Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Newport/Morehead City NC
1259 PM EST Thursday Jan 29 2015
high pressure will move offshore this afternoon. A cold front with
limited moisture will move through the area late tonight into Friday
morning. High pressure will build over the area late Friday into
Sunday. Another frontal system will affect the area Sunday night
into Monday with high pressure building into the area Tuesday.
Near term /until 6 PM this evening/...
as of 1230 PM Thursday...no changes with update.
as of 615 am Thursday...high pressure cresting over the area this
morning will move slowly offshore this afternoon with light winds
expected. The next shortwave moving across the eastern US will
approach late with a gradual increase in high clouds this morning and
middle clouds late today. Return flow does not develop until late when
clouds will be increasing. This will limit high temperatures a bit
with expected highs most locations 45 to 50 degrees.
Short term /6 PM this evening through 6 am Friday/...
as of 330 am Thursday...main concern tonight is how much
precipitation develops ahead of advancing cold front associated
with low pressure moving across the northeast states. None of the
models generate much in the way of quantitative precipitation forecast (<0.10") but MOS probability of precipitation in
all guidance for all of our sites are in the 20-50% range (highest
coastal locations). Think best approach is to use a blend of the
MOS which resulted in 20% probability of precipitation far inland and north and 40% coast.
Think the area that has the best chance to see some light
measurable precipitation will be south of Highway 264 and east of
Highway 17 in the 8z-14z time frame. Overnight lows will be in the
middle to upper 30s and may occur in the evening as winds expected to
pick up out of the southwest around midnight. With a deep low
layer of above freezing temperatures not expecting any p-type
Long term /Friday through Wednesday/...
as of 330 am Thursday...the cold front will reside well off the
Carolina coast Friday evening while the upper trough shifts
northeast into New England. High pressure over the midwestern
states will build southeast over the region Friday night through
Saturday. Northwesterly winds diminish somewhat Friday night with
low temperatures well below normal...low 20s inland to near 30 along the
coast with a lingering breeze making temperatures feel like the teens.
Despite full insolation Saturday...low level thicknesses fall to
1280-1290 meters yielding temperatures in the low to middle 40s with some
upper 30s across the northeastern portions of eastern NC. The
surface ridge center will shift east through South Carolina
Saturday and off the southeastern U.S. Coast by Saturday night.
Saturday night will see moderating temperatures despite mainly calm
winds. Middle and high level cloud cover will increase late as warm air advection
aloft develops ahead of next system. Lows will quickly fall into
the upper 20s prior to midnight before a leveling off of temperatures or
a slight rising trend ensues.
Disagreement amongst model suite for the Sunday night into Monday
system continues with 00z guidance. A broad short wave will swing
through the eastern Continental U.S. With weak cyclogenesis across the
Carolinas/Virginia Sunday night. Large spread amongst deterministic
guidance with the GFS upper shortwave and surface low development
deeper and farther west...the Gem much slower than all other
guidance...and the European model (ecmwf) weaker with its upper/surface solutions
and closer to the coast. Respective ensembles also suggest wide
spread indicative of inconsistency within model scheme and between
models. Despite the uncertainty...it appears a high pop/low quantitative precipitation forecast
scenario is likely as plentiful moisture will be available with
the system despite relatively weak forcing aloft.
It is Worth mentioning that if enough moisture is present on the
backside of the departing and strengthening low...as suggested by
the 00z GFS and European model (ecmwf) guidance...forecast soundings indicate a
brief period of frozen precipitation possible late Monday afternoon into
Monday evening mainly for northeastern sections. Given considerable
disagreement amongst guidance...will leave out mention in grids
for now and continue to monitor trends.
Zonal flow aloft develops behind the departing upper shortwave
trough late Monday night. Temperatures will be a few degrees below climatology
Monday with frontal passage then low level thicknesses fall to
around 1280-1290 meters Tuesday as high pressure builds over the
region from the midwestern states. Expect highs in the upper 30s
north to lower 40s south on Tuesday.
Aviation /18z Thursday through Monday/...
short term /through 18z Friday/...as of 1230 PM Thursday...high
confidence in VFR conditions through the taf period. Departing high
pressure and dry conditions will prevail over the area through
this evening then a cold front with limited moisture will move
into the area with a chance for a few light rain showers
especially at the koaj and kewn taf sites after 06z. The
precipitation is not expected to be heavy enough to produce sub
VFR conditions. Expecting a gradual increase in middle and high level
clouds with light winds becoming SW and increasing to 5 to 10 miles per hour
this evening ahead of the cold front. Cold air advection behind front will
produce gusty northwest winds 15-25 kts Friday morning.
Long term /Friday through Monday/...
as of 330 am Thursday...VFR expected Friday though windy with wind
gusts 20-30 knots from the northwest during the day. Winds diminish Friday
night through Sat as high pressure builds in with mainly clear
skies. Next chance of precipitation arrives Sun night with
possible sub-VFR conditions late Sunday night into Monday.
short term /through tonight/...
as of 1230 PM Thursday...no changes to winds/seas forecast with
update...but did adjust/expand Small Craft Advisory headlines for stronger winds
late tonight and Friday. Seas have subsided central waters and
adjusted Small Craft Advisory headline there for Small Craft Advisory conditions redeveloping late
this evening. Also added Small Craft Advisory for Albemarle Sound and north of
Oregon Inlet for Friday into Saturday.
as of 1030 am Thursday...no changes with update. Seas down to 4-5
feet at Duck buoys and allowed Small Craft Advisory to expire at 10 am for north of
Oregon Inlet. Seas still around 6 feet central waters will be
subsiding this afternoon but winds there increasing again tonight.
as of 615 am Thursday...complicated forecast as no sooner do the
current advisory conditions diminish this morning then conditions
deteriorate again tonight as a cold front moves into the waters with
increasing west-southwest flow. The prefrontal flow will be
strongest over the southern and central waters and the Pamlico
Sound. For the waters north of Oregon Inlet once seas subside this
morning conditions will be remain sub advisory until late Friday
morning when the stronger Post frontal northwesterly flow Cranks up.
Details: northerly winds are in the process of diminishing early
this morning and are expected to drop below 15 knots late this
morning with seas finally subsiding below 6 feet around 15z. The
flow becomes light west-southwest late today then increases to 15 to
25 knots this evening over the southern and central waters along with
the Pamlico Sound with a corresponding increase in seas. The front
is forecast to cross the waters around 12z Friday with the flow
veering to west late and eventually northwest Friday morning.
Long term /Friday through Monday/...
as of 330 am Thursday...generally poor boating conditions expected
in the long term with several strong frontal systems passing
through the waters. Northwest winds increase behind eastward moving cold
front Friday afternoon at strong Small Craft Advisory levels
though cannot rule out a few gusts to gale force especially for
the outer waters. Winds slowly diminish Saturday as high pressure
builds south of the waters. Seas expected to peak in the 10-12 feet
range Saturday morning before dropping below 6 feet late Saturday
afternoon or evening. The surface ridge will shift east well south
of the waters Saturday night into Sunday...shifting winds west
late Saturday and eventually southwesterly by Sunday. Southwest
winds and increasing seas expected again Sunday night into Monday
ahead of a developing frontal system...which should cross the
eastern NC coastal waters Monday. Winds and seas are expected to
remain elevated at Small Craft Advisory levels through Monday night.
Marine...Small Craft Advisory from 4 am Friday to 10 am EST Saturday
Small Craft Advisory from 7 am Friday to 10 am EST Saturday
Small Craft Advisory until 1 PM EST this afternoon for amz152-
Small Craft Advisory from 10 PM this evening to 10 PM EST
Saturday for amz152-154.
Small Craft Advisory from 10 PM this evening to 1 PM EST
Saturday for amz156-158.
Small Craft Advisory from 7 am Friday to 9 PM EST Saturday for