


Area Forecast Discussion
Issued by NWS Raleigh/Durham, NC
Issued by NWS Raleigh/Durham, NC
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015 FXUS62 KRAH 171106 AFDRAH Area Forecast Discussion National Weather Service Raleigh NC 706 AM EDT Fri Oct 17 2025 .SYNOPSIS... Canadian high pressure will build across and offshore the Middle Atlantic states through Saturday. && .NEAR TERM /THROUGH TONIGHT/... As of 340 AM Friday... A longwave ridge extending this morning from the e-cntl Gulf to the upr Great Lakes will progress ewd and into the Middle Atlantic through 12Z Sat. Meanwhile, a shortwave perturbation now over ern TX will deamplify while lifting newd, through the wrn periphery of the aforementioned ridge, and into the srn Middle Atlantic. The latter feature will be accompanied by a shield of cirrus and cirrostratus that will overspread cntl NC late this afternoon and especially early tonight, with southwest to northeast clearing likely across the srn Piedmont and Sandhills late. At the surface, Canadian high pressure will drift ewd and across the Middle Atlantic and Carolinas. Associated light and variable wind today will quickly calm with nightfall. Temperatures today will be near to slightly below persistence ones in the mid 60s to lwr 70s. Although the aforementioned high clouds may limit otherwise optimal radiational cooling with widespread calm, their limited opacity and longevity should allow low temperatures to reach the 40s throughout cntl NC. && .SHORT TERM /SATURDAY AND SATURDAY NIGHT/... As of 355 AM Friday... Shortwave ridging will briefly re-amplify across the Carolinas Sat, between a weakening perturbation that will move across and offshore the srn Middle Atlantic and an upstream trough forecast to amplify across the MS Valley and mid-South by 12Z Sun. At the surface, high pressure initially centered over the ern Carolinas will drift offshore and promote the development of a warming, return, sly flow ahead of a cold front that will approach from the west and stretch by 12Z Sun from a deepening, 990-995 mb low over MI, swwd into the lwr MS Valley. The warming/modifying airmass over cntl NC will remain deeply dry, capped, and stable. As such, skies will be mostly sunny/clear, except for some lingering high clouds across nrn NC with the deamplifying perturbation Sat morning and some additional, late arriving ones Sat night, ahead of the aforementioned upstream trough. Temperatures will consequently trend above average, with highs in the 70s and lows in the 50s, with the latter regulated by a stirring, sly breeze in a tightening MSL pressure gradient between the departing/offshore high and the approaching cold front. && .LONG TERM /SUNDAY THROUGH THURSDAY/... As of 355 AM Friday... A deep mid/upper trough will traverse across the OH and TN Valleys on Sunday, becoming negatively tilted as it crosses the Appalachians and Mid-Atlantic on Sunday night. An associated surface cyclone will move NNE from MI into SE Canada, dragging a cold front to its south that crosses central NC on Sunday night and is associated with a likely decaying band of showers. The deterministic GFS and CMC are a bit wetter than last night, but their ensemble means still only depict around a tenth of an inch or less. The ECMWF and many of its ensembles continue to be slightly wetter than the GFS and CMC because they dig a deeper trough and develop a secondary low over the northern Mid-Atlantic. However, the ECMWF is trending drier and toward later development of the low, with the 00z run not closing it off until PA/NJ instead of over the OH Valley. Also, the total QPF of the deterministic and ensemble mean is still only a tenth to a quarter inch. Think the best upper forcing being well to our north, meager instability, and overall progressive nature of the system will really limit rainfall amounts. So not expecting any hazardous weather or a significant dent in the ongoing abnormally dry and drought conditions across our region. The biggest impact may end up being strong SW winds during the day Sunday, as there will be a tight pressure gradient between the low over SE Canada and broad high pressure in the western Atlantic. Model soundings and planar data indicate frequent gusts of 25-35 mph, and can`t rule out some in the 35-40 mph range especially in any showers. High temperatures will be above normal and range from lower-to-mid-70s in the northern Piedmont to upper-70s elsewhere. Forecast lows Sunday night are upper-40s to lower-50s. Monday will turn sunny and cooler as high pressure builds in behind the front. NW downsloping flow will bring dew points down to the 30s and lower-40s, and while confidence in wind gusts is low and will depend on whether that secondary low develops, can`t rule out some fire weather concerns especially if rain the previous day is very limited. Forecast highs are in the mid-60s to lower-70s on Monday with lows in the mid-to-upper-40s on Monday night. Another cyclone looks to track east from the Upper Great Lakes into New England on Tuesday and Wednesday, dragging another cold front through central NC on Tuesday night. However, this low looks weaker and the associated mid/upper trough broader. Deterministic and ensemble guidance has even lighter amounts (if any) compared to Sunday`s event. After a brief warmup on Tuesday with highs in the 70s, it will cool down again on Wednesday/Thursday to mid-60s to lower-70s, under sunny skies as high pressure builds back in. && .AVIATION /11Z FRIDAY THROUGH TUESDAY/... As of 705 AM Friday... Canadian high pressure and associated dry air and influence for VFR conditions, and light and variable surface winds, will build across NC through tonight. Outlook: Swly surface winds will strengthen and gust to around 30-35 kts Sunday, ahead of a cold front that will move across cntl NC with an accompanying band of low VFR to MVFR ceilings and chance of rain/showers Sunday evening. && .RAH WATCHES/WARNINGS/ADVISORIES... None. && $$ SYNOPSIS...MWS NEAR TERM...MWS SHORT TERM...MWS LONG TERM...Danco AVIATION...MWS