Area forecast discussion
National Weather Service Baltimore Maryland/Washington District of Columbia
914 PM EDT Tuesday Jun 18 2013
Synopsis...
a weak cold front will sag south through the area overnight. High
pressure will build behind this front Wednesday....remaining off
the northern middle- Atlantic shore through this weekend.
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Near term /until 6 am Wednesday morning/...
cold front on northwestern doorstep. Area clrd out nicely bhd afternoon shra/tsra...
but a few thunderstorms and rain have survived...making its way into northern Maryland/eastern wva.
WRF-arw4 has been capturing evolution well thus far...and will be
basing updt on it. Radar trends have been downward in terms of
strength...but do feel we/ll be able to hold onto at least isolate
activity for at least several more hours. Probability of precipitation have been retooled to be
more cdfnt-centric.
While there may be a decent surge of drier air coming bhd the
fnt...am wondering if it/ll make it into County warning forecast area until mixing returns
aftr daybreak. Therefore...have maintained flow becoming northerly but have
resisted some model guidance suggesting that winds will pick up overnight. That
makes patchy fog more possible...but condensation will be fighting
dropping dewpoints.
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Short term /6 am Wednesday morning through 6 PM Wednesday/...
surface high builds across the northern mid-Atlantic...pushing frontal
boundaries south. Light north flow will keep temperatures below
normal...expect highs in the upper 70s to around 80f. Dry and mostly
sunny.
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Long term /Wednesday night through Tuesday/...
near normal temperatures in return flow midweek through the weekend.
Isolate/scattered afternoon thunderstorm activity in the terrain west from
the Blue Ridge each day. Low pressure will be exiting the CST Wednesday morning west/
high pressure building in from the upper Midwest. Very plsnt days/ngts expeceted
Wednesday and Thursday west/ highs in the l80s..lows ranging from the m50s in The
Highlands to the m60s in the cities.
&&
Aviation /01z Wednesday through Sunday/...
cold front will be dropping across area overnight. Scattered rain showers/thunderstorms and rain appchg from the
north. These seem to be missing mrb on all sides. Only other site at
risk may be iad...but they should be decaying by that point. Its
still qstnbl whether whatever is left wll miss terminal to the west.
Otherwise...chances of any rain showers/thunderstorms and rain overnight very low. If an Airport is
affected...it/ll be a brief period of MVFR to perhaps IFR visibility
restriction.
Areas MVFR fog possible overnight...contingent on how quickly drier air
mvs southward and whether winds dcpl or not. That places hiest risk at
cho. Any restriction should erode fairly quickly after sunrise.
VFR conds and light flow expected outside of potential morning fog
through the weekend.
&&
Marine...
north winds will occur bhd a weak cold front overnight. Some guidance suggesting values
may approach Small Craft Advisory criteria during the surge of drier air. Am
skeptical of that at this time...and have kept winds 10-15 knots. However...may
experience an increase once daytime mixing resumes.
Winds expeceted to remain below Small Craft Advisory values through the weekend.
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Lwx watches/warnings/advisories...
District of Columbia...none.
Maryland...none.
Virginia...none.
WV...none.
Marine...none.
&&
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