002 FXUS62 KRAH 021750 AFDRAHArea Forecast Discussion National Weather Service Raleigh NC 150 PM EDT Thu Oct 2 2025
.SYNOPSIS... Canadian high pressure will build across the eastern US, then offshore, through the weekend.
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.NEAR TERM /TODAY AND TONIGHT/... As of 200 AM Thursday...
*Classic Fall Day
Canadian high pressure centered over the Mid-Atlantic and Carolinas will dominate the pattern as upper-level ridging and rising heights aloft build in from the west.
This setup will deliver a a classic fall day with low humidity(BL dewpoints in the 40s and lower 50s) and cooler-than-normal temperatures. Under mostly sunny skies, with a healthy scattering of fair weather cumulus, highs will reach the upper 60s to near 70 north, and the lower/mid 70s across the south.
A period of gusty NELY winds (15 to 25 mph) is expected through late morning/midday, before diminishing during the afternoon.
Tonight, strong radiational cooling beneath clear skies and light winds will bring a crisp fall night, with lows dipping into the mid/upper 40s north, to lower 50s south. These conditions will likely mark the first heating degree days of the season for much of central NC.
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.SHORT TERM /FRIDAY AND FRIDAY NIGHT/... As of 200 AM Thursday...
* Another picture-perfect Fall Day
Underneath a 588 dm ridge, Canadian high pressure will remain entrenched over the region, reinforcing a dry, stable airmass over central NC. Slight moderation of the cP airmass will result in a very modest uptick in temperatures compared to Thursday. Highs will range from near 70 across the north to mid 70s across the south.
Some high clouds may move in Friday evening/night, which could locally temper radiational cooling. Even so, another crisp and cool autumn night is expected, with lows in the lower to mid 50s, and some mid/upper 40s possible in more rural outlying areas.
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.LONG TERM /SATURDAY THROUGH THURSDAY/... As of 148 PM Thursday...
An anomalous mid-level ridge will re-amplify over eastern Canada Saturday before shifting over the northeast US Sunday into Monday. An upper trough will then move across the Great Lakes/Ohio Valley/northeast US Tuesday into Thursday.
At the sfc, high pressure will remain centered just off the Delmarva Peninsula Saturday, shifting a bit further offshore through Sunday. While flow Saturday will be weak, it will remain a bit more enely in nature. This should keep daytime highs a few degrees cooler (upper 70s to around 80) than Sunday when flow turns more esely and highs reach the lower 80s. Deeper, anomalous moisture should stay south and west of our area promoting a dry weekend. Overnight lows in the mid/upper 50s to lower 60s are expected each night.
Persistent esely flow early next week should enhance moisture flux across our area. Mid-level vorticity associated with remnants of an upper wave over the Deep South may promote scattered showers Monday and Tuesday (especially over the NC/SC border; western and southern Piedmont). Overall though, QPF should be limited early next week. Beyond Tuesday, deterministic and ensemble guidance is surprisingly in good agreement wrt to the timing of the aforementioned upper trough and the eastward progression of an associated cold front. In general, a better chance for widespread pre-frontal rain looks promising later Wednesday through mid-Thursday. It`s a bit too far to get into details, but it is worth noting that guidance currently maximizes mid/upper forcing well to our north. As such, higher QPF may trend north of us as well. Although, some instability may be possible Wednesday afternoon and evening which could enhance rain rates in isolated cells. We`ll continue to monitor as we get closer to middle of next week.
Otherwise, expect highs in the mid/upper 70s to lower 80s during this period. Ensembles/deterministic guidance is also in pretty good agreement pushing the post-frontal cooler airmass into our area by next Thursday. As such, our current forecast suggests highs in the upper 60s/lower 70s (overnight lows in the upper 40s/lower 50s) as possible on Day 8.
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.AVIATION /18Z THURSDAY THROUGH TUESDAY/... As of 145 PM Thursday...
Nely flow, around high pressure over the Middle Atlantic and beneath a couple of low-level temperature inversions, will favor periods of stratocumulus clouds based between 2500-5000 ft AGL - lowest in the morning and highest during the afternoon. The NAM and its higher- resolution Nest version indicate an associated period of MVFR ceilings will be possible from near GSB to FAY Fri morning, which seems plausible given similar, short-lived MVFR ceilings occurrence at INT earlier this morning. Additionally, there is a signal the NAM and other model guidance for areas of fog and low stratus over the nrn NC Piedmont and Southside VA Fri morning, including near and especially northeast of GSO.
Outlook: While persistent high pressure over the Middle Atlantic will favor primarily VFR conditions, associated nely to ely flow around it will favor both periods of stratocumulus based around and just above MVFR range and also a risk of patchy fog, as low-level moisture gradually increases through the weekend. The chance of showers will also gradually increase early to especially mid-next week, ahead of an approaching cold front.
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.RAH WATCHES/WARNINGS/ADVISORIES... None.
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SYNOPSIS...MWS NEAR TERM...CBL SHORT TERM...CBL LONG TERM...Luchetti AVIATION...MWS
NWS RAH Office Area Forecast Discussion