863
FXUS62 KRAH 090101
AFDRAH

Area Forecast Discussion
National Weather Service Raleigh NC
900 PM EDT Tue Oct 8 2024

.SYNOPSIS...
Canadian high pressure will extend from the middle MS Valley to the
southern middle Atlantic through Wednesday, ahead of a moisture-
starved cold front that will move south across the region Wednesday
night. Stronger Canadian high pressure will follow and build from
the Great Lakes to the Carolinas through Friday.

&&

.NEAR TERM /THROUGH TONIGHT/...
As of 900 PM Tuesday...

Sfc analysis this evening depicted a 1016 mb high centered over
southeast VA.  Here locally, winds have gone calm over much of the
area (a few sites still showing some light nely flow).  With the
addition of clear skies, we should see good radiational cooling
tonight with lows generally in the mid 40s to lower 50s.  Other than
the traditional cool spots, think that those in the far northeast
Coastal Plain/Piedmont have the best chance to see temps dip near 40
given their close proximity to the center of the high. Both the MAV
and MET statistical guidance take KTDF (Roxboro) and KHNZ
(Henderson) closer to 40.  Otherwise expect dry conditions to
persist tonight.

&&

.SHORT TERM /WEDNESDAY AND WEDNESDAY NIGHT/...
As of 150 PM Tuesday...

High pressure over the area, extending in from the Mid MS and TN
valley region, will be in place for most of the daytime. A
reinforcing shot of cooler air will build in Wed night as a 1025 mb
high builds into the Great Lakes and a cold front moves through NC.
Our day will start off sunny. However, with increasing southwest
flow at mid to upper levels and a 120+ kt jet streak overhead, upper-
level moisture from Hurricane Milton will lead to increasing mid and
high cloudiness, primarily late in the day into the overnight hours.
Highs during the day will be about 3 or so degrees warmer than Tue,
owing to low-level thicknesses some 10 m higher, in the low 70s N to
upper 70s S. Lows will somewhat tricky Wed night, dependent on how
dense the cirrus will be from Milton, as well as the timing of the
frontal passage. We went closer to MAV/MET MOS guidance west of US-1
and north of US-64 with mid to upper 40s, where clouds should clear
out earlier. Further south and east, we have generally lower 50s.
This is roughly near normal for early October.

&&

.LONG TERM /THURSDAY THROUGH TUESDAY/...
As of 150 PM Tuesday...

A series of Canadian high pressure systems sinking over central NC
and dry cold frontal passages will keep the forecast dry into early
next week. The first front will have cleared most of central NC by
Thurs morning and continue to sag south into the Southeast. The
tightening pressure gradient Thurs between the high over the Great
Lakes and TC Milton over FL will lead to a gusty day with winds 10-
15 mph with gusts up to 25 mph, especially for the southern
Piedmont, Sandhills, and southern Coastal Plain, through the
daylight hours.

Low-level thicknesses drop to around 1340-1350m by Fri morning and
will support temps in the 40s, with some of the outlying rural areas
of the Piedmont possibly reaching into the upper 30s if they can
remain decoupled through a majority of the night. Weakening surface
pressure gradient, clear skies should promote a more optimal
radiational cooling night Fri night into Sat morning when mid/low
40s will become more common. Similar to Fri morning, upper 30s will
be possible in the outlying rural areas of the NC Piedmont.

A second cold front will approach on the tail-end of low pressure
system shifting through the Great Lakes and southern Quebec late Sun
into Mon. Mid-level moisture rotating into the region and the right
entrance region of the 100-140kt upper jet will support increasing
cloud cover and perhaps some light rain and/or some showers along
and behind the cold front, but model guidance remains inconsistent
on generating measurable precip, so have opted to keep the forecast
dry for now. Behind the front Tues into Tues night, a noticeably
cooler airmass is expected to surge into the area with 1320-1330m
thicknesses. This time period may need to watched for the first
potential for patchy frost, especially in outlying rural areas of
the Piedmont.

&&

.AVIATION /23Z TUESDAY THROUGH SUNDAY/...
As of 840 PM Tuesday...

...Expect predominately VFR conditions through the period...

Calm winds and clear skies tonight will likely support some patchy
radiational fog, mainly at fog prone locations like KRWI where
overnight lows are expected to approach it`s crossover temp. Light
northerly winds are expected Wednesday with upper-level moisture
from Hurricane Milton leading to an increase in high cloudiness
during the afternoon and evening.

Outlook: A couple areas of Canadian high pressure will extend across
NC and favor VFR conditions throughout the forecast period.

&&

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

&&

$$
SYNOPSIS...MWS
NEAR TERM...Luchetti
SHORT TERM...Kren
LONG TERM...Swiggett
AVIATION...CBL/MWS