469
FXUS62 KRAH 200147
AFDRAH

Area Forecast Discussion
National Weather Service Raleigh NC
944 PM EDT Thu Sep 19 2024

.SYNOPSIS...
An upper level low over the eastern Carolinas will lift northeast
along the Mid Atlantic coast through Friday and then persist as an
upper level trough just off the East Coast through the weekend. An
upper level ridge of high pressure will move into the northern Gulf
States late in the weekend and then extend into the Southeast states
through early next week.

&&

.NEAR TERM /THROUGH TONIGHT/...
As of 944 PM Thursday...

The upper trough axis has shifted offshore this evening, with
primarily nwly flow over central NC.  A residual embedded mid-level
impulse continues to generate some weak convection in the NC/VA
mountains/foothills.  While most of this activity should wane and
stay out of our area, an isolated shower may trickle into the Triad
over the next hour or so.  Otherwise, expect dry conditions
overnight with lows in the lower to mid 60s.

More concerning tonight is the potential for areas of dense fog. A
few sites across the central to northern Piedmont have shown lower
visibility from fog in the past hour or so. Given clear conditions
tonight and residual anomalous moisture over the area, we`ll likely
see dense fog increase in coverage over much of the Piedmont
especially closer to sunrise (~08 to 12Z).  Will have to monitor
overnight, but a dense fog advisory may be needed for portions of
the Piedmont.

&&

.SHORT TERM /FRIDAY THROUGH FRIDAY NIGHT/...
As of 105 PM Thursday...

Aloft, the trough off the mid-Atlantic coast will continue to shift
ewd over the Atlantic, allowing high pressure to ridge enewd into
the area. A lobe of vorticity in the upper levels will swing sewd
through central NC Fri morn/aft, while a trailing mid-level
disturbance follows Fri aft/eve. At the surface, a low will continue
to meander off the northern mid-Atlantic/New England Coast Fri/Fri
night, while high pressure ridges swd through central NC. Some lower
dewpoint air should push into the far northeast portions of central
NC as the high ridges in. While widespread convection is not
anticipated, if showers do develop, the best chance would be over
the western Piedmont during the morn/aft with the passage of the
vort max aloft, and over the northeast Piedmont/northern Coastal
Plain during the aft/eve, generally along the dewpoint gradient as
the high ridges swd. The NAM does have some MUCAPE in the 500-1000
J/Kg range Fri morn through the eve, thus an isolated storm or two
is still possible if/where convection occurs. Highs should generally
range from around 80 degrees NE to mid 80s south, with lows in the
upper 50s to mid 60s expected.

&&

.LONG TERM /SATURDAY THROUGH THURSDAY/...
As of 325 PM Thursday...

Saturday morning, surface high pressure will be centered over
eastern Canada with a pressure ridge extending all the way to the
Gulf Coast. A weak front will move across the area Saturday night.
Am not terribly impressed by the depth of the moisture with the
front, but there are too many models, deterministic and ensembles,
to keep a dry forecast in that time period. Rainfall does not appear
to be substantial, but have gone ahead and added slight chance pops
across the northern half of the area. Sunday and Monday continue to
have a dry forecast as high pressure reestablishes itself, with just
the Triad being clipped on Tuesday with a slight chance of showers
in advance of the next front. Low pressure will move across the
Great Lakes during the middle of the week, and it currently appears
that the most likely timing for any showers or thunderstorms with
the upcoming cold front will be Wednesday night. Highs will be
slightly above normal for the weekend, then drop a few degrees below
normal for the weekdays. Lows will be near normal through the
extended period.
&&

.AVIATION /00Z FRIDAY THROUGH TUESDAY/...
As of 735 PM Thursday...

VFR conditions will persist for the next several hours as most of
today`s convection has diminished. There are a few isolated VA
mountain showers/storms that may approach KINT/KGSO the next few
hours, but this activity should also wane with time.  Otherwise,
there continue`s to be a good signal for widespread fog potential
early Friday morning. Will maintain low visibilities at all sites
between ~08 to 13Z via dense fog.

Any lingering fog/stratus should lift by mid to late Friday morning.
Otherwise, convection chances should be fairly limited Friday
compared to recent days.

Outlook: Areas of overnight and early morning fog and perhaps low
stratus are expected on Friday and Saturday morning. A transient
system may bring a few showers or storms to the area on Saturday
night otherwise a return to more tranquil weather is expected for
Sunday through Tuesday. -Blaes

&&

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

&&

$$

SYNOPSIS...Blaes
NEAR TERM...Luchetti
SHORT TERM...KC
LONG TERM...Green
AVIATION...Luchetti/Blaes