Area Forecast Discussion
Issued by NWS Wakefield, VA
FXUS61 KAKQ 192104
Area Forecast Discussion
National Weather Service Wakefield VA
404 PM EST Sun Feb 19 2017
A backdoor cold front pushes south across the Eastern Shore
tonight as high pressure builds well north of the region through
Monday. High pressure slides offshore Tuesday ahead of a
weakening front, which crosses the area Tuesday night. High
pressure returns Wednesday.
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
Current wv imagery shows an upper trough pushing well off the
Carolina coast, with a ridge amplifying through the Mississippi
Valley. Weak high pressure is centered over the Tennessee and
Ohio Valleys, with another area of high pressure N of the Great
Lakes. A cold front is trailing back into the Great Lakes
associated with low pressure over Ern QB. This front will push
through the Ern Shore later tonight. Temperatures remain mild
this afternoon ranging from the upper 60s to low 70s across most
of the area. Temperatures will gradually fall through the 60s
into the 50s this evening, with overnight lows eventually
averaging in the low/mid 40s.
.SHORT TERM /6 AM MONDAY MORNING THROUGH WEDNESDAY/...
Surface high pressure builds across New England swd through the
Mid-Atlantic coast Monday as an amplified ridge builds across
the Ohio Valley and Great Lakes. This will produce onshore flow
in the wake of the backdoor front resulting in cooler
temperatures, primarily along the coast, and still well above
normal (+1.0-1.5 st dev) along and W of I-95. Forecast highs
range through the 50s over the Ern Shore, to the upper 50s/low
60s along the wrn shore of the Bay through coastal SE VA/NE NC
under a sunny sky.
High pressure will remain over the region Monday night with low
temperatures dropping into the low/mid 30s N/NE to the upper
30s/around 40 SW under a mostly clear sky. The high gradually
slides offshore Tuesday as a weakening mid-level cold front
approaches from the W. Mixing will be limited, only to about
950-925mb, with high temperatures ranging from the low/mid 50s
NE to the low 60s SW. Mostly clear/sunny Monday night into early
Tuesday with increasing mid and high clouds from W-E by aftn.
The mid-level cold front (per 700mb theta-e) will slide across
the area From NW-SE. This will result in a period of mostly
cloudy to overcast conditions. Any forcing associated with a
weakening and elongated shortwave trough will be very minimal if
possibly non- existent, so PoPs have been capped to less than
15%. Lows will generally be in the 40s. The airmass behind this
system will be milder, so highs will once again soar well above
normal ranging from the mid/upper 60s for the interior Ern Shore
to the upper 60s/low 70s W of the Bay, locally cooler for the
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
The models are in good agreement in the extended range showing a
flat ridge over the eastern US for the second half of the work
week. That ridge will amplify into Saturday as a trough lifts
out of the central plains into the Great Lake states which will
knock the ridge down by Sunday and return the area to more
westerly zonal flow. Overall, this will lead to another period
of above normal temperature and just a chance for showers as the
cold front crosses the area Friday night into Saturday morning.
On Wed night into Thursday as the high slides off the coast, the
flow will turn sw and should see a good warm up ahead of a weak
front that tries to drop in from the north. The guidance suggest
the possibility of some light showers especially across the
northern part of the cwa Thursday into Thursday night. But with
the area having been dry for the last several weeks will not
mention any chance of rain with this week front as the ridging
aloft may end up keeping the front just north of the area.
Expect above normal temperatures with readings with highs in the
uppers 60s to the mid 70s. The next strong sfc low will lift
from the central plains into the Great Lakes on Friday into
Saturday dragging a cold front across the region on Saturday.
The guidance is a little suspect on how much moisture is
available and with the trough and dynamics lifting NE away from
the area have kept pops at chance with the front and QPF at this
point looks to be pretty low still, less than 0.25". Behind the
front, temperatures will return closer to normal but still above
normal, but just not 20 to 25 above normal as Thursday into
Saturday will be.
.AVIATION /21Z SUNDAY THROUGH FRIDAY/...
VFR conditions across the CWA this afternoon with few clouds
except some mid/high level clouds over the Eastern Shore. Those
clouds should thin and/or move out of the vicinity by late
afternoon and early evening. Winds are mostly light out of the
NW-N less than 10 kt. Mostly SKC expected overnight.
OUTLOOK...High pressure and VFR conditions over the region on
Monday. Scattered showers possible Tue night. Otherwise, dry
weather through Thursday.
Very quiet period of weather on the marine side for the next 5 to 7
days as long periods of high pressure with just one weak front that
tries to push into the area. The period begins with high pressure,
centered over Hudson`s Bay and nosing down the coast. This will set
up a northerly flow. This will push a weak back door front toward
the Mid-Atlantic states, but the bulk of the cold advection is well
to the east of the waters so expect the winds to remain below sca
levels everywhere. The axis of the high slides over the area on
Monday night and lingers there through Wednesday morning when the
next front approaches the area. This will keep winds light out of
the north/northeast. The front looks to weaken as it arrives and
may not even make it into the waters. This will finally help to
kick the winds to the SW, but with the gradient week the winds will
still be in the 5 to 10 kt range. The front will lift back to the
north on Thursday and the sw will persist Thursday and Friday, but
again the winds will remain on the light side of around 10 kt.
The next front will not arrive until next Saturday. Behind the
front will be the next chance for any small craft conditions.
Record highs for today:
* Site 2/19 Forecast highs
* RIC: 78 (1961) 73
* ORF: 73 (1907) 68
* SBY: 72 (1961) 71
* ECG: 77 (1939) 69
Temperatures will be cooler but still above normal Monday and
Tuesday. Another warm and well above normal period is expected
Wednesday through Friday and it is possible that records highs
will be challenged.