169
FXUS62 KRAH 290028
AFDRAH

Area Forecast Discussion
National Weather Service Raleigh NC
825 PM EDT Tue May 28 2024

.SYNOPSIS...
A series of moisture-starved, reinforcing cold fronts will lead high
pressure from central Canada and the Great Lakes to the Middle
Atlantic and Carolinas this week.

&&

.NEAR TERM /THROUGH TONIGHT/...
As of 825 PM Tuesday...

A broad upper trough over the eastern United States will continue to
drift east overnight. The 00Z Greensboro sounding shows some minimal
saturation between 6 and 12 thousand feet, but otherwise the
sounding is dry. A line of thunderstorms is currently over eastern
North Carolina associated with the surface cold front near the
Atlantic coastline. Meanwhile, a line of showers is currently moving
across south-central Virginia with a drift to the south, but do not
expect that any rainfall should make its way across the state border
into North Carolina. Mainly diurnal cumulus clouds should continue
to fade away over the next couple of hours, and overnight lows will
range from the mid 50s to the mid 60s.

&&

.SHORT TERM /WEDNESDAY AND WEDNESDAY NIGHT/...
As of 355 PM Tuesday...

A shortwave trough now over WI/IA will dig sewd into the OH Valley
tonight and then pivot across and offshore the Middle Atlantic Wed-
Wed night.

At the surface, an Appalachian-lee trough will develop with diurnal
heating Wed and be overtaken by a moisture-starved, reinforcing cold
front that will settle south across the Carolinas Wed night.

Like that which is occurring with the shortwave trough pivoting
across the Middle Atlantic today, diurnally-driven convection will
likely redevelop and accompany the aforementioned shortwave trough
that will pivot across the region Wed, with the greatest coverage
from the NC/VA border nwd. While the forecast will remain a dry one
for now, a slight/small chance of an afternoon shower/storm may be
needed over at least the nrn NC Piedmont. It will otherwise remain
less humid than recent days, and slightly cooler, with highs in the
low-mid 80s and lows mostly in the 50s to around 60.

&&

.LONG TERM /THURSDAY THROUGH TUESDAY/...
As of 232 PM Tuesday...

A short wave trough pivoting across the eastern Great Lakes on
Thursday will move off the Northeast and Mid-Atlantic coastal
regions by early Friday and will be followed by sfc high pressure
building into much of the Eastern US during the rest of Friday and
into early Saturday.  This high will bring with it a relatively
cooler airmass into our region, which will result in high temps Thu-
Sat in the upper 70s to lower 80s, which is several deg below
normal.  The main forecast challenge is whether or not the
aforementioned s/w trough will have enough moisture or to work with
across our area to result in any shower activity with it`s passage.
The majority of the guidance suggests areas well north and east of
Raleigh will have the best chance to see a passing shower late on
Thursday or Thursday night, and the NBM keeps PoPs aob 14% across
our entire CWA.  For now will go with NBM keeping our forecast dry
during that time (PoPs below 15%), but if PoPs continue to trend
higher, they may be needed across our northeast and far eastern
zones.

Once the high moves offshore by mid-Sunday, look for a warming and
moistening trend with temps near normal for the rest of the period.
Both the GFS and ECMWF suggest a series of low-amplitude s/w troughs
will transit the westerly upper flow and may provide enough forcing
for some isold mainly diurnal shower/tstm activity late in the days
Sunday through Tuesday, but certainly not a washout during that time
with overall low QPF.

&&

.AVIATION /22Z TUESDAY THROUGH SUNDAY/...
As of 610  PM Tuesday...

24 hour TAF period: VFR conditions are expected through the next 24
hours. The possibility of a shower is non-zero, but is too low to
include in the forecast. Isolated/scattered diurnal cumulus should
fade with sunset, with skies becoming mostly clear overnight.
Another round of VFR diurnal cumulus clouds and non-zero chance of
rain is expected again Wednesday afternoon.

Outlook: Canadian high pressure will build from cntl Canada to
the middle Atlantic and favor VFR conditions in cntl NC through Sat.
As the high shifts offshore, sly flow and increasing moisture will
increase the risk of patchy fog and stratus Sun morning and a chance
of showers/storms Sun afternoon-night.

&&

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

&&

$$
SYNOPSIS...MWS
NEAR TERM...Green
SHORT TERM...MWS
LONG TERM...np
AVIATION...Green/MWS