Special Marine Warning 113, NWS Newport/Morehead City, NC

Area Forecast Discussion
National Weather Service Newport/Morehead City NC
519 PM EDT Tue Aug 3 2021

.SYNOPSIS...
A frontal boundary will more or less remain stalled over the
area through the rest of the week as several waves of low
pressure develop along it.

&&

.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
As of 300 PM Tuesday...Rain has overspread our area, with the
heaviest rain now moving onshore and impacting areas especially
along and south of a line from Kinston to New Bern. An area of
low pressure off the South Carolina coast will slow move toward
the Crystal Coast toward daybreak, along a stationary front just
offshore. The combination of this low and frontal boundary
nearby, will increase convergence leading to a rainy night over
all of Eastern North Carolina.

Dual Pol one hour estimates already show many pockets of 1" per
hour totals, with some stationary showers earlier this
afternoon producing estimates of 2"+ per hour. PWATS on our 12Z
sounding were 2", and RAP model soundings show PWATS peaking
around 2.5" toward midnight tonight! Warm cloud depths approach
14,000, along with a tall skinny cape, all signs pointing to
very efficient rain showers over the next 12 to 18 hours. Flash
Flood Watch will continue all areas. Again the focus for a
longer period of heavy rain, and thus the highest totals, will
be along and near Highway 17 and points south. It should be
noted areas along the coast remain in a moderate risk for
exceeding flash flood guidance per WPC. Elsewhere, while totals
may not be quite as high as along the coast, per the recent
rainfall and excellent rain producing conditions tonight,
anybody would be at risk for flash flooding.

&&

.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH 6 PM WEDNESDAY/...
As of 315 PM Tuesday...By daybreak the area of low pressure
mentioned above, and frontal boundary, will be near or just
along the Crystal Coast to the central Outer Banks. Heavy rain
should continue, but the back edge of the rain should be
approaching from the west as drier air works into the region. By
late morning with the low over the central Pamlico Sound, the
heavy rain threat should be over for the majority of the area as
PWATS drop under 2". The exception will be over the Outer Banks
where bands of heavy rain are possible into the afternoon.
Elsewhere scattered showers are possible, but the widespread
rains should be well east. With a longer break in precipitation
tomorrow, temps may recover a bit more than today or generally
well into the 70s to near 80.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH TUESDAY/...
As of 315 AM Tue...Deep, tropical moisture will remain over the
area through late week as a stalled front lingers over the
region. A series of low pressure areas will move along the front
and bring periods of heavy showers and storms with torrential
downpours across eastern NC through at least Thu. A months worth
or more of rain could fall over portions of eastern NC over the
course of only 3 or 4 days resulting in a threat of flash
flooding. The heaviest rains are expected along the coast where
8-10" could fall through Fri.

Wednesday through Thursday...A very wet couple of days are on
tap through the middle of the week. The unseasonably strong
trough over the southern Appalachians remains in place
(potentially cutting a low off at its base), ensuring that a
deep tropical moisture plume remains over the area. PWAT values
of 2-2.5 inches prevail through the period. At the surface, the
boundary will generally remain along the coast, with several
weak waves riding along it about every 18 to 24 hours, leading
to periods of increased rainfall coverage and intensity. The
heaviest rainfall is currently expected to fall along and east
of the boundary, with 5 day QPF in the neighborhood of 6-10
inches possible from the inner banks to the coast, with 3-6
inches possible further inland over the coastal plain. Given
that much of the area has received normal to well above normal
precip over the past couple of weeks, there will be a
significant flash flooding threat that will require close
monitoring. Persistent cloud cover and rainfall will moderate
temps through the period, and instability will accordingly be
limited, with any severe threat currently seeming secondary to
the heavy rainfall threat.

Friday through Sunday...Persistent strong trough over the
Eastern US will finally lift out of the region by Fri, only for
another mid-level trough, albeit weaker, to dip through this
weekend to extend our period of unsettled weather. Another weak
low will form along a lingering coastal boundary Saturday before
pushing out Sunday. In terms of QPF, will not expect as much
heavy rain compared to earlier in the week, but the additional
rainfall will certainly add insult to injury. More zonal pattern
begins to emerge Sunday, allowing the wet weather pattern to
finally begin breaking down.

&&

.AVIATION /21Z TUESDAY THROUGH SUNDAY/...
SHORT TERM /Through Wed/...
As of 1225 PM Tue...Poor flying conditions expected thru taf
period. Shra will become numerous rest of the aftn and cont
thru the night with period of heavy rain and reduced vsbys.
Cigs mainly MVFR early this aftn expected to grad lower to IFR
thru early evening and cont in that range into Wed morn. Heavier
precip may begin to shift NE of taf sites Wed aftn with cigs
lifting back to MVFR. NAM model shows potential for LLWS with
good srly low lvl jet Wed morn...GFS/ECMWF keep stronger winds
mainly E of taf sites so wl not added LLWS at this point.

LONG TERM /Wednesday night through Saturday/...
As of 315 AM Tue...An extended period of very active weather is
expected through at least Thursday. Ample low level moisture
and periods of heavy rainfall will likely bring prolonged
visibility and ceiling restrictions at all terminals, with the
greatest confidence closer to the coast (EWN and OAJ).
Conditions possibly improve Fri and Sat, though some vis and
ceiling restrictions may linger in scattered to numerous showers
and tstms.

&&

.MARINE...
SHORT TERM /through Tomorrow/...
As of 515 PM Tues...Updated winds and seas based off of
observations and latest 18z model data, which shows stronger
winds both tonight and tomorrow. Have also moved up the start
times for most of the SCAs to right now, and added the Croatan
and Roanoke Sound zone for strong southerly winds expected
tomorrow.

A quasi stationary frontal boundary offshore will remain
bisecting the area through early tonight, before lifting to the
north overnight. Before that occurs strong wind gusts to 25 kts
out are expected on both sides of the front (out of the NE to
the north of the front, and out of the S to the south of the
front). Then tomorrow morning as low pressure strengthens across
interior Eastern NC, stronger southerly flow will develop with
winds becoming 15-25 kts and even briefly 30-35 kts, before the
low moves off to the north and east tomorrow afternoon. Seas
are expected to be 5-7 ft now through tomorrow morning, and then
increase to 6-8 ft and possibly higher over the central and
southern waters.

LONG TERM /Wednesday night through Saturday/...
As of520 PM Tue...Another low pressure area is forecast to move
along the front Thursday. Southerly winds diminish to 10-20 kt
Thu with seas subsiding to 3-5 ft Thu night. Marine conditions
relax further Fri and Sat with SSW flow 10-15 kts and seas
3-4ft.

&&

.HYDROLOGY...
As of 330 PM Tue...No changes to the flash flood watch for all
of Eastern North Carolina. Model guidance and QPF from WPC
continue to show 6" to 10" of rain possible along the coast and
this will remain our highest area of concern for flash flooding.
Farther inland QPF amounts drop off slightly, with 3" to 6"
expected. However, flash flooding is still possible over all of
Eastern NC given the very efficient rain processes and the very
slow storm motion. Isolated higher amounts are possible given
such a primed atmosphere. We will see a substantial break
Wednesday afternoon and Wednesday night. A new round of rain
will approach the area again Thursday, but early signs show the
heaviest rain may be even farther east or even mostly offshore.
Future adjustments to the watch may be needed after we get
through our heavy rain tonight into Wednesday.

&&

.MHX WATCHES/WARNINGS/ADVISORIES...
NC...Flash Flood Watch through Thursday evening for NCZ029-044>047-
     079>081-090>092-094-193>196-198-199-203>205.
MARINE...Small Craft Advisory until 11 PM EDT Wednesday for AMZ135.
     Small Craft Advisory from 7 AM to 6 PM EDT Wednesday for
     AMZ231.
     Small Craft Advisory from 2 AM Wednesday to 6 AM EDT Thursday
     for AMZ150-152.
     Small Craft Advisory until 6 AM EDT Thursday for AMZ154-156-
     158.

&&

SYNOPSIS...MHX
NEAR TERM...EH
SHORT TERM...EH
LONG TERM...JME/ML
AVIATION...RF/JME
MARINE...EH/JME/SGK
HYDROLOGY...MHX

Hazardous Weather Outlook
National Weather Service Newport/Morehead City NC
720 AM EDT Tue Aug 3 2021

NCZ029-044>047-079>081-090>092-094-193-194-198-041130-
Martin-Pitt-Washington-Tyrrell-Mainland Dare-Greene-Beaufort-
Mainland Hyde-Duplin-Lenoir-Jones-Pamlico-Northern Craven-
Southern Craven-Inland Onslow-
720 AM EDT Tue Aug 3 2021

...FLASH FLOOD WATCH IN EFFECT THROUGH THURSDAY EVENING...

This Hazardous Weather Outlook is for eastern North Carolina.

.DAY ONE...Today and tonight.

Please listen to NOAA Weather Radio or go to weather.gov on the
Internet for more information about the following hazards.

   Flash Flood Watch.

Heavy rain expected this afternoon and tonight will bring a threat of
localized flooding and difficult travel.

.DAYS TWO THROUGH SEVEN...Wednesday through Monday.

Please listen to NOAA Weather Radio or go to weather.gov on the
Internet for more information about the following hazards.

   Flash Flood Watch.

An active weather pattern will continue over the region through much
of the week with periods of heavy rain expected bringing a threat of
of localized flooding.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is not expected at this time.

NCZ195-196-199-203>205-041130-
West Carteret-East Carteret-Coastal Onslow-Northern Outer Banks-
Ocracoke Island-Hatteras Island-
720 AM EDT Tue Aug 3 2021

...MODERATE RIP CURRENT RISK IN EFFECT THROUGH THIS EVENING...
...FLASH FLOOD WATCH IN EFFECT THROUGH THURSDAY EVENING...

This Hazardous Weather Outlook is for eastern North Carolina.

.DAY ONE...Today and tonight.

Please listen to NOAA Weather Radio or go to weather.gov on the
Internet for more information about the following hazards.

   Moderate Rip Current Risk.
   Flash Flood Watch.

Heavy rain expected this afternoon and tonight will bring a threat of
localized flooding and difficult travel.

.DAYS TWO THROUGH SEVEN...Wednesday through Monday.

Please listen to NOAA Weather Radio or go to weather.gov on the
Internet for more information about the following hazards.

   Flash Flood Watch.

An active weather pattern will continue over the region through much
of the week with periods of heavy rain expected bringing a threat of
of localized flooding.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is not expected at this time.