Area Forecast Discussion
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FXUS61 KLWX 011816
Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
216 PM EDT Fri Jul 1 2016
A cold front will pass through the area tonight. High pressure
will build over the area for Saturday into Saturday night. A warm
front will move into the area Sunday into Sunday night...and a
wave of low pressure will ride along the boundary and pass through
our area Monday into Tuesday. High pressure may return for the
middle portion of next week.
.NEAR TERM /THROUGH TONIGHT/...
A Severe Thunderstorm Watch is in effect for locations along and
east of the Blue Ridge and Catoctin Mountains through northern
Virginia. The watch is in effect until 10 pm this evening.
High pressure remains over the Atlantic and a cold front will
approach the area from the Ohio Valley late this afternoon and
evening. A southerly flow ahead of the boundary has resulted in
warm and humid conditions...which will lead to an unstable
atmosphere. The most instability is located near and east of the
Blue Ridge Mountains ahead of a pressure trough where dewpoints
will be in the upper 60s/lower 70s has resulted in MLCAPE values
around 1500-2000 J/KG.
An upper-level trough will dig into upstate New York through this
evening and this will cause deep layer shear profiles to
strengthen. 0-6 KM bulk shear will be around 40 knots. The
pressure trough will act as the primary lifting mechanism for
showers and thunderstorms to develop. The combination of moderate
to strong shear along with high instability enhances the threat
for severe thunderstorms. The primary threats will be damaging
wind gusts and large hail from Multicell clusters and/or
Supercells. An isolated tornado cannot be ruled out...especially
if there is an easterly component to the surface wind from a
The best chance for severe thunderstorms will be along and east of
the pressure trough that will setup near the Blue Ridge and
Catoctin Mountains between 4 pm and 8 pm this afternoon and
The cold front will pass through the area late this evening and
drier air will move in behind the boundary overnight.
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
High pressure will build overhead for Saturday into Saturday
night...bringing dry conditions along with low humidity. There
will be some high clouds in the zonal flow aloft.
A warm front will build north into the area Sunday into Sunday
night. Warm advection and isentropic lift will lead to more clouds
along with an increasing chance for showers. The best chance for
showers will be late Sunday into Sunday night.
.LONG TERM /MONDAY THROUGH FRIDAY/...
A storm system will ride along a warm front across the Ohio
Valley Monday and Monday night. Showers and thunderstorms will
develop along the front and accompany the storm system.
Showers and thunderstorms will linger Tuesday along an
associated trailing cold front. If any showers remain Tuesday
night, they would most likely be focused over the Potomac
Highlands and central Shenandoah Valley.
As the main storm system moves off the East Coast Tuesday night, a
brief area of high pressure will build into the eastern half of
the region for Wednesday and Wednesday night. There is a chance for
a few showers in the Potomac Highlands Wednesday night.
The threat for showers and thunderstorms, again, will be expected
Thursday through Friday as the pattern remains active.
.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
Thunderstorms will impact the terminals late this afternoon into
early this evening. A few thunderstorms may be severe...with
damaging winds and large hail being the primary threats.
Cigs/vsbys may briefly drop to IFR levels in heavier
thunderstorms. Drier air will move in overnight and VFR conditions
are expected through Saturday night with high pressure in control.
A warm front will return for Sunday...bringing the chance for some
showers and possible subvfr cigs. The best chance for showers and
subvfr cigs will be Sunday night.
Ifr conditions expected Monday and Monday night with showers
and thunderstorms. Winds south 5 to 10 knots Monday and Monday
Thunderstorms may impact the waters this afternoon into this
evening. Damaging wind gusts and large hail will be the primary
threats. High pressure will build in behind a cold front overnight
and northwest winds are expected. A small craft advisory is in
effect for the Maryland Chesapeake Bay and lower Tidal Potomac
River overnight through Saturday morning.
Winds should decrease later Saturday into Saturday night as high
pressure builds overhead. A warm front will move into the waters
Sunday and a wave of low pressure will ride along the
boundary...passing through the area Monday into Tuesday. Showers
and thunderstorms are possible during this time...especially
Monday into Monday night. High pressure may return for the middle
portion of next week.
Tidal anomalies are running about a half foot above normal this
afternoon. Water levels will stay below flood stage however will
reach action stage at sensitive locations at Annapolis, Alexandria
and DC SW/Waterfront during the high tide cycle late this
afternoon and evening. Will have to monitor tidal anomalies during
the higher of the two high tides overnight...but offshore flow
should be developing.
MARINE...Small Craft Advisory from midnight tonight to noon EDT
Saturday for ANZ530>534-537>543.