Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Newport/Morehead City NC
151 PM EDT Monday Apr 27 2015
high pressure will build into the area through Tuesday. Low
pressure will affect the area Wednesday into Thursday. High
pressure will build in over the weekend and remain into the
beginning of the week.
Near term /until 6 PM this evening/...
as of 1010 am Monday...mid-morning update mainly to capture temp,
dewpoint, sky cover trends. A quasi-stationary vertically stacked
low pressure system will reside over the Canadian Maritimes though
the near and short term periods with surface high pressure ridges
into the region from the northwest. Expect dry conditions today
with precipitable waters below 0.50" from the 12z kmhx sounding and forecast
soundings, but with steep low level lapse rates expect to see
scattered cumulus develop this afternoon. With more sunshine and
low level thicknesses around 1350-1360 meters expect highs a few
degrees either side of 70 f...except low to middle 60s across the obx.
Short term /6 PM this evening through 6 am Tuesday/...
as of 4 am Monday...expect period of clouds this evening into the
early morning hours Tuesday as a rather robust vorticity lobe pivots
around the upper low to the northeast...with clearing late. The
sub-cloud layer remains very dry and not anticipating any precipitation
to reach the ground so will keep probability of precipitation below 15 percent. Light
mixing and a dry airmass at the surface will prevent fog development
tonight. Lows expected to be around 5-10 degrees below normal...in
the middle 40s inland to upper 40s to around 50 along the coast.
Long term /Tuesday through Sunday/...
as of 4 am Monday...coastal low to affect the area for the midweek.
Tuesday/Tuesday night...with weak surface ridge of high pressure
in place...expect dry weather with light north/NE winds with
comfortable high temperatures around 70 with dewpoints down in the
low/middle 40s during the afternoon.
Wednesday/Wednesday night...as an upper low closes off over the
Tennessee/Ohio Valley region...strengthening surface low pressure
will move across Georgia and South Carolina during Wednesday and
Wednesday night. Expect light precipitation to reach our far
western counties during the morning hours on Wednesday and
overspread the area Wednesday afternoon/night with probability of precipitation increasing
to likely over much of the area.
Thursday/Thursday night...the strengthening sub-1000 mb low will
move along our coast Thursday morning then move slowly north of
the area by Thursday night. Strong middle-level shortwave energy on
the back side of the low will lead to continuing good chances of
rain...especially over the northeastern half of the County Warning Area and Outer
Banks into Thursday night.
Friday/Friday night...as the surface and attendant upper low move
slowly north up the middle-Atlantic coast on Friday...there will
still be sufficient energy in the middle-levels to steepen lapse
rates and lead to at least a small chance of light rain.
Saturday through Sunday...as the strong surface low finally
stubbornly moves away from the middle-Atlantic region...high pressure
will build in over the region for the weekend with dry weather and
temperatures slowly edging closer to normal with highs into the
middle 70s and lows in the middle 50s.
Aviation /18z Monday through Saturday/...
short term /through 12z Tuesday/...
as of 140 PM Monday...VFR conditions will prevail through the taf
period. Scattered clouds have developed this afternoon with
daytime heating. Expect clear skies...tonight through Tuesday as
high pressure builds in from the northwest. Not expecting any fog
development as there will be a light northwest wind flow.
Long term /Tuesday through Friday/...
as of 405 am Monday...VFR conditions are expected Tuesday as dry
high pressure builds over the region. Conditions deteriorate by
early Wednesday through Thursday as strengthening low pressure
moves slowly along the coast. Widespread rain will likely lead to
periods of sub-VFR ceilings and visibility. Conditions improve
Friday...but there will still be sufficient upper energy for some
widely scattered showers.
short term /tonight and Monday/...
as of 1015 am Monday...latest surface and buoy observations indicate
north/north-northwest winds 10-15 kts across most waters with Diamond buoy gusting
above 20 knots and seas hovering between 5-6 feet. Adjusted forecast to
indicate the 6 feet seas lingering slightly longer but did not reissue
scas for the now, considering the scas already in effect for tonight
into early Tuesday morning. High pressure ridging in from the northwest with
northwest winds around 5-15 knots is expected to continue across the
waters today, though may become onshore near the southern coast
this afternoon as a seabreeze tries to develop, especially along
the Crystal Coast. Seas will remain around 3-5 feet north and 2-4
A robust vorticity maximum associated with a vertically stacked low pressure
across the Canadian Maritimes will move across the region tonight
which will serve to tighten the pressure gradient, especially
after midnight. Expect north to northwest winds to increase to
10-20 knots and possibly briefly around 25 knots across the central and
northern waters late tonight. Seas build back to 4-6 feet north of
Ocracoke Inlet but continue around 2-4 feet to the south. Raised
another Small Craft Advisory for the surge expected late tonight through Tuesday
Long term /Tuesday through Friday/...
as of 410 am Monday...Small Craft Advisory conditions will be
ongoing at the beginning of the period early Tuesday before ending
around 18z Tuesday. Expect light north winds Wednesday and
Wednesday night...becoming more easterly by late Wednesday night
and increasing to at least 10 to 15 knots. Lots of uncertainty
regarding the marine forecast for Thursday into Friday...all
dependent on eventual track of surface low. Best consensus is
bringing the low right along the coast and latest model wind
fields would keep bulk of the stronger winds further offshore and
currently have the strongest winds at 15 to 20 knots from the
northwest Thursday night into Friday. Seas build to 4 to 6 feet
during this period. Deviation in the track of the low could lead
to much higher winds and will continue to monitor.
Marine...Small Craft Advisory from 4 am to 1 PM EDT Tuesday for amz150-