Portsmouth, Virginia 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

445
FXUS61 KAKQ 160550
AFDAKQ

AREA FORECAST DISCUSSION
National Weather Service Wakefield VA
150 AM EDT Fri May 16 2025

.SYNOPSIS...
Widely scattered strong to severe thunderstorms are possible
today. Conditions turn warm, with summerlike heat and humidity
Friday and Saturday, and mainly afternoon and evening showers
and storms possible ahead of a cold front.

&&

.NEAR TERM /UNTIL 6 AM THIS MORNING/...
As of 910 PM EDT Thursday...

Key Messages:

- The Severe Thunderstorm Watch has been canceled.

- Mild tonight with lows in the mid to upper 60s.

Thunderstorms have either dissipated or moved out of the area
this evening with CIN increasing which should prevent further
storm development. As such, the Severe Thunderstorm Watch has
been canceled. Mostly dry conditions are expected overnight with
patchy fog possible late tonight into early Fri morning. Mild
and partly to mostly cloudy skies are expected tonight with lows
in the mid- upper 60s to around 70F SE.

&&

.SHORT TERM /6 AM THIS MORNING THROUGH SATURDAY NIGHT/...
As of 400 PM EDT Thursday...

Key Messages:

- Isolated to scattered showers and storms possible Friday and
Saturday afternoons/evenings, some of which could be strong to
severe.

- Temperatures trend warmer, with a summer-like feel on Friday.

Upper air ridging will continue to influence the region, while an
upper level low strengthens over the northern Midwest. The ridging
and sub-sequential SW flow will bring warm temperatures to the area.
Highs are looking to warm up to the upper 80s to lower 90s with
dewpoints in the upper 60s to lower 70s. With the high humidity, the
day will feel hot and muggy in the lower to mid 90s during peak
daytime heating hours.

The big question for Friday will be if storms develop. The forcing
mechanisms do not look to be strong, with ridging aloft and fairly
constant pressure heights. With the highs in the upper 80s to lower
90s and the trough heights near 5800 mb, the capping may be more
easily broken with the weaker trough. Any lifting would have to come
from some boundary, potentially as excess energy from the MCS to the
northwest. The CAMs model (excluding the NAM) show initiation and a
large convective complex Friday evening into overnight. There is
uncertainty based on the recent CAMs, which show that storms may
develop earlier. Models tend to struggle with events like this, so
they are taken with caution. The coverage amount and timing remains
in low confidence as model show very little agreement. If these
storms can develop, they would enter a volatile environment for
strong to severe storms. The moisture and warm temperatures will
help the atmosphere become very favorable for high levels of
instability. Recent CAMS models show values 2500+ J/kg of SBCAPE.
Efficient shear to support thunderstorm growth is likely with models
showing values of effective shear of 40-50 kt. Lapse rates from 7.0-
7.5 C/km and strong DCAPE could be favorable for strong winds and
severe hail. With this environment, Friday is an all-hazards type of
threat. In fact, SPC has upgraded the entire CWA today for this
event, now with most all of VA and MD under a slight risk (level
2/5) and NC under a marginal risk (level 1/5). SPC has the wind
threat as the highest risk at 15% for VA and MD as well as a 2%
tornado risk and 5% within the slight risk.

As for Saturday, a cold front will move through the region in the
afternoon, but after the daytime highs is reached in the upper 80s.
The environment will be similar to today`s, favorable with ample
instability and shear, but yet again the forcing mechanism will be
the limiting factor as the front is forecast to weaken before
reaching the area. With the warm temperatures like Friday,
instability values of 1500-2000 J/kg SBCAPE are expected. Supportive
shear values for storm development are forecast as well.
Additionally, SPC has the majority of the area in a slight risk
(level 2/5) except for the far NW counties of the CWA. There is
still lower confidence in timing and coverage, but isolated to
scattered showers and storms are possible, with a few potentially
becoming severe.

&&

.LONG TERM /SUNDAY THROUGH THURSDAY/...
As of 400 PM EDT Thursday...

Key Messages:

- Drying out Sunday into the early half of next week as high
pressure returns.

- Unsettled weather could return Wednesday and Thursday.

Behind Saturday`s cold front, high pressure will move back into the
region from the north. An upper air trough will take over the
majority of the CONUS. The next surface low pressure system will
begin to develop out in the Central Plains. With the high pressure,
dry conditions will be favorable for the first half of next week.
Temperatures will return to seasonable with the trough. An upper
level low is favored to develop in the Midwest Wednesday and
Thursday, which will lead to an unsettled weather pattern. Afternoon
showers and storms chance will increase in the middle of the week.

&&

.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
As of 145 AM EDT Friday...

CIGs are VFR at the terminals to start off the forecast period.
A marine layer may attempt to push inland early this morning
(mainly after ~08z) with MVFR/IFR CIGs possible at SBY. Patchy
fog is also possible at SBY and RIC. MVFR or IFR VIS will be
possible in any fog. MVFR CIGs may linger at SBY until 14-15z.
Additional showers and thunderstorms develop later today, with
potentially two rounds impacting the TAF sites, the first round
being this afternoon and the second round tonight. Highest
confidence for showers/storms this afternoon is at RIC and PHF,
where a PROB30 has been introduced from 18 to 21z. While there
is a decent amount of uncertainty with respect to timing, some
of the storms could be severe with gusts up to 50 kt (or
higher).

Outlook: Additional showers/storms will remain possible into
early Saturday morning. Another round of sub-VFR CIGs and patchy
fog is also possible at SBY early Saturday morning. Predominate
VFR conditions return over the weekend.

&&

.MARINE...
As of 300 PM EDT Thursday...

Key Messages:

- Generally sub-SCA conditions into the weekend, but with
  elevated SW flow ahead of a cold front Saturday, and elevated
  NW flow behind the front Sunday-Monday.

- Locally strong to severe storms possible into tonight and
  again late Friday/Friday night.

A weak pressure gradient across the area this aftn has led to
light and variable winds, slowly shifting from SW to more of an
E-SE direction across the lower Bay, and to the S elsewhere.
Seas are still a bit elevated with SE swell, at 3-4 ft, with
waves in the Bay/rivers/sound 1 foot or less, except near 2 ft
at the mouth of the bay. Scattered storms, potentially strong to
severe, are possible this evening/tonight, especially for the
Bay/rivers and will be handled via MWS/SMWs as needed.

Otherwise, winds increase a bit on friday, becoming S-SW
~10-15 kt, with yet another round of scattered showers and
storms possible, but mainly holding off until very late in the
aftn or early evening into Friday night. There may be brief
period of elevated, near sub-SCA SW winds Saturday afternoon
and evening, especially across the lower James/lower Bay. Winds
veer around to the W/NW Sunday and Sunday night in the wake of
a passing cold front. Next chance for SCA level winds comes with
a secondary surge of cooler, drier air Sunday night into
Monday, though this remains uncertain at this range.

&&

.HYDROLOGY...
As of 300 PM EDT Thursday...

Flood Warnings continue along the James River, at Richmond-
Westham, and Richmond Locks have crested, but will remain in
minor flood stage through Friday night. See water.noaa.gov for
more site- specific information.

&&

.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...None.
NC...None.
VA...None.
MARINE...None.

&&

$$

SYNOPSIS...MAM/SW
NEAR TERM...RMM
SHORT TERM...KMC/SW
LONG TERM...KMC/SW
AVIATION...AJB/RMM
MARINE...LKB
HYDROLOGY...