Portsmouth, Virginia 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

533
FXUS61 KAKQ 021910
AFDAKQ

AREA FORECAST DISCUSSION
National Weather Service Wakefield VA
310 PM EDT Wed Apr 2 2025

.SYNOPSIS...
Very warm temperatures are expected from Thursday through
Sunday as a large ridge builds across the East Coast. Shower and
storm chances increase on Friday as a backdoor cold front moves
into the area and stalls. A higher chance for showers and
storms arrives late Sunday into Monday as a cold front slowly
crosses the area. Much cooler temperatures are expected early
next week with the potential for below freezing temperatures
Tuesday night.

&&

.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
As of 200 PM EDT Wednesday...

Key Message:

- Partly to mostly cloudy and seasonable today.

Strong low pressure is tracking through the Midwest this afternoon,
with high pressure shifting offshore of the New England coast. A
deep upper trough resides over the western CONUS with upper ridging
building over the srn Mid-Atlantic and Southeast. A warm front
continues to approach the FA from the south and temps are generally
in the 60s across central, south, and southeast portions of the
FA...but are struggling to get out of the 50s in the Piedmont and
eastern shore thanks to lower cloud cover and an onshore component
to the flow. The strong low moves into the Great Lakes tonight,
lifting the warm front N across the FA. Therefore, expect lows
tonight in the upper 40s NE to lower 60s SW early this evening with
warming temps overnight. Winds become S and breezy late tonight
behind the warm front as well with temps warming to the mid-upper
60s by sunrise Thu.

&&

.SHORT TERM /6 AM THURSDAY MORNING THROUGH SATURDAY/...
As of 200 PM EDT Wednesday...

Key Messages:

- Well above normal temperatures are expected Thursday through Saturday
  outside of locally cooler temperatures on the eastern shore.

- Shower/storm chances increase by Friday.

Low pressure moves from the Great Lakes into SE Canada Thu with a
cold front approaching the Appalachians. Meanwhile, upper ridging
continues to build over the eastern CONUS through the end of the
week, leading to gradual height rises. With the sfc low in SE Canada
and high pressure shifting to near Bermuda by Thu, the flow will
become SW and increase. This will allow for very warm and likely dry
wx for much of the period. In fact, lower to mid 80s are expected
across most of the area on Thu. In addition, it will feel humid as
well as dew points rise into the mid-upper 60s by Thu aftn. While
there will be instability in place Thu aftn/evening, the rising
upper heights and warming mid-level temps very likely create enough
of a cap to inhibit convective initiation (with a better chc of
tstms to our north/northwest). However, if an isolated tstm manages
to develop across the Piedmont on Thu, it could become strong to
severe (but feel the chance of this is very low). SPC has a Marginal
Risk for severe wx across northern portions of the area on Thu to
account for the highly conditional threat. Otherwise, Thu will be
breezy with SSW winds gusting to 25-30 mph.

A few showers will continue to be possible Thu night as a backdoor
cold front slowly drops S across the N portions of the FA. The
backdoor front continues to slowly drift SW through the day Fri
before stalling. The temperature forecast will be highly dependent
on where that backdoor front ends up. South of the front, temps
likely soar well into the 80s, but it will struggle to get out of
the 60s north of the front. A weak shortwave may round the ridge Fri
providing enough lift for scattered showers/storms along the front.
However, confidence is only low-moderate as mid-level temps will be
warm so we`ll likely have a capping inversion to contend with.
As such, will only have 20-40% PoPs mainly Fri afternoon into Fri
evening with any showers/storms tapering off Fri night. Cannot rule
out a few strong storms given dew points in the mid (possibly upper)
60s. Dry and very warm/humid for most areas on Sat as the backdoor
front retreats to the north (but may struggle to cross the eastern
shore). Highs will be well into the 80s for most with 60s/70s on the
eastern shore.

&&

.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
As of 200 PM EDT Wednesday...

Key Messages:

- Well above normal temperatures are expected on Sunday.

- Scattered to numerous showers and storms are possible Sunday
  afternoon through Monday.

- Cooler conditions arrive early next week with below freezing
  temperatures possible Tuesday night.

The large ridge finally breaks down during the second half of the
weekend as the stalled front to our north approaches and crosses the
area. Breezy SW winds develop Sun with winds increasing to 15-20 mph
with gusts up to 30 mph. This will help temps to rise even more with
widespread upper 80s possible as the front nears. Shower/tstm
chances increase Sunday afternoon/evening with the highest precip
chances expected Sunday night and Monday as the front slowly crosses
the area from NNW-SSE. Thunder chances become confined to far SE
portions of the area by Monday aftn with post-frontal stratiform
rain possible farther NW. Rain chances end from NW-SE Mon-Mon night
as much cooler/drier air filters into the area behind the front.
Cool/dry wx is expected on Tue/Wed with highs struggling to get out
of the 50s. The coldest night looks to be Tue night where widespread
lows in the low-mid 30s are in the forecast...with below freezing
temps possible in spots.

&&

.AVIATION /19Z WEDNESDAY THROUGH MONDAY/...
As of 115 PM EDT Wednesday...

VFR conditions prevail at the terminals early this afternoon,
but cloud bases have lowered to 4000-8000 ft at RIC. CIGs
continue to lower this evening into tonight as a warm front
approaches and crosses the area. IFR CIGs are likely overnight
at RIC, with low-end MVFR near the coast. No fog is expected as
winds will remain at least 10-12 kt. Conditions improve to MVFR
then VFR on Thu as the warm front moves N of the area. ESE
winds of 10-15 kt with gusts of ~20 kt become SE tonight and
veer to the SW on Thursday after the warm front moves N of the
terminals.

Outlook: CIGs improve to VFR/MVFR by Thursday afternoon.
Mainly dry Thu/Thu night outside of an isolated shower/tstm
INVOF SBY. A backdoor front crosses part of the area on Friday,
leading to a 20-40% chc of showers/tstms during the aftn/evening
(highest at RIC/SBY). Dry/VFR on Sat as the front moves back
north of the area.

&&

.MARINE...
As of 310 PM EDT Wednesday...

Key Messages:

- SCA conditions develop over the Chesapeake Bay and rivers of
eastern  Virginia due to an increasing E to SE wind this afternoon
and evening.

- SCA conditions develop over the coastal Atlantic N of Parramore
Island later tonight into Thursday due to an increasing southerly
wind and building seas.

- Another period of SCA conditions are possible later this  weekend
and early next week ahead of, and behind a strong cold front.

Afternoon weather analysis shows a 1034mb High pressure just off the
coast of coast of New England and a sub 990 Low pressure across
central Iowa. Over the past couple of hours the pressure gradient
from these two systems have tightened and winds speeds have begun to
increase across the local waters. Winds this afternoon are between
10 to 15 kt with gusts upwards of 20 kt. Seas are between 2 to 3 ft
in the bay and 3 to 4 ft in the ocean. Winds this evening are
progged to shift form E-SE this afternoon to SE by this evening with
sustained winds at or just above 15 kt and gusts at or just slightly
above 20 kt. Seas are not expected to rise much and stay close to 3
to 4 ft across the bay and ocean. However, latest guidance has shown
5 ft seas building across the two northern ocean zones this evening
and lasting through Thursday evening. With these ingredients lining
up Small Craft Advisories have been issued for the Rivers, bay, and
two ocean zones. The rivers are expected to drop off later tonight
as winds decrease, however, the bay will last through the early
morning hours of Thursday. The two ocean zones do not come into
affect until later this evening when the seas start to increase.
These two zones last till 0z Friday. However, they could potentially
need to be extended due to seas remaining elevated.

By Thursday, High pressure settles off the Southeast coast. The wind
is expected to be SW 10-15kt with gusts to 20kt Thursday night, and
15-20kt with gusts to 25kt N of Parramore Is., where again SCAs will
likely need to be extended as seas remain 4-6ft. A back door cold
front is progged to move along the coast Friday. The S- SW winds
will diminish ahead of the front, and will shift to E to ENE 8-12kt
behind the front. Seas will primarily be 2-3ft S to 3-4ft N Friday,
and 2-3ft by Friday night, with 1-2ft waves in the bay. The backdoor
front lifts back N as a warm front Saturday, with a SW wind
increasing to 15-20kt with gusts to 25kt later Saturday night into
Sunday as the pressure gradient tightens between high pressure off
the Southeast coast and a cold front approaching from the W. Seas
build to 4-5ft S to 5-7ft N. The initial cold front crosses the
region Monday, with a secondary cold front following Monday night
into Tuesday. CAA with this front has the potential to bring
additional SCA conditions in a N to NW wind.

&&

.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...None.
NC...None.
VA...None.
MARINE...Small Craft Advisory until 4 AM EDT Thursday for ANZ630-631.
     Small Craft Advisory until 1 AM EDT Thursday for ANZ632-634.
     Small Craft Advisory until 10 PM EDT this evening for
     ANZ635>638.
     Small Craft Advisory from 1 AM to 9 PM EDT Thursday for ANZ650-
     652.

&&

$$

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