Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Wakefield Virginia
324 am EDT Thursday Sep 18 2014
a weak cold front crosses the area this afternoon and evening.
High pressure builds south and across the middle Atlantic region
through the upcoming weekend.
Near term /today/...
latest msas showing high pressure over the region with the old frontal
boundary stalled along the Gulf Coast extending NE to a low off the
Carolina coast. A secondary cold front was moving south from the
Leaned toward the sref solution once again. Models agree in moving the
high off the coast today. Upper low over eastern Canada begins to fill and
move east allowing the cold front to move south and cross the forecast area
this afternoon & evening. A weak middle level short wave prognosticated to track along
the mts with this front. This feature provides just enough support
for some shower activity across western half of forecast area with the best sprt
over the northwestern most counties. Kept 20 pop western half of forecast area xcpt 30 pop
across northwest Piedmont. Any measurable precipitation will be minimal...a few
hundredths at best. Some patchy fog to start out the day will yield
to pt sunny skies. Highs 75-80.
Short term /tonight through Saturday/...
front settles south of the area tonight with high prs building in
from the north. Mainly dry...xcpt for a few lingering showers across
the Piedmont early. Lows m50s-l60s.
Tsctns continue to show some middle & upper level moisture across the area Friday
and Friday night along with a east-NE wind. Dry as models don't sprt any
precipitation. Highs M-u70s. Lows in the m50s-l60s.
Data showing moisture increasing a bit along southeastern coastal sctns Sat as a weak
trough prognosticated to rotate west and apprch the coast Sat morning. This
could be enough of a trigger for some lght showers across the southeastern coastal
areas. Confidence rather low that this occurs...so kept isolated probability of precipitation
along the southeastern coastal areas for now. Temperatures moderate to near seasonable
norms. Highs u70s-l80s.
Long term /Saturday night through Wednesday/...
mainly going with a blend of the 12z GFS and 12z European model (ecmwf) for the
extended period. The center of hi pressure will move into the northern Atlantic
Sat night. Weak low pressure will lift NE off the southeast and middle Atlantic CST Sat
night into Monday morng. Will maintain a dry forecast during this period
with a mostly clear or partly cloudy sky. Lows Sat night in the upper
50s to middle 60s. Highs on sun in the upper 70s to lower 80s. A cold
front will cross the area late Sun night and Monday...bringing a slight
chance of showers. Hi pressure will then build from the lower Great Lakes ewrd into
southern New England Tuesday through Wednesday. Lows will range through the 60s Sun
night...range from the upper 50s to middle 60s Monday night...and range through the
50s into the lower 60s Tuesday night. Highs in the upper 70s to lower 80s
Monday...and mainly in the lower to middle 70s Tuesday and Wednesday.
Aviation /07z Thursday through Monday/...
VFR expected to persist through the 06z taf period. Short wave
trough moving through area this afternoon/evening may bring threat
of showers/possible thunderstorms. However...timing and expected coverage too
uncertain to include in tafs at this time.
High pressure slowly builds across the Great Lakes into New
England through Sat...with a somewhat breezy 10-20 knots NE flow
continuing at korf/kecg. Overall...still expect a fair amount of
cloud cover in this pattern but likely too much mixing and
overnight cloudiness for any significant fog development.
Small Craft Advisory for seas around 5 feet will continue south of the Virginia border
through 10z (6am).
NE or east winds will dominate the waters through Sat...due to hi pressure bldng
from the Great Lakes eastward and off the New England CST. Wind speeds will
likely remain around 15 knots or less through the period. Waves will be 1 to
3 feet and seas generally 2 to 4 feet through Friday. Some longer period
swells (12-15 sec) will continue today due to distant tc Edouard. A
little stronger NE or east winds expected Friday and Friday night due to strong
hi pressure to the north-northeast. This will result in waves 2 to 3 feet (possibly
reaching near 4 feet mouth of the bay)...and seas bldng to 4 to 5 feet
by late Friday into Sat.
Maryland...moderate rip current risk through this evening for mdz025.
NC...moderate rip current risk through this evening for ncz102.
Virginia...moderate rip current risk through this evening for vaz098>100.
Marine...Small Craft Advisory until 6 am EDT early this morning for