Area Forecast Discussion
Issued by NWS Wakefield, VA-- Remove Highlighting --
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FXUS61 KAKQ 121158
Area Forecast Discussion
National Weather Service Wakefield VA
658 AM EST Thu Jan 12 2017
High pressure remains over the western Atlantic today. A
backdoor cold front drops down from the north this afternoon
and evening as high pressure builds over New England. Some
unsettled weather is expected during the upcoming weekend.
.NEAR TERM /THROUGH TONIGHT/...
Latest surface analysis places a frontal boundary stretching
from the eastern Great Lakes region southwestward into the
Southern Plains. High pressure remains over the western
Atlantic. The pressure gradient between these features has
resulted in a south to southwest wind of 5-15 mph early this
morning. The added mixing has limited fog to little more than
patchy, shallow ground fog. However, the obs and satellite
indicate that stratus has begun to develop over the Piedmont,
with some visible across the southeast forecast area as well.
Temperatures begin the day in the low to mid 50`s (actually near
seasonal highs). The NAM holds onto the low level moisture
through mid morning, but with warm temperatures and warm
advection associated with breezy southwest winds, temperatures
will have little trouble warming into the mid 60`s today (15-20F
above seasonal averages). Continued to stay on the cool-side of
guidance given the ground will be cool and moist, even with
most of the snow gone. Mostly cloudy this morning becomes partly
sunny this afternoon.
The cold front slowly approaches the region from the north
tonight as the strong Canadian upper low tracks across the Great
Lakes. Mild again tonight thanks to ongoing southwest
winds/mixing and increasing clouds across the north. Lows
generally in the upper 40`s to around 50. Mixing will again
limit fog development, with patchy shallow ground fog at best.
.SHORT TERM /FRIDAY THROUGH SATURDAY/...
Strong surface high pressure (1045+mb) builds across the Great
Lakes Friday in wake of the potent upper low lifting over the
Canadian Maritimes. An associated cold front drops into the
region, pushing into the northern portions of the area by mid to
late morning. The front progged to push through the region
through late Friday as the upper high weakens over the
Southeast. The wind becomes northerly behind the front, along
with falling temperatures. With a slightly quicker front
compared to 24 hours ago, have trended temperatures down
slightly with highs forecast now in the low to mid 50`s north to
low 60`s south. Highs will be reached early afternoon, with
temperatures falling into the 40`s through late Friday. Have
also increased cloud cover to cloudy Friday as BUFR soundings
and model guidance indicate high relative humidity in the low
levels. Based on the lack of forcing and westerly flow aloft,
have kept POPs silent late Friday. High pressure continues to
build into the region from the north-northeast Friday night.
Temperatures steadily fall overnight with lows eventually
ranging from the low 30`s north to the mid to upper 30`s south.
12/00Z guidance continues to indicate some light overrunning
precipitation, with GFS/NAM 295K surfaces spreading the
overrunning moisture across the northwest half of the local area
toward the Maryland Eastern Shore. Enough low level cold air
arrives late (mainly below 900mb) to bring a chance of
rain/freezing rain/sleet across the northern forecast area.
850Mb temps expected to stay between +3 to +5C. Best chances for
light freezing rain expected from Caroline County eastward to
the Northern Neck to the Maryland Eastern Shore, where
temperatures are forecast to be the coldest. Farther south
toward Richmond and the Middle Peninsula, sleet may mix with the
cold rain at times.
High pressure slides off the Northeast coast Saturday as the
frontal boundary stalls over the Southeast. The result will be
ongoing northeast flow and wedge conditions. Overrunning/warm
air advection continues, with ongoing light rain/drizzle
Saturday morning through the afternoon, especially across the
north and northeast. Temperatures and low level thicknesses warm
through the afternoon, with the p-type becoming all rain across
the forecast area. Overall, forcing and moisture will be
limited, resulting in only light QPF amounts. A shortwave
tracking across the Northeast Saturday may enhance the light
rain briefly, but QPF amount expected to be at or below 15
hundredths of an inch through Saturday. Cloudy again Saturday
with highs in the upper 30`s north to mid 40`s south.
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
High pressure slides across New England early next week with a
weakening frontal boundary meandering across the sern US.
Several weak impulses of energy progged to move east across the
region resulting in periodic chcs for pcpn Sunday and Sunday
night. Thermal profiles suggest some mixed pcpn (rain/sleet)
across the lwr MD eastern shore late Saturday night/early Sunday
morning. Otw, cloudy with light rain/drizzle. Lows Saturday
night in the 30s. Highs Sunday in the 40s except lwr 50s srn
most zones. Lows Sunday night in the 30s.
A warm front lifts north across the area Monday as low pressure
tracks NE into the upr Gt Lakes region. The trailing cold front
not progged across the area until next Thursday. Despite the fa
being in the "warm sector" data suggests plenty of moisture at
different levels to keep the skies rather cldy with periodic
chcs for pcpn. Went ahead and changed pcpn type to more of a
convective one Tuesday and Wednesday. Highs Monday mid 40s-lwr
50s. Lows Monday night mid 30s to lwr 40s. Highs Tuesday ranging
from 50-55 eastern shore to the lwr 60s west of the bay. Lows
Tuesday night in the 40s. Highs Wednesday from the lwr-mid 50s
Eastern shore to lwr-mid 60s west of the Bay.
.AVIATION /12Z THURSDAY THROUGH MONDAY/...
South to southwest winds of 5 to 15 knots this morning and mid
to high level clouds have limited fog development early this
morning. Stratus has developed over the Piedmont into central
Virginia, but with no impact on the TAF sites early this
morning. Cannot rule out a brief few to scattered low clouds
into Richmond. Low level wind shear still an issue early this
morning, until winds at the surface increase.
A warm front lifts north of the region today, with more breezy
southwest flow. Expected gusts to 25 to 30 knots. Stratus will
be slow to burn off this morning over the Piedmont, but expect
VFR conditions beyond mid morning today. Scattered to broken mid
level clouds expected this afternoon.
A backdoor cold front drops back into the area late tonight into Friday,
shifting winds back to the N/NE as strong high pressure builds
north of the region. This has the potential to bring another
round of degraded flight conditions late tonight through Sat,
with some mixed precipitation possible by Sat morning over the N
and mainly rain elsewhere. Continued flight restrictions
possible into Sunday as a frontal boundary lingers across
southern Va or NC.
SCA headlines remain in place for the Ches Bay and northern
coastal waters into/through this eve as SW gradient tightens.
Gusts to between 25-30 kts over the coastal waters are possible
with minimal SCAs in the Bay. Will also have (patchy) morning
fog across the waters before the winds increase. Will carry
Backdoor cold front moves N-S across the waters Fri turning the
winds back into a NNE direction. Models continue to indicate a
meager gradient over the waters...but with a 1045+mb surface
high tracking across the Great Lakes...(low end) SCA (wind)
conditions are possible. Seas also build to 4-6 ft into Fri
night. Sfc hi pres slides into New England Sat...ridging
S over the FA waters. Onshore flow persists.
Latest storm surge guidance indicates a (prolonged) period of
below normal tides into Sat. Tidal locations along the Atlantic
coast...lower Ches Bay/James River can expect departures of
-1.0 to -1.3 MLLW. A Low Water Advisory will continue through
21Z/12...and probably will need to be extended further.
-- Changed Discussion --Well above normal temperatures are expected today across the
region. Some record maximum temperatures may be challenged, just
a few days after setting several record lows.
Records Max Temps for today, Jan 12:
Richmond: 71 (2005)
Norfolk: 75 (1890)
Salisbury, MD: 64 (1932)
Elizabeth City, NC: 70 (2005, 1963)
Wallops Island: 65 (1980)
-- End Changed Discussion --
MARINE...Low Water Advisory until 4 PM EST this afternoon for ANZ632-
Small Craft Advisory until 6 PM EST this evening for
Small Craft Advisory until 5 AM EST Friday for ANZ650-652.