Area Forecast Discussion
Issued by NWS Sterling, VA
FXUS61 KLWX 241450
Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
1050 AM EDT Fri Jun 24 2016
An upper-level disturbance will pass through the area today. High
pressure will build into the region tonight through Sunday. The
high will move off the coast Sunday night into Monday and a cold
front will pass through Tuesday.
.NEAR TERM /THROUGH TONIGHT/...
Mild and humid conditions are across the Mid-Atlantic region this
morning as a stalled frontal boundary remains in place just to our
north. High pressure is across the Great Lakes and New England
this morning. The air mass across Pennsylvania and New Jersey is
considerably drier than the one in our region and the front is
expected to nudge southward today and tonight, bringing the drier
air with it.
Until that happens, however...the Mid-Atlantic region is still
susceptible to showers and thunderstorms while warm and humid
airmass remains in place. A shortwave trough co-located with an
upper level jet will swing through the region this afternoon.
Showers and thunderstorms are expected to continue developing late
this morning and afternoon as conditions continue to destabilize.
Low clouds have been persistent across northern regions but more
sun has been reaching the ground across more southerly portions of
the CWA. This may lead to increased instability across a region
that moderate shear profiles. Hi-res guidance is showing
disorganized iso-sct convection by this afternoon into this
evening. Difficult to determine exactly where best activity will
be but thinking currently remains focused on Shenandoah Valley and
Blue Ridge areas of Virginia where the approaching weak front
bringing cooler and much drier air from the north will likely
reach last. SPC has included part of the CWA in slight risk,
namely across central VA...with marginal risk extending across
most of VA...as well as DC and southern MD. Further north...the
drier air advecting in will likely limit severe threat.
The shortwave trough will move off the coast tonight. Showers will
linger into the evening hours especially across the SW portion of
.SHORT TERM /SATURDAY THROUGH SATURDAY NIGHT/...
High pressure will move into the region Saturday and N-NE winds
are expected. Some guidance is depicting a low cloud deck and if
that doesn`t happen, fog is likely Saturday morning. Either
should break by afternoon with the exception of the highlands
where low clouds may persist. A stray shower is also possible in
the highlands...forced mainly by the mountains themselves. Max
temps in the low 80s expected Saturday. High pressure will build
into the region further Sat night and calm and clear conditions
.LONG TERM /SUNDAY THROUGH THURSDAY/...
High pressure will remain overhead Sunday...bringing dry and
seasonably warm conditions along with low humidity. The high
will move off the coast Sunday night into Monday and a cold front
will approach from the west later Monday. A southerly flow will
usher in more humid conditions ahead of the boundary...and this
may lead to some showers and thunderstorms...especially during the
afternoon and evening hours.
The cold front will pass through Tuesday...bringing the chance for
a few more showers and thunderstorms. High pressure will return
for Wednesday and Thursday behind the cold front...bringing cooler
and less humid conditions.
.AVIATION /15Z FRIDAY THROUGH TUESDAY/...
Low clouds this morning have been tough to lift at some terminals
but appears to be doing so now. For the rest of the afternoon,
prevailing vfr conditions are expected. SHRA/VCTS is possible this
afternoon with the best chance of TS at CHO. Heavy rain and gusty
winds possible this afternoon...again mainly around CHO.
SHRA will wane this evening. N-NE winds expected at the terminals
and low cigs are possible tonight with a better chance for IFR
conditions. Fog is also possible tonight into Saturday morning
causing sub-vfr vsbys. Sub-vfr cigs and vis possible Sat night
into Sunday morning as well.
High pressure will bring vfr conditions Sunday afternoon into
Monday. A few showers and thunderstorms are possible Monday
afternoon into Monday night. A cold front will pass through
Tuesday...bringing the chance for a few more showers and
N-NE winds expected on the waters through Saturday night.
Showers and perhaps an isolated t-storm are expected through this
afternoon. Showers will likely cause brief periods of gusty winds.
At this time...coverage seems to be isolated... but an isolated
special marine warning is not out of the question.
High pressure will remain over the waters Sunday before moving off
to the east Sunday night. Winds will turn toward the southeast
during this time...but speeds should remain below sca criteria.
An approaching cold front Monday may trigger some showers and
thunderstorms during the afternoon and evening hours. A few more
showers and thunderstorms are possible Tuesday into Tuesday
night as the cold front passes. Gusty winds are possible in any
thunderstorms that develop. High pressure will build during the
middle portion of next week.