410
FXUS62 KRAH 150609
AFDRAH

Area Forecast Discussion
National Weather Service Raleigh NC
209 AM EDT Mon Sep 15 2025

.SYNOPSIS...
Low pressure will drift into, and meander over, eastern NC through
mid-week, while Canadian high pressure will otherwise extend across
the eastern US.

&&

.NEAR TERM /THROUGH TONIGHT/...
As of 150 PM Sunday...

Latest satellite imagery reveals an offshore low churning off the
coast of southern NC. At mid-levels, a shortwave is present along
the GA/FL coastline. At the surface, high pressure from eastern
Canada is entrenched southward across the Mid-Atlantic.

Lots of mid and high clouds will continue to be the story for the
rest of today and tonight. The offshore low is forecast to move
slightly northward over the next 18-24 hours, but still remain east-
southeast of the NC coast. Dry weather is expected overall through
tonight, though cannot rule out some isolated light rain or showers
over the eastern Coastal Plain near daybreak as the low-level
moisture transport on the northwest side of the low penetrates
inland to a degree. The deeper moisture, however, holds off until
later Mon. After highs a few degrees on either side of normal today
in the upper 70s to lower 80s, lows tonight will generally be above
normal in the upper 50s to lower 60s.

&&

.SHORT TERM /MONDAY THROUGH MONDAY NIGHT/...
As of 150 PM Sunday...

* Large model spread favors low confidence forecast on rainfall
  timing, extent, and amounts, but a heavy rain signal possible
* Below normal highs favored, with gusty winds in the afternoon

The offshore low is forecast in much of the guidance to track west-
northwestward, through Mon night, perhaps reaching near Hatteras by
Tue morning. Meanwhile, the closed upper-low is expected to be over
central NC by this same time, west of the surface low.

While the general specifics are discussed above, there remains a
high degree of model spread in overall specifics on the westward
extend of the precipitation shield, timing, and expected QPF
amounts. Overall, that leads to a low confidence forecast and is
worth mentioning at the outset. That said, the current model
consensus keeps the heaviest rainfall amounts just north and east of
central NC. The 50th percentile of the LREF shows anywhere from a
trace to a quarter inch along/east of US-1. This would not be
concerning. However, there are some high-end outliers, such as the
06z ECMWF, 12z NAM NEST, and 12z GEM-RDPS, which show anywhere from
1 to 3+ inches over portions of the northeast Piedmont and central
to northern Coastal Plain. Details are likely to change as models
come into better agreement, but there does appear to be a trend
toward a potential heavy rain signal from Raleigh east to Rocky
Mount to Roanoke Rapids. Precipitable water values could reach 1.5
to 2 inches by Mon night in this region, in conjunction with deep
925-850 mb moisture transport. It would also appear that the higher
rainfall solutions have higher elevated instability above the stable
surface layer, favoring isolated storms capable of heavier rainfall
rates.

While some rain showers will be possible east of US-1 during the
early part of the day and afternoon, the best moderate and steady
showers with embedded thunder will come Mon night into early Tue as
moisture increases to the northwest of the low. Though, rainfall
amounts may be limited over the western Piedmont.

Highs will be below normal from the upper 70s west to low/mid 70s
east. Gusts out of the NE will at times reach 15 to 25 mph, possibly
up to 30 mph over the Coastal Plain as the low deepens. Lows will be
in the lower 60s.

&&

.LONG TERM /TUESDAY THROUGH SUNDAY/...
As of 150 PM Sunday...

A mid level low initially over coastal GA/SC will slowly ease
northward across our area Tuesday into Wednesday. This system will
then move into VA later this week before dissipating out through the
weekend.

At the sfc, a low will likely be hanging near or just offshore the
Outer Banks Tuesday morning. There still remains quite a bit of
spread on where exactly this low will track through Wednesday.
Consequently this adds uncertainty to potential rainfall totals and
wind gust potential. Overall, ensembles generally push the highest
anomalous moisture north into the Mid-Atlantic Tuesday and
Wednesday. As such, LREF ensembles are in pretty good agreement
keeping the highest QPF up into VA and areas further north. However,
some of the higher res guidance (particularly the NamNest) inches
the low a bit further west before tracking it north and pumps a bit
deeper convection and higher rain totals over central NC. This may
end up being an outlier, but its worth mentioning that there is a
non-zero chance for a bit higher rainfall totals Tuesday. By
Wednesday, the system will have drifted north and while linger rain
will be possible on the backside of the low, the overall QPF should
be lower on Wednesday. Temperatures Tuesday will be below normal in
the upper 60 to mid 70s.

Beyond rainfall, some of higher-res guidance is also fairly bullish
on wind gust potential on the western side of the low. Think the
strongest winds will remain close to the coast, but if the low track
further west areas east of Raleigh could see gusts as high as 30 mph
or so Tuesday afternoon and evening.

Beyond Wednesday, we`ll see weak ridging build in aloft which should
favor drier conditions and a warming trend into next weekend. Low-
end rain chances will return next weekend as well as a few mid-level
waves move along the coast and approach the TN valley to our west.

&&

.AVIATION /06Z MONDAY THROUGH FRIDAY/...
As of 200 AM Monday...

Initially VFR conditions will transition to MVFR and IFR through
tonight, as a shield of rain and flight restrictions spread inland
ahead of coastal low pressure that will drift into eastern NC.
Surface winds will also strengthen and become gusty with daytime
heating later this morning (after 13-14Z), strongest at RWI, FAY,
and RDU.

Outlook: High probability of sub-VFR conditions through Wednesday,
with the most adverse conditions likely across the KRWI, KRDU and
KFAY terminals, as the surface low is forecast to move across
eastern NC and linger through late Wednesday. Improving conditions
are possible on Thursday and especially Friday.

&&

.RAH WATCHES/WARNINGS/ADVISORIES...
None.

&&

$$

SYNOPSIS...MWS
NEAR TERM...Kren
SHORT TERM...Kren
LONG TERM...Luchetti
AVIATION...MWS/Blaes