Area Forecast Discussion
Issued by NWS Sterling, VA
FXUS61 KLWX 080213
Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
913 PM EST Wed Dec 7 2016
High pressure over the area tonight ahead of a cold front that will
move through the Mid-Atlantic Thursday morning and midday. High
pressure returns to the area Friday into the weekend. Another cold
front crosses the area Monday followed by another Wednesday.
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
No problems expected overnight. High pressure will be over the
region. High clouds continue to increase courtesy of a 150 knot
jet that will be tracking across PA/NY. Lows primarily around
freezing inland, mid 30s urban/nearshore.
.SHORT TERM /6 AM THURSDAY MORNING THROUGH FRIDAY NIGHT/...
Cold front crosses the area from the west late morning through
the afternoon. Risk for precip increases from west to east across
the southern half of the CWA. Went for chance PoPs for the SErn
zones through the morning. Wet-bulb zero values marginal for snow
where PoPs are highest over St. Marys county. Non-accumulating light
snow east of the line from Fredericksburg to Annapolis seems to be
worst case scenario with rain/snow mix more likely.
Colder air begins moving into the area Thursday night. Expect
winds to increase to 15-20 mph overnight...and then 25-30 mph
Friday. Lows Thursday night in the mid 20s..wind chills dropping
into the teens before sunrise west of I-95. A cold day Friday with
highs only in the low 40s east of the Blue Ridge...30s west...20s
Upslope snow showers will likely occur Thursday night and Friday.
For the time being we are forecasting 1-2 inches. If later shifts
raise the total higher we may need to issue an advisory. For the
far western zones our criterion is 3-5 inches in a twelve hour
Continued cold Friday night with lows 25-30.
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
High pressure will remain in control Saturday. An upslope flow
could generate snow showers in the Potomac Highlands, mainly early
The high will move to the East Coast Saturday night, before moving
offshore Sunday. Temperatures will remain chilly despite a return
flow evolving Sunday.
A storm system should move northeast across the Great Lakes toward
southeastern Canada Sunday and Sunday night. A trailing cold front
will move across the region Sunday night, bringing a chance of rain
or snow showers late Sunday and Sunday night.
Strong high pressure should build in behind the front Monday through
Tuesday, bringing very chilly air into the region once again.
As the high moves east, the next storm system could bring a chance
of rain or snow showers Tuesday night and Wednesday.
.AVIATION /02Z THURSDAY THROUGH MONDAY/...
VFR conditions tonight with light flow. A cold front crosses the
area from the west Thursday morning with MVFR cigs and rain/snow
chances mainly SE of DC metros/southern MD. Gusty NW winds
expected Thursday afternoon through Friday...along with low level
Vfr conditions Saturday and Saturday night. Winds northwest 5 to 10
knots Saturday becoming light and variable Saturday night.
Light and variable flow through sunrise under high pressure. A
cold front moves through the waters Thursday morning with west-
northwest winds increasing to gusts of 25 kt through the afternoon.
SCA in effect from noon for most waters...3pm for southern MD
waters. SCA for all waters then through Friday. Could see isolated
gale gusts Thursday late afternoon and late Thursday night,
possibly into Friday morning.
No marine warnings expected Saturday and Saturday night. Winds
northwest 10 knots Saturday. Winds northwest 5 to 10 knots Saturday
MARINE...Small Craft Advisory from noon Thursday to 6 PM EST Friday for
Small Craft Advisory from 3 PM Thursday to 6 PM EST Friday for