Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Baltimore Maryland/Washington District of Columbia
348 am EDT Tuesday Aug 4 2015
a cold front will continue to gradually shift southeast through
the area today. High pressure will build into the area later
tonight through Wednesday. The boundary will return north as a
warm front and stall out over the area for Thursday and Friday.
Low pressure will ride along the boundary...passing through the
region Thursday night and Friday. High pressure will gradually
build in behind the low next weekend.
Near term /through tonight/...
a weak cold front has moved into the area early this morning.
Instability actually increased overnight due to a Theta-E ridge
axis just ahead of the front. Therefore...showers and
thunderstorms did develop...mainly across eastern West Virginia
into northern Maryland. This activity will continue to push to
the east-northeast early this morning but it should weaken as it
moves into a more stable environment.
The cold front will gradually slide south and east through the
area today. Little temperature gradient is associated with the
boundary...but there will be a dewpoint gradient. A westerly
downsloping flow behind the front along with sunshine will allow
for hot conditions. With higher humidity south and east of the
boundary a few showers and thunderstorms are expected to pop up
this afternoon and evening. Moderate shear profiles suggest that
some storms can become severe. The best chance for severe
thunderstorms will be near and east of Interstate 95 where
humidity will be higher ahead of the boundary during peak heating.
The boundary will continue to slide south tonight and high
pressure will build overhead...causing dry and comfortable
Short term /Wednesday through Thursday/...
high pressure will remain in control for Wednesday through
Wednesday night while the cold front stalls to our south. A west
to northwest flow will usher in dry and cooler conditions during
this time. Although...maximum temperatures Wednesday will still be near
climatology due to sunshine and a downsloping flow.
The boundary will return north as a warm front Thursday and it
will stall out overhead late in the day. Low pressure will ride
along the boundary and approach from the west late in the day.
Clouds will increase and there is a chance for showers and
isolated thunderstorms...especially during the afternoon hours.
Timing is still a little uncertain as of now due to divergence
with the guidance.
Long term /Thursday night through Monday/...
the wave of low pressure will pass through the area Thursday night
into Friday...and another one may ride along the boundary and pass
through later Friday into Saturday. This will bring a better
chance for showers and possible thunderstorms.
As the second wave of low pressure departs...the boundary will
slide to the south and high pressure may return later in the
weekend into early next week.
Aviation /08z Tuesday through Saturday/...
a few thunderstorms are expected near kmrb until around 9z this
morning. Elsewhere...convection should remain off to the north and
A cold front will pass through the terminals today and a few
thunderstorms are possible during the afternoon and evening
hours...mainly across the eastern terminals.
High pressure will bring VFR conditions tonight through Wednesday
night. Northwest winds may gust around 15 to 20 knots Wednesday
afternoon. The cold front will return as a warm front for Thursday
through Saturday. Waves of low pressure will ride along the
boundary...increasing the chances for showers and possible
thunderstorms. Subvfr conditions are likely during this time.
showers and thunderstorms early this morning may approach the
northern Chesapeake Bay...as of now most of the activity should
remain off to the north and west.
A cold front will pass through the waters later this afternoon and
evening. A few thunderstorms are possible...and gusty winds/hail
are possible in the stronger storms. High pressure will build over
the waters later tonight through Wednesday night as the boundary
stalls to our south. A Small Craft Advisory is in effect for
middle portions of the Bay and lower tidal Potomac through this
evening. Winds may approach also Small Craft Advisory criteria Wednesday.
The boundary will return north as a warm front for Thursday
through Saturday and it will stall out overhead during this time.
Waves of low pressure will ride along the boundary...increasing
the chances for showers and thunderstorms.
a south to southwest flow has caused anomalies to increase to
between one quarter and one half foot above normal.
However...water levels are expected to remain below minor flooding
District of Columbia...none.
Marine...Small Craft Advisory until noon EDT today for anz532-533-
Small Craft Advisory until midnight EDT tonight for anz534-537-