797
FXUS62 KRAH 301853
AFDRAH

Area Forecast Discussion
National Weather Service Raleigh NC
255 PM EDT Sun Jun 30 2024

.SYNOPSIS...
A cold front will push through the area tonight into Monday. High
pressure will then extend into the southeast Monday and Tuesday,
with a gradual return of heat and humidity by the end of the week.

&&

.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 255 PM Sunday...

Overnight showers and storms should be exiting the southern coastal
plain by Monday morning as a fairly stout cold front for the season
(10-15F temp drop across OH this afternoon), surges into the area
from the north.  a 40m+ drop in 1000-850mb thicknesses combined with
dewpoints dropping into the 50s (some guidance suggests upper 40s
with mixing) will result in a much welcomed relief from the heat.
highs will top out several degrees below normal in the low to mid
80s. Also behind the front, winds will gust to 15kt to perhaps as
high as 20kt.  RH values will also dip into the lower 30s across
northern areas.  This does not met any criteria for fore weather
hazards, but given the recent drought development, it is worth
noting.

Lows Monday will be in the upper 50s and lower 60s.

 &&

.LONG TERM /TUESDAY THROUGH SUNDAY/...
As of 255 PM Sunday...

A common summertime airmass moderation will occur throughout the
week as the sub-tropical ridge, briefly tempered by today`s
shortwave and cold front, will build back east across the region,
while the Bermuda highs allows moisture to return back across the
region with winds turning to southerly by late Wednesday into
Thursday.  The upper ridge, progged to again reach 596dm+ by
Thursday across the southeast US, will also support the return of
highs in the mid/upper 90s areawide and potentially 100s in some
locations.  Dewpoints are also progged to trend back into the lower
70s, particularly in the east on the downshear side of the lee
trough.  This will may again result in dangerous heat and humidity
as has been observed for the past few days.  Rain chances will hinge
on the lee trough and other diurnally forced circulations Thursday
into the weekend,  Models to hint at a weak cold front by Sunday
Monday with an upper trough over the northern US.  Confidence in
that remains low at days 7/89.

&&

.AVIATION /18Z SUNDAY THROUGH THURSDAY/...
As of 120 PM Sunday...

Scattered showers and storms will continue to blossom across central
NC this afternoon and evening.  Except for temporary sub-VFR
conditions from heavy downpours, terminals should remain VFR through
early tonight. Additionally, some sub-VFR fog and ceilings may
develop just ahead of a cold front at KRWI/KRDU/KFAY late tonight.
However, any lingering stratus or fog will quickly lift to VFR as
the front pushes through to the coast by sunrise Monday morning.
Behind the front, a brief period of stronger nely sfc flow will
spread across the area with some gustiness up to 20 kts possible
through early afternoon.

Outlook: VFR conditions will continue Monday through Thursday as dry
high pressure extends down into central NC.  Return flow on Friday
will promote increasing humidity and the chance for diurnal showers
and early morning fog/stratus next weekend.

&&

.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...bls
NEAR TERM...Luchetti
SHORT TERM...bls
LONG TERM...bls
AVIATION...Luchetti