Scientific Forecaster Discussion
fxus62 kmhx 150517
Area forecast discussion
National Weather Service Newport/Morehead City NC
1217 am EST sun Dec 15 2019
high pressure will build across the area today then slide
offshore Monday. A strong cold front will cross late Tuesday or
Tuesday night, followed by cold high pressure the remainder of
the work week. Low pressure is expected to develop off the
coast next weekend.
Near term /until 6 am this morning/...
as of 1010 PM Saturday...mid-level clouds and even a few
sprinkles accompanied a weak shortwave across the region this
evening. As the shortwave exits the coast, the last of the
clouds are crossing the sounds counties at late evening and
should move offshore shortly. Skies overnight will be clear with
gusty westerly winds as area of 4 mb/3 hr pressure rises moves
east from the Piedmont over the next several hours. Despite the
wind, low temperatures will drop to the upper 30s inland to mid/
upper 40s coast as dewpoints drop into the 30s by morning.
Minimal changes made to the current forecast for this update.
Short term /6 am this morning through 6 PM today/...
as of 2 PM Sat...high pressure will continue to build over the
area, making for a pleasant and quiet day with temps near climo.
Low level thickness values and mostly sunny skies support highs
Long term /tonight through Saturday/...
as of 1 PM Sat...drier and mild conditions are expected through
Monday. Another cold front will cross the area Tuesday, bringing
additional chances for rain, and then colder high pressure
builds into the region through Friday. The next storm system
could impact the area beginning Friday night into Saturday.
Sunday night and Monday...500 mb heights gradually increase aloft as
surface high pressure passes to our south, settling offshore late
Sunday through Monday. Dry conditions on tap with temps well above
normal given the deep subsidence and primarily SW low level flow.
Tuesday...high pressure will continue to ridge in from offshore
Tuesday morning, as a strong cold front and upper level trough
approach from the west. Guidance continued to trend a bit slower
today with the front reaching and crossing the area in the evening.
Additionally, guidance is indicating the potential for two rounds of
showers/storms...the first with the primary band of low level
moisture convergence well ahead of the front, followed by a could of
hours of drier conditions before another round of showers/storms
arrives with the primary front. Have tweaked pops accordingly, but
still have likely to categorical as the two rounds of rainfall is
expected to bring appreciable rainfall to all of eastern NC. Expect
very warm temperatures, with lows only in the 60s Tuesday morning,
and then warming up into the upper 60s in the afternoon despite
widespread clouds and rain. Given the warm and moist atmosphere,
some isolated thunderstorms will also be possible, but should be
relegated to the immediate coast and offshore. Severe threat looks
marginal, as uncertainty remains with how much instability will
develop onshore, but the dynamic profile is impressive with 50-70
kts of bulk shear present.
Wednesday through Saturday...behind the cold front, colder high
pressure will build in from the west for this period, as the the
eastern US remains underneath an expansive longwave trough.
Strong cold air advection will limit high temps on Wednesday, despite sunny skies,
with readings only reaching the mid 40s across the area.
Cold air advection will continue Wednesday night, and very cold temperatures are
expected as the axis of a strong shortwave trough crosses the area.
Low temps will likely fall into the mid to upper 20s across most of
the area, with low 30s on the Outer Banks and beaches. With low
level heights slow to recover Thursday, and modest cold air advection continuing,
expect highs only to reach the low to mid 40s. Conditions will
finally begin to moderate Friday with high temps back into the low
to mid 50s. The next storm system may arrive in the form of a
coastal low late Friday into Saturday, but there is considerable
uncertainty with major differences between the most reliable global
Aviation /05z Sunday through Thursday/...
short term /through tonight/...
as of 1215 am Sunday...high confidence in VFR thru period with
mainly clr skies as high pres builds across. Dewpts are
dropping inland and combined with a west breeze shld preclude fog
formation thru daybreak.
Long term /Mon through Thursday/...
as of 1 PM Sat...VFR conditions are expected through Tuesday
morning when another cold front moves through the area and may
bring a period of MVFR/IFR conditions through Wednesday morning.
VFR returns later Wednesday through the end of the period.
short term /through Sunday/...
as of 1015 PM Saturday...latest msas analysis showing area of 4
mb/3 hr pressure rises crossing the eastern Piedmont and moving
into eastern NC. Gusty west winds have already starting
increasing on the area waters and would expect them to peak over
the next several hours per latest high-resolution guidance.
Expecting west winds 20-30 knots over all waters and will keep the
Small Craft Advisory in place into Sunday morning. High pressure will build over
the waters sun, with winds and seas gradually subsiding. West
winds 15-20 kt early becoming west/SW 10-15 kt by afternoon.
Long term /Sunday night through Thursday/...
as of 1 PM Sat...high pressure passing south of the area will bring
light SW winds Sunday night, becoming S Monday at 10-20 kts, with
seas 3-5 ft. Small craft conditions will likely return late Monday
afternoon ahead of an approaching cold front, with winds at south-southwest 20-
30 kts and seas building to 7-10 ft through Tuesday evening. Then, a
cold front will move through the area and turn winds to the NW,
still at 20-30 kts through Wednesday. High pressure building into
the area will bring improving conditions Thursday.
Marine...Small Craft Advisory until 7 am EST this morning for amz135.
Small Craft Advisory until 5 am EST early this morning for
Small Craft Advisory until 5 PM EST this afternoon for amz152-
Small Craft Advisory until noon EST today for amz150-156-158.