Scientific Forecaster Discussion
Area forecast discussion...corrected
National Weather Service Baltimore Maryland/Washington District of Columbia
401 am EDT Wednesday Oct 22 2014
Low pressure will persist along the coast through Thursday. High
pressure will return to the area Friday and remain through the weekend.
Near term /today/...
As of 07z...upper low centered over the western Maryland shore of the
Chesapeake Bay per water vapor satellite imagery. The lower level
low is shifted a bit farther east per regional radar imagery. The
surface low is at most 1008mb and off the central middle-Atlantic coast per
obs/buoys. Middle-level instability ahead of the upper low has allow some
thunder over the Delaware-Maryland-Virginia with a few strikes in Harford County. This
low complex will continue to shift southeast through sunrise then
merely drift east through today. Thunder threat will end by sunrise
as the upper low moves east.
Rain will continue to rotate through the area this morning. The
heaviest will remain east of the Blue Ridge. Three inches storm
total is expected across Baltimore/Harford counties where one to two
have already fallen. Could be a flood threat there and this will
need to continue to be monitored. Otherwise...rain will retract east
from the Allegheny Highlands (though upslope persists) through the
afternoon as the low moves offshore.
Maximum temperatures limited by clouds and precipitation...around 60f for most of the
area. Raised temperatures to the low 60s for cho and shd based on expected
sunshine and downsloping northwesterly flow without cold air advection.
Short term /tonight through Thursday/...
There is not expected to be much which will help keep the strong
wind field above the surface. Therefore...the only expected Wind
Advisory threat for tonight is thought to be on ridgetops. Min
temperatures middle to upper 40s with sustained winds around 20 miles per hour for lower
Thursday...gusty. Think the 00z GFS is too high...but wind gusts of
30 to 40 miles per hour are expected as the low slowly moves northeast from the
central mid-Atlantic. Maximum temperatures upper 50s to low 60s in the well mixed
Long term /Thursday night through Tuesday/...
Time of partial eclipse for District of Columbia Thursday - 5:52 PM to 6:17 PM. Balt is
5:51 to 6:15. Approx 1/4 of sun will be covered...southwestern part of the sky.
Qustn will be whether it will be vsbl due to clouds...which should be
diminishing during this time period. Best chances for viewing will most likely
be in the western part of the County Warning Area and central shen vlly.
Cutoff low looks to be near Cape Cod Friday morning. High pressure building into
middle altc should provide good weather for the end of the workwk and then a
very plsnt weekend. Highs in the mu60s...lows gnrly in the 40s xcpt
l50s in the cities. This is pretty close to climatology norms for the
latter part of Oct.
A dry cold fnt may come through the area sun...then it's looking Lake A
big ridge of high pressure moves over the east CST for the 1st part of next
weak. Highs a70 lows in the 40s xcpt l50s in the city and along the Bay.
Aviation /07z Wednesday through Sunday/...
MVFR conds in periodic rain today as low pressure drifts east from
the area (currently right over the District of Columbia metros). Northwest winds increase
with gusts 25 to 30 knots by this afternoon. Strong winds tonight and
Thursday...gusts generally 30 to 35 knots.
VFR conds expeceted through the extend period. Winds should begin to abate Thursday night.
Periodic rain today with any thunder ending by middle morning. Small Craft Advisory
through today as northwesterly flow increases. Gales over at least the southern Maryland
waters tonight as the gradient increases. May need gales for all
waters tonight into Thursday.
Small Craft Advisory conds likely to continue Thursday night and Friday. It looks lake weekend boating
conds should be Good. Water temperatures in the m60s.
District of Columbia...none.
Marine...Small Craft Advisory until 6 am EDT Thursday for anz530>543.