Area Forecast Discussion
Issued by NWS Raleigh/Durham, NC
Issued by NWS Raleigh/Durham, NC
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024 FXUS62 KRAH 291619 AFDRAH Area Forecast Discussion National Weather Service Raleigh NC 1220 PM EDT Tue Sep 29 2026 .WHAT HAS CHANGED... * Above average uncertainty exists with timing and amounts from the next chance of rain: this weekend. && .KEY MESSAGES... As of 245 AM Tuesday... 1) Well above average and unseasonably hot temperatures will develop this week and continue until a front wavers over the srn Middle Atlantic with a chance of rain this weekend. && .DISCUSSION... As of 245 AM Tuesday... KEY MESSAGE 1... Well above average and unseasonably hot temperatures will develop this week and continue until a front wavers over the srn Middle Atlantic with a chance of rain this weekend. A sub-tropical ridge will progress and strengthen across the South Atlantic states this week. The ridge will then lose influence this weekend, as a weakening, positively-tilted trough settles across the region ahead of a vigorous nrn stream trough forecast to amplify and pivot across the Great Lakes. At the surface, a Canadian high now centered across the OH Valley and Great Lakes will progress across and offshore the Middle Atlantic through midweek, then to near Bermuda by Fri. Sly flow around the Bermuda high, and ahead of a wavy front that will settle into and probably waver over the srn Middle Atlantic this weekend, will contribute to warming temperatures through the week and to near/around 90 F by Thu and especially Fri. While hotter, the pre-frontal airmass will not become particularly humid, with only modest low-level moisture characterized by surface dewpoints in the lwr-mid 60s forecast ahead of the front on Sat. When combined with weak mid-level lapse rates of generally less than 5.5 C/km, instability should remain weak and supportive of mostly scattered convection during the afternoon. A better chance of rain will result behind the front, probably later in the weekend for cntl NC, when and where sly and strengthening 850 mb flow will favor isentropic lift and rain. Some degree of cold air damming would also result, but uncertainty for this weekend remains regarding the frontal location, possible weak wave development along the front, and the extent of post-frontal CAD. Regardless, there is a consistent signal in model guidance for the front to move offshore by early Mon, with another Canadian high poised to build across much of the ern US early to mid next week. && .AVIATION /18Z TUESDAY THROUGH SUNDAY/... As of 1220 PM Tuesday... High confidence in VFR conditions holding across central NC terminals through at least this evening, although areas of scattered to broken clouds based at 5k-8kft AGL will persist across NE sections (including RWI and RDU) through the afternoon, as a mid level disturbance swings through. Later tonight, the combination of light winds and increasing low level moisture over eastern areas will prompt development of patchy fog producing a period of IFR/LIFR vsbys 08z-12z, mainly at RWI/RDU/FAY, with the highest confidence at RWI. Any fog should quickly lift and dissipate by 15z. Elsewhere, at INT/GSO, fair skies should prevail through midday Wed. Surface winds will remain light and variable through the period. Looking beyond 18z Wed, VFR conditions are likely to hold through at least Fri, although areas of sub-VFR vsbys in fog are possible each morning especially in the east, with the highest potential for fog early Fri morning. The chance for showers and storms producing sub- VFR conditions will increase by Sat and remain high through Sun, ahead of an approaching front. -GIH && .CLIMATE... Record High Temperatures: September 30: KRDU: 89/1954 October 1: KGSO: 90/1986 KRDU: 90/1986 && .RAH WATCHES/WARNINGS/ADVISORIES... None. && $$ DISCUSSION...MWS AVIATION...Hartfield