Area Forecast Discussion Issued by NWS Wakefield, VA
000
FXUS61 KAKQ 061148
AFDAKQ
AREA FORECAST DISCUSSION
National Weather Service Wakefield VA
648 AM EST Wed Dec 6 2023
.SYNOPSIS...
A strong upper trough will swing across the area through this
afternoon. High pressure builds in tonight through Thursday,
before pushing offshore on Friday. A strong frontal system
likely impacts the region on Sunday, bringing milder weather and
a better chance for widespread rain Sunday and Sunday night.
&&
.NEAR TERM /THROUGH TONIGHT/...
As of 645 AM EST Wednesday
Recent satellite imagery showing the upper trough axis about to
swing through the local area over the next few hours. KAKQ
radar showing majority of scattered shower activity over Hampton
Roads as of this writing. The past few runs of HRRR continue to
show additional scattered shower activity filling back in as
the trough axis pushes toward the coast by midday, and will
therefore carry 20-40% PoP mainly centered from Louisa to
Norfolk through late morning, tapering off by late morning. Did
note a few reports of wet snow or graupel just to our northwest
north of our area in the Charlottesville vicinity via MPing,
but will likely not have enough steady pcpn locally for much if
any reports of mixed precipitation, even over the US-15
corridor out in our far NW counties. Therefore removed snow
shower wording from the grids in Louisa/Fluvanna counties.
Otherwise, no major changes needed attm.
As of 325 AM EST Wednesday...
Latest analysis and early morning WV satellite continues to
show a potent mid-level shortwave diving southeast across the
region early this morning. Surface low pressure continues to
deepen well offshore of the Carolina coastal plain, as cool
1031+mb high pressure builds east from the Missouri Valley into
the Mid- south early this morning.
Forecast is largely playing out as expected this morning.
Initial batch of light showers is pushing through the area, and
is weakening with downsloping winds serving to scour out
precipitation as it pushes toward the coast. Continued 20-40%
PoP this morning for isolated to widely scattered showers
through sunrise, but as that PoP would imply, quite a few will
miss out on showers altogether.
As the upper trough axis crosses through late this morning, do
expect another round of showers to push in later this morning
through midday. There remains a small chance for a few
snowflakes or graupel to briefly mix in across the piedmont
during this period. Maintained SNSH wording along the US-15
corridor ~12-13z this morning. Otherwise, cool and cloudy
conditions for much of the day. Becoming increasingly breezy
this afternoon, as pressure gradient tightens with approaching
high pressure with the deepening low offshore. Subsidence
behind the passing trough will allow for clearing from NW to SE
from mid to late afternoon into early evening at the coast. The
clouds in combination with the gusty NW winds will make for a
chilly day with highs only rising into the mid to upper 40s.
W-NW winds will average 10-15 mph inland, 15-20 mph along the
coast, with gusts between 20-30 mph from I-95 on east are also
forecast, peaking during the mid to late aftn and slowly
diminishing this early evening. Total QPF generally once again
averaging less than 0.10".
High pressure continues to build into the region tonight. This
will bring a gradually clearing sky, with winds slowly relaxing
inland (remaining breezy along the coast). Markedly cooler
tonight, especially inland with lows in the low to mid 20s, with
upper 20s to mid 30s along the immediate coast.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY/...
As of 320 AM EST Wednesday...
Remaining dry and cool relative to climo on Thursday with high
pressure centered south of the local area. A shortwave will pass
north of the region, leading to a bit of increased cloudiness
across the northern half of the forecast area. Otherwise, it`ll
be mostly sunny for most with highs in the upper 40s to around
50. Not quite as cold Thursday night with light SW flow across
the region, lows will range from the upper 20s NW to the mid to
upper 30s SE. High pressure slides offshore Friday morning,
lingering offshore through the day on Friday. Temperatures begin
to warm on Friday with highs generally in the upper 50s to
around 60.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
As of 320 AM EST Wednesday...
The weekend will begin with little fanfare weatherwise.
Surface high slides moves well out to sea Friday night through
the weekend, with increasingly southerly flow allowing dry and
milder weather to prevail Friday night and Saturday. Meanwhile,
low pressure will begin to take shape over the central and
southern high plains Friday night. That system is forecast to
lift E-NE along a strong cold front Friday night into Saturday
from the Gulf Coast up through the Ohio Valley.
00z/6 Models remain in good agreement regarding rainfall moving
through the area, but are still split to a degree on timing.
The latest GFS is now seemingly a bit of a fast outlier to the
remainder of guidance, with the CMC/ECMWF and even the GFS`
parent GEFS ensemble a forecast period or so slower. Given that
the system takes on a negative tilt as it ejects northeast
across the Ohio and Tennessee valleys, have steered the forecast
a bit toward the slower solution, holding the rain over the
area through Sunday evening. The triple point low will lift into
the eastern Great Lakes Sat night into Sun morning, with the
pre- frontal warm front lifting through the area Sat evening.
Shallow WAA/isentropic lift will allow clouds to start to
increase across our area during this period, with the widespread
precipitation from the W-SW still appearing likely to
overspread our area on Sunday. Temperature-wise, temperatures
quickly moderate with return flow regime setting in across the
region. Highs saturday in the upper 50s eastern shore to mid 60s
inland. Sunday also looks quite mild with highs well above
normal once again into the mid 60s to around 70 degrees.
This system looks to bring some beneficial rainfall to the
region, with both the latest ensemble mean of the 00z GEFS
showing in excess of 0.50" of rainfall areawide and the EPS
showing ~0.50-1.00". Will also need to keep an eye on potential
for gusty winds and even a thunderstorm threat Sunday afternoon
into Sunday night with such a dynamic system and very strong
winds just off the surface. We will fine tune these details over
the coming days. Behind the system, look for much cooler and
drier air to filter into the region Monday into the middle of
next week. Dry weather early next week as high pressure builds
over the region in the wake of the front, with highs in the 50s
and lows in the 30s.
&&
.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
As of 645 AM EST Wednesday...
Low-end VFR/MVFR CIGs just pushing into our NW and expect these
should gradually expand SSE into central VA through the next few
hours, reaching the coast by mid-morning. These Sub-VFR CIGs
are ahead of a potent upper trough which will cross the area
through this morning. Winds are light out of the N-NNE inland
(NNE along the coast), with winds to become NW all terminals by
midday. MVFR CIGs are likely at all terminals (outside of SBY)
after 12-14z and lingering into early afternoon along the coast.
Some localized IFR CIGs are possible across central and SE VA,
with best chances at RIC between 13-15z, though there is a lower
chance of short-lived IFR at PHF-ORF between 14-16z. Continued
to hold CIGs aoa 1000 ft in the TAF at this point for all
terminals except RIC with guidance trending toward keeping CIGs
predominately in MVFR range. Additionally, scattered showers
will be pushing through the area this morning, clearing out by
early afternoon. Gradual clearing and gusty winds (gusts to
20-25 kt) ensues behind the clipper system from late morning
into this afternoon from NW to SE.
Outlook: Once VFR/dry conditions return later today, they look
to prevail through the remainder of the work week. A strong cold
front approaches from the west from Saturday night into Sunday,
bringing our next chances for sub-VFR conditions and gusty
winds, along with additional periods of rainfall.
&&
.MARINE...
As of 320 PM EST Tuesday...
Winds will shift from NE to N and increase this morning as an
area of low pressure continues to deepen well east of the Outer
Banks. At the same time, an area of high pressure, centered over the
central U.S., will build east towards the coast today. The pressure
gradient between the high pressure to the west and low pressure to
the east will result in N winds at 20-25 kt and gusts 30-35 kt this
afternoon and continuing into tonight. A Small Craft Advisory is in
effect today and tonight for all local waters. The increased N winds
will allow for seas to build to 5-7 ft, and waves in the bay 3-5 ft
today and tonight.
Winds are expected to decrease on Thursday and become more NW-WNW at
10-15 k,t then WSW at 15-20 kt by the afternoon as the low pressure
move farther out to sea and the center of high pressure moves over
the Southeast U.S.. Since the center of the high pressure will
remain to our south, winds will be southwesterly 10-20 kt Friday and
Saturday. Seas will be between 3 and 5 ft during this time, and
waves in the bay will be 1-2 ft. A strong storm system is likely to
impact the East Coast on Sunday. Strong S winds are possible ahead
of a cold front with gale conditions possible.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...None.
NC...None.
VA...None.
MARINE...Small Craft Advisory until 7 AM EST Thursday for ANZ630>632-
634.
Small Craft Advisory from 10 AM this morning to 1 AM EST
Thursday for ANZ633-638.
Small Craft Advisory from 10 AM this morning to 10 PM EST this
evening for ANZ635>637.
Small Craft Advisory from 10 AM this morning to 7 AM EST
Thursday for ANZ650-652-654.
Small Craft Advisory from 10 AM this morning to 1 PM EST
Thursday for ANZ656-658.
&&
$$
SYNOPSIS...MAM
NEAR TERM...MAM
SHORT TERM...AJB/MAM
LONG TERM...AJB/MAM
AVIATION...MAM/SW
MARINE...CP