Area Forecast Discussion Issued by NWS Newport/Morehead, NC
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453
FXUS62 KMHX 191700
AFDMHX
Area Forecast Discussion
National Weather Service Newport/Morehead City NC
100 PM EDT Mon Apr 19 2021
.SYNOPSIS...
A weak area of low pressure will lift along the coast today. A
strong cold front moves through the area late Wednesday. High
pressure will build in from the west Thursday and Friday. Next
storm system will arrive in the region by next weekend.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
As of 915 AM Mon...No signif changes planned for today.
Increasing shra and a few tsra expected from mid day on as well
defined short wave crosses with sfc low lifting NE across
region. Cold temps aloft and strong shear may lead to a few
marginally severe storms despite limited instab.
Prev disc...Latest analysis shows weak low pressure lifting
along the NC coast this morning, while low amplitude shortwave
trough moves through the Appalachians. Weak low pressure will
lift along the coast today as shortwave trough and sfc front
move eastward pushing through this afternoon. SPC has upgraded
the NE portions of the forecast area to a Marginal Risk for svr
wx today. Isolated strong to severe storms will be possible,
mainly between 12-6pm. Main threats will be large hail and
damaging wind gusts. Only real limiting factors today are
moisture availability and modest instability. Diurnal heating
along with dewpoints increasing to 55-60 deg may lead to MU CAPE
values 500-1000 J/kg. This combined with bulk shear 60+ kt will
be supportive of a svr threat. 500mb temps -18 to -20 C and low
freezing levels around 8 kft support the large hail threat.
Several 00z CAMS (HRRR, NSSL WRF, NAM 3k) show a more organized
line trying to develop across the NE cwa, near area of better
convergence and instability. Best chances look like areas north
of Hwy 70 and east of Hwy 17. Convection will push off the coast
late afternoon and early evening. Highs today ranging from the
mid to upper 60s to mid/upper 70s...warmest across the southern
zones.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM TUESDAY/...
As of 245 AM Mon...Low pressure will continue to push ENE, as
high pressure builds in from the west. Precip will shift off the
coast by early evening. Skies will grad clear from west to east
this evening, with drier and cooler air filtering in. Patchy fog
will be possible early Tuesday morning, with light winds and
little temp/dewpoint spread. Lows in the mid to upper 40s
inland and low to mid 50s for the beaches.
&&
.LONG TERM /TUESDAY THROUGH MONDAY/...
As of 330 AM Mon...A strong cold front will push through the
area Wednesday afternoon, with much cooler air behind it and
potential for frost. A potentially strong low pressure area and
cold front will push through next weekend.
Tuesday...Mainly dry as transitory high slides through ahead of
next deep shortwave trough digging through the ctrl plains
states. Temps near climo in the 70s for highs.
Tuesday night through Wednesday...Area will be under influence
of strengthening return flow Tue night and esp Wed, as stronger
front is progged to push through by late in the day. 19/00z
guidance still in good agreement wrt timing, pushing the front
offshore by early Wed evening. Global model suite still in
disagreement on how much moisture return is available for
thunderstorm development. ECM continues more robust with
moisture, esp nrn half, and have cont to advertise chc pops
here, with only slgt chc south where more iso covg expected.
Some sfc based instability forms along with strong shear (50+ kt
bulk shear) in place, so if any storms can organize, a strong
to marginally severe storm would be possible.
Wednesday night through Friday...Much cooler and drier airmass
expected behind the front with high pressure building in from
the W. We could have some frost concerns, mainly inland zones.
Coldest night still looks to be Thu night/Fri morning as center
of high pres will be closer to ENC. EC/GFS mos guidance show
lows falling into the low to mid 30s. Have edged temps down a
few degrees, advertising widespread mid 30s inland from the
coast Fri morning. Highs Thu and Fri generally in the 60s with
dewpoints only in the 20s each afternoon.
Saturday through Sunday...Temps rebound quickly back to near
climo Sat as progressive shortwave advances eastward through the
ern CONUS. 19/00Z global models all have a potential strong
storm system and cold front impacting the area by Sat, and have
inc pops to low end likelies. The ECM is esp ominous with this
system, indicating a deepening low pres system tracking through
the ctrl Carolinas. This scenario would certainly produce a
severe weather threat, as GOM moisture would be plentiful with
deep layer srly flow in place. Second half of the weekend should
be dry with subsident flow behind departing system.
&&
.AVIATION /18Z MONDAY THROUGH SATURDAY/...
Short Term /through Tue/...
As of 1255 PM Mon...Pred VFR conditions expected. Best
potential for shra/isold tsra will be N and E of taf sites next
few hrs as front/sfc low cont to push E. May see a brief
lowering of cig/vsbys next cpl hrs. NW to N winds will gust up
to 20 kts thru late this aftn. Skies shld clear thru evening
with decreasing winds as high pres builds in. Late tonight as
winds go light/calm could see some fog with mdls showing best
threat N and added a tempo to PGV for MVFR vsbys. Whatever fog
develops will quickly lift Tue morn with PC to mclr skies the
rest of the day.
Long Term /Tuesday night through Friday/...
As of 330 AM Mon...Pred VFR conditions expected through the
period. Mainly dry Tue night, then another chc of showers or
storms Wed as a strong cold front approaches.
&&
.MARINE...
Short Term /through tonight/...
As of 915 AM Mon...No changes with good surge developing later
today as sfc low shifts NE of region. Cont SCA for all but
inland rivers.
Prev disc...Latest obs show E/ENE winds 5-15 kt with seas 2-3
ft across the waters. Big changes on the way today as low
pressure lifts northward and cold front races towards the
waters. Main change this morning was to increase winds to 20-25
kt late this afternoon and evening, with guidance in better
agreement showing stronger N/NW winds developing on the backside
of the deepening low. Increasing confidence that all waters
will see a period of 20-25 kt winds late this afternoon and
evening as low pressure strengthens off the coast. HRRR even
shows a brief period of gale force winds moving through the
waters between 5-8 pm. NWPS shows seas building to 4-5 ft,
though some 6 ft seas will be possible across the outer northern
and central waters. Will go with a SCA for all coastal waters
and sounds late this afternoon and early evening. Winds will
diminish quickly late tonight into early Tue morning with seas
grad subsiding.
Long Term /Tuesday through Friday/...
As of 330 AM Mon...Have used a heavier blend of the NBM, as
NWPS generally too low on seas through the period. A strong cold
front will approach the waters Wednesday, pushing through
Wednesday afternoon and early evening. SCA conditions likely to
develop Wed afternoon with gusty SW flow ahead of the front,
then stronger NW winds 20-30 kt and seas 4-7 ft developing
behind it. Conditions improve with diminishing winds and seas by
Thu.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...None.
MARINE...Small Craft Advisory from 5 PM this afternoon to 10 PM EDT
this evening for AMZ135.
Small Craft Advisory from 4 PM this afternoon to 10 PM EDT
this evening for AMZ131-230-231.
Small Craft Advisory from 5 PM this afternoon to 2 AM EDT
Tuesday for AMZ152-154.
Small Craft Advisory from 5 PM this afternoon to 11 PM EDT
this evening for AMZ156-158.
Small Craft Advisory from 4 PM this afternoon to 11 PM EDT
this evening for AMZ150.
&&
$$
SYNOPSIS...MHX
NEAR TERM...RF/CQD
SHORT TERM...CQD
LONG TERM...TL
AVIATION...RF/TL
MARINE...RF/CQD/TL