627
FXUS61 KAKQ 181310
AFDAKQ

AREA FORECAST DISCUSSION
National Weather Service Wakefield VA
910 AM EDT Thu Jul 18 2024

.SYNOPSIS...
Showers and storms continue today as a cold front slowly pushes
through the area. Showers diminish tonight as the front moves
south, then focus mainly over southern Virginia and North
Carolina Friday. The front lifts back north, bringing unsettled
conditions back to most of the area on Saturday.

&&

.NEAR TERM /THROUGH TONIGHT/...
As of 900 AM EDT Thursday...

Key Messages:

- Additional heavy rainfall likely today across south-central/SE
  VA & NE NC where a Flood Watch has been issued.

- Slight risk of SVR also possible for far southern VA and NE
  NC, marginal into central VA.

9AM Update:
Decided to add a few more of our SW counties to the Flood Watch
today (Mecklenburg/Brunswick/Greensville and Northampton NC)
based on rainfall reports from last night of 1-3" and locally
over 4" in SW Mecklenburg County around Clarksville. In
addition, streamflows have seen a modest rise in this area.
These conditions combined with the potential for more heavy rain
this afternoon warrant the expansion of the Flood Watch.

Previous discussion below...
The latest analysis indicates an upper level trough over
Ontario/Quebec, with a shortwave pushing east towards the St
Lawrence Valley. At the sfc, a cold front extends SW from low
pressure across Quebec, to near the western slope of the
Appalachians. Warm and very humid locally with just a few
showers over the SE. Heavier rain from a few hrs ago has pushed
offshore, but given PWATs still ~2.4" across the SE in advance
of the front, have decided to issue a Flood Watch for far SE VA
(including southside Hampton Roads and all of NE NC). This is
approximately co-located with the latest 00Z/18 HREF PMMs 50%
contour for 3"/3hr (a small are with a 70% contour is still in
place over mainly the center of our NE NC zones). There is a
Marginal ERO for most of the remainder of the forecast area, but
expect showers to diminish in coverage and intensity later in
the aftn in these areas as drier air moves in from the NW.

Will also need to watch the severe weather potential this aftn
afternoon with a few of the CAMs being quite aggressive. There
will again be plenty of instability tomorrow, with ~2000 to 3000
J/kg of MLCAPE in place across the region despite the clouds.
We will also have slightly more effective shear over the area
compared to today, with 25-30 kt. The primary hazard continues
to be damaging wind gusts, with the hail threat remaining
limited due to weak mid- level lapse rates (though SPC does show
a 5% prob for hail). If we can fully destabilize, as some of
the CAMs have been showing, there is the potential for a
corridor of greater damaging wind potential. For now, SPC has
the far southern portion of VA and NE NC in a Slight risk and a
Marginal to up into central VA including metro RIC.


The front pushes just south of the local area tonight into
Friday, with the highest rain chances confined to the southern
areas. With some clearing and drier air/lower dew pts, lows Thu
night drop into the low-mid 60s NW, with lower 70s SE (where its
stays humid with more clouds).

&&

.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
As of 415 AM EDT Thursday...

Key Messages:

- Scattered showers/storms south on Fri, but mainly dry north.

-Showers/storm chances increase Saturday as the front lifts back
 north.

Drying out for the northern half of the area Friday, with only
scattered shower and storm chances by Friday afternoon (over the
south). Partly sunny N and mostly cloudy S with high
temperatures mainly in the low-mid 80s (more comfortable N and
central where dew pts will be in the 60s).

The upper trough moving into New England looks to flatten out later
Friday while the area of high pressure off the Southeast coast
begins to gradually retrograde back westward slightly. The front is
forecast to lift back north into the southeastern portion of the
area and stall out into Saturday. The best rain chances Friday night
will be across northeast North Carolina in the vicinity of the
boundary, then chances spread back north on Saturday as the front
shifts. The higher rain/storm chances on Saturday will be south of
the I-64 corridor where likely PoPs remain in the forecast.

&&

.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
As of 415 AM EDT Thursday...

Key Messages:

- Unsettled with above normal rain chances.

- Humid with average temperatures fairly close to normal.

A positively tilted trough will start to dip down into the mid
Mississippi Valley on Sunday, as the upper ridge remains
centered off the SE coast. This pattern remains fairly
consistent through the middle of next week, keeping a most SW
flow aloft in place. The stalled front won`t move very much,
but it does become a bit more diffuse on Sunday so generally
should see rain chances focus in the aftn/evening rather than
all day. Variably cloudy and a bit warmer with highs in the mid
80s to around 90F. A similar setup persists through Wed, with at
least high chc PoPs each day focused primarily in the
aftn/evening (PoPs avg 45-55% SW to 35-45% NE). It remains humid
with dew pts in the 70s, but high temperatures remain in check,
generally in the mid 80s to around 90F so at least an extended
break from any excessive heat.

&&

.AVIATION /13Z THURSDAY THROUGH MONDAY/...
As of 730 AM EDT Thursday...

Mainly VFR but some MVFR CIGs may affect the terminals through
midday, along with scattered showers. Showers and tstms become
more widespread by early aftn, with flight restrictions likely
in heavy rain. Strong gusty winds will also be possible in the
storms, especially across southern VA and NE NC between ~18Z and
~00Z.

Outlook: The front will push farther S tonight as drier air
pushes in from the NW, with some local IFR-MVFR restrictions
still possible at ORF/PHF/ECG, mainly VFR to the north. Mainly
VFR/dry Friday over the north and central, with flight
restrictions possible mainly for ECG. The boundary lifts back N
Saturday with showers and tstms scattered to likely for most
areas. Sunday will see scattered, mainly aftn/evening
showers/storms.

&&

.MARINE...
As of 345 AM EDT Thursday...

Key Messages:

- A weak cold front crosses the northern waters today and
  stalls near the VA/NC border this evening before pushing south
  of the area on Friday.

Low pressure is centered over eastern Canada with a trailing front
extending to the south and southwest over the Mid-Atlantic states.
Winds have decreased from earlier this morning with SW flow now
generally 10-15 kt. Waves in the Ches Bay are 1-2 ft with seas 2-4
ft.

All SCA headlines have expired or been cancelled. Seas for the
northern coastal waters briefly built to ~5 ft but have since fallen
back to around 4 ft. The front makes slow SE progress today before
stalling across the SE third of the area this afternoon and evening.
Areas ahead of the front will see the potential for additional
showers and storms this afternoon with locally enhanced
winds/waves/seas in and around convective cells. The front is
expected to clear the region by early Friday with winds becoming
N or NE behind the boundary. This front is forecast to lift
back northward on Saturday with flow veering to SE. Weak
synoptic gradient will keep conditions below SCA thresholds
through the end of the period. The front will likely linger in
the region into early next week with the relative higher chances
for showers and storms focused over the southern half of the
area. Waves will average 1-2 ft in the bay with seas 2-3 ft well
into next week.

There is a moderate rip current risk for the northern beaches today
with a low risk for VA Beach and points S. Low rip risk at all
beaches on Friday.

&&

.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...None.
NC...Flood Watch through this evening for NCZ012>017-030>032-102.
VA...Flood Watch through this evening for VAZ065-079-087-095>098.
MARINE...None.

&&

$$

SYNOPSIS...LKB
NEAR TERM...JDM/LKB
SHORT TERM...AJB/LKB
LONG TERM...AJB/LKB
AVIATION...AJB/LKB
MARINE...RHR