Area Forecast Discussion
Issued by NWS Wakefield, VA-- Remove Highlighting --
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FXUS61 KAKQ 190412
Area Forecast Discussion
National Weather Service Wakefield VA
1112 PM EST Sat Feb 18 2017
A weak area of low pressure moves through the Carolinas
overnight into Sunday morning, with high pressure returning by
Sunday afternoon. A backdoor cold front pushes through the
Eastern Shore Sunday night, as high pressure builds well north
of the region and slides off the coast by Tuesday.
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
-- Changed Discussion --Quick update to account for the batch of light rain/shwrs
tracking NE across the Piedmont despite the 20+ temp/dp temp
Late this evening, a srn stream trough was moving thru the
Tennessee Valley. Expect high and mid level clouds overnight
into Sun morning, as the upper system/trough weakens as it
slides acrs the central Appalachians to the Mid Atlc/SE coast.
Other than maybe a sprinkle, dry conditions should prevail
under a mostly cloudy to cloud sky. Lows will range fm the
upper 40s to lower 50s.
-- End Changed Discussion --
.SHORT TERM /6 AM SUNDAY MORNING THROUGH TUESDAY/...
Low pressure ambles offshore Sunday as weak high pressure
builds in from the west. 850mb temperatures drop to around
+6-8C, but will be offset by downsloping albeit light NW flow.
Above normal temperatures continue (+1.5-2.0 st dev) with
decreasing clouds. Forecast highs range from the upper 60s to
low 70s west of the Bay and for the interior Ern Shore, with
locally cooler temperatures at the immediate coast.
High pressure builds into the Ern Great Lakes Sunday night and
pushes a backdoor cold front through the Ern Shore. This high
(1030+ mb) will continue to build ewd Monday resulting in
onshore flow along the coast, which will result in cooler (but
still above normal) temperatures along the coast, while the
Piedmont will remain mild. Lows Sunday night/Monday morning
range from 40-45F. Forecast highs range from the low/mid 50s for
the Ern Shore, to the low/mid 60s in the I-95 corridor, to the
low 70s over the Piedmont. Mostly clear/sunny Sunday night into
Surface high pressure will prevail over the region Monday night
with low temperatures dropping into the low/mid 30s NE to the
upper 30s/around 40 W under a mostly clear sky. The high
gradually slides offshore Tuesday as a weakening 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. Mainly clear early with increasing high
clouds by aftn.
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
High pressure slides off the Mid Atlantic Coast Tue night and
settles over the Southeast coastal waters on Wed. The area
continues to sit in the middle of split flow aloft (primarily
westerly flow) with active systems passing well north and well
south. Models still struggling in regard to how far south to
bring precip associated with nrn system. However, available
shortwave moisture/energy is still being sheared apart. Have
maintained ongoing precip forecast by keeping a slight chance
for showers mainly across nwrn half of CWA during Tue night with
dry conditions for Wed as aforementioned shortwave moves
offshore. Otherwise, expect a dry forecast through Thu night
with temperatures running anywhere from 15-20 degrees above
seasonal normals. Lows generally mid 40s to mid 50s. Highs
generally mid-upper 60s to lower 70s inland/low-mid 60s
immediate coast. Next big system to potentially impact the Mid
Atlantic Region exits the Plains Thu night and tracks northeast
into the Great Lakes on Fri. Increasing south winds and decent
warming ahead of a strong cold front is anticipated for Fri/Fri
night. Scattered showers will be possible Fri aftn/evening and
maybe even some thunder...but only if the timing of the frontal
passage doesn`t change (i.e. the arrival of the front will
likely slow down its ewd progression as upper level troughing
digs behind the sfc low). Forecast highs for Fri are currently
in the low-mid 70s inland/low-mid 60s beaches, however they
could easily end up being several degrees warmer due to a
tightening pressure gradient and subsequent well-mixed
environment, ample warm air advection occurring ahead of the
front, and longer daytime hours as we approach meteorological
spring. Lows Fri night will be highly dependent on when the
frontal passage occurs. Warm temps should be anticipated through
most of the night with readings falling in the Piedmont and far
nw counties closer to sunrise. For now, lows Fri night will be
around 50F (+/- a few degrees).
.AVIATION /04Z SUNDAY THROUGH THURSDAY/...
Weak low pressure moves through the Carolinas overnight and then
off the coast in the morning. High pressure slowly strengthens over
the Mid Atlantic States Sunday and Monday then slides off to the
east and south Tuesday. A southwest flow prevails during midweek.
Mid level moisture will produce a band of mid level clouds over most
of the TAF sites overnight which will diminish Sunday morning. VFR
conditions will prevail through the 00Z TAF period. Southwest winds
veer to northwest and north on Sunday.
OUTLOOK...Mainly dry weather is expected through Thursday.
Sfc pressure gradient has tightened up a bit this aftn and a
slight uptick in winds has been observed. Winds generally south
10-15kt. Wind speeds will hold steady around 10-15kt through
tonight while veering to the sw overnight as a weak trough
crosses the waters late tonight/early Sun morning. The trough is
expected to push ewd the rest of Sun as a more defined sfc low
develops well of the Southeast Coast. The end result will be
winds becoming light (10kt or less) from the nw. Sub-SCA
conditions will prevail Mon through Thu. Wind speeds aob 15kt,
seas 2-3ft, and waves 1-2ft. Wind direction n on Mon, becoming
onshore ne-se Mon night through Tue, then s-sw Tue night through
No records were set on Saturday. Listed below are the records
and actual highs for Saturday.
Also listed are the records for Sunday. Forecast high
temperatures fall short of records but come rather close at SBY.
* Site Sat 2/18 High Sat Sun 2/19 Forecast Sun highs
* RIC: 77 (2011) 74 78 (1961) 72
* ORF: 77 (1937) 7673 (1907) 67
* SBY: 75 (1976) 68 72 (1961)71
* ECG: 80 (1976) 71 77 (1939) 67