Area Forecast Discussion Issued by NWS Raleigh/Durham, NC
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000
FXUS62 KRAH 271451
AFDRAH
Area Forecast Discussion
National Weather Service Raleigh NC
Issued by National Weather Service Blacksburg VA
1051 AM EDT Wed Sep 27 2023
.SYNOPSIS...
Strong high pressure over the northern US along with a lingering low
pressure offshore will lead to persistent cloudy and cool conditions
through at least Saturday. High pressure will settle into the region
late weekend into early next week.
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.NEAR TERM /THROUGH TONIGHT/...
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As of 1045 AM Wednesday...
For the near term update this morning, the cool and mostly
cloudy conditions persist as low level moisture interacts with
the strong classical CAD wedge. Have tweaked some temps down a
tad and any slight breaks in the stratus shouldn`t do much for a
diurnal heating component given this setup. The main deeper
layer moisture axis and associated precip should stay mainly SE
of the CWA so have kept pops dry but there could be a few stray
obs of light rain or drizzle. Previous discussion follows...
As of 148 AM Wednesday...
Low overcast with a cool NE breeze today.
Strong high pressure over eastern Canada will continue to provide a
moist NE flow off the Atlantic throughout central NC as it extends
deep into the SE states through tonight. A low overcast is expected
to persist through the day. There may be some light, patchy drizzle
at times especially in the Triad region. Highs will be kept down by
the NE breeze and cloudiness. Expect highs in the mid to upper 60s
across the Piedmont, with lower 70s in the SE. The overcast skies
will continue tonight. Lows will be in the mid 50s to lower 60s.-- End Changed Discussion --
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.SHORT TERM /THURSDAY THROUGH THURSDAY NIGHT/...
As of 227 AM Wednesday...
Continued cloudy and rather cool and breezy through Thursday.
Strong surface ridging will continue to extend into the Carolinas
through Thursday night. This occurs as a positively tilted mid/upper
trough moves through the Ohio River Valley toward the Appalachians.
As the upper trough approaches, an inverted surface trough is
forecast to develop near the coast. This will keep the rain
chances confined to the coast. There will be an increase in some
mid/upper level moisture, but the strong ridge axis is expected
to keep any precipitation limited to spotty drizzle. Low overcast and
a NE flow is expected to continue. This will again limit highs
to the 60s/lower 70s SE. Lows will be in the 50s to lower 60s.
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.LONG TERM /FRIDAY THROUGH TUESDAY/...
As of 235 AM Wednesday...
Dry weather is expected for the extended, with temperatures slowly
moderating above normal early next week. Little has changed in the
extended part of the forecast. If anything, the forecast has
continued to trend drier, with somewhat more seasonal temperatures
for the weekend.
The shortwave trough over northern IL Wed will be located near the
lower Great Lakes Fri morning. This trough is still forecast to
track offshore of the Mid-Atlantic Sat, then slowly track ESE over
the Atlantic over the weekend into early next week. To the west, a
591 dm ridge over the lower Mississippi Valley will expand northward
into the Mid-Mississippi/TN/OH valleys Sat into Tue, setting up an
Omega blocking pattern with troughing to our east and over the
Rockies and Intermountain West. The NE flow due to a surface high
extending down from the NE US will lose its influence by early next
week. This should favor less low clouds for the latter part of the
period, along with temperatures rising from near normal in the mid
70s to near 80 Fri-Sun into the lower 80s Mon-Tue. An offshore
surface low tied to the aforementioned mid-level trough and the
surface high to our north will promote some occasional gusty winds
at times Sat-Mon, especially over the Coastal Plain, with gusts of
15-25 mph during the daytime.
As for precipitation chances for the extended, the trend the last 3
days has been for a drier pattern, with the better moisture and lift
remaining offshore of the Carolinas. While we certainly cannot rule
out some stray drizzle or light rain over the Coastal Plain Sat/Sun,
most areas are expected to remain dry.
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.AVIATION /15Z WEDNESDAY THROUGH SUNDAY/...
As of 640 AM Wednesday...
24 hour TAF period: IFR to LIFR conditions are expected through
around 15z with low CIGS. These CIGS may lift a bit, into the MVFR
category between 15z and 21z. However, CIGS will again lower tonight
back to IFR conditions. VSBYS should be VFR for the most part, with
some patchy drizzle with MVFR VSBYS, especially around KINT and
KGSO.
Outlook: A persistence pattern will continue as north to northeast
low-level flow will bring a threat for sub-VFR conditions through
the forecast period, particularly overnight into the early afternoon
hours.
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.RAH WATCHES/WARNINGS/ADVISORIES...
None.
&&
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SYNOPSIS...Hartfield
NEAR TERM...PWB/AB
SHORT TERM...PWB
LONG TERM...Kren
AVIATION...PWB