Scientific Forecaster Discussion
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Area forecast discussion...updated
National Weather Service Baltimore Maryland/Washington District of Columbia
929 PM EDT Friday Apr 18 2014
high pressure over New England will stretch southward toward the
middle-Atlantic coast this evening. An area of low pressure will
pass through the southeast states Saturday. A cold front looks to
move through the region Tuesday. High pressure will build back
into the region Wednesday.
Near term /through Saturday/...
surface high pressure will continue to move east off the middle
Atlantic coast tonight. High clouds will stream overhead through
the night as low pressure moves across Florida and off the
Georgia coast on Saturday. All of the rainfall associated with
this system is expected to stay south of the forecast area
overnight and into Saturday. High pressure will ridge across the
region helping to scour remaining cloud cover leading to a
pleasant Saturday. Afternoon high temperatures will likely reach
the 60s in most locations.
Short term /Saturday night through Monday night/...
surface high pressure will build southeastward along the eastern
slopes of the Appalachian Mountains Saturday night as an upper level
high builds east across the Ohio Valley toward the middle Atlantic
coast. Temperatures will lower into the lower to middle 40s. Winds
will be northeast and light.
During the day Sunday into Sunday night...high pressure shifts
offshore only to hug the coastal areas. Conditions will be dry with
light and variable winds. High temperatures Sunday will reach the
middle 60s across much of the region...a few degrees below normal.
Long term /Tuesday through Friday/...
an upper level through will dig across the eastern US over the
first half of next workweek. The associated low will deepen over
the Great Lakes Monday night before progressing off of the New
England coast during the day on Wednesday. This low will swing a
cold front through the middle Atlantic during the day on Tuesday and
Tuesday evening...likely bringing rain for the entire area.
Eastern portions of the County Warning Area could see high temperatures in the middle to
upper 70s on Tuesday in prefrontal warm air advection. Confidence
is low in the potential for weak instability ahead of the cold
front...so left thunder out of the forecast for now...but may have
to add thunder if confidence increases that solar heating will be
plentiful enough to destabilize the atmosphere ahead of the front.
Cooler air will work its way into the area Tuesday night and
wednesdays highs will be in the about 10 degrees cooler than
tuesdays. High pressure will settle in along the eastern Seaboard
for the second half of the workweek...leading to dry conditions
through Friday morning. Low pressure over the Northern Ohio valley
could bring a warm front through the area Friday.
Aviation /02z Saturday through Wednesday/...
VFR conditions expected during the valid taf period.
VFR conditions Saturday night through Monday with high pressure in
control. Winds northeast 5 to 10 knots becoming light and southerly
by Monday. IFR conditions are possible in low ceilings and rain
showers as a cold front passes the area Tuesday.
east flow is expected to switch to the north for Saturday...but speeds are
expected to remain below Small Craft Advisory thresholds through the period.
No marine hazards expected Saturday night through Monday. High
pressure will shift offshore and hug the coast...keeping a slight
onshore flow across the waters. A Small Craft Advisory may be
necessary Wednesday through Thursday morning in breezy Post
frontal northwest flow.
District of Columbia...none.