Scientific Forecaster Discussion
fxus62 kmhx 100900
Area forecast discussion
National Weather Service Newport/Morehead City NC
400 am EST Tue Dec 10 2019
a strong cold front will move through tonight and early
Wednesday bringing wet and unsettled conditions with it. High
pressure will build north of the area through Thursday, with
another system likely impacting the area Friday perhaps into
Near term /through today/...
as of 250 am Tuesday...broad and deep moist southwesterly flow
continues over the southeastern U.S. This morning ahead of a
shortwave trough digging into central Texas as seen on WV
imagery. At the surface south/southwesterly flow is in place
ahead of a cold front current just west of the Appalachians,
while weak high pressure attempts to ridge in from the east.
Early this morning a threat of sea fog continues with locally
lower visibilities impacting portions of the outer banks; the
Airport in Hatteras has been sitting between 4-5 miles most of
the night. Water temps are still in the mid 50s in the Pamlico
Sound so this threat should be on and off through the day.
The other forecast challenge today is temps with record breaking
warmth possible today as forecast 1000-850 mb thicknesses reach
~1390 meters, suggesting a few 80s are possible mainly across
southern zones and widespread 70s elsewhere. This is dependent
on better insolation due to cloud breaks. For record
information see the climate section below. A few coastal showers
are expected to linger off obx throughout the day, perhaps
increasing in coverage late as convergence increases ahead of
the approaching front.
Short term /tonight/...
as of 255 am Tuesday...weather quickly deteriorates tonight as
cold anafront moves through the region overnight into Wednesday
morning. Href continues to hint at a weak instability axis
persisting along the coast and have a mention of thunder from
downeast Carteret along the obx. Ensemble guidance supports
moving pops to categorical for the overnight period with
precipitation amounts generally around a quarter of an inch or
so. A few hi-res models suggest some enhanced frontogenetic
forcing immediately along the coast as cooler air intrudes could
lead to enhanced rain totals - didn't go quite as aggressive
with quantitative precipitation forecast as guidance but do show locally higher amounts for
Carteret and areas northeast.
Long term /Wednesday through Monday/...
as of 4 am Tue...periods of unsettled weather expected through
much of the long term period, with roller coaster temps as a
progressive/amplified active weather pattern is expected.
Wednesday...a strong cold front will have passed through the
area by sunrise Wed. The front will be an anafront, with much of
the precip along and behind it, so some lingering rain expected
Wed morning, especially eastern areas. Further west, rapid
drying and cooling is expected as temps will not budge much for
highs, as cold air advection will be ongoing all day. Expect blustery
conditions and temps in the 40s all day for the region.
Wednesday night through Thursday...strong high pressure will build
in from the north with much cooler and drier air mass. Lows will
be near or below freezing for all but the coastal areas, where
brisk north-northeast winds will keep temps in the 30s and low 40s. Despite
the widespread sunshine, highs Thu only in the 40s area wide.
Friday through Saturday...rain chances inc Fri as deep srly
flow increases with digging long wave trough across the lower MS
River Valley, which will spur low pressure development over the
deep south. This low will ride up the coast rapidly, with rain
becoming likely through the day Fri, peaking Fri evening when
best upward vertical velocity/fgen/pwats will converge. Bumped pops up to
categorical this period, as good model to model consistency as
well as spaghetti ensembles converging on this solution.
Widespread moderate to heavy rain will be possible. Depending on
exact track of the low, there could be potential for strong to
even severe storms if storm track is further inland. Latest
10/00z ecm indicates aoa 500 j/kg of sfc based CAPES advecting
into the area with plentiful shear.
Sunday through Monday...drier conditions with near to above normal
temps expected late weekend to early next week as quasi zonal
flow develops. Another system may quickly be moving in, but this
feature difficult to pinpoint this far out in time, so will
leave Monday dry attm.
Aviation /08z Tuesday through Saturday/...
short term /through Tuesday/...
as of 1240 am Tue...moderate confidence in VFR conditions
overnight. Very moist atmospheric profile with overcast (if not
transparent) mid and high level clouds will linger for most of
the period. Conditions remain well mixed tonight and will remain
so into the morning with SW winds overnight holding at 5-10 kt,
however any weakening could lead to rather rapid fog/stratus
development given moist antecedent conditions. Confidence is too
low to specify any period of sub-VFR conditions overnight.
Gusty SW winds veer northwest as front pushes across the area overnight
into Wednesday morning with precipitation and sub-VFR conditions
Long term /Wed through Sat/...
as of 4 am Tue...unsettled weather is expected to continue very
early Wednesday with gusty winds, scattered showers and periods
of sub-VFR conditions likely. Dry weather returns quickly by
late morning early afternoon as high builds in. Another system
moves in by Friday with the development of rain with more sub
VFR conditions expected through Friday night to perhaps early
short term /Tuesday/...
as of 305 am Tuesday...south/southwesterly flow continues over
the waters at around 10-15 knots with seas ranging from 5-9 feet
off the coast. Small Craft Advisory continues the entire period with persistent
SW flow continuing ahead of an approaching cold front,
eventually veering west and northwest late as the front passes over the
waters. Seas will slowly subside to 5-6 feet through the day
before building back late with a northerly surge behind the
Long term /Wed through Saturday/...
as of 4 am Tue...no changes to previous thinking with an active
weather pattern expected through the end of the week and into
the weekend which will result in hazardous boating conditions
with strong winds and elevated seas at or above 6 ft through the period.
Winds will shift north 20-30 kt behind cold front Wed into thur
with large dangerous seas continuing above 6 ft through at least
Sat as yet another storm system moves through the waters Fri
night and Sat.
record high temps for 12/10 Tuesday
New Bern 79/2007 (kewn asos)
Cape Hatteras 73/1986 (khse asos)
Greenville 79/2007 (coop - not kpgv awos)
Morehead City 73/2007 (coop - not kmrh asos)
Kinston 78/2007 (coop - not kiso awos)
Jacksonville 79/2007 (knca asos)
Marine...Small Craft Advisory until 7 PM EST Sunday for amz150-152-154-