Area Forecast Discussion
Issued by NWS Sterling, VA
FXUS61 KLWX 170727
Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
327 AM EDT Fri Mar 17 2017
.SYNOPSIS...A warm front will move into the area late tonight
into early Saturday before a cold front passes through Saturday
afternoon. High pressure builds over the area early next week.
Another cold front will cross the area on Tuesday.
.NEAR TERM /THROUGH TONIGHT/...High pressure will move over the
Mid-Atlantic region this morning. Clear skies and light to calm
winds have resulted in a cold morning. High pressure will move
off the east coast by this afternoon and mid- high level clouds
will move into the region from the west. Light southerly flow
will result in temps climbing into the 40s/L50s today.
Low pressure located over N MN this morning will move southeast
across the Great Lakes today. A warm front will approach the region
and overrunning will result in rain and snow showers moving across
the region this afternoon. Snow showers will begin at the higher
elevations where temps are cooler then as evaporative cooling
occurs, snow will mix in with rain showers further east. A light
dusting is possible north and west of the I-95 corridor this evening
however sfc temps during this time will likely be above freezing and
accumulation, if any would be on grassy surfaces. Snow showers are
expected to result in light accumulation of around 1-2 inches across
the Allegheny front during this time. Due to the marginal
temperatures, advisory not expected at this time.
Temps are going to stay steady if not rise overnight as the warm
front pushes through the Mid-Atlantic region. Rain and snow showers
will change to all rain by Saturday morning however favorable areas
where cold air can get trapped mainly across western Maryland may
result in fzra. Confidence is low as sfc temps will be marginal but
depending on how cold they get this evening may result in light
icing. No advisory issued during this time due to low
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...Low pressure along a
cold front will move through the region Saturday morning. A
strong shortwave trough will lag behind the sfc feature and move
overhead Saturday afternoon/evening. Pressure falls and mid-
level forcing will likely lead to scattered rain showers across
the region. Activity will move eastward by Saturday evening.
Snow showers expected along and west of the Allegheny Front
through Saturday night. Accumulations of 1-3 inches are possible
during this time.
The shortwave trough will move eastward Sunday and snow showers will
come to an end in the mtns.
.LONG TERM /MONDAY THROUGH THURSDAY/...Rain showers expected
late Monday and Mon night into early Tue as a cdfnt crosses the
area. High pressure builds over the area during the middle of
next week leading to cool and dry conditions. A developing storm
system over the mid section of the country will draw milder air
into the area for next weekend with a chance of showers for next
.AVIATION /07Z FRIDAY THROUGH TUESDAY/... VFR conditions expected today.
Rain and snow showers are likely Friday afternoon-Saturday
morning. The best chance for snow will be across KMRB with rain
more likely elsewhere. Sub-VFR conditions are possible during
this time. A cold front will cross the terminals Saturday.
Scattered rain showers are possible Saturday afternoon. NW winds
will increase behind the front.
Rain showers late Mon and Mon night. Cdfnt crosses the area
around 12Z Tue with shifting winds. High pressure then builds
during the middle of next week.
.MARINE... High pressure moves off the east coast today. S winds will
increase by Friday evening and SCA conditions are expected for
portions of the waters through Saturday morning. A cold front will
pass through Saturday and high pressure will approach Saturday
night. A Small Craft Advisory may be needed for portions of the
waters during this time.
Cold and breezy conditions Sunday, some showers possible as front
SCA conditions possible Mon night through Wed.
MARINE...Small Craft Advisory until 6 AM EDT early this morning for
Small Craft Advisory from 8 PM this evening to 6 AM EDT
Saturday for ANZ532>534-537-540-541-543.