457
FXUS62 KRAH 061041
AFDRAH

Area Forecast Discussion
National Weather Service Raleigh NC
640 AM EDT Sun Jul 6 2025

.SYNOPSIS...
Tropical Storm Chantal will drift slowly north northwestward across
the coast of South Carolina this morning. The remnant low pressure
system will then drift slowly north to northeastward across central
North Carolina this afternoon through early Monday.
&&

.NEAR TERM /TODAY AND TONIGHT/...
As of 250 AM Sunday...

* Flood Watch in effect for all but the northeast zones of central NC

* Remnants of Chantal will bring a low-end tornado threat for the
  Sandhills into the Central Coastal Plain south of US-1

A Flood Watch was hoisted for all but the northeast zones of central
NC. The remnants of Tropical Storm Chantal will bring widespread
showers and embedded storms to most of central NC through early Mon
with highs this afternoon mainly in the 80s. Chantal as of 2 am was
about 85 miles southwest of Wilmington, NC, with maximum sustained
winds of 50 kt (60 mph) and 1002 mb. Satellite and radar do depict
the system is starting to wrap up and become more defined. The
latest NHC track takes the system to the NW before moving into the
central NC Sandhills and weakening as a depression as it tracks ENE
into the northern Coastal Plain by Mon morning.

While the model guidance has come into much better agreement with
regards to Chantal`s track and QPF footprint, there is still some
uncertainty. Nevertheless, there was enough confidence to go with a
Flood Watch for most of the area. In discussions with WPC with
respect to left/right track solutions, the anticipated QPF footprint
did not change much from the day shift Sat. If anything, the system
may be moving a bit faster overall. The highest QPF, based on a
suite of model guidance, including the CAMs/HREF and which matches
well with the ECMWF AIFS model, shows the highest totals from the
Triangle westward, over the western and southern Piedmont to
Sandhills region of central NC. It appears that a trough over the MO
valley region to Great Lakes and over the north-central Gulf may be
helping to pull Chantal further to the NW, producing a band of
higher QPF on its NW side. In this region of central NC, rainfall
amounts of 1 to 3 inches, locally 4+, are possible. However, as has
happened so often in our area, the QPF footprint may be off by 50 to
100 miles. Also, some guidance is still indicating other alternate
scenarios, such as the HRRR, which shows higher totals to the north
and east of Chantal over the Coastal Plain. As such, given this
potential uncertainty, we included portions of the Coastal Plain in
the Flood Watch, in case minor changes to the track/QPF occur with
future updates.

In addition to the flash flood threat, a tornado threat will exist
for the Sandhills to the central Coastal Plain, largely south and
east of the Triangle. Enhanced low-level flow/shear and instability
with low/mid 70s dewpoints will favor the potential for low-topped
supercells over eastern NC, where the right front quadrant of
Chantal will overspread. It would appear the greatest threat for any
isolated tornadoes would be between mid-morning into early evening,
when the system is more wrapped up, during peak heating, and prior
to becoming an extratropical depression.

Pockets of scattered showers and embedded storms will exist into the
overnight, but should lessen after midnight as the system pulls NE.
Lows will be in the low/mid 70s.

&&

.SHORT TERM /MONDAY AND MONDAY NIGHT/...
As of 250 AM Sunday...

The remnants of Chantal will gradually lift NE into VA during the
aftn or eve on Mon. Morning pockets of showers and clouds should
give way to some partial sunshine in the aftn/eve as weak westerly
flow aloft overspreads the area. That should favor a warmer and also
humid day with upper 80s E to low 90s W. Even with its departure,
scattered showers and storms will be possible, especially along/east
of US-1 closer to the departing low. That said, I would not be
surprised if there is less overall storm coverage owing to weak
westerly downslope flow. There will, however, be a weak trough over
the OH valley with a developing weak lee trough in western NC that
could still favor isolated/scattered storms. Any storms should die
out after sunset, with lows muggy in the mid 70s with possible fog
and stratus.

&&

.LONG TERM /TUESDAY THROUGH SATURDAY/...
As of 245 AM Sunday...

* Hot and humid on Tuesday with highs in the lower to mid 90s with a
  few of the typically hotter spots threatening the upper 90s. It
  will be humid as well with heat index values of 100 to 105 across
  much of the area except the Triad where it will be a touch cooler.

* Largely diurnally driven convection is expected for the second
  half of the work week into the weekend with the greatest rain
  chances on Thursday and Friday.

* It will be continued hot on Wednesday, likely a few degrees cooler
  than Tuesday. High temperatures will then cool off for Thursday
  and Friday with a good deal of cloud cover and rain chances.

Weak ridging will become established across the Southeastern U.S. on
Tuesday. With morning low level thickness values in the 1420s, high
temperatures will climb into the lower to mid 90s across much of the
area. A few of the hotter spots such as Maxton and Raleigh may make
it into the upper 90s. The hottest ENS member has a high of 99 at
RDU. Will need to monitor the need for a heat advisory with heat
index values of 100 to 105 currently forecast across much of the
area at this point with the potential for heat index values to be a
little higher. A few afternoon and evening storms are possible on
Tuesday but coverage should be much more limited than the Wednesday
through Friday period.

The threat of mainly afternoon and evening storms increases for
Wednesday through Friday period as the westerlies drop into the
Great Lakes and OH Valley on Wednesday and then push east toward the
Appalachians on Friday. An associated cold front approaches on
Thursday and moves into the region on Friday. These forcing
mechanisms along with PW values of around 2.0 inches or greater will
support an active period with above climatology PoPs. With the
increased cloud cover and rain chances along with a slightly cooler
airmass arriving late in this period, highs on Thursday and
especially Friday will range near or slightly below average.
Friday`s highs should range in the mid 80s to around 90.

The pattern becomes more uncertain over the weekend as the cold
front is forecast to drop into the region and then persist across
the Carolinas through the weekend. Forecasting the passage and
position of cold fronts in our region at longer ranges during the
summer can trying, so confidence is limited in forecast details for
the weekend. -Blaes

&&

.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
As of 640 AM Sunday...

The remnants of Tropical Storm Chantal will bring widespread showers
with embedded storms across the terminals, earliest at FAY and
latest at GSO/INT. The heavier bands of showers and storms are
favored between the late morning and early evening hours, with the
highest confidence of TSRA at FAY, RWI, and RDU, where IFR or lower
restrictions are possible. These sites as well could briefly improve
to VFR outside of storms. The Triad terminals (GSO/INT) should see
MVFR to IFR rain, especially after 18z and through the end of the
TAF period. A storm could impact GSO between 20 and 00z, but
confidence was too low to include at this time. Waves of showers and
some storms may continue to the end of the TAF period, especially at
RDU. Regardless, MVFR-IFR ceilings are favored near GSO, RDU, FAY,
and RWI with the gradual movement of the remnants of Chantal. NE
winds may gust at times into the lower 20s kts, especially at FAY,
RDU, and RWI.

Outlook: After Chantal exits early Mon, a humid airmass will favor
areas of morning stratus and fog and afternoon-evening
showers/storms through most of this coming week.

&&

.RAH WATCHES/WARNINGS/ADVISORIES...
Flood Watch from 6 AM EDT this morning through late tonight
for NCZ007-008-021>025-038>042-073>078-083>086-088-089.


&&

$$
SYNOPSIS...Blaes
NEAR TERM...Kren
SHORT TERM...Kren
LONG TERM...Blaes
AVIATION...Kren/MWS