Area Forecast Discussion
Issued by NWS Raleigh/Durham, NC
Issued by NWS Raleigh/Durham, NC
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749 FXUS62 KRAH 181926 AFDRAH Area Forecast Discussion National Weather Service Raleigh NC 325 PM EDT Fri Sep 18 2026 .WHAT HAS CHANGED... * No significant changes to the forecast. && .KEY MESSAGES... As of 325 PM Friday... 1) Strong to severe wind gusts will be possible with thunderstorms this afternoon and evening, generally to the west of the I-95 corridor. 2) Scattered to numerous showers and thunderstorms are expected on Monday and Tuesday. Locally excessive rainfall will be possible. 3) A CAD pattern looks to set up from mid to late next week, resulting in mostly cloudy skies, patchy light rain and drizzle, and below-normal high temperatures. && .DISCUSSION... As of 325 PM Friday... KEY MESSAGE 1... Strong to severe wind gusts will be possible with thunderstorms this afternoon and evening, generally to the west of the I-95 corridor. An area of showers and thunderstorms has expanded in coverage early this afternoon ahead of a cold front that is advancing from northwest to southeast. As of 2pm, the front is in Virginia, generally parallel to the VA/NC state border, but it appears that the front should slow down through the afternoon and evening hours, finally pushing south into North Carolina after midnight. In North Carolina, MLCAPE values are anywhere between 1000 and 2500 J/kg, with the greatest values near the Triad. DCAPE values also have the greatest values near the Triad, just above 1000 J/kg. Although wind shear should be minimal and will not do much to organize thunderstorms, the 12Z HREF is in fairly good agreement that a cluster of storms will develop across the Triad and move from north to south across the area. In fact, if the models are slightly behind on their initialization, the storms that are currently across the Triad will likely be the cluster that moves to the south. The greatest coverage is expected to extend as far east as the Triangle, although coverage should be more scattered farther east across Rocky Mount and Goldsboro. The SPC marginal risk (level 1 of 5) generally extends from Interstate 95 to the west, with the greatest threat of severe weather between 4 and 9pm. Damaging wind will be the threat. Most precipitation should come to an end after midnight. KEY MESSAGE 2... Scattered to numerous showers and thunderstorms are expected on Monday and Tuesday. Locally excessive rainfall will be possible. As a mid/upper trough develops over the Upper Midwest and Great Lakes region early next week, a backdoor cold front will approach central NC from the north on Monday, passing through the region on Tuesday. Ahead of the front, a warm and moist air mass will prevail, with highs mostly in the upper-80s to lower-90s on Monday before becoming cooler (within a few degrees of normal) for Tuesday. PW values will be around 2-2.25 inches (125-150% of normal) both days as SW flow aloft brings Gulf moisture into the Carolinas. This combined with weak to moderate instability will result in scattered to numerous showers and thunderstorms. This will be beneficial for the ongoing drought but could bring locally excessive rainfall with hourly amounts of 2+ inches possible where storms merge or train. Thus WPC has the entire region in a marginal (level 1 of 4) risk for excessive rainfall both Monday and Tuesday, with a slight (level 2 of 4) risk over our far north. KEY MESSAGE 3... A CAD pattern looks to set up from mid to late next week, resulting in mostly cloudy skies, patchy light rain and drizzle, and below-normal high temperatures. Mid/upper troughing will strengthen and build into the Eastern US from Wednesday through Friday. Meanwhile, anomalously strong surface high pressure will nose down from SE Canada and northern New England into the lee side of the Appalachians, as a surface low drifts north in the western Atlantic, though models differ substantially on its placement. This will result in robust N/NE low-level flow and a likely CAD pattern across the southern Mid-Atlantic. Current forecast highs are in the upper-60s to upper-70s, but some raw guidance such as the GFS is even cooler. Forecast lows are generally mid-50s to mid-60s. POPs are in the slight to low chance range, and given the stable CAD regime, precipitation is more likely to be of the stratiform variety (patchy light rain and drizzle) as opposed to convective. && .AVIATION /18Z FRIDAY THROUGH WEDNESDAY/... As of 130 PM Friday... 24 hour TAF period: Scattered showers and thunderstorms are beginning to develop across central North Carolina, with the greatest coverage around INT/GSO. The coverage is expected to expand over the next few hours, and TEMPO groups for thunderstorms with gusty wind were maintained at 4 of 5 TAF sites - confidence is not high enough to go with a TEMPO group as far east as RWI. INT just had a wind gust to 31 kt with IFR visibility, and this will be possible at each of the terminals this afternoon into the evening. After convection comes to an end tonight, IFR/LIFR ceilings are expected to develop late tonight into Saturday morning, although again, there is slightly less confidence as far east as RWI with the amount of cloud cover and whether ceilings will form. While there could be some minimal visibility restrictions, low ceilings will drive the flight category. Conditions may be slow to scatter out Saturday morning. Outlook: There will be a chance of afternoon showers and thunderstorms at all terminals, with the highest chance at FAY. MVFR ceilings appear likely to develop Saturday night into Sunday morning. After mostly dry conditions Saturday night through Sunday night, expect widespread precipitation Monday through Tuesday, eventually becoming more scattered. Restrictions will be possible through this period as well. && .RAH WATCHES/WARNINGS/ADVISORIES... None. && $$ DISCUSSION...Green/Danco AVIATION...Green