Area Forecast Discussion
Issued by NWS Raleigh/Durham, NC

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000 FXUS62 KRAH 230847 AFDRAH Area Forecast Discussion National Weather Service Raleigh NC 345 AM EST Fri Feb 23 2018 .SYNOPSIS... A strong sub-tropical ridge aloft situated off the Southeast U.S. coast will weaken while drifting south toward the Bahamas through Friday night. Meanwhile, a front will become quasi-stationary over northern NC today, then retreat north as a warm front tonight and Saturday. && .NEAR TERM /THROUGH TONIGHT/... As of 325 AM Friday... The strong surface pressure rises on the order of 3mb/3hr across southern and central VA earlier this evening, in association with the +1040 mb sfc high centered over New England, has really began to wane/fade(1mb/3hr)across northern NC, thus signaling imminent stalling of the back-cold front that has just pushed south through RDU. The front will briefly stall across central NC through mid to late morning, with the front eventually lifting back north as a warm front during the afternoon and evening as 925-850 mb flow strengthens to 15-20kts. This will result in slow and gradual warming across the northern half, with a period of spotty drizzle possible within the low overcast ceilings, with temperatures making a charge late in the day as the low ceilings lift and scatter out. Meanwhile, south of the front, it will be business as usual with temperatures quickly warming into the 70s. Highs ranging from mid 60s North to upper 70s/near 80 south. While it may scatter out this evening, expected areas of fog and stratus to develop overnight. Lows in the upper 50s to lower 60s. && .SHORT TERM /SATURDAY AND SATURDAY NIGHT/... As of 325 AM Friday... While slightly dampened, the subtropical ridge over the SE US will continue to be the dominate weather feature over the region, deflecting the better rain chances west of the area, with a continuation of record warmth in both daytime highs and warm nighttime lows. Shortwave disturbances, ejecting NE in the SW flow aloft, ahead of the shortwave trough lifting from the Rockies into the Northern Plains and Upper Midwest, could support a stray shower or two, especially across the NW Piedmont. Otherwise it remain mostly dry with a mixture of clouds in the morning, and some sun by the afternoon. Breezy SWLY winds will develop by the afternoon and will continue into the evening and overnight as a 40 to 50 kt low-level jet spreads in from the west. Highs in the 75 to 80. Lows in the 60s. && .LONG TERM /SUNDAY THROUGH THURSDAY/... As of 345 AM Friday... The Long Term period continues to look active, with two pertinent weather systems likely to impact the forecast area. Warmer than normal conditions Sunday afternoon will be replaced with more seasonable values by Monday afternoon and likely persisting through at least Thursday. A strengthening mid latitude cyclone will progress north and east across the Great Lakes on Sunday inching an associated cold front east of the mountains. A relatively strong area of high pressure over the western Atlantic will slowly slide east, allowing the front to cross through portions of central North Carolina before stalling across our area. Some significant model differences when it comes to how far the front will make it east, with the GFS consistently showing a more vigorous initial surge with the boundary, stalling the front closer to the coast. The ECMWF on the other hand stalls the front further inland, allowing a disturbance to develop Sunday night into Monday, spreading higher QPF amounts across the forecast area. Have tried to blend the two solutions, allowing POPs to linger through Monday evening, and notching the average QPF amount closer to a half inch between Sunday and Monday. High pressure will build into the mid Atlantic briefly Tuesday and Wednesday, allowing the sun to re-emerge and drier conditions along with more seasonable temperatures to win out albeit briefly. Cloud cover will be on the rise by Wednesday morning as a warm front lifts north through the Carolinas, once again introducing showers that will likely persist through Thursday night. && .AVIATION /06Z FRIDAY THROUGH TUESDAY/... As of 105 AM Friday... 24-Hour TAF Period: A back-door cold front will continue to settle slowly south into central NC through 12z. The front will briefly stall over the area this morning, before retreating north into VA this afternoon and evening. Ceilings will lower to to IFR to MVFR behind the front(KINT, KGSO, KRDU, and KRWI). Meanwhile, south of the front, at KFAY, expect conditions to remain predominately VFR, except for a brief period of IFR to MVFR in fog between 08 to 12z. Ceiling in the 800-1500 ft range will persist into the morning, gradually scattering out during the afternoon. Expect a brief period of ENELY winds behind the front through 15z, becoming southerly by the afternoon. Looking ahead: The sub-tropical ridge will weaken and drift south, but maintain influence over the Carolinas. As a result, a persistence forecast of late night-morning stratus and fog, lifting and scattering to high MVFR-low VFR each afternoon, will generally continue through the weekend. Isolated to scattered showers are possible Saturday afternoon, especially at KINT and KGSO. However, the better chance of rain will accompany a frontal zone that will settle into, and possibly stall over the Carolinas, late Sun into early next week. && .CLIMATE... RDU Records: Date | High Year | High Min Year ------------------------------------------ 02/23 79 1980 57 1962 02/24 81 1982 58 1985 GSO Records: Date | High Year | High Min Year ------------------------------------------ 02/23 74 2017 52 1922 02/24 79 1982 55 1985 FAY Records: Date | High Year | High Min Year ------------------------------------------- 02/23 80 1922 55 1922 02/24 83 1930 60 1975 && .RAH WATCHES/WARNINGS/ADVISORIES... None. && $$ SYNOPSIS...MWS NEAR TERM...CBL SHORT TERM...CBL LONG TERM...JJM AVIATION...CBL/MWS CLIMATE...RAH is the U.S. government's official web portal to all federal, state and local government web resources and services.