509
FXUS62 KRAH 301459
AFDRAH

Area Forecast Discussion
National Weather Service Raleigh NC
1058 AM EDT Sun Jun 30 2024

.SYNOPSIS...
Bermuda high pressure will remain locked in over central NC this
weekend. A cold front will push through the area tonight into
Monday. Post-frontal high pressure will extend into the southeast
Monday and Tuesday.

&&

.NEAR TERM /TODAY THROUGH TONIGHT/...
As of 1058 AM Sunday...

A Heat Advisory remains in effect through today for all but the
Northwest Piedmont and part of the Southern Piedmont in central NC.

Marginal to Slight Risk of severe thunderstorms this afternoon into
the evening.

Marginal Risk of excessive rainfall, mainly eastern Piedmont,
Sandhills, and Coastal Plain.

Negligible changes were made this morning as the inherited forecast
looks to be on track.

Water vapor imagery this morning depicted broad troughing over the
northeast/mid-Atlantic, with suppressed ridging over the deep south.
A few weak mid-level impulses were also evident, one generating
convection over central TN, and the other generating some isolated
convection over far SW VA.  Nearer the sfc, a remnant outflow
boundary has generated some light showers over the  far NW piedmont
this morning.

At the sfc, latest observations depict a cold front extending from
northwest PA southwestward through southern OH/IN/IL.  Ahead of this
front, swly sfc flow has picked up across central NC along a sfc
trough axis centered over the western Piedmont. As the
aforementioned upstream mid-level impulses pivot eastward, showers
and storms will initiate along the sfc trough, growing in coverage
with southeastward movement later this afternoon/evening.  Effective
shear is stronger to our north, but upwards of 20 to 25 kts may
extend down into our northern Piedmont/Coastal Plain later this
afternoon. This is supported by forecasted hodographs, which are
more elongated further up into south central VA, but with some
stretching extending south into our northern areas (within the
slight risk area).  Overall, the synoptic pattern should support
primarily multi-cellular storm modes for central NC today and
tonight. While the better shear will be further north, given strong
instability expected this afternoon, and perhaps some trailing
stronger shear in the north, a few isolated damaging wind gusts
could be possible later today in these areas.

The initial wave of pre-frontal convection should push southeast of
the area by midnight. However, an additional round of showers and a
few storms will be possible along the sfc cold front which will
drive south into our area from south-central VA overnight.  HREF
guidance continues to paint the highest probabilities for
showers/storms along the cold front to be mainly for those east of I-
95 tonight.  Overall, QPF should be highest for those east of US-1,
with upwards of an inch or so possible (localized higher amounts
will be likely). Given the deep moisture expected today, and perhaps
some slower motion storms, there is a non-zero chance for isolated
flooding primarily in the Coastal Plain urban areas. Overall though,
chances for flooding seem rather low today.

Temperatures will rise into the mid to upper 90s today, and given
deeper moisture, dew points should struggle to mix out this
afternoon. Thus, the Heat Advisory will remain in place through
tonight as heat indices rise above 105 this afternoon.

&&


.SHORT TERM /MONDAY THROUGH MONDAY NIGHT/...
As of 310 AM Sunday...

Relief from the heat and humidity!

The cold front will be SE of central NC during the morning and this
will allow cooler and drier air to overspread the region courtesy of
the Great Lake surface high pressure. There will be some lingering
shower chances in the far SE early and some low stratus/fog in the
morning. Expect partly sunny skies in the afternoon and much cooler.
Highs only in the lower to mid 80s, with upper 70s north. Mostly
clear and cool conditions are expected Monday night with lows in
the mid 50s to lower 60s.

&&

.LONG TERM /TUESDAY THROUGH SATURDAY/...
As of 222 AM Sunday...

Aloft, the mid-level anticyclone will once again build into the
region from the west, sitting over the TN Valley/Deep South Tue and
Wed. A series of northern stream s/w disturbances will track
eastward from the northern Plains through the Great Lakes/OH Valley
from Tue through Sat, with each successive s/w slowly suppressing
the high southward. However, the high should generally remain over
the Deep South and Southeast US through Sat. At the surface, as the
high moves eastward through the Northeast/northern mid-Atlantic
Tue/Tue night, it will continue ridging southward into the area.
Once the high moves out over the Atlantic on Wed the ridge will also
shift east out of the area, with a lee trough developing Wed night
and remaining in place through Sat. Expect swly flow and the
advection of warm, moist air into the area to take over once again.
Temperatures may actually be near to slightly below normal Tue, but
once the warm advection commences on Wed, they will quickly rise
back above near/slightly above normal Wed and be well above normal
by the end of the week. As for rainfall, as the mid-level ridge
gradually gets suppressed south and the lee trough strengthens, some
diurnally driven convection will be possible Thu, but more likely
Fri and Sat aft/eve. Latest forecast heat index values do creep back
to around 105 again in a few spots on Thu. Heat index values of 105
to 109 becoming greater in coverage (much of central NC) for Fri and
Sat.

&&

.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
As of 630 AM Sunday...

Generally VFR conditions will mostly prevail through the morning,
but some low stratus early this morning will be around KFAY. Then,
this afternoon from about 17z to 00z, scattered to possibly numerous
thunderstorms are expected ahead of a cold front and move E/SE from
the NW Piedmont into the Coastal Plain. Brief gusty winds, heavy
rain and sub-VFR ceilings and visibilities are possible with any
storm. Outside of storms, winds will generally be around 10-15 kts,
veering slightly from southerly this morning to more southwesterly
today.

Beyond 06z-12z Monday: A secondary surge of weaker showers/storms
with associated sub-VFR ceilings and visibilities will be possible
along the passing cold front late tonight in the east.

VFR conditions should return Tuesday and Wednesday as dry high
pressure extends into central NC.

&&

.RAH WATCHES/WARNINGS/ADVISORIES...
Heat Advisory until 8 PM EDT Sunday for NCZ008>011-024>028-
040>043-075>078-083>086-088-089.

&&

$$
SYNOPSIS...Badgett
NEAR TERM...Luchetti
SHORT TERM...Badgett
LONG TERM...KC
AVIATION...Badgett