261
FXUS62 KRAH 120732
AFDRAH

Area Forecast Discussion
National Weather Service Raleigh NC
332 AM EDT Sun May 12 2024

.SYNOPSIS...
High pressure will build across the southeastern United States today
before moving offshore Monday. Expect an unsettled weather pattern
starting Tuesday and continuing through the rest of the week.

&&

.NEAR TERM /TODAY THROUGH TONIGHT/...
As of 330 AM Sunday...

Radar echos have finally completely dissipated across the Sandhills
and southern Coastal Plain, with just a deck of clouds there that
will exit in the next couple hours. Elsewhere there will be clear
skies the rest of the night. A few sites have reported reduced
visibilities from fog/mist, but the rain that fell this evening was
so light that the fog/mist should stay very isolated.

Dry NW flow will prevail today across central NC between ridging
over the lower-mid MS Valley and a closed mid/upper low that water
vapor imagery depicts currently spinning over Lake Erie. At the
surface, low pressure will move SE from Upstate NY and weaken, as
high pressure drifts east from the TN Valley to stretch from VA/NC
to off the NJ coast on Monday morning. PW values today are only
modeled to be around half an inch (40-50% of normal) with good
mixing and downsloping helping dew points bottom out in the lower-to-
mid-40s. Statistical guidance even shows upper-30s dew points in the
far NW Piedmont. A dry and very pleasant Sunday will result, with
only some scattered cumulus below the subsident inversion at about
700 mb. NW winds could gust up to 15-25 mph during the day. Today`s
1000-850 mb thicknesses will be about 10 m higher than yesterday,
supporting high temperatures from the mid-70s to lower-80s.

As winds diminish to mostly calm Sunday evening/night, decent
radiational cooling conditions will help lows drop to the mid-40s to
lower-50s, though high clouds spreading in from the SW could inhibit
cooling a bit.

&&

.SHORT TERM /MONDAY THROUGH MONDAY NIGHT/...
As of 330 AM Sunday...

Shortwave ridging will move across central NC on Monday, ahead of a
shortwave trough (or closed low) that slowly moves east across KS
and MO. Meanwhile surface high pressure will shift fully offshore,
helping the low-level flow turn southerly. This WAA will be offset
by broken mid and high clouds overspreading the area as the flow
aloft turns southwesterly. So high temperatures should be similar to
Sunday, in the upper-70s to lower-80s. Clouds will lower and further
thicken Monday evening and Monday night as the aforementioned low
pushes a warm front through the Southeast US and mostly light rain
from isentropic lift begins to spread into central NC from SW to NE.
Models differ on timing, with the NAM fastest and GFS slowest, but
currently the best guess is for rain to begin in the southern and
western Piedmont on Monday evening and in much of the NE Piedmont
and Sandhills overnight Monday night. It may not begin in the
Coastal Plain until Tuesday morning. Lows Monday night will be much
milder, in the upper-50s to mid-60s.

&&

.LONG TERM /TUESDAY THROUGH SATURDAY/...
As of 305 AM Sunday...

Surface low pressure should be over southern Illinois at the
beginning of the extended forecast and precipitation will extend
well to the east, with rain increasing in coverage through the day.
Models begin to diverge with the surface feature Tuesday night, with
the 00Z GFS showing two low centers by Wednesday morning (over KY/TN
and DE) while the 00Z ECMWF has one broad center over OH. Regardless
of which scenario plays out, think that a bit of a dry slot will
develop over the Carolinas Tuesday night and there should be a bit
of a lull in shower coverage. The last two runs of the ECMWF are
suggesting that the upper trough helping to support the surface low
could close off into an upper low over the mid-Atlantic on
Wednesday, helping to intensify the surface low as it passes to the
north. While some rain could linger Wednesday evening, conditions
should then dry out as high pressure settles over Quebec and a ridge
extends along the eastern seaboard on Thursday. Meanwhile, the next
system will be developing in the Plains, and with models indicating
it may move east a little more slowly, have removed all pops from
the forecast Thursday night. Had enough confidence to add likely
pops across western counties Friday, but the models diverge too much
after this to go with anything higher than chance pops through
Saturday. Tuesday remains the coolest day in the forecast with
widespread highs in the 70s and possibly even upper 60s near the
Virginia border, otherwise temperatures should be near climatology,
around 80 and 60 degrees.

&&

.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
As of 150 AM Sunday...

VFR conditions will prevail through the next 24 hours. A band of
cloud ceilings around 7-10 kft and weakening sprinkles/showers is
currently moving south across the southern Piedmont and Sandhills
(including FAY). The precipitation will be south of FAY in the next
half hour or so and completely out of central NC or dissipated
within the next hour or two at most. They are so light that
visibilities will remain VFR wherever it does rain. The band of
clouds will push SE of the entire area by 09z, with clear skies
behind it. More scattered cumulus are possible during the day today,
but they will stay above the VFR threshold. NW winds will pick up by
mid morning, gusting up to 15-20 kts, which will last into the
afternoon before diminishing in the evening.

Looking beyond 06z Mon: VFR conditions and dry weather are expected
through at least Mon. Rain and isolated storms, with a high chance
of sub-VFR conditions and increasing winds aloft, are expected to
overspread the area starting Mon night, with sub-VFR conditions
lasting through Wed morning, although shower chances will persist
through Wed. Dry VFR conditions should return for Thu.

&&

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

&&

$$
SYNOPSIS...Green
NEAR TERM...Danco
SHORT TERM...Danco
LONG TERM...Green
AVIATION...Danco/Hartfield