Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Newport/Morehead City NC
150 am EDT Monday Sep 22 2014
a strong cold front will move through the area Monday morning.
High pressure will build north of the area Tuesday and persist
through the week while a trough of low pressure lingers offshore.
Near term /tonight/...
as of 1215 am Monday...added slight chance of showers northwest half of
area overnight. Scattered showers ahead of front are holding together
moving east of rah...and latest mesoscale models support isolated activity
northwest sections overnight. Minor adjustments to sky cover as well...but
temperatures and winds okay.
as of 945 PM Sunday...minor adjustments made to temperature/ dew point
trends. Return flow has developed across the area as a cold front
is now on the Lee side of the Appalachians. Although clear across
the region...clouds will increase in the early morning hours ahead
of the front. Tems still prognosticated to settle into the middle 60s inland
to low 70s along the immediate coast.
Previous discussion...water vapor imagery indicates a strong
northern stream shortwave moving into the northeast this evening.
This system will accelerate a surface cold front currently moving
through the Appalachian Mountains...through most of eastern NC by
12z Monday morning. Scattered convection attendant to the cold
front is forecast to diminish with loss of heating and veering
downslope westerly flow over NC. Thus not expecting any
precipitation overnight although a stray shower cannot be ruled
out late far western zones. Expect patchy middle clouds to stream
across the area tonight. No change to overnight low temperatures
with readings in the middle/upper 60s inland and lower 70s along the
Short term /Monday/...
as of 605 PM Sunday...main forecast concern is precipitation
forecast Monday as front is forecast to briefly stall along or
just off of the southeast coast. A narrow ribbon of moisture is
expected over the region but with only weak low level convergence
expected think precipitation chances will be low. Will indicate a
30% chance over the eastern portion of the area and will also add
a chance for thunder along the Crystal Coast where frontal
interaction with the sea breeze may enhance potential for deep
convection during peak heating. Despite a wind shift to northwest/north
during the morning...there should be enough breaks in the clouds
to allow temperatures to still reach the upper 70s/low 80s by
early afternoon as cold advection will be delayed until Monday
Long term /Monday night through Sunday/...
as of 315 PM Sunday...a robust upper trough will move across the
eastern Continental U.S. Monday and Monday night. Models continue to indicate a few
lingering showers along the immediate coast Monday night into early
Tuesday morning with moist southwesterly flow persisting aloft as the middle
level trough axis remains just west of the coast. Strong high
pressure at the surface 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 12z European model (ecmwf) is similar to its 00z
run which 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. The European model (ecmwf) also suggests an
inverted trough setup along the Carolina coast. 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 though continued a
small blend with the GFS to account for guidance disagreement.
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 /06z Monday through Friday/...
short term /through 06z Tuesday/...
as of 145 am Monday...prevailing VFR conditions are expected through
the taf period. Main weather maker will be a rapidly moving cold
front which will move through most of eastern NC by 12z this morning
before deaccelerating this afternoon near the southeast coast.
Scattered showers will be in the vcty of kpgv next few hours...then
threat expected to be isolated and not warrant inclusion in tafs.
Pressure gradient ahead of front will keep winds mixed enough to
preclude fog early this morning. Wind shift to nearly with frontal passage this
morning but speeds less than 10 knots through the day.
Long term /Monday night through Friday/...
as of 315 PM Sunday...high pressure will build south into eastern
NC Monday night and persist through midweek. 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 /tonight and Monday/
as of 1215 am Monday...no changes with update except to add slight
chance of showers alb sound overnight per near term discussion.
as of 945 PM Sunday...no changes needed to the update. Return flow
has developed (10-15kts with higher gusts) across all waters as a
cold front approaches from the west. Winds will increase slightly
as the gradient tightens ahead of the front which will cross
Monday morning. Currently...seas are 4 to 6 feet across the
northern/central waters and 3 to 4 feet across the southern
Previous discussion...Small Craft Advisory will continue for the
central and northern coastal waters as seas continue around the 6
foot range at the buoys. Winds have dropped off a bit as they
continue to back to the west...but are expected to increase to 15
to 20 knots overnight as a cold front approaches the waters late
tonight. The front is expected to move offshore Monday morning
getting hung up over the southern waters during the afternoon.
Winds will shift to the northwest/north behind the front Monday. Latest local
Swan model shows seas in the 4 to 5 foot range during the day
Long term /Monday night through Friday/...
as of 315 PM Sunday...poor boating conditions expected for much of
the long term. High pressure well north of the waters will build
south into the region Monday night through middle week with NE winds
15-25 knots and elevated seas 5-7 feet with nearshore seas 3-5 feet. Some
guidance indicates a weak inverted trough develops offshore by Wednesday
while other guidance suggests an inverted trough develops much
farther south with little impact on the NC coastal waters.
Uncertainty is higher than average beginning Wednesday due to these
differences. Long range wavewatch guidance indicates that elevated
seas and Small Craft Advisory conditions are likely to extend into
Marine...Small Craft Advisory until 8 am EDT Monday for amz150-152-154.