Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Baltimore Maryland/Washington District of Columbia
1014 am EST sun Mar 1 2015
high pressure will move east early today as an upper level
disturbance approaches from the west. Moisture will overspread the
region today creating a wintry mix. A cold front will cross the
area tonight. High pressure builds on Monday and continues
through Tuesday. A warm front will cross the area Tuesday night.
Then a strong cold front will cross the region late Wednesday as
cold high pressure builds in for Thursday and continues into the
Near term /through tonight/...
low pressure will pass by to our west today into tonight while
high pressure remains off the New England coast. The southerly
flow has overrun the surface cold air in place...resulting in
precipitation breaking out across the area. Precipitation started
off as snow/sleet across most areas earlier this morning. Warmer
air has worked its way in aloft...and this will continue to be the
case through early afternoon. Snow has already changed to sleet
and freezing rain across southern Maryland into the Washington and
Baltimore metropolitan areas as well as central Virginia. The snow
across northern areas will change to a wintry mix by early this
afternoon. The main ptype this afternoon into early this evening
will be freezing rain. Therefore...the winter headlines will
continue with warnings across northeastern Maryland where the most
ice is expected due to higher precipitation amounts. Will have to
keep an eye on southern Maryland and portions of the Washington
metropolitan area. Ice accumulations may approach warning criteria
across these areas as well.
Further west into the Shenandoah Valley and eastern West
Virginia...ice accumulation from freezing rain is expected but ice
amounts will be closer to a tenth of an inch due to less
precipitation. The downsloping southwest flow at the low-levels is
cutting back on precipitation amounts across these areas.
Freezing rain will end from SW to NE late this afternoon and evening
across the region. Forecast soundings Show Low level moisture will stay
around and therefore patchy drizzle or freezing drizzle is expected
through tonight. Freezing drizzle would continue to cause a hazard
this evening and therefore ww advisories and ws warning continues
A cold front will move through the region late tonight. Snow showers
are expected across the western slopes. An additional inch of
snowfall is expected through Monday morning.
Short term /Monday through Monday night/...
weak high pressure builds over the area on Monday and continues
into Monday night. Some upslope snow showers in the western
mountains to start the day...but should end by middle day. Highs on
Monday will moderate as 850 mb temperatures really not that cold...with
readings still well below seasonal normals for early March.
On Monday night...a warm front will approach from the southwest as
high pressure retreats east. Sub-freezing surface temperatures...but
precipitation should hold off as shown by 00z European model (ecmwf) and GFS.
Long term /Tuesday through Saturday/...
on Tuesday...as the warm front moves northeast precipitation should increase
throughout the day. Wednesday afternoon temperatures will be the warmest in
quite some time...as 50s will be prevalent...the mex MOS shows
l60s across southern portions of the County Warning Area. However amount of cloud
cover and any precipitation could temper highs on Wednesday.
Models continue to show more organized precipitation for late Wednesday into
Wednesday night ahead of a strong cold front. Amounts of one inch liquid
are possible Wednesday night.
Thu-Sat...the cold front will be east of the area early Thursday as high
pressure builds in. Dry weather expected through Saturday with
below normal temperatures.
Aviation /15z Sunday through Thursday/...
snow has changed to sleet and freezing rain across most of the
terminals. Any leftover snow across the northern terminals will
change to sleet and freezing rain by noon. Ceilings/visibilities will
deteriorate to IFR levels this afternoon. Precipitation will move
away from the terminals later this afternoon and evening...but IFR
conditions may continue.
VFR conditions Monday and Monday night.
VFR conditions expected early Tuesday...sub-VFR possible Tuesday night
through Wednesday night in precipitation.
southerly winds are expected today...but speeds will remain below
Small Craft Advisory criteria. The flow will turn toward the northwest behind the
front by Monday.
Small Craft Advisory gusts possible Monday behind the cold front in northwest flow. Winds
expected to be 10kt or less Monday night.
Winds will pick up prior to cold frontal passage with Small Craft Advisory possible
beginning late Tuesday night and continuing through frontal passage
on Wednesday night.
District of Columbia...Winter Weather Advisory until 3 am EST Monday for dcz001.
Maryland...Winter Weather Advisory until 6 am EST Monday for mdz501.
Winter Weather Advisory until 3 am EST Monday for mdz003-004-
Winter Storm Warning until 3 am EST Monday for mdz005-006-011-
Virginia...Winter Weather Advisory until 6 am EST Monday for vaz503.
Winter Weather Advisory until 7 PM EST this evening for
Winter Weather Advisory until 3 am EST Monday for vaz028-031-
WV...Winter Weather Advisory until 6 am EST Monday for wvz501-503-
Winter Weather Advisory until 7 PM EST this evening for wvz055-
Winter Weather Advisory until 3 am EST Monday for wvz050>053-
Marine...Small Craft Advisory from 9 am to 6 PM EST Monday for