135
FXUS62 KRAH 080604
AFDRAH

Area Forecast Discussion
National Weather Service Raleigh NC
205 AM EDT Mon Jul 8 2024

.SYNOPSIS...
A weak frontal zone extending from Chesapeake Bay through the
Piedmont of the Carolinas will weaken further today before
dissipating tonight. Mid and upper level high pressure will build
across the area through mid week, before another cold front
approaches Wednesday night. This front will then stall out and hold
over the western and central Carolinas through Friday.

&&

.NEAR TERM /TODAY AND TONIGHT/...
As of 205 AM Monday...

Continued partly to mostly cloudy and humid but with slightly lower
convection coverage expected today.

The degree and extent of morning cloudiness will play a role in the
initiation of showers/storms today. An MCV and persistent widespread
rain with embedded storms covering much of central SC has scraped
across our SW areas, bringing locally heavy rain to Anson county in
the last couple of hours, although cloud tops with this feature
continue to warm steadily as it drifts ESE. This MCV appears to be
locked to a very weak and diffuse frontal zone stretching over the
Carolina Piedmont, and this front should continue to weaken today. A
very moist column persists over our area, with PWs in the 2-2.5"
range, 150%-175% of normal, although the highest values are expected
to push slightly NW to be situated more over the NW Piedmont, nudged
by the upper low off the Carolina coast tracking to the SSW toward
the N Bahamas. Narrow mid-upper level ridging will build today from
the central FL panhandle NE through central NC, which will keep our
mid level flow and steering very weak, thus slow and meandering
outflow-steered convective cells/clusters may produce a localized
mostly nuisance flooding risk once again today. The presence of
nocturnal stratus well into the morning and abundant debris mid and
high clouds in tandem with slightly warmer mid levels should cut
back on SBCAPE a bit today, too, which with poor deep layer shear
should hinder storm organization. Will have scattered showers and
isolated storms through this morning, with pops then rising to good
chance in the afternoon, highest in the W and SE (the latter likely
focused on old boundaries and sea breezes). Expect pops to again
decrease in the evening, although given the potential for another
round of MCVs and warm/moist low levels to keep some amount of
marginal elevated CAPE going well past sunset, confidence in a dry
overnight is pretty low. Expect highs in the upper 80s to mid 90s,
followed by lows in the 70s. -GIH

&&

.SHORT TERM / /...
As of 250 PM Sunday...

To be updated shortly.

&&

.LONG TERM /TUESDAY THROUGH SUNDAY/...
As of 250 PM Sunday...

* Typical summer pattern through the weekend
* Some storms possible Tuesday/Wednesday, becoming more numerous
  late in the week

Precip chances look to decrease on Tuesday as an offshore upper low
off the NC coast dives southwestward toward Florida. In its wake,
mid level heights appear to increase by a few meters and this may be
enough to further inhibit storm development across the area. While
similar PW`s will be in place area-wide, very limited forcing and
instability outside of an area near a lee trough across the western
Piedmont should keep storms isolated/widely scattered in nature.

Meanwhile, the remnant circulation and moisture associated with T.C.
Beryl will be drawn inland and absorbed into a longwave trough
approaching the western Great Lakes later this week. This will spawn
a relatively deep surface cyclone that will track northward across
the Great Lakes into southern Ontario. An attendant surface boundary
will make an eastward run at the mountains, but likely stall/wash
out before it makes it across. However the remnant boundary and/or
lee troughing will likely result in an area of enhanced surface
convergence which will be stall out and be slow to exit the area.
Nearly all global models suggest a plume of increased PW`s will be
drawn inland from off the SE coast on Wednesday, interacting with
and serving as a necessary ingredient for increased shower and
thunderstorm coverage to close out the week. There is a general
consensus among the ensembles that Thursday and Friday could be
particularly active as a weak surface low develops along the stalled
surface boundary to our south and tracks through central NC. Looking
at the 100 member grand ensemble of the Canadian, GFS, and EC
ensemble forecast systems, nearly 80 percent suggest precip across
the area on Thursday and nearly 90 percent on Friday, which is an
unusually high amount of agreement for this time of year at this
lead time. Of course exactly how much rain will fall, and exactly
where the surface boundary and low track set up, is still TBD but
the trend of increasing late-week PoPs will continue. Precip chances
should remain elevated (although slightly lower as compared to
Thursday/Friday), as we get into the weekend.

Temperatures this week should be within a few degrees of normal.
Through mid week with mid level ridging sneaking in from the east,
temps should make a solid run into the mid 90s area-wide and it is
on these days (Tuesday and Wednesday) where heat indices could make
a return to dangerously high values. However increased cloud cover
and precip chances will knock readings back into the mid/upper 80s
Thursday, especially Friday, and possibly into Saturday as well
before returning to normal by Sunday. Lows throughout the period
generally upper 60s to mid 70s.

&&

.AVIATION /06Z MONDAY THROUGH FRIDAY/...
As of 1230 AM Monday...

Confidence is high in widespread sub-VFR stratus (mostly IFR/LIFR)
and areas of mostly MVFR fog persisting across much of central NC
until mid morning, particularly affecting INT/GSO/RDU, with slightly
lower confidence at RWI/FAY. Patchy rain will dwindle but linger
over the far SW edges of the forecast area through daybreak, however
much of the area will stay dry through mid morning. IFR clouds will
be slow to improve, likely rising to MVFR between 14z and 16z
(slowest in the W Piedmont) and to VFR by 18z. FAY is likely to see
MVFR/IFR cigs lasting a shorter time, 10z-14z, with 08z-14z at RWI.
Scattered showers and storms are expected today, through the central
sections (RDU) late morning/early afternoon then over the NW and SE
areas (INT/GSO and FAY) mid afternoon through early evening, with
storms likely to develop over the higher terrain and drift into the
Triad, and along an inland-moving sea breeze toward FAY. Overall
coverage is expected to be lower than over the last two days, and
showers and storms should start to decrease and diminish by mid to
late evening. Periods of sub-VFR cigs/vsbys and gusty/erratic winds
are possible in and near any storms today. Outside of any storms
today/tonight, surface winds will be light and variable, mainly from
the S (SE through SW).

Looking beyond 06z Tue, there is a chance for sub-VFR cigs/vsbys
early Tue morning, mainly across the S, but should be less coverage
than this morning. A general pattern of scattered to numerous
showers and storms primarily each afternoon through evening will
continue through Fri, with the highest chances late Wed night
through Fri, and at least some chance of early-morning sub-VFR
clouds/fog each day. -GIH

&&

.CLIMATE...
Record High Minimum Temperatures:

July 7:
KGSO: 73/2019
KRDU: 77/1900
KFAY: 78/2017

July 8:
KGSO: 76/2010
KRDU: 78/1986
KFAY: 79/2012

July 9:
KGSO: 76/1987
KRDU: 74/2014

&&

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

&&

$$

SYNOPSIS...Hartfield
NEAR TERM...Hartfield
SHORT TERM...
LONG TERM...DL
AVIATION...Hartfield
CLIMATE...RAH