527 FXUS62 KRAH 030507 AFDRAHArea Forecast Discussion National Weather Service Raleigh NC 107 AM EDT Fri Oct 3 2025
.SYNOPSIS... Canadian high pressure will build across the eastern US, then offshore, through the weekend.
&&
.NEAR TERM /THROUGH TONIGHT/... As of 210 PM Thursday...
A mid/upr-level ridge, and accompanying mid-level high/anticyclone centered in 12Z-observed upr air data over the OH Valley, will progress slowly ewd and across the srn Middle Atlantic tonight. Associated deep dryness, characterized by PWs of generally 0.5" to 0.8" and 50-60% of normal, will remain in place over cntl NC.
At the surface, 1033 mb Canadian high pressure centered this afternoon over the Northeast will become centered over the Middle Atlantic tonight, while continuing to ridge swwd across the Carolinas and Southeast. Initially breezy and occasionally gusty nely surface winds this afternoon over cntl NC will lessen after sunset, then probably fully decouple/calm in all but the Coastal Plain and urban Piedmont overnight.
Mainly clear and mostly calm will favor strong radiational cooling and seasonably cool low temperatures in the mid 40s to lwr 50s, supported by statistical (MOS) guidance that typically outperforms all other in such regimes.
&&
.SHORT TERM /FRIDAY AND FRIDAY NIGHT/... As of 310 PM Thursday...
Some degree of a Rex blocking pattern will evolve over parts of the ern US into the weekend, as a mid/upr-level trough now digging across the mid MS Valley settles across the lwr MS Valley and cntl Gulf Coast, equatorward/beneath a persistent ridge over the OH Valley and Middle Atlantic.
At the surface, the center of Canadian high pressure will migrate down the Middle Atlantic coast and maintain seasonably mild/cool nely flow over cntl NC.
While deep dryness, characterized by PWs of generally 50-70% of normal, will remain, stratocumulus moisture in nely around the ridge and beneath a couple of low-level temperature inversions, will too - supportive of scattered to areas of broken, diurnal stratocumulus. Skies should otherwise be mostly clear. With little to no change in airmass or proximity of the Canadian high, temperatures should be near to slightly above persistence ones: highs in the 70s and lows in the mid-upr 40s to lwr-mid 50s, with the latter again supported by statistical (MOS) guidance that is favored in such regimes.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/... As of 105 AM Friday...
* Slightly above normal temperatures through mid-week before decreasing on Thursday.
* Dry high pressure expected through the weekend, with the potential for moisture to return starting at the beginning of the work week ahead of a cold frontal passage.
Surface high pressure will dominate the weather pattern over central NC during the start of the long term period. Sunday through mid- week, the high pressure will slowly move further off the mid- Atlantic coast, allowing maximum temperatures to be slightly above normal each afternoon. High temperatures will generally be in the upper 70s to low 80s each afternoon through Wednesday, with lows in the upper 50s to mid 60s. Wednesday night into Thursday, a cold frontal passage will pass through the region which will drop temperatures. The highs on Thursday look to be in the mid 60s to low 70s, with lows dropping into the upper 40s to mid 50s Thursday night.
The high pressure should keep the forecast mostly dry through Tuesday. However, as the high continues to shift further offshore, moisture will start to increase over the region starting on Monday. A disturbance looks to move through the Southeast Monday and Tuesday, which could bring an isolated shower either day, especially in the south. Rain chances look to increase Wednesday and Thursday ahead of the cold fropa. Some instability around about 1000 J/kg looks to be possible Wednesday afternoon into the evening, meaning that a few embedded stronger storms will be possible.
&&
.AVIATION /06Z FRIDAY THROUGH TUESDAY/... As of 100 AM Friday...
Canadian high pressure entrenched over the region will support prevailing VFR conditions through the 24 hr TAF period. Winds will remain from the NE, with a brief period of post-sunrise gustiness expected at KFAY.
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.
&&
.RAH WATCHES/WARNINGS/ADVISORIES... None.
&&
$$
SYNOPSIS...MWS NEAR TERM...MWS SHORT TERM...MWS LONG TERM...LH AVIATION...CBL/MWS
NWS RAH Office Area Forecast Discussion