996
FXUS62 KRAH 080128
AFDRAH

Area Forecast Discussion
National Weather Service Raleigh NC
928 PM EDT Sun Jul 7 2024

.SYNOPSIS...
A weak frontal zone extending from the Chesapeake Bay into the
Piedmont of the Carolinas will linger and weaken before dissipating
by Tuesday. Mid and upper level high pressure will then build across
the area before another cold front approaches late in the work week.

&&

.NEAR TERM /OVERNIGHT/...
As of 928 PM Sunday...

The convection has mostly ended across central NC with some
lingering rain patches attm, as the sfc front has slipped south and
now extends from approx the CLT region ENE to KGSB and then north to
the ORF area. Cooler sfc air behind the front is evident in latest
sfc obs with readings in the lower 70s and even some upper 60s temps
currently across our northeast Piedmont and northern Coastal Plain
zones, with mid-upr 70s across much of the rest of central NC except
some lingering 80s readings near the SC border. Will make a few
tweaks to forecast temps overnight to account for current trends.

Otherwise, the rain should gradually taper off after 06Z tonight as
both instability and larger-scale forcing wanes. Until then, in
additions to some lingering patchy rain, we can`t completely rule
out a few widely sct tstms across our southern-most zones where the
front hasn`t yet cleared the area. And it`s also worth noting that
several MCVs across the Carolinas and Southeast states...as noted in
current water vapor imagery, including one notably just west of the
CLT area, appear to be drifting slowly to the southeast...and thus
should have limited impact on our weather overnight as they should
stay south of our area.  Finally, the latest HRRR suggests some
stratus will continue to develop and expand overnight across much of
the Piedmont region, perhaps extending all the way toward I-95...
this stratus formation occurring over areas that received the
heavier rain earlier today.

&&

.SHORT TERM /6 AM MONDAY MORNING THROUGH MONDAY NIGHT/...
As of 250 PM Sunday...

* Continued shower/thunderstorm chances, albeit it with lower areal
  coverage
* Brief periods of heavy rain likely the primary threat with any
  storms that develop

We should have a very similar synoptic setup across the area
tomorrow with PW`s still running around 2 to 2.2". The presence of a
stalled surface boundary may be lacking though and with only a lee
trough and sea breeze to contend with, the overall triggering
mechanisms for convection may ultimately be the limiting factor.
Storms are once again favored across the western Piedmont along with
the Sandhills/southern Coastal Plain, with lesser chances elsewhere.
Storms are likely to be outflow dominant and pulse-type in nature
given very weak steering flow around 15kts or less. While wet
microbursts would be a possibility with any storms that approach
severe limits, locally heavy rainfall from slow moving/training
storms would likely be the primary threat tomorrow.  However given
relatively limited areal coverage, we shouldn`t need any flood
watches. PoPs in the 20-40 percent range area-wide are the general
consensus from the NBM, HREF, and other global models and this seems
reasonable at this point.

Temps will be on par with today`s values with highs in the upper
80s/lower 90s with lows falling into the lower 70s.

&&

.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 /00Z MONDAY THROUGH FRIDAY/...
As of 740 PM Sunday...

Through 00Z Tuesday: Convection is slowly diminishing in coverage
this evening; however we are seeing a variety of flt conditions
across central NC attm depending on where the rain is falling. As
the evening progresses into the overnight hours, the rain should
mostly end, however across much of the Piedmont we expect a shield
of stratus to form, which will lower flt conditions aob IFR after
05Z across much of the Piedmont, including KINT, KGSO, and KRDU, and
possibly extending as far east as KRWI and KFAY.  This stratus will
linger through about 14Z before cigs slowly lift back to VFR by 17
or 18Z Monday.  Winds will generally be aob 10kt, but direction will
be highly variable based on outflow boundaries, and the locations of
the synoptic front which currently extends from KAFP to KPOB to
KGSB.

After 00Z Tuesday: A rather typical summer pattern of scattered
afternoon and evening showers and storms along with some late night
and early morning stratus and fog is expected through the period
with the coverage of storms and restrictions expected to uptick on
Wednesday and increase for Thursday and especially Friday.

&&

.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...Blaes
NEAR TERM...np
SHORT TERM...DL
LONG TERM...DL
AVIATION...np
CLIMATE...RAH