Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Baltimore Maryland/Washington District of Columbia
256 PM EST Monday Nov 30 2015
High pressure is moving into the Gulf of Maine. A warm front over
South Carolina will slowly lift to the north and into the middle
Atlantic Tuesday...with a cold front swinging through Wednesday.
High pressure builds in for the latter part of the week.
Near term /tonight/...
"cldy damp drzly..." not welcome words to most but that's what
we've got in the middle Atlantic as the area is in a cad wedge between the
ME high and front across the Carolinas. Low level nerly flow keeping
the area moist and cool. Not much is expeceted to change during the overnight.
Have 90-100 probability of precipitation across the area west/ little diurnal variation. Lows from
the m30s at the higher elevs to them40s lower southern Maryland.
Short term /Tuesday/...
Carolina fnt is prognosticated to move back to the north ahead of the cold fnt
presently developing over Kansas. Timing of warm fropas often do not behave
as the models project...but as of now there is agreement that the
warm should be moving back across the County Warning Area around 18z Tuesday. This will lead
to a showery environment west/ highs getting into the l50s. But
confidence is not high on temperatures - it's possible that lower southern Maryland could
see it get much warmer if the warm fnt pushes through during Erly afternoon
while Allegany County stays in m40s if cooler damming wedge is not
eroded b4 Sundown.
Long term /Tuesday night through Monday/...
A cold front will bisect the Ohio Valley Tuesday evening and slowly
progress eastward through Wednesday. The overall timing is just a
little slower than the overnight forecast cycle. A low will develop
over the southern Appalachians and lift along the front
Wednesday...which slows its eastward movement. A strengthening low level jet
and precipitable waters above an inch could lead to times of more moderate
showers. Even so...expected amounts and relatively dry antecedent
conditions should preclude flooding concerns. Total precipitation amounts
through Wednesday will range from 0.75 (nw) to locally in excess of
2 inches (se). There will be little change to temperatures Tuesday night
with most locations in the 40s. Sided with cooler guidance Wednesday
with highs in the middle 50s north/west and near 60f S/E.
Cold front pushes east Wednesday night...with the chance of rain
decreasing east of the Blue Ridge during the evening hours. However
middle/upper level trough will still need to rotate through...and there
is a fairly strong vorticity maximum associated with it. Have chance of snow
showers in favored upslope areas...although any amounts will be
light as moisture is not deep. Just decreasing clouds to the east.
Lows will drop into the 30s with low 40s east of I-95.
High pressure will build across the region Thursday and
Thursday night...allowing dry conditions with near average
An upper level disturbance will quickly slide across the
Great Lakes region Friday...but leaving no signature of
precipitation in the middle-Atlantic region. Temperatures will
remain near average.
High pressure will become reestablished across the middle-
Atlantic Friday night through Sunday night...bringing another
string of days of near average temperatures and sunshine.
High pressure moves offshore Monday...but dry conditions and
near average temperatures will continue.
Aviation /19z Monday through Saturday/...
Ceilings expeceted to stay at IFR levels through the rmdr of the daylgt hours and
tonight. Some imprvmnt is expeceted Tuesday afternoon as a cold fnt aprchs the amid
IFR or lower conditions will remain possible Tuesday night into
Wednesday with periods of rain...moderate at times. Cold front moves
through Wednesday afternoon...allowing ceilings/visibilities to improve.
Increasing westerly wind gusts to 20 knots in front/S wake.
VFR conditions Thursday through Thursday night. Winds gusting
over 20 knots Thursday.
Small Craft Advisory in effect in the Main Channel of Maryland ches Bay for remainder of
Southerly flow continues Tuesday night and Wednesday. Think low
levels will be stable enough to keep wind speeds below Small Craft Advisory criteria.
Cold front pushes east Wednesday afternoon and evening. Winds will
become westerly with Small Craft Advisory conditions increasingly likely Wednesday
Small craft advisories are likely Thursday. No marine hazards
District of Columbia...none.
Marine...Small Craft Advisory until 6 PM EST this evening for anz533-