Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Baltimore Maryland/Washington District of Columbia
343 am EDT Wed Oct 26 2016
Synopsis...high pressure will remain over the region through
tonight. A cold front will cross the area Thursday afternoon and
evening. High pressure returns Friday and Friday night.
Near term /until 6 am this morning/...high pressure is centered over
the mid-Atlantic region this morning. Temperatures have dropped
into the l40s/30s with the exception of the city centers and
places along the waters early this morning. Some mid-high clouds
over the Shenandoah Valley and portions of The Highlands are
keeping conditions warmer. Freeze warnings and frost advisories
will continue until 9am this morning.
High pressure slowly moves east today and a weak return flow will
begin this afternoon. Max temps in the 50s and 40s in the mountains
are expected. A warm front will move northward across the Ohio
Valley region this afternoon and evening. High pressure in place
across the mid-Atlantic will keep the warm front from moving
northward across the region, however, mid-high clouds will
increase from west to east today and tonight in response to the
warm front aloft. As moisture advects northward, showers are also
possible, however, they should stay west and north of the mid-
Atlantic region as the associated low pressure system moves into
the Great Lakes region by Thursday morning.
Short term /6 am this morning through Friday night/...low pressure
will move across Lake Erie and Lake Ontario Thursday while a cold
front approaches the mid-Atlantic region. The warm front will move
through the region by Thursday afternoon. Clouds and showers are
expected, however, the greatest forcing will be associated with
the sfc low to our north. Rainfall amounts should not exceed a
half inch into Thursday night. Winds will also increase ahead of
the cold front Thursday afternoon and then behind the front
Thursday evening. Winds at higher elevations will also be greater
and gusts up to 35-40 mph will be possible during this time.
The cold front moves to the east by Friday morning. Dry conditions
are expected with the exception of showers tapering off across the
Allegheny Front. High pressure will move overhead by Friday
evening, however, it should quickly move east of the region by
Long term /Saturday through Tuesday/...heights will be rising on
Sat with 850 mb temps climbing to 13c close to the 90% percentile
for late Oct. This will support warm temperatures well into the
70s and close to 80f in Charlottesville. Will need to watch rh's
closely on Sat for an enhanced fire weather threat in case
dewpoints do not recover as models suggest. A shortwave-trough
and associated cdfnt cross the area Sun afternoon. A few showers
appear possible along the Mason-Dixon line Sun morning. Temperatures
could actually turn out to be warmer on sun especially south of the
Potomac River due to downslope flow. A brief cool down expected on
Mon but temps expected to rebound again for the middle part of next
week as ridge of high pressure amplifies over the southeast U.S.
Into the mid-Atlantic. Temperatures likely to rise well into the
70s and possibly low 80s middle of next week.
Aviation /07z Wednesday through Sunday/... VFR conditions are
expected through tonight. Clouds will increase from west to east
this afternoon. A cold front will approach the region Thursday and
showers are possible. Cigs will lower with these showers and MVFR
conditions are possible at this time. Winds will increase Thursday
as well and gusts up to 20-30kts are possible in the afternoon and
evening. VFR conditions are expected Friday-Friday night.
VFR conditions expected Sat and sun.
Marine... northerly winds around 10kts expected on the waters today
and tonight. Southerly winds will increase ahead of a cold front
Thursday. The cold front will pass through Thursday evening and
gusty northwest winds are expected behind the front overnight
Thursday. A Small Craft Advisory will likely be needed for the
waters Thursday through Thursday night. Winds may approach gale
conditions mainly across the Main Channel of the Bay
Thursday/Thursday night however confidence is low if a Gale Warning
will be needed. Northwest winds will continue Friday and Small Craft Advisory conditions are
expected during this time. Winds should diminish Friday night.
Small craft conditions are possible Sat afternoon and Sat night.
District of Columbia...frost advisory until 9 am EDT this morning for dcz001.
Maryland...frost advisory until 9 am EDT this morning for mdz011-013-014-
Freeze warning until 9 am EDT this morning for mdz003>006-501-
Virginia...frost advisory until 9 am EDT this morning for vaz025-026-038-
Freeze warning until 9 am EDT this morning for vaz027>031-039-
WV...freeze warning until 9 am EDT this morning for wvz050>053-055-