Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Newport/Morehead City NC
124 am EDT Tuesday Apr 21 2015
a cold front will move offshore late tonight. High pressure
builds over the region Tuesday and Wednesday. A weak cold front
will cross the area Thursday. Another disturbance will affect the
region by next weekend.
Near term /tonight/...
as of 100 am Tuesday...a line of strong thunderstorms are moving
through north/central NC and will continue to progress eastward
tonight. Given lift with the surface front and middle-level
forcing...this line may hold together in terms of intensity and
clip the northern sections of the County Warning Area. The main threat with the
line is isolated tornadoes and potential for damaging winds.
Therefore...a Tornado Watch has been issued for Martin County and
the Albemarle Sound. Hail can also not be ruled out with this line
as temperatures fall in the middle-levels and sufficient lift is being
realized. The line will move through by the early morning hours at
which point the severe threat will wane. Showers across the obx
will also continue track east with some isolated rumbles of
Previous discussion...main question is whether there will be
redevelopment of showers and thunderstorms later this evening as a
jet maximum moves over the region. Convection that was occurring
earlier today west of the region has diminished greatly in
coverage and intensity during the past hour. Not seeing much
activity upstream so starting to have lower confidence in this
occurring but with only 30% probability of precipitation in the forecast feel it is better
to wait and watch then to remove only to see something develop.
The cold front should move offshore around 09z ending the threat
of precipitation. Overnight mins will range from the upper 50s
inland to lower 60s coast.
Short term /Tuesday/...
as of 345 PM Monday...cold front clears the coast early in the
morning with much drier air filtering into the region. Dewpoints
drop into the 40s to lower 50s over much of the County Warning Area during the
afternoon Tuesday under generally sunny skies as high temperatures
top out in the pleasant low/middle 70s. Gusty northwest winds early
drop quickly by afternoon as high pressure builds east.
Long term /Tuesday night through Monday/...
as of 300 PM Monday...long term period will begin warm with mainly
dry conditions followed by cooler and possibly unsettled weather
late in the week.
Tuesday night/Wednesday...seasonable conditions with cool overnight
lows and warm highs on Wednesday. Zonal flow brings near climatology temperatures
and dry weather to the region. Highs should generally be in the 70s
with lows in the upper 40s to middle 50s.
Wednesday night/Thursday...some minor differences in moisture
availability with cold front that will sag into the area on
Thursday. Have continued to side with drier solution with GFS appearing
to have a wet bias. Deterministic European model (ecmwf) more in line with its
ensemble mean in keeping the area dry...therefore have no higher
than a 20 pop late Wednesday night into Thursday. Another seasonable day on
Thursday with highs in the 70s as winds shift northwesterly behind the
Thursday night/Friday...dry weather behind the front with sunny dry
and cooler weather. Slightly below climatology expected with lows in the
40s to near 50 and highs in the middle 60s to near 70.
Friday night/Saturday...a pronounced southern stream system looks to
affect the area this weekend. Timing differences this far out though
guidance is exhibiting run to run consistency so have increase probability of precipitation just
a bit. Deterministic CMC/GFS indicate a southern track with the low
but the ecm has trended north and would have the area in the warm
sector. Will side with the more consistent southern solution for now and
indicate a cooler regime with stratiform rain showers. Should a more
northerly solution verify...east NC would have a threat for thunderstorms.
General cooler pattern would persist early next week as broad
troughing expected across the eastern Continental U.S..
Aviation /06z Tuesday through Saturday/...
short term /through Tuesday night/...
as of 100 am Tuesday...expecting mainly VFR conditions through
the taf period. Exception will be when an approaching cold front
is expected to trigger scattered showers/thunderstorms which could
produce brief MVFR to IFR conditions. This precipitation is
expected to be east of the taf sites after 09z with the cold
front moving offshore by 10z. Drier air will be moving into the
area behind the front late tonight and Tuesday.
Long term /Tuesday night through Saturday/...
as of 300 PM Monday...high pressure builds across eastern
NC Tuesday into Wednesday yielding mostly VFR conditions. A weak
front will move south into eastern NC Thursday but with limited
moisture so expect mostly VFR conditions Thursday. A better chance
for precipitation arrives next weekend.
short term /tonight and Tuesday/...
as of 100 am Tuesday...no major changes made to the forecast.
Strong southwesterly flow ahead of the front will continue over
the next couple hours. Wind gusts over the Pamlico Sound are
hovering around 25 kts...but feel this will be short lived. So
have held off on Small Craft Advisory for now. Current seas are around 4 to 6 feet.
Previous discussion...south winds are running 15 to 20 knots with
some higher gusts across the central and southern waters. Winds
will continue at 15 to 20 knots while becoming southwest late this
evening the shift to northwest late tonight. Seas will generally
be in the 5 to 7 foot range per latest local nwps/Swan model. Seas
should subside during the day Tuesday as westerly flow diminishes
below 15 knots.
Long term /Tuesday night through Saturday/...
as of 300 PM Monday...high pressure will build over the NC waters into
Wednesday with winds shifting more westerly, 5-15 knots. Seas will
diminish to 2-4 feet Tuesday night through Wednesday. A cold front
will move south into the northern waters Thursday and shift south of
the waters by Thursday night. Could see a brief period of marginal
Small Craft Advisory conditions Wednesday night ahead of the frontal boundary with SW winds
increase to 20-25 knots. Winds veer northwest behind the front Thursday around 5-
15 knots with pleasant boating conditions expected and seas around 2 to
Marine...Small Craft Advisory until 8 am EDT this morning for amz150-