Area Forecast Discussion
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FXUS61 KLWX 261942
Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
242 PM EST Sun Feb 26 2017
High pressure will return to the area tonight and Monday. A
warm front will then lift north into the area Tuesday into
Wednesday followed by another cold front Wednesday night.
.NEAR TERM /THROUGH TONIGHT/...
The center of high pressure can be found across the southern
Appalachians this afternoon. This ridge axis will translate east
of the mountains tonight, with return flow commencing during the
overnight hours. Since the area will be under high pressure,
skies will be clear (visible satellite suggests we`re already
almost there as of 230 pm) and winds will decouple. That would
suggest that radiational cooling would be favorable. However,
mid and high level moisture will be rebounding overnight in
return flow, and these clouds will ultimately impede cooling.
Will be keeping the cities (DC and Baltimore) and Bayshore
communities above freezing, and everyone else will be below. The
early evening hours will provide a good gauge on the eventual
.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
The forecast area will be in a prolonged period of
south/southwest flow Monday-Tuesday, with intervals of enhanced
isentropic lift. Above that, flow 500 mb and above will be
rather fast westerlies. There will be sufficient upglide to
support more clouds than sun by Monday...and it may end up
mostly cloudy. Moisture return will be better Tuesday/Tuesday
night, and that`s when PoPs will be higher. Temperatures will
get progressive warmer once again, into the range of well above
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
A cold front will push across our region Wednesday, before moving
offshore Wednesday night. Scattered to numerous showers and a couple
of thunderstorms will develop ahead of and along the cold front,
mainly during the afternoon and evening hours. The main threat will
be damaging wind gusts. Once the front passes and the winds shift to
the west-northwest, some upslope snow showers could develop
Wednesday night and linger into early Thursday. Temperatures ahead
of the cold front will also be very mild in the 70s in most places
except along the shores of the Chesapeake Bay and over the
Appalachian Mountains. Temperatures should quickly fall through
the 60s into the 50s behind frontal passage.
Upslope snow showers should end around midday in the Appalachians on
Thursday. About the same time, an upper level disturbance is
expected to approach the region from the Great Lakes and bring a
chance for a mix of rain or snow Thursday afternoon into Thursday
night. The exact track of the disturbance will determine the
An associated surface cold front will bring a re-inforcing
shot of colder air into the region on Friday, along with a
chance for rain showers in the eastern zones and more upslope snow
showers in the Appalachian Mountains.
A strong ridge of high pressure should build in behind Friday`s
front on Saturday and linger right on into Sunday. Dry conditions
and seasonably chilly temperatures are expected both days.
.AVIATION /19Z SUNDAY THROUGH FRIDAY/...
VFR conditions tonight into Monday under high pressure. Mid and
high level clouds increase Monday/Monday night, but there will
be no operational impact. Moisture continues to build Tuesday,
which may lead to some showers. Any restrictions likely would
be no worse than MVFR, and that may be limited. Will also need
to monitor increasing wind aloft Monday night and Tuesday night
in case LLWS thresholds may be met.
Ifr to lifr conditions expected Wednesday afternoon and evening
within rain showers and thunderstorms. Mvfr conditions
Wednesday overnight and Thursday with a lingering shower. Vfr
conditions Thursday night. Winds southwest 10 knots Wednesday.
Winds becoming west-northwest 10 to 15 knots gusts 20 knots
Wednesday night. Winds west-northwest 15 knots gusts 25 to 30
knots Thursday. Winds becoming west and diminishing 5 to 10
knots Thursday night.
Winds decreasing this afternoon as high pressure builds. Have a
staggered end to the Small Craft Advisory.
Winds will be light tonight under the ridge. Return (south) flow
will begin Monday morning. Mixing on Monday afternoon likely
will support gusts in the mid teens, ie: just under Small Craft
Advisory conditions. On Tuesday, however, thresholds likely will
SCA looks likely on southerly winds as warm front lifts north of
the region Wednesday, then gales possible Wednesday night and
Thursday behind the cold front. A chance of thunderstorms also
exists late Wednesday and Wednesday night as the cold front
MARINE...Small Craft Advisory until 6 PM EST this evening for
Small Craft Advisory until 4 PM EST this afternoon for ANZ534-