Portsmouth, Virginia 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

082
FXUS61 KAKQ 230601
AFDAKQ

AREA FORECAST DISCUSSION
National Weather Service Wakefield VA
101 AM EST Sat Nov 23 2024

.SYNOPSIS...
An upper level low lingers over the area this afternoon before
moving offshore tonight into Saturday. Weak high pressure
builds over the area late in the weekend, bringing a gradual
warmup for the first half of next week. Unsettled weather
returns around Thanksgiving.

&&

.NEAR TERM /UNTIL 6 AM THIS MORNING/...
As of 1255 AM EST Saturday...

Key Messages...

- A few light showers over the Eastern Shore taper off over the
  next few hours.

- Gusty westerly winds continue through the night and into
  Saturday.

Evening analysis shows a double barrel low off the Mid Atlantic
and New England coast with a few light showers across the MD
Eastern Shore. Expect these showers to move offshore over the
next few hours with clouds diminishing overnight. Temps as of
1250 AM ranged from the low-mid 40s with W winds occasionally
gusting around 20 mph. Lows tonight are not expected to be as
cold with temps in the upper 30s to around 40F for most (warmer
along the coast).

&&

.SHORT TERM /6 AM THIS MORNING THROUGH MONDAY/...
As of 220 PM EST Friday...

Key Messages...

- A ridge builds back in bringing seasonable temperatures and
  dry weather.

As the upper level trough and vertically stacked low leaves the
region Saturday into Sunday, breezy conditions will last
throughout Saturday with persistent northwest flow. Wind gusts
are forecasted to be between 20-30mph. Skies will have mainly
cleared besides some cumulus clouds developing in the afternoon
hours. Temperatures will have warmed up slightly with highs
being in the middle to upper 50s across the CWA. By Saturday
night into Sunday morning winds will begin to diminish as a
ridge and high pressure move into the region. With the winds
diminishing and skies clearing, decent radiational cooling
should occur allowing temperatures to drop into the lower to
middle 30s inland and upper 30s along the coast. Sunday
temperatures will warm back up Sunday with highs in the lower
60s and lows in the upper 30s and lower 40s. Monday will be the
warmest day of next week as southerly flow returns to the area
ushering in warmer air. Highs will be in the middle 60s and lows
in the lower 50s.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
As of 340 PM EST Friday...

Key Messages...

- Mild temperatures continue Tuesday.

- Cooler temperatures arrive Tuesday night into Wednesday behind a
cold front.

- An unsettled pattern develops by late week with rain chances
increasing.

An upper ridge is forecast to push offshore of the Mid-
Atlantic coast Monday night as a trough dives into the Great Lakes
and deepens by Tuesday. A cold front associated with the upper
trough pushes across the Mid-Atlantic region late Monday night into
early Tuesday. The operational 22/12z ECMWF along with the EPS have
more moisture than the deterministic GFS and GEFS. However, each
ensemble suite has limited to no probabilities of QPF >= 0.1".
Therefore, confidence in showers is rather low and the current PoP
forecast for late Monday night/early Tuesday morning reflects the
NBM with 20-30% PoPs N, 15-20% into southern VA, and 15% or less
over NE NC. Mild Monday night into Tuesday, with lows Monday night
in the upper 40s to lower 50s, followed by highs Tuesday in the mid
60s to near 70F with downsloping westerly flow.

The upper trough deepens and shifts E across the Northeast Tuesday
night into Wednesday. Surface high pressure along with a dry/cool
airmass builds into the area Tuesday night into Wednesday. Forecast
lows Tuesday night drop into the lower to mid 30s N to the upper
30s/lower 40s SE, followed by highs in the 50s Wednesday. Another
trough, initially over the Central Plains Wednesday moves E and
deepens over the Eastern CONUS Thanksgiving Day into Thursday night
with developing surface low pressure. Again, the EPS has more
moisture than the GEFS, but even the GEFS has 30-50% probs for >=
0.5" rain Thursday into Friday, with the EPS slightly higher and
with a broader more northward footprint of >= 0.5" rainfall probs.
Confidence in timing, track, and intensity remain low, but there
increasing confidence for rain later Thanksgiving Day into Thursday
night/early Friday. Highs Thanksgiving Day will likely reflect a CAD
set-up with upper 40s NW to lower 60s SE. Lows Wednesday night and
Thursday night are mainly in the upper 30s NW to mid/upper 40s SE.
There is a potential for a much cooler/colder airmass to arrive late
next week in the wake of the late week system.

&&

.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
As of 100 AM EST Saturday...

MVFR CIGs remain possible near SBY until around 8-9z with a few
light showers possible mainly E of the terminal. Any rain moves
offshore by 9z with clouds continuing to diminish. Otherwise,
VFR conditions are expected to prevail through the 6z taf period
with SCT mid level clouds expected by the afternoon. Clouds
clear tonight. W winds remain ~10 kt with gusts up to 20 kt
through mid morning before becoming NW and increasing to ~15 kt
with gusts up to 20-25 kt from mid-late morning through the
afternoon. Winds diminish to ~5 kt inland and 5-10 kt along the
coast tonight as high pressure builds in.

Outlook: Mainly dry conditions continue into mid week, though
there is a low chance of a few showers Monday night into early
Tuesday with a cold front passage.

&&

.MARINE...
As of 230 PM EST Friday...

Key Messages:

- Small Craft Advisories remain in effect for all area waters
  through 4 PM this afternoon.

- Gale Warning are in effect for all area waters from 4 PM into
  Saturday morning.

- Benign marine conditions begin Sunday amd last through early next
  week.

Latest analysis shows a strong upper level trough across the East
Coast. Surface low pressure is centered over the NY/PA border
bringing cooler, drier air to the area and a ramp up of elevated W
winds 15-20 kt with gusts up to 30 kt. The surface low pressure will
shift to be centered off-shore this evening, which combined with
cool air being pushed down across the waters, will increase the wind
speeds to Gale conditions with sustained winds 25-35 kt with gusts
up to 45 kt over the ocean and winds 25-30 kt with gusts up to 35 kt
in the Bay. These winds will reach Gale force this evening and last
through early Saturday morning. Once the pressure gradient relaxes,
the winds will slowly decrease to sub-SCA conditions. It is most
likely that SCA will be needed to replace the Gale Warning until
early morning hours Sunday. After that, high pressure will move into
the area bringing calmer NW winds and seas, so sub-SCA conditions
are expected until the next cold front potentially on Tuesday.

Waves and seas are currently 1-2 ft in the Bay and 2-4 ft in the
coastal waters. They are expected to increase as winds pick up,
resulting to waves 4-6 ft in the Bay and 5-7 ft, occasionally 8 ft,
in the coastal waters overnight while peak winds occur. Seas will
then diminish during the day Saturday through early next week.

&&

.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...None.
NC...None.
VA...None.
MARINE...Gale Warning until 7 AM EST this morning for ANZ630>634-638.
     Small Craft Advisory until 4 PM EST this afternoon for
     ANZ635>637.
     Gale Warning until 10 AM EST this morning for ANZ650-652-654-
     656-658.

&&

$$

SYNOPSIS...HET
NEAR TERM...RMM/SW
SHORT TERM...HET
LONG TERM...AJZ
AVIATION...RMM
MARINE...KMC