Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Newport/Morehead City NC
1037 PM EST Wednesday Mar 4 2015
a cold front will move through eastern North Carolina from the
northwest Thursday. High pressure will build in for the weekend.
Low pressure may affect the region early next week.
Near term /rest of tonight/...
as of 1030 PM Wednesday...the cold front currently resides from the
Tidewater region of Virginia west-southwest to southeastern
Tennessee, slowly heading east towards eastern NC. Warm advection
on moist southwesterly flow continues tonight with areas of fog
possible near along the coastal sections of Onslow and Carteret
counties. Could also experience intermittent fog along the Outer
Banks depending on extent of boundary layer mixing. Significant
mixing has inhibited temperatures from falling near dewpoint this
evening and thus have removed mention of fog from inland areas.
Winds should remain mixed enough to prevent fog formation
overnight though with dewpoints in the low 60s, cannot completely
rule out brief fog just prior to sunrise if winds can sufficiently
Models remain in close agreement in the short term. Mild temperatures
will persist overnight due to moist SW flow. Thursdays high temperatures
will occur early morning then fall most of the day as cold high
pressure build south over the region. Most of the area will be
dry overnight. The exception will be the northern coastal plain
through the Albemarle Sound counties and far northern Outer Banks
where low chance probability of precipitation for rain will exist after midnight.
Short term /Thursday/...
as of 330 PM Wednesday...little change to previous forecast. Models
close in timing on front dropping through from the north. The
west-east oriented front will move through the northern Outer
Banks & northern coastal plain shortly after daybreak reaching the
South Coast early Thursday afternoon. Front will clear the entire
area by early evening. Probability of precipitation will quickly increase to categorical
along and behind the front. Forecast soundings indicate precipitation
type will remain rain during the day. Temperatures will fall
during the day once the front passes and will retain appropriate
wording in the upcoming zone package.
Long term /Thursday night through Wednesday/...
as of 300 PM Wednesday...good model agreement Thursday night with
widespread rain in wake of cold front...gradually ending as a period
of sleet and freezing rain northwest to southeast during the night. Given warm
antecedent conditions...only minor sleet accumulation expected
with a few hundredths of an inch of freezing rain accretion on
exposed surfaces...and some slick spots possible bridges and
Operational models continue to have some differences on
Friday...with NAM showing redevelopment of wdsrd light
rain/freezing rain over all of eastern NC during the day...while GFS
and European model (ecmwf) limit precipitation to coast with temperatures near or just above 32.
Given model differences...continued previous low confidence forecast
of mainly chance probability of precipitation across area with just 20% inland of Highway 17
after middle morning. Did increase probability of precipitation along coast S of Oregon Inlet
to likely for rain with chance of freezing rain. Another few
hundredths of freezing rain possible along coast.
Gusty north-NE winds expected along coast with cold air advection surge Thursday night and
could see wind advsy criteria mainly for Outer Banks.
Clearing and colder conditions expected Friday night...then high
pressure with moderating temperatures Sunday into Monday. Models continue to
have differences with next possible southern stream system Tue-Wed...and
just covered with 20% chance of rain to indicate low forecast confidence
at this time.
Mav guidance continues to have cold bias with min temperatures Thursday night and
Friday night and leaned to previous forecast which is line more with met
MOS. Coldest temperatures expected Friday night with some middle 20s inland.
Temperatures moderating to near normal sun-Wed.
Aviation /03z Thursday through Monday/...
short term /through 00z Friday/...
as of 1035 PM...VFR conditions early this evening may diminish to
MVFR/IFR overnight if winds sufficiently diminish allowing areas
of fog to develop and impact area taf sites. Maintained a period
of IFR in lowered ceilings/visibilities for all taf sites between roughly
06-12z, though this may be overly pessimistic given strong
boundary layer mixing as of 03z. Indicated a brief MVFR period
Thursday morning ahead of the cold front then forecast soundings
and MOS all agree on a period of IFR ceilings as winds shift
north/northeast and moisture becomes trapped under the frontal
inversion. Cold air will Chase the moisture from west to east
Thursday evening/night so could see light freezing rain/sleet late
evening into Thursday night.
Long term /Thursday night through Monday/...
as of 300 PM Wednesday...sub-VFR conditions expected Thursday
night with widespread rain in wake of cold front...with precipitation
changing to period of sleet and freezing rain before ending. MVFR
ceilings likely to linger during the day Friday. Clearing expected
Friday night with VFR prevailing rest of period. Gusty north-NE winds
15-25 miles per hour in wake of front Thursday night into Friday.
short term /through Thursday/
as of 1030 PM Wednesday...latest surface and limited buoy data
indicate south-southwest winds 15-25 knots with seas 3-5 feet though 5-7 feet seas
likely for the outer fringes of the central coastal waters.
Adjusted the marine dense fog advisory as most locations have been
void of fog issues/development this evening under a strong
southwesterly flow, except for the Onslow/Carteret County coast
where the dense fog advisory remains in effect until Thursday
morning. Based on latest model data will issue gale warnings for
all coastal waters...the Albemarle and Pamlico sounds and
Alligator river...with small craft advisories for the remaining
rivers. Front will drop into the northern waters shortly after
daybreak Thursday and reach the southern waters in the early
afternoon. Winds will rapidly veer from southwest to north and
increase once the front passes.
Long term /Thursday night through Monday/...
as of 300 PM Wednesday...gale warnings posted for all waters
except Small Craft Advisory southern rivers with high confidence in period of 25 to 35
knots winds across area Thursday night into Friday morning due to strong cold air advection
in wake of Arctic front. Winds will gradually diminish Friday and
Friday night to less than 20 knots by Sat morning...but elevated seas
will linger outer waters into Sat morning. Lighter winds and seas
expected to prevail rest of weekend into Monday.
Leaned to local nwps for seas most of period. Heights peaking 8-12
feet late Thursday night/early Friday.
Marine...Small Craft Advisory from 5 PM Thursday to 10 am EST Friday
Gale Warning from 5 PM Thursday to 10 am EST Friday for amz130-
Dense fog advisory until 6 am EST Thursday for amz156-158.