Area Forecast Discussion
Issued by NWS Sterling, VA-- Remove Highlighting --
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FXUS61 KLWX 242059
Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
459 PM EDT Mon Oct 24 2016
High pressure over the region through midweek. A cold front will
cross the area Thursday afternoon and evening. High pressure
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
Temperatures have warmed to the mid 60s over much of the
area...mid 70s in the central Shenandoah Valley. Winds should
drop off after sunset allowing for good radiational cooling
conditions. This will cause a rapid cooling tonight...possibly
into the lower 30s in Highland and Pendleton counties. Because of
this we issued a freeze warning for these counties. This will be
the final one of the season for these counties as growing season
is considered over on the 25th. To the immediate north and east of
this area we have issued a frost advisory.
East of the Blue Ridge lows will be in the 40s.
.SHORT TERM /6 AM TUESDAY MORNING THROUGH WEDNESDAY NIGHT/...
High pressure over the region Tuesday through Wednesday. Highs
will be 55-60 over the majority of the area.
The coldest night of the week is expected to be Tuesday night.
High pressure will be settled over the Mid Atlantic. Portions of
eastern WV are forecasted to drop into the lower 30s. Given latest
trends...decided to issue a freeze watch for northern and western
zones. A frost advisory may be needed for much of the remainder of
the forecast area. If freezing conditions indeed occur across the
current freeze warning area...this portion of the freeze watch
will likely be cancelled as the growing season will have ended. Of
note is that for the far western zones, the growing season should
have ended nearly two weeks ago. Given this, regardless of whether
freezing temperatures occur by Wednesday morning, the growing
season will be declared over in these areas on Wednesday
afternoon. Further east, for the majority of the CWA, the growing
season still has another week before it is considered late and two
additional weeks before it is so far overdue as to be considered
Wednesday temperatures will again rise to 55-60. Lows Wednesday
night around 40.
.LONG TERM /THURSDAY THROUGH MONDAY/...
A mid/upper level shortwave trough and associated surface
low/frontal system will traverse the area Thursday. Although the
shortwave aloft is pretty stout, the majority of the forcing passes
to the north. In addition, there is not much opportunity for
moisture return. So while there will likely be scattered showers
around, precipitation amounts may average pretty light and confined
mainly to northern portions of the CWA.
Breezy conditions behind the front will usher in a renewal of cool
temperatures for the end of the week.
Another wave of low pressure may pass to the north of the area over
the weekend leading to a similar outcome (a brief period of milder
temperatures, scattered showers then breezy and cooler conditions).
.AVIATION /21Z MONDAY THROUGH SATURDAY/...
VFR conditions expected tonight through Wednesday night.
Mainly VFR Thursday into Friday. A few showers are possible
Thursday as low pressure passes to the north but restrictions
should be minimal. Southwesterly winds of 10 to 15 knots Thursday
will become northwesterly Thursday night into Friday.
Small craft advisory has been of marginal values and primarily
over the Bay. The upper Potomac portion will drop off this
evening. Will leave remainder of the overnight portion intact for
now but would not be surprised to see further reductions in the
SCA by following shifts. Gusts could resume again after mid
A tightening gradient between high pressure to the southeast and
low pressure passing to the north will likely result in winds to
Small Craft Advisory levels Thursday. Gusty winds will likely
persist in a northwesterly pressure surge following the passage of
low pressure to the north Thursday night into Friday.
MD...Freeze Watch from late Tuesday night through Wednesday morning
VA...Freeze Watch from late Tuesday night through Wednesday morning
Freeze Warning from 3 AM to 9 AM EDT Tuesday for VAZ503-504.
Frost Advisory from 3 AM to 9 AM EDT Tuesday for VAZ025>027-
WV...Freeze Watch from late Tuesday night through Wednesday morning
Freeze Warning from 3 AM to 9 AM EDT Tuesday for WVZ505-506.
Frost Advisory from 3 AM to 9 AM EDT Tuesday for WVZ055-501-
MARINE...Small Craft Advisory until 6 PM EDT Tuesday for ANZ530>534-
Small Craft Advisory until midnight EDT tonight for ANZ535-536.