157
FXUS61 KAKQ 171808
AFDAKQ

AREA FORECAST DISCUSSION
National Weather Service Wakefield VA
208 PM EDT Wed Jul 17 2024

.SYNOPSIS...
An unsettled period begins late this afternoon through
Thursday, as a cold front pushes through the area and stalls
across the Carolinas. Shower chances focus mainly over southern
Virginia and North Carolina Friday, then return to all zones by
Saturday.

&&

.NEAR TERM /THROUGH TONIGHT/...
As of 200 PM EDT Wednesday...

Key Messages:

- Heat Advisories remain in effect for the entire area today
  (other than the MD beaches).

- Showers/storms become fairly widespread this evening into tonight.

- There is a Slight Risk for severe weather roughly along and
  north of US-460 with a Marginal Risk for most of the
  remainder of the CWA.

This afternoon, high pressure remains anchored well off the SE
coast to Bermuda. Meanwhile, a lee trough is in place just to
the east of the Blue Ridge and a cold front is well NW of the
region over portions of the Great Lakes/Ohio Valley.

The cold front remains well to the NW of the area into tonight,
with storms developing on the lee trough with strong low level
destabilization (ML CAPE ranging from 1500 to 2000 J/kg).
Mid level lapse rates are quite weak and with the hot humid
airmass, hail will be unlikely. Deep layer shear increases to a
modest 20 to 30 knots later this afternoon across the northern
half of the area as the mid level flow increases with the
approach of the upper trough. Storms will primarily be linear
clusters and somewhat disorganized, but a marginal supercell or
two cannot be ruled out, along with bowing segments. The primary
threat with the strongest storms will be damaging wind gusts.
SPC continues with the northern half of the forecast area in a
Slight Risk for severe weather and a Marginal Risk elsewhere
(technically only GEN thunder along the Albemarle sound). In
addition to the severe weather threat, there will also be a
localized heavy rain threat as moisture pools ahead of the
front, with PWATs surging to 2.2+", though the best chances for
widespread heavy rain into tonight are still expected to be
mainly north of the forecast area.

Showers/storms gradually diminish by or shortly after
midnight, with lingering showers and embedded storms possible
overnight (but with little SVR threat). Lows in the lower 70s NW
to the mid-upper 70s SE.

&&

.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
As of 350 AM EDT Wednesday...

Key Messages:

- Marginal SVR risk Thursday central and south. Heavy rain
  threat, primarily across the SE.


On Thursday, PoPs ramp back up in the mid/late morning as the
actual cold front pushes into the region, gradually moving south
through the day Thursday, before eventually stalling near the
NC/VA border Thursday night. Highest shower/storm chances will
be focused across the southern half of the area on Thursday.
Locally heavy rainfall will be possible, with a Day 2 Slight
Risk ERO for far southern Virginia and northeast North Carolina.
where much of the guidance is forecasting in excess of 2" of
QPF. Also, the 00Z/17 HREF probability matched means have a 50%
chc for 3"/3hr centered over NE NC Thu aftn with 30% probs up
into SE VA. There is a Marginal ERO for the remainder of the
forecast area, but expect showers to diminish in coverage and
intensity over the north by late aftn. Widespread clouds and
rain on Thursday will keep temperatures mainly in the 80s,
though a few spots could reach 90F if the morning remains mostly
dry with some partial sunshine.

The front pushes just south of the local area Thursday night
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). 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).

&&

.LONG TERM /SATURDAY THROUGH TUESDAY/...
As of 400 AM EDT Wednesday...

Key Messages:

- Daily rain chances persist as the front lifts back north and
stalls over the southeastern portion of the area.

- Temperatures look to stay near normal.

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. A positively tilted
trough will start to dip down into the mid Mississippi Valley
on Sunday allowing our flow to become more southwesterly. 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. Variable cloudy
and a bit warmer with highs in the mid 80s to around 90F.
Remaining a bit unsettled into early next week, with the
southern and western portions of the area having the best
chance for rain/storms. After a brief, partial break from the
humidity (especially up north), 70+ degree dewpoints will
stream back into the area for this forecast period making it
feel humid once again. The somewhat good news is that
temperatures aren`t expected to be nearly as hot during the
extended period as they have been, with high temperatures
Mon-Tue forecast to top out in the mid to upper 80s to near
90F, which is right around or even slightly below normal for
this time of year.

&&

.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
As of 200 PM EDT Wednesday...

Scattered showers and thunderstorms develop later this
afternoon through this evening, bringing localized sub-VFR
conditions. The best thunderstorm chances are initially focused
near ts Albemarle Sound, with VCTS at ECG. Otherwise, scattered
showers and storms will mainly be W of the terminals until late
in the afternoon, have mention of VCTS starting in the 22-00Z
timeframe, with prevailing SHRA at all but ECG starting ~00Z and
thereafter into tonight. Overall, SHRA/TSRA diminish overnight.
Gusty winds, frequent lightning, and heavy rain will be
possible with any storms, with IFR- LIFR flight restrictions in
VSBY. Gusty winds in excess of 40kt will be possible in the
storms as well, especially at RIC/SBY. Showers and storms taper
off from W to E later tonight as forcing weakens. The cold front
lags back to the NW into Thu morning, then pushes S through the
FA on Thu with scattered to numerous showers and storms
redeveloping. Periodic flight restrictions (mainly VSBYs) are
expected due to locally heavy rain along with gusty winds.

Outlook: The front will push farther S Thu night into Friday as
drier air pushes in from the NW. The boundary lifts back N
Saturday. The chance for showers/tstms is less Friday (except
over far SE VA/NE NC) and then increases again Saturday. Sunday
will see scattered, mainly aftn/evening showers/storms.

&&

.MARINE...
As of 315 AM EDT Wednesday...

Key Messages:

- Small Craft Advisories are in effect for the Chesapeake Bay and
  lower James River this morning.

- Winds and seas increase again this evening with SCA conditions likely
  in the Chesapeake Bay as well as the Atlantic waters north of
  Cape Charles Light.

Bermuda high pressure remains dominant offshore with a lee
trough over inland areas. The gradient between these features
has tightened enough to justify marginal SCA headlines in the
Ches Bay as well as the lower James River this morning with SW
winds 15-20 kt and a few gusts to 25 kt. Winds are expected to
fall back to 10-15 kt by mid morning. The surface trough will
sharpen this afternoon with the potential for increased coverage
of showers and storms into this evening. Will hold off on
additional headlines for the bay/James for now but a period of
SW 15-20 kt winds is likely late this afternoon into the
overnight hours. Confidence in seeing 4-6 ft seas in the
northern coastal waters has increased enough to hoist SCA
headlines from this afternoon into early Thursday. Elevated seas
should be rather short-lived with seas averaging 2-4 ft from
late Thursday morning through early next week. Guidance
continues to slow the frontal passage across the region Thursday
with additional showers and storms likely south of the boundary
Thursday afternoon. Still think the front will move south of
the waters on Friday with N or NE winds 5-10 kt behind the
boundary. Sub-SCA winds/waves/seas look to persist well into
next week.

A moderate rip current risk is forecast today and tomorrow for the
northern beaches (including Ocean City). Low rip risk today and
Thursday for VA Beach into the northern NC OBX.

&&

.CLIMATE...
A record high min temperature was tied yesterday/Tue 7/16 at
SBY. Records are listed below for today/Wed 7/17. Record highs
are unlikely and although record high mins may be challenged,
showers and storms late in the day/tonight may lead to calendar
date mins lower than what is observed this morning.

- Record Highs:

- Site:  Wed 7/17

- RIC:   100 (1980)
- ORF:   100 (1887)
- SBY:    99 (2012)
- ECG:    99 (1942)

- Record High Mins:

- Site:   Wed 7/17

- RIC:    76 (2005)
- ORF:    80 (2021)
- SBY:    80 (1983)
- ECG:    80 (2019)

- Highest 1-hr Heat Index Value on record (P.O.R. 1948-2024):

- RIC:   117 (7/17/1980)
- ORF:   118 (8/18/2017)
- SBY:   122 (7/15/1995)
- ECG:   119 (7/5/1999)

&&

.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...Heat Advisory until 8 PM EDT this evening for MDZ021>024.
NC...Heat Advisory until 8 PM EDT this evening for NCZ012>017-
     030>032-102.
VA...Heat Advisory until 8 PM EDT this evening for VAZ048-060>062-
     064>069-075>090-092-093-095>100-509>525.
MARINE...Small Craft Advisory until 10 PM EDT this evening for
     ANZ630>632-634.
     Small Craft Advisory until 7 AM EDT Thursday for ANZ650-652.
     Small Craft Advisory until 4 AM EDT Thursday for ANZ654.

&&

$$

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