Area Forecast Discussion
Issued by NWS Wakefield, VA-- Remove Highlighting --
-- Discussion containing changed information from previous version are highlighted. --
FXUS61 KAKQ 151514
Area Forecast Discussion
National Weather Service Wakefield VA
1014 AM EST Wed Feb 15 2017
Low pressure lifts over the Carolinas this morning as a cold
front approaches from the northwest. The cold front crosses the
area this afternoon. High pressure builds into the region
Thursday through Saturday.
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
-- Changed Discussion --Latest GOES water vapor imagery places the potent northern
stream upper low over the eastern Great Lakes Region and the
deamplifying southern stream shortwave over the Tennessee
Valley. Moisture plume also visible spreading from the southern
stream wave northeastward over the central Appalachians. At the
surface, the northern stream cold front has reached the Ohio
Valley with the southern stream cold front located over the Deep
South. Light to moderate rain has spread into the region ahead
of an area of low pressure lifting across the Deep South.
Regional radar indicates the best coverage from s-central VA to
the Ern Shore with drying beginning to nudge into the Piedmont.
Note, there has been significant bright-banding on the radar
this morning. Cool cloud heights are also indicated. Categorical
POPs continue across much of the region this morning as rain
spreads eastward across the local area. The low pushes offshore
early afternoon as the northern stream cold front pushes across
the local area this afternoon. Have kept categorical POPs across
the southeast thru mid afternoon today, but expect some
scattered showers along the northern stream front east of
Interstate 95 later this afternoon. Best moisture pushes
offshore late afternoon as dry, downslope flow overspreads the
region. Aside from the phasing upper level systems, a strong jet
couplet will provide impressive forcing for ascent. Given the
forcing and +1 standard deviation precipitable waters, have
increased QPF amounts across the region. Amounts will range from
one quarter to one half inch across much of the local area to a
few hundredths for the northwest Piedmont.
Temperatures level off this morning in the mid to upper 40`s,
warming behind the precip this afternoon into the low to mid
50`s. Cloudy this morning, becoming clear inland this afternoon
thanks to dry, northwest flow. Cloudy conditions remain along
the coast. Winds become northwest this afternoon, increasing to
10-15 mph with gusts of 20-25 mph.
-- End Changed Discussion --
.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY/...
Deep/anomalous upper trough locates over the Northeast tonight
as the trough axis pushes offshore. Additional energy on the
backside of the upper trough digs over the Delmarva, but with
the front well offshore and a dry air mass surging into the
region, expect very little moisture to remain along the coast.
However, based on the dynamics, steep lapse rates, and falling
temperatures/thicknesses, will keep a mention of a slight chance
for snow showers/streamers over the lower Virginia Eastern
Shore through late tonight. No accumulation is anticipated. Sky
becomes clear inland thanks to downslope/dry flow, but will keep
a partly cloudy sky northeast. Cold, with lows in the mid to
upper 20`s inland to low 30`s near the coast.
The upper low lifts over the Canadian Maritimes Thursday as
broad cyclonic flow prevails over the Northeast. Dry downslope
flow results in dry conditions and a sunny to mostly sunny sky
Thursday. 850Mb temperatures level off around -8 to -10C (-1
standard deviation). Highs Thursday in the mid to upper 40`s.
Breezy, with a northwest wind of 10-15 mph inland and 15 to 20
mph Eastern Shore. Gusts 30-35 mph Eastern Shore. Deep mixing
results in minimum relative humidity values in the 20-30 percent
range, but precipitation today and cool temperatures expected
to mitigate any fire weather concern. A shortwave progged to dig
over the Ohio Valley late Thursday and into the Kentucky Valley
Thursday night. Dry conditions are forecast, but expect an
increase in mid to high clouds late Thursday through Thursday
night. Lows in the mid to upper 20`s.
High pressure slides off the Southeast coast Friday as the
shortwave pushes offshore. Another shortwave drops over the
Delmarva in northwest flow aloft, resulting in some mid to late
afternoon clouds. Return flow and modest warm air advection
pushes highs into the mid 50`s inland and upper 40`s northeast.
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
Long term period will feature mainly dry weather with slowly
increasing temps through the period. For Fri night, an upr-level
shortwave ridge builds into the area with sfc high pres remaining in
the vicinity. Expect low temps in the 30s under a mostly clear sky
with light southerly flow. Winds remain southerly into Sat as low-
level thicknesses rise, allowing for well above normal temps...highs
in the low/mid 60s most areas; upr 50s Lwr Ern Shore. Southern
stream trough approaches the region Sat night, pushing across the
region Sun. An associated weak area of low pres is progged to lift
along the SE coast. Clouds increase Sat night along with a slight
chance of rain over the srn half of the FA. The trough pushes
offshore Sun night with dry and clearing conditions. High temps Sun
and Mon in the mid 60s most areas; near 60 Lwr Ern Shore.
.AVIATION /15Z WEDNESDAY THROUGH SUNDAY/...
Light rain has spread over central Virginia this morning ahead
of low pressure lifting over the Carolinas. VFR conditions
prevail, indicating the light nature of the precip. Expect
light rain to increase in coverage as a potent upper level
disturbance approaches the region. Rain spreads south and east
through the morning hours, reaching the southeast area late
morning/early afternoon. Rain may become moderate to locally
heavy at times, reducing visibilities to MVFR/localized IFR.
Ceilings lower to MVFR mid morning, with IFR expected across
southeast Virginia and northeast North Carolina late
morning/early afternoon. Conditions improve late today as the
cold front pushes across the region. Some lingering precip
possible across the Eastern Shore as the disturbance tracks
across the region. Westerly winds this morning become northwest
this afternoon generally around 10 knots. Gusts to 20 knots
expected along the coast late today and this evening.
Outlook: VFR conditions are expected tonight through Saturday.
Winds will be gusty behind the front on Thursday, winds could
occasionally gust in excess of 20 knots out of the NW. The next
potential for sub-VFR conditions will be Saturday night and into
Sunday as weak low pressure lifts along the southeast coast.
Sub-SCA conditions currently with light winds across the
area and seas of 2-4 ft, waves 1-2 ft or less. A slowly developing
surface low tracks E from the Great Lakes and then rapidly intensifies
off the New England coast tonight and Thu. Will have SCA headlines
for all zones starting either late this aftn or this evening. Appears
that this system will be a little stronger than earlier anticipated,
and have bumped winds up a few KT from previous forecast, with a fairly
strong SCA event expected for the Bay and coastal waters. Expect a
brief surge of higher gusts to 30 KT or perhaps a little higher with
the initial push of CAA early this evening, then winds may diminish
a bit later tonight. However, as the sfc low continues to intensify
off the New England coast/Canadian Maritimes (down to ~965 to 970
mb) on Thu, expect winds to ramp back up and a period occasional
gusts to Gale force will be possible over the coastal waters
(especially over the N). Still do not think this warrants a Gale
Warning, but if the sfc low were to be a little farther S than
guidance, may need to upgrade to Gales over the northern coastal
waters. Seas will not be excessive despite the strong winds as
the flow will be offshore (will avg 4-6 ft). High pressure
builds in for the end of the week and winds and seas/waves
subside slowly Thu night (have extended the SCA`s through
06Z/Fri northern coastal zones, 03Z Bay and southern areas).
Lighter winds and sub-SCA conditions Fri-Sun.
MARINE...Small Craft Advisory from 4 PM this afternoon to 4 PM EST
Thursday for ANZ635>638.
Small Craft Advisory from 4 PM this afternoon to 10 PM EST
Thursday for ANZ630>632-634.
Small Craft Advisory from 7 PM this evening to 7 PM EST
Thursday for ANZ633.
Small Craft Advisory from 7 PM this evening to 10 PM EST
Thursday for ANZ654-656-658.
Small Craft Advisory from 7 PM this evening to 1 AM EST Friday