES/WARNINGS/ADVISORIES... None. && $$ SYNOPSIS...WSS NEAR TERM...WSS SHORT TERM...Ellis LONG TERM...Badgett AVIATION...WSS CLIMATE...Badgett is the U.S. government's official web portal to all federal, state and local government web resources and services.