Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Newport/Morehead City NC
411 am EDT sun Sep 21 2014
low pressure will lift north along the coast during the day today. A
cold front will move through the area Monday. High pressure will
build north of the area Tuesday and persist through the week while a
trough of low pressure lingers offshore.
Near term /today/...
as of 223 am sun...strong low pressure will off the coast this
morning...moving toward the north as upper level energy swings
through. Continued rain will extend over much of eastern North
Carolina...with the heaviest rain along the coast and Outer
Banks...closest to the low pressure. Precipitable waters will be
around 2 inches in the morning near the coast...diminishing further
inland. Limited instability so heavy rain will be the main threat.
As low lifts away from the area will have decreasing chances of
precipitation from west to east during the afternoon hours. With
decreased moisture and westerly flow...skies should become partly
cloudy. Temperatures should remain somewhat steady...or rise
slowly...during the morning with the extensive cloud cover...but
should recover quickly in the afternoon into the middle 80s.
Short term /tonight/... as of 235 am sun...flow will become
southwesterly this evening as a cold front approaches the area
from the west pushed by a deep upper level trough. Models in good
agreement on timing of this front. Will have increasing clouds
during the nighttime hours ahead of the approaching system. Not an
awful lot of moisture with this boundary...and upper level energy
remains west of the front...so am expecting pre-frontal conditions
to remain dry tonight. Front is expected to be over the area by
the end of the period...sunrise Monday.
Long term /Monday through Saturday/...
as of 345 am Sunday...a robust upper trough will move across the
eastern Continental U.S. Monday and Monday night while a cold front will push across
eastern NC Monday morning...then push offshore Monday afternoon. Models
continue to indicate a few showers during the morning across western
sections...but coverage expanding across eastern sections with
perhaps a few thunderstorms during the afternoon with a combination of
improving upper level dynamics with the region in the right entrance
of the upper jet...greater moisture with precipitable waters around 1.75" along
the coast...and slightly higher instability with diurnal heating.
Most models also indicating a few showers lingering along the
immediate coast Monday night with moist southwesterly flow persisting aloft as
the middle level trough axis remains just west of the coast. With the
above consideration have increased probability of precipitation Monday afternoon and Monday night.
Strong high pressure builds in from the northwest Monday night into Tuesday and
continues to ridge in from the north through the week as the high
slowly migrates across the middle-Atlantic and New England states
bringing comfortable fall like temperatures. However...models are
not in good agreement with the evolution of the upper trough beyond
Monday night which leads to increased uncertainty in the forecast for
middle to late week. The European model (ecmwf) cuts off the southern portion of deep
middle-level trough over South Carolina Tuesday afternoon through
Wednesday while the GFS keeps a broad trough over the eastern US. As
a result...the European model (ecmwf) is much wetter showing precipitation surging back into
the region Tuesday night through much of the rest of the extending
period while the GFS is drier with only a few showers lifting into
the region Thursday into Friday...mainly southern and eastern sections.
Wpc generally favors a blend of the European model (ecmwf) mean and GFS and followed
suit. Temperatures will remain fairly consistent with highs
middle/upper 70s with a few lower 80s and nighttime lows mainly in the
upper 50s to middle 60s through the period.
Aviation /08z Sunday through Thursday/...
short term /through tonight/...
as of 1253 am sun...IFR conditions across eastern North Carolina
tafs this morning low ceilings associated with areas of rain. Low
pressure off the coast will continue to pump moisture and showers
into the area through the nighttime hours and continuing through the
morning hours. Will also have reduced visibilities in the areas of
rain. As the low pressure moves up the coast...expect improving
conditions to MVFR to start middle morning with VFR conditions expected
by early afternoon over all sites as the low pressure moves north of
the area with decreasing moisture...and low level flow becomes more
Long term /Monday through Thursday/...
as of 345 am Sunday...could see some temporary reductions to MVFR
with a few showers along the cold front Monday. Inland tafs mainly
affected in the morning...then transitioning to coastal sections
during the afternoon. High pressure building in from the north Tuesday
and expect pred VFR. Model uncertainty exists between GFS/European model (ecmwf) on
extent of moisture/precipitation into the area Wednesday and Thursday leading
to below normal confidence in the forecast...but could see some
showers with reduced ceilings/visibilities if the wetter European model (ecmwf) solution
verifies. A more moist boundary layer by Wednesday and Thursday may
also lead to patchy fog during the late night and early morning
hours with MVFR and possible IFR conditions.
short term /today and tonight/
as of 214 am sun...low pressure off the South Carolina coast will
move north through the North Carolina waters today. East and
northeasterly flow will run 20 to 25 knots as the gradient tightens
with the approaching low pressure. Seas will remain 6 to 8 feet this
morning. Low expected to be north of the waters by early afternoon
with wind turning around to northwesterly. Speeds will remain 20 to
25 knots until the low moves out of the area during the afternoon
hours when the relaxing gradient will allow the northwest and
westerly flow to drop to 10 to 15 knots. Flow will become
southwesterly by late afternoon ahead of an approaching cold front.
Seas 4 to 5 feet in the southern waters...remain 5 to 6 feet in the
northern waters. Speeds will pick up again to around 20 knots after
sunset with the tightening gradient....allowing seas to remain above
Small Craft Advisory criteria in the northern waters through the night.
Long term /Monday through Thursday/...
as of 345 am Sunday...poor boating conditions expected for much of
the long term. A cold front will push across eastern NC Monday...
pushing into the offshore waters during the afternoon. SW/west winds
around 10-20 knots shift to northwest/north around 10-15 knots after frontal passage Monday
afternoon into Monday evening. North/NE winds increase to around 15-25 knots
late Monday night and continue through the rest of the long term as
strong high pressure builds into the region from the north and a weak
inverted trough lingers offshore. Longer range wavewatch guidance
indicates that elevated seas and Small Craft Advisory conditions are
likely to extend into next weekend.
Marine...Small Craft Advisory until 8 am EDT Monday for amz150-152-154.
Small Craft Advisory until 9 PM EDT this evening for amz156-