Scientific Forecaster Discussion
fxus62 kmhx 181331
Area forecast discussion
National Weather Service Newport/Morehead City NC
931 am EDT Wed Sep 18 2019
Hurricane Humberto is forecast to move east-northeast well
east of the area the next several days. Strong high pressure
will build in from the north and northeast though the end of the
week bringing the first touch of Fall weather to the area. The
high will become centered over the region this weekend.
Near term /today/...
as of 930 am Wed...no sig changes needed to previous forecast
for morning update. As strong high pres builds in from the north
will get our first taste of Fall weather as gusty NE winds lead
to much cooler temps with very comfortable humidity. Mainly clr
skies across the region this morn with some scu skirting the
CST. Mdls show some increase in scu over ern tier today with
onshore flow and expect sct to at times bkn clouds, further west
shld remain mclr. Highs expected to be in the 70s area wide with
winds gusting aoa 30 mph for the beaches from Cape Lookout north.
Short term /tonight/...
as of 230 am Wed...strong high pressure will continue to build
in from the north, while tc Humberto continues to move east/NE well
offshore of the US coast. Gradient will remain tight between
the high and Humberto, bring gusty NE winds along the coast.
Expect pc skies east to mclr west with pleasant lows in the low to mid
50s deep inland to low/mid 60s most beaches.
Long term /Thursday through Tuesday/...
as of 300 am Wed...tc Humberto will bring indirect coastal
impacts to east NC through the end of the week, though high
pressure will build in bringing pleasant sensible weather to the
region with below climo temps for a change. By the weekend the
upper ridge will shift directly over the eastern Seaboard with
longwave troughing setting up over the intermountain west, and
temps moderating back to near normal, then above normal by early
Thursday...gradient gradually begins to weaken Thursday as tc
Humberto quickly marches eastward, although some gusts up to 30
mph are still possible early in the day. With high pressure
firmly in control still expecting only a few clouds and an
otherwise pleasant day with dewpoints in the 50s highs mainly
in the low to mid 70s. Weakening winds overnight should allow
lows to fall into the low to mid 50s inland while good mixing
over obx keeps lows above 60. Temperature forecast derived based
off of 1000-850 mb thickness climatology, which favored coolest
guidance and then a degree or two lower beyond that.
Friday through Saturday...highs moderate a bit on Fri with a
rise in low lvl thicknesses supporting readings in the mid/upr
70s interior to low/mid 70s obx. Another chilly night Fri night
with sfc high directly overhead providing clr skies and calm
winds. Model guidance is typically too warm with such excellent
radiational cooling regimes and leaned the forecast a couple
degrees beyond the lowest guidance, resulting in a forecast of
lows in the low/mid 50s away from the beaches, to low 60s along
the coast. High temps moderate back to near climo in the low/mid
80s inland to upr 70s obx, though with the continued very dry
airmass (tds in the 50s) it will still feel very pleasant.
Sunday through Tuesday...return swrly flow continue to moderate
temps back to climo and above, with highs in the mid 80s, and
lows moderating back into the 60s. It will continue to be dry
however with upr ridge holding strong over the southeast conus,
although guidance suggests that ridge will eventually break down
with longwave troughing ejecting out of the central U.S.
Aviation /13z Wednesday through Sunday/...
short term /through tonight/...
as of 630 am Wed...pred VFR thru period. Mainly clr thru mid
morn then may see more scu spread onshore thru aftn, however
bulk of these clouds shld be east of taf sites and any cigs
expected to be above 3000 ft. Some clouds will cont overnight
but again best cvrg to the east with VFR cigs. NE winds will gust
15 to 25 kts mainly mid to late morn thru aftn.
Long term /Thu through Sunday/...
as of 310 am Wed...strong high pressure builds in mid to late
week with Humberto passing well offshore bringing continued
gusty winds thur, esp during the afternoon when mixing is
maximized. Otherwise, good flying conditions with mainly sunny
skies and lower humidities preventing widespread fog formation
through late week. With calm winds expected this weekend there
may be patchy light fg/br each morning.
short term /through tonight/...
as of 930 am Wed...strong NE winds and dangerous seas will
continue through the period. Latest obs show north/NE winds 20-30 kt
with seas 8-10 ft. High pressure will continue to build in from
the north through Thu, producing a tight pres gradients between
the high and tc Humberto. NE winds of 25 to 35 kts
expected...highest central and srn wtrs plus Pamlico Sound where
gale warnings cont with Small Craft Advisory all other wtrs. The northern waters
may see some gale force gusts as well, but will keep strong Small Craft Advisory
there at this time. Seas peak at 6-13 ft this evening, highest
across the outer central waters.
Long term /Thu through Sunday/...
as of 315 am Wed...Small Craft Advisory conditions or expected through much of
the long term with gusty NE winds early but dangerously large
seas lingering into the weekend as combined swells from tc
Humberto and gradient between the cyclone and building high
pressure impact the waters.
Winds will be diminishing Thursday as tc Humberto moves further
east but frequent gusts of 25 knots or higher are still expected
for much of the day with sounds and rivers eventually dropping
off by Thursday evening. Dangerous seas will lag the decreasing
wind as swells only slowly subside. Swan wave model holds on to
higher seas longer than other guidance and favored a forecast
showing seas decreasing slightly faster. Still, at least 6 foot
seas will linger until Saturday evening. Winds veer westerly to
southwesterly for the weekend at 10 knots or less.
as of 930 am Wed...longer period swells from tc Humberto will
lead to a high threat of rip currents this week. In addition to
the swells, strong NE winds will cont into Thu as strong high
pres builds in from the NE. These winds combined with the swells
will produce large seas likely aoa 10 feet over portions of the
coastal wtrs. With waves heights in surf zone expected to be 8
ft or higher will continue high surf advisory from Cape Lookout
north. The high surf will cont thru the end of the week and may see
some overwash in vulnerable locations during high tides.
The persistent strong NE flow will increase water levels over
the southern Pamlico Sound and lower Neuse River. Think could
see inundation of 1 foot to poss close to 2 feet in spots and
will issue coastal flood advisory for eastern Carteret, southern
Craven and Pamlico counties into Thu morn.
NC...beach hazards statement until 8 PM EDT this evening for ncz195-
Coastal flood advisory until 11 am EDT Thursday for ncz094-194-
High surf advisory until 8 PM EDT Friday for ncz196-203>205.
Marine...Small Craft Advisory until midnight EDT tonight for amz136.
Small Craft Advisory until noon EDT Thursday for amz131-137-
Gale Warning until 1 am EDT Thursday for amz135-152-154-156-
Small Craft Advisory until 2 PM EDT Saturday for amz150.