Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Newport/Morehead City NC
1209 am EDT Wednesday Sep 17 2014
a cold front will move through the area late today and tonight.
High pressure will build over the area from the north Wednesday
through Saturday. The high will move off the coast Sunday ahead of
the next cold front...which is expected to move through the
Near term /until 6 am this morning/...
as of 1210 am Wednesday...just issued new set of zones to account for
convection moving southeast across far southern counties. Counties
near the Albemarle Sound will likely remain dry overnight.
Previous disc...clouds increasing over eastern North Carolina this
evening as upper level energy moves across the area. Thunderstorms
west of the area moving east. Timing brings them into western
sections of forecast area by around midnight. Current forecast
covers this...except will up the probability of precipitation in the western sections.
Surface boundary lying east to west across the area with some
showers along it over the Outer Banks area. Boundary slow to move
at this time...but still expect it to be south of area by sunrise.
Short term /6 am this morning through 6 am Thursday/...
as of 250 PM Tuesday...the front will continue to move south of the area
Wednesday as a weak wave of low pressure develops along it. Surface high
pressure will build into the area from the north as upper trough
deepens along the eastern Seaboard. Models continue to show scattered
showers/thunderstorms developing as weak shortwave moves through flow
aloft. Will continue low chance/SC probability of precipitation through the day...with
best chances across the southern half of forecast area. Low level
thickness values...NE/E flow...and 850mb temperatures 12-14c support
highs 75-80 degrees.
Long term /Thursday through Wednesday/...
as of 230 PM Tuesday...there will be a moist onshore flow early this
forecast period with some short wave energy as a broad trough over the
eastern states gradually sharpens. Moisture should be limited with
only light showers and sprinkles expected. Will forecast slight
chance precipitation for Wednesday night and Thursday. Lots of low cloud cover
expected Wednesday night and Thursday which will hold high temperatures in the middle to
upper 70s Thursday. Lows Wednesday night low to middle 60s across inland areas and
upper 60s to low 70s coast.
The upper ridge gradually builds over the area late in the week and
during the weekend and will continue a mostly dry forecast Friday
through Sunday. The only chance albeit slight for precipitation appears to be along
the immediate coastal sections Friday night and Sat associated with a
weak coastal trough. Temperatures slowly moderate back to near normal levels
into the low 80s by the end of the weekend.
Aviation /04z Wednesday through Sunday/...
short term /through tonight/...
as of 627 PM Tuesday...mainly clear skies across area tafs this late
afternoon...but with some isolated to scattered middle level clouds.
Surface boundary is draped from the central Outer Banks to around
Kinston...and will continue to drop south through the area. Some
showers have formed along the boundary over the waters. Any showers
that do form tonight will be isolated in nature...so have not
included them in the tafs. However subvfr conditions likely in any
showers. Models not agreeing on timing of boundary...however it
should be south of the tafs by the early morning hours.
Northeasterly flow behind the front will be light with loose surface
gradient. Areas of MVFR fog possible in the predawn hours...and may
have MVFR ceilings in the afternoon in the moist northeasterly flow.
Weak upper level energy will move over eastern North Carolina
Wednesday afternoon for a chance of some showers/thunderstorms. Have
not included them as probability is low.
Long term /Wednesday night through Sunday/...
as of 230 PM Tuesday...mainly VFR conds expected through Thursday except for
patchy late night fog/and stratus. Mainly VFR conds expected Friday
through Sunday as a stronger high builds in from the north with less precipitation
chances and better low level mixing reducing fog/St threat. Could be a
few showers along coastal areas Friday night into Sat but should be
limited in coverage.
short term /through Wednesday/...
as of 925 PM Tuesday...front is moving slowly toward the south with
continued northeasterly wind over the northern waters and south
southwesterly flow over the southern waters. Still on track to move
south of the waters by sunrise.
Previous disc...as of 639 PM Tuesday...northeasterly flow in the northern
waters with southwesterly flow continuing in the southern waters
this late afternoon. Speeds 10 knots or less with seas 2 feet.
Surface frontal boundary has dropped into the central waters...and
will continue to sag southward through the waters during the
nighttime hours with wind becoming generally northeasterly by
sunrise. Models disagree on strength of surge behind the
front...ranging from 10 to 20 knots. Will go on the lower range.
Long period swell...13-16 seconds...from distant tc Edouard showing
up in the buoy observations. However seas remain at 2 feet.
Wavewatch and local nwps continue to run 1-2ft higher than hurricane
wavewatch. Will again back up the timing of the Small Craft Advisory
until sunrise Wednesday based on current observations and model
Will continue seas 4-6ft Wednesday mainly in long period southeasterly swell. Wind
will be northeasterly around 10 knots with high pressure building
over the waters.
Long term /Wednesday night through Sunday/...
as of 230 PM Tuesday...wave models are consistent showing long period
swell from distant tc Edouard at 5-7 feet through Wednesday night. Swell will
diminish Thursday and should be a period of sub Small Craft Advisory seas...however NE winds
will begin to increase Thursday to 15 to 25 kts late and continue through Friday
with seas again building to 5 to 7 feet into the early part of next
weekend sply across the central waters.
Marine...Small Craft Advisory from 8 am this morning to 9 am EDT Sunday
Small Craft Advisory from 2 PM this afternoon to 5 am EDT
Thursday for amz156-158.
Small Craft Advisory from 11 am this morning to 5 am EDT
Thursday for amz150.