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081
FXUS62 KRAH 261859 RRA
AFDRAH

Area Forecast Discussion
National Weather Service Raleigh NC
255 PM EDT Fri Jul 26 2024

.SYNOPSIS...
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After a cold front crosses the region, high pressure will bring dry
weather for the weekend.
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&&

.NEAR TERM /THROUGH TONIGHT/...
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As of 255 PM Friday...

The bulk of heavy rainfall has tracked immediately to the south of
the forecast area today, first in South Carolina and eventually
tracking into southern North Carolina. Sampson County still appears
likely to be the area that will have the heaviest rainfall, although
additional showers (with no lightning so far) have developed in a
broken line extending from the Richmond metro area towards the
Triad, and two flood advisories (one in VA, one in NC) have been
issued along with this line of showers. Coverage of showers and
thunderstorms should maximize over the next few hours, with coverage
then steadily decreasing through the evening. The HRRR has been the
high-resolution model of choice today, and several consecutive runs
of the HRRR show a line of showers holding together near the VA/NC
line through sunset then diminishing in coverage. Have stuck close
to the HRRR guidance, keeping higher pops along the VA/NC line
around sunset with decreasing pops after that. The bulk of any
remaining showers should be across the southeast after midnight.
While it was already noted that the heaviest showers have remained
to the south of the forecast area, feel that it is still prudent to
hold onto the flood watch at this time for Cumberland, Hoke,
Sampson, Scotland, and Wayne Counties through 7pm. Overnight lows
will range from 65 to 70 degrees.
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&&

.SHORT TERM /SATURDAY THROUGH SATURDAY NIGHT/...
As of 236 PM Friday...

The front will slide south of our southern areas Saturday, as flow
aloft turns nwly. PWAT will drop to 70 - 80% of normal across
central NC as dew points across the piedmont mix out into the 60s
Saturday afternoon. Some lingering low-level moisture across the far
southeast may limit mixing some as dew points may hover near 70
through Saturday afternoon. As such, a few diurnal, isolated showers
could be possible in our far southeast locations Saturday afternoon.
However, expect any isolated activity to quickly wane with loss of
heating.

High pressure to our north will induce persistent cooler/drier nely
flow through Saturday evening. As such, daytime highs will max out
in the lower to mid 80s. Overnight, the high will continue to slide
down the east coast as drier air knocks dew points down into the
50s. Winds will subside, and given clear skies, good radiational
cooling conditions (especially northeast sections) will support
overnight lows in the lower 60s.

&&

.LONG TERM /SUNDAY THROUGH FRIDAY/...
As of 210 PM Friday...

Sun/Sun night: The largely dry weekend continues, under a ridge of
surface high pressure. Unless Sat ends up dry, Sun has a high
potential to be the first totally dry day across our forecast area
since July 4th. Central NC will be situated beneath narrow mid level
ridging, between a closed low off the Mid Atlantic/Northeast coast
and a shortwave trough over IA/MO lifting slowly NE into WI/IL,
yielding a dry and subsiding column with little to no CAPE and PWs
generally aob 1". Apart from a little morning fog/stratus across the
S, expect plenty of sunshine Sun, and largely clear skies Sun night
except for a few residual mid/high clouds floating in from late-day
convection over the central Appalachians. This insolation should
partially offset thicknesses about 15 m below normal, favoring highs
in the 80s to near 90. Lows should be in the mid 60s to around 70.

Mon/Mon night: The quiet weather will begin to transition back to
more seasonable temps and convection Mon. The surface ridge
extending over the area will weaken and push SE, supplanted by
developing lee troughing through the Piedmont. Aloft, the closed low
off the Northeast coast will pivot and retrograde NW, moving onshore
over New England, while the Midwest shortwave trough tracks slowly E
over the Great Lakes region and Ohio Valley, tamping down our
weakening narrow ridge and putting us into weak cyclonic mid level
flow on the SE edge of the shortwave trough, while PWs near 2" will
surge back into central NC from the SW. Expect a return to scattered
showers and storms, mainly across the west, during the afternoon
through mid evening, with coverage lessening but chances persisting
esp over the Piedmont and into our NE overnight, as indicated by
LREF precip probabilities. Highs should again be mostly in the 80s
with thicknesses holding just a bit below normal as cloud cover
increases. Lows in the upper 60s to lower 70s.

Tue-Fri: We`ll be back to daily chances for showers and storms,
primarily but not restricted to each afternoon and evening. The New
England mid level low looks likely to become absorbed into the baggy
trough over the Great Lakes/Ohio Valley, keeping central NC within a
weak cyclonic mid level flow through mid week, while a hot ridge
builds over the central CONUS. Expect Tue/Wed pops to be at or above
climatology. By Wed night/Thu, there are some model indications that
the baggy trough will shift off the E Coast, propelled by a
prominent shortwave trough crossing the Upper Midwest and into the N
and W Great Lakes region through Fri, although significant model
differences in timing of this shortwave emerge. Thus, we could have
a period of time beneath brief ridging aloft between the E Coast
trough and this incoming trough, or the E Coast trough could linger
in place, as the 00z op ECMWF depicts. And this sort of northwest
flow regime with mid level speed maxes upstream over the Midwest can
often translate to nocturnal MCSs (or their remnants) that can track
ESE through VA/NC with reduced predictability, even at shorter
ranges. With this falling forecast confidence late in the week, will
keep pops Thu/Fri near climatology for now, and temps within a few
degrees of normal. -GIH

&&

.AVIATION /18Z FRIDAY THROUGH TUESDAY/...
As of 145 PM Friday...

TAF period: All terminals are currently MVFR or VFR, with VFR
conditions expected by later this afternoon. While the bulk of
precipitation this afternoon is expected to remain near FAY, showers
will be possible at any terminal, with an explicit mention at
RDU/FAY and no mention at INT/GSO where showers will be more
isolated. Similarly, FAY also has the highest potential for any
thunderstorms. Precipitation chances should steadily decline this
evening, coming to an end overnight. However, low ceilings will
develop across southeast North Carolina this evening and expand
northwest, with all sites eventually expected to drop to IFR
ceilings. The lowest ceilings should occur around sunrise, after
which time cloud heights should lift as clearing skies move in from
north to south. Wind should be out of the east through the bulk of
the TAF period, with the highest winds expected Saturday.

Outlook: Dry weather is forecast for the rest of Saturday and all of
Sunday before an unsettled pattern reasserts itself and brings a
chance of showers and thunderstorms to the region again Monday
through Wednesday, with the highest chances for precipitation at
INT/GSO.

&&

.RAH WATCHES/WARNINGS/ADVISORIES...
Flood Watch until 7 PM EDT this evening for NCZ078-085-086-088-089.

&&

$$

SYNOPSIS...Green
NEAR TERM...Green
SHORT TERM...Luchetti
LONG TERM...Hartfield
AVIATION...Green