Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Newport/Morehead City NC
336 am EST Thursday Nov 26 2015
high pressure will extend over the Carolinas from the northeast
through early next week. A cold front will approach from the west
Tuesday and move offshore Wednesday.
Near term /until 6 PM this evening/...
as of 2 am Thursday...high pressure has now shifted off the New
England coast but continues to nose southwest across the middle-
Atlantic and Carolinas. A weak inverted/coastal trough remains
along the NC coast. A very sharp moisture gradient exists across
eastern NC as noted in 0421z satellite blended total precipitable
water product, which indicates precipitable water values around 0.9-1.0 inches
just off the coast to 0.6-0.7 inches across our coastal plain
counties. Kmhx radar trends indicate weak returns migrating
westward off the ocean but most light showers dissipate as they
progress west into the drier environment. Will hold onto slight
change probability of precipitation for the far eastern zones (coastal Carteret, Hyde and
Dare counties) though expect quantitative precipitation forecast amounts to be less than 0.05
inches. Middle clouds have also migrated westward with better
moisture, inhibiting maximum radiational cooling for inland
locations. Low temperatures will range from the middle 40s inland to middle 50s
along the coast. Removed mention of fog from forecast as clouds
will inhibit cooling and formation of surface-based inversion
needed to decouple winds.
The surface ridge over the Canadian Maritimes will shift farther
east today though continue to extend southwestward over Easter NC.
Blocking across the north-central Atlantic Ocean will aid in the
development of a broad upper low over the western Atlantic with
weak upper ridging nosing northeast across the Carolinas. The weak
inverted/coastal trough appears to diminish today and have removed
probability of precipitation for coastal/obx areas though will keep a small slight chance
for the coastal waters since cannot completely rule out weak
showers in higher moisture environment. 1000-850 mb low- level
thicknesses continue building trend today, reaching 1350-1355
meters this afternoon supporting maximum temperatures in the low 70s across
inland sections to middle 60s along the coast, despite northeasterly
flow across the region.
Short term /6 PM this evening through 6 am Friday/...
as of 2 am Thursday...the surface ridge well northeast of the
region will continue to extend over eastern NC tonight though a
secondary ridge centered over western NC/Virginia appears to take over
the regime by late tonight/early Friday morning which will shift
winds more northerly than the persistent east-northeasterly flow
experienced over the past few days. Some guidance continues to
indicate a weak coastal/inverted trough along the NC coast tonight
so will maintain a slight change pop for the coastal waters but
keep eastern NC dry. Partly cloudy skies will inhibit maximum
radiational cooling with light northeasterly winds. Minimum temperatures
expected in the middle 40s inland to the middle/upper 50s along the
Long term /Friday through Wednesday/...
as of 325 am Thursday...relatively dry and seasonal weather
through the weekend. A better chance of rain early next week.
Friday through Sunday...will continue low probability of precipitation along the immediate
coast on Friday as pesky inverted trough lingers along the coast.
Any rainfall amounts will be very light. Upper ridge should hold
over the region through Saturday as the coastal trough dissipates.
The ridge flattens a bit on Sunday with heights lowering bringing
slightly cooler temperatures even though the main axis of moisture
remains north of the area and no rainfall is expected.
Temperatures will be some 10 degrees above normal Friday and
Saturday as highs into the lower 70s Friday and upper 60s on
Sunday night through Wednesday...with the upper level flow becoming
southwest with embedded shortwave energy in the flow Monday and
Tuesday...rain chances will slowly increase. Expect showers to be
more spotty on Monday with a slightly better coverage on Tuesday as
models indicate a bit more lift and quantitative precipitation forecast.
The GFS is more progressive in drying the area out on Wednesday
while the European model (ecmwf) holds on to a bit more moisture and chances of
rain early in the day. Have trended toward the drier solution for
Wednesday. With the upper level flow remaining west/SW through
midweek...do not expect any intrusions of any unseasonably cold
air with temperatures generally at or above normal.
Aviation /08z Thursday through Monday/...
short term /through 06z Friday/...
as of 1 am Thursday...VFR conditions expected through the taf
period. High pressure over the Canadian Maritimes continues to
nose south over eastern NC through today. Brief steam/ditch fog
has been problematic over the past few nights but conditions are
not as favorable tonight thanks to increased middle clouds and
boundary layer mixing, thus mentioned MVFR fog conditions as
tempo from 08-12z for pgv/iso/oaj. Northeasterly winds less than
10 knots expected today.
Long term /Friday through Tuesday/...
as of 330 am Thursday...VFR conditions should continue through
the weekend with limited moisture. As usual can not rule out
possibility of patchy early morning fog/stratus most mornings.
Lower clouds are likely to increase Monday and especially Tuesday
as rain chances increase and some brief sub-VFR conditions are
short term /today and tonight/...
as of 210 am Thursday...latest surface and buoy data indicate
northeast winds 10-20 kts with seas 5-8 feet across the coastal
waters. No changes to ongoing small craft advisories as building
swell due to broad low pressure far offshore and Canadian high act
to increase long period northeasterly fetch. Local nwps/Swan and
wavewatch in good agreement on seas building 6-8 feet by this
afternoon, and 7-9 feet tonight.
Long term /Friday through Monday/...
as of 335 am Thursday...Small Craft Advisory conditions will
continue on the coastal waters through the extended period as very
strong northern Atlantic high pressure leads to a long east-northeast fetch
of winds generally 10 to 15 knots with some gusts to 20 knots
mainly Friday and Friday night. This will send continuous east-northeast
swells toward the Carolina coast with seas as high as 8 to 10 feet
particularly in the Friday through Saturday time frame. Elevated
seas may continue into the middle of next week as another strong
high builds south from New England early next week.
as of 3 PM Wednesday...persistent east-northeasterly fetch will
result in building long period swells through the end of the week,
which may combine with high astronomical tides to produce high
surf/minor coastal flooding/beach erosion issues during high tide
Marine...Small Craft Advisory until 7 PM EST Sunday for amz152-154.
Small Craft Advisory until 7 am EST Sunday for amz156-158.
Small Craft Advisory from noon today to 7 am EST Sunday for