Area Forecast Discussion
Issued by NWS Sterling, VA
FXUS61 KLWX 220139
Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
939 PM EDT TUE JUN 21 2016
A cold front will cross the region tonight. High pressure will
briefly build in from Canada on Wednesday. A warm front will lift
north across the region Wednesday night. Another cold front will
cross the region later Thursday and Thursday night. High pressure
will build back across the area for the weekend.
.NEAR TERM /THROUGH WEDNESDAY/...
Sunset finally having an impact on convective trends. The cold
front has sagged into northern Maryland and the eastern West
Virginia. South of there, we still have transport of humid air
toward the convergent zone. Further, effective bulk shear still
ranging fron 50-60 kt per mesoscale analysis. Therefore, there
still are a few thunderstorms near the front. Severity has been
waning. Have cleared southern Maryland from the recently extended
watch, and if these trends continue we will be able to drop the
rest prior to 11 pm. In fact, per HRRR the overnight hours should
High pressure from Canada will usher in drier air for the region
on Wednesday. Temperatures will drop a bit but northwesterly
downslope flow likely to prevent a big drop.
.SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY/...
Front that moves through as a cold front tonight will push back
north as a warm front on Wednesday night with rain and perhaps
embedded thunder moving back across the region. Very warm and
humid air mass moves in behind warm front for Thursday and we will
have another potential round of severe weather later Thursday into
Thursday evening. As front drops back south on Thursday night the
showers and thunderstorms will move southeast away from the area.
An upper trough of low pressure will swing across the region
Friday. There is a chance for a lingering shower or thunderstorm,
mainly across the west and south.
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
High pressure will build into the region Friday night through
Sunday. Drier and cooler air will follow throughout the weekend.
This same area of high pressure will move offshore and closer
to southern New England Sunday night and Monday. A warm and more
humid return flow will evolve Sunday night through Tuesday. This
will help in fueling showers and thunderstorms each period. A few
thunderstorms could contain gusty winds.
.AVIATION /02Z WEDNESDAY THROUGH SUNDAY/...
VFR forecasts will prevail for the rest of the evening. However,
the threat for brief localized restrictions continue for isolated
thunderstorms. If that does transpire, IFR still not out of the
High pressure returns Wednesday. Front moves back in as a warm
front with more rain later Wednesday night into early Thursday.
Another round of severe weather possible later Thursday into
Ifr conditions possible near CHO with any showers or
thunderstorms Friday. Vfr conditions all terminals Friday night.
Winds northeast around 5 knots Friday becoming southeast around 5
knots Friday night.
Have allowed Small Craft Advisory to expire, as any higher wind
gusts have been within thunderstorms. Conditions improve later
tonight and continue dry thru Wednesday, though winds may be near
SCA limits on Wednesday. Warm front moves in with more rain later
Wednesday night then SCA looking likely ahead of next cold front
on Thursday into Thursday night, along with another round of
No marine hazards expected Friday and Friday night.