Area Forecast Discussion
Issued by NWS Sterling, VA
FXUS61 KLWX 180800
Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
400 AM EDT SAT JUN 18 2016
High pressure will persist across the area into Monday. A cold
front will slide southeast into the area Tuesday into Wednesday.
.NEAR TERM /TODAY/...
As of 3 am, a 1021mb surface high stretches from the Great Lakes
to the northern Mid-Atlantic. A light east wind is across the MD
portion of the Chesapeake Bay with calm wind inland. An upper
level trough extending SE from the Canadian Maritimes continues to
cause areas of mid-level clouds over the area east of the Blue
Ridge. Any valley fog this morning will dissipate quickly in the
early rising and strong June sun.
Today, the area of high pressure shifts southeast across the area
and off the Mid-Atlantic coast. A light onshore flow will develop
over the area. Sunny skies expected as the upper trough axis also
shifts SE. Went above Superblend guidance two degrees or so based on
.SHORT TERM /TONIGHT THROUGH MONDAY NIGHT/...
Surface high pressure lingers over the area through Monday. Warming
trend with 90s by Monday. Again went a couple degrees above the
Superblend through the short term. Low pressure that pushed
southeast across the area Thursday will return to just off the Mid-
Atlantic coast Monday. The only effect on local weather should be
slightly enhanced NEly flow.
An approaching trough Monday should have preceding showers and
thunderstorms that may reach NWrn zones around sunrise. Added chance
thunder for those zones late Monday night to account for the risk.
.LONG TERM /TUESDAY THROUGH FRIDAY/...
A warm day Tuesday ahead of the upper level short wave tracking
across Ontario. Highs should reach the upper 80s...possibly
touching 90. At the surface a cold front west of the Appalachians will
be a reflection...and likely provide a focus for convection.
Showers/isolated thunderstorms will be possible Tuesday night.
Lows in the 60s.
The cold front is expected to push south of the forecast area
Wednesday. Showers will be on the wane in the central Shenandoah
Valley as that upper level trough digs into the eastern U.S. - not
exactly the "normal" weather pattern for the first days of summer.
This will lead to highs in the lower 80s. Lows Wed night in the
upper 50s west of the Blue Ridge...lower 60s east except mid 60s
in the cities and along the Bay.
The western US ridge/eastern trough is expected to remain in place
through next Friday. This will keep temperatures about five
degrees below normal.
.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
VFR conditions and light winds through Monday under high pressure.
Only exception is chances for valley fog. Periodic IFR at KCHO
should persist through 10Z this morning.
Cold front moves through Tuesday afternoon into Wednesday, with a
chance for a brief period of showers and storms (and sub-VFR)
along it. VFR conditions return by midday Wednesday.
High pressure just north of the area producing 10 knot east winds
this morning across the waters. High pressure shifts south across
the area today and will persist through Monday - expect tranquil
conditions through this time.
Winds strengthen some along/near cold front Tuesday into Wednesday
possibly causing a scattered thunderstorms. Winds decrease
Wednesday as high pressure returns to the area.
East flow around 10 knots persists today. Minor inundation around
current high tide at sensitive sites on Bay - no flooding expected
on upper tidal Potomac. Anomalies up to one foot above normal
persist with minor coastal flooding expected again at Straits Point
and Annapolis tonight before anomalies decrease.
MD...Coastal Flood Advisory until 8 AM EDT this morning for MDZ014.
Coastal Flood Advisory until 5 AM EDT early this morning for