Special Weather Statement, NWS Raleigh, NC

Area Forecast Discussion
National Weather Service Raleigh NC
155 PM EDT Fri Aug 3 2018

.SYNOPSIS...
The upper level trough over the Appalachians is expected to
gradually weaken through Saturday. Bermuda high pressure will build
in from the western Atlantic this weekend and early next week.

&&

.NEAR TERM /THROUGH TONIGHT/...
As of 1203 PM Friday...

...Threat of flash flooding persists over the Piedmont...

Widespread areas of showers and considerable cloudiness have
actually tempered the instability thus far across central North
Carolina. One band of showers continued to push NNE through much of
the region from Fayetteville and Raleigh/Durham to Rocky Mount. The
rainfall amounts have been on the order of 0.25 to 0.75 within this
region. This activity affected the western part of the region
earlier and left behind a low stratus layer. This low level
cloudiness has been very slow to thin or dissipate. Late morning
data analysis indicated only a very slow destabilization in the SE
zones where the MLCapes were only nearing 500-800 J/KG under the
breaks in the overcast. Late morning temperatures were in the mid to
upper 70s, with less than 5 degree T/Td spread noted. This time on
Thursday, the MLCapes were already nearing 1500 to 2000 in the SE,
with temperatures in the lower 80s.

The CAMS that appear to have the best handle on the current radar
and data suggest that showers and isolated thunderstorms will
continue to progress NNE through the eastern Piedmont, northern
Sandhills, and northern Coastal Plain through early afternoon,
limiting instability. However, the lingering mid/upper trough
over the Appalachians and the south to north conveyor belt of
very deep subtropical moisture will aid in rapid convective
growth through the afternoon as breaks in the overcast occur.

Of particular interest, CAMS indicate somewhat of a consolidation
of convection this afternoon over central NC. This occurs as
the northward surging outflow boundary, currently depicted on radar
and satellite (associated with the SC cluster of storms), merges
with additional convection developing/moving NE out of the
Blue Ridge (associated with the upper trough itself). The main
area of concern may again be the Piedmont this afternoon.

If destabilization can occur before this occurs, then a strong
uptick in shower and storm coverage and intensity will occur. This
would obviously enhance the flash flood risk given the saturated
soil. (FFG)values have lowered to 1.5 to 1.8 inches/3 hours in many
areas, less than 1 inch in an hour in the Watch area.

Since we are not as unstable due to the persistent showers and
clouds this morning, any severe wind event will be isolated.
However, we may again have to be more liberal in the issuance
of SVR in the wet urban areas given the saturated soil. It may only
take 40 mph to blow down trees in this anomalously wet situation as
compared to 58-60 mph for near normal antecedent soil conditions in
early August. This was the case on Thursday as 30+ calls of trees
being blow over in the Winston-Salem area occurred with 35-40 mph
wind gusts in thunderstorms that occurred after 2-5 inches of rain
had fallen in the previous 48 hours.

&&

.SHORT TERM /SATURDAY THROUGH SATURDAY NIGHT/...
As of 325 AM Friday...

Shortwave energy crossing the Great Lakes region today will finally
help kick the northern end of the mid level trough to the ENE across
S Quebec/St. Lawrence Valley/Northeast Sat, resulting in a lighter
mid level flow from the W or WNW over NC, prompting a drying of the
column. A portion of the W Atlantic ridge will ooze westward across
the Southeast states Sat, and the rising heights and cutting-off of
the Gulf will further reduce precip coverage, although the still-
high surface dewpoints and daytime heating (boosted by a clearing-
out of the mid and high clouds) should fuel afternoon convection,
especially across the SE half of the forecast area where moderate
CAPE is projected (although deep layer shear is apt to be marginal).
Will have chance pops, higher SE than NW, peaking in the afternoon
through early evening, followed by lower chances through the
overnight, primarily in the far SE, along with partial clearing,
mainly across the NW. This drier trend will be very welcome in the
Triad area. Highs should edge back to just a bit below normal, with
highs of 85-90. Lows 69-73. -GIH

&&

.LONG TERM /SATURDAY THROUGH THURSDAY/...
As of 315 PM Thursday...

The Atlantic subtropical ridge builds west on Saturday and
Sunday with a west to east oriented ridge axis centered near
KCHS on Sunday afternoon with heights of 595dm. Precipitable
water values on Saturday will range from 1.8 in the west to 2.1
in the east with PW values dropping a bit on Sunday. The air
mass across central NC will be weak to moderately unstable
during the afternoon and evening with frictional convergence
near the coast, convergence near a weak Piedmont trough and
differential heating in the mountains leading to widely
scattered thunderstorms. Highs will range in the mid 80s to
around 90 over the weekend with lows in the lower 70s.

The upper level ridge shifts further west early next week with
the ridge becoming centered over the southern Plains by Wednesday.
A short wave trough in the westerly flow aloft moves across the
Mid Atlantic and Carolinas on Monday and with some forcing for
ascent and cooler air aloft, thunderstorm chances increase a
bit. The flow aloft becomes more northwesterly on Tuesday with
disturbances aloft supporting convective chances in the 30-40%
range. Upper-level heights fall on Wednesday ahead of a stronger
short wave trough that arrives in the OH Valley late in the
day. The stronger flow aloft should support a more prominent
Piedmont trough on Wednesday which will allow for an increase in
convective coverage. Low level thickness values increase next
week supporting highs in the upper 80s to lower 90s with some
guidance even suggesting a couple of degrees hotter on Tuesday
and Wednesday.

&&

.AVIATION /18Z FRIDAY THROUGH TUESDAY/...
As of 155 PM Friday...

Periods of MVFR to IFR VSBYS and MVFR CIGS are expected through
00z/Sat. A return to generally MVFR to VFR conditions are
forecast between 00z and 06z/Sat. Rapid development of low stratus
(LIFR) expected overnight through 12z/Sat., gradually lifting
to MVFR and VFR CIGS through 18z.

Looking beyond 18z Sat, generally MVFR CIGS expected to become
VFR through Saturday night, with predominate VFR VSBYS. However,
there is a chance of MVFR CIGS and VSBYS in the afternoon
and early evening Saturday and Sunday.

Generally VFR conditions expected early next week, with widely
scattered to scattered storms in the afternoon and evening hours
Monday through Wednesday.

&&

.RAH WATCHES/WARNINGS/ADVISORIES...
Flash Flood Watch through 800 PM Friday evening for NCZ007>010-
021>026-038>041-073>076-083-084.

&&

SYNOPSIS...Badgett
NEAR TERM...Badgett
SHORT TERM...Hartfield
LONG TERM...Haines
AVIATION...Badgett

Hazardous Weather Outlook
National Weather Service Raleigh NC
334 AM EDT Fri Aug 3 2018

NCZ011-027-028-042-043-077-078-085-086-088-089-040900-
Halifax-Nash-Edgecombe-Johnston-Wilson-Harnett-Wayne-Scotland-Hoke-
Cumberland-Sampson-
334 AM EDT Fri Aug 3 2018

This Hazardous Weather Outlook is for central North Carolina.

.DAY ONE...Today and Tonight.

Showers and storms today could produce heavy downpours, leading to
areas of standing water that may make travel hazardous.

.DAYS TWO THROUGH SEVEN...Saturday through Thursday.

Hazardous weather is not expected at this time.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is not expected at this time.

NCZ007>010-021>026-038>041-073>076-083-084-040900-
Person-Granville-Vance-Warren-Forsyth-Guilford-Alamance-Orange-
Durham-Franklin-Davidson-Randolph-Chatham-Wake-Stanly-Montgomery-
Moore-Lee-Anson-Richmond-
334 AM EDT Fri Aug 3 2018

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

This Hazardous Weather Outlook is for central 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.

.DAYS TWO THROUGH SEVEN...Saturday through Thursday.

Hazardous weather is not expected at this time.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is not expected at this time, although spotters
are encouraged to report measurements of excessive rainfall or any
observed flooding to the National Weather Service.

Special Weather Statement
National Weather Service Raleigh NC
243 PM EDT FRI AUG 3 2018

NCZ041-042-077-031945-
Johnston NC-Harnett NC-Wake NC-
243 PM EDT FRI AUG 3 2018

...A STRONG THUNDERSTORM WILL AFFECT CENTRAL HARNETT...SOUTHWESTERN
WAKE AND WEST CENTRAL JOHNSTON COUNTIES UNTIL 345 PM EDT...

At 242 PM EDT, Doppler radar was tracking a strong thunderstorm near
Lillington, moving northeast at 35 mph.

Wind gusts up to 50 mph will be possible with this storm.

Locations impacted include...
Lillington, Fuquay-Varina, Angier, Holly Springs, Coats, Seminole,
Raven Rock State Park, Buies Creek, Duncan and Shearon Harris
Reservoir.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Seek shelter in a nearby building or vehicle. Wind gusts as high as
50 mph are capable of knocking down small or weakened trees and
blowing around trash cans, potted plants, lawn furniture and other
light outdoor objects.

&&

LAT...LON 3542 7902 3554 7896 3558 7892 3559 7893
      3565 7890 3565 7868 3547 7853 3529 7877
TIME...MOT...LOC 1842Z 211DEG 31KT 3545 7884

HAINES

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE RALEIGH NC
250 PM EDT FRI AUG 3 2018

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0215 PM     TSTM WND DMG     3 SW FAYETTEVILLE       35.04N 78.94W
08/03/2018                   CUMBERLAND         NC   911 CALL CENTER

            TREE DOWN AT FAISON AVE AND JOHN MARSHALL RD
            IN FAYETTEVILLE.

&&

JFD

Special Weather Statement
National Weather Service Raleigh NC
253 PM EDT FRI AUG 3 2018

NCZ042-043-077-078-089-032000-
Johnston NC-Sampson NC-Harnett NC-Wayne NC-Wilson NC-
253 PM EDT FRI AUG 3 2018

...A STRONG THUNDERSTORM WILL AFFECT WAYNE...NORTHEASTERN SAMPSON...
EAST CENTRAL HARNETT...JOHNSTON AND SOUTHWESTERN WILSON COUNTIES
UNTIL 400 PM EDT...

At 252 PM EDT, Doppler radar was tracking a strong thunderstorm 11
miles southeast of Dunn, or 15 miles northwest of Clinton, moving
northeast at 40 mph.

Wind gusts up to 50 mph will be possible with this storm.

Locations impacted include...
Goldsboro, Smithfield, Clayton, Dunn, Mount Olive, Benson, Fremont,
Walnut Creek, Micro and Selma.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Seek shelter in a nearby building or vehicle. Wind gusts as high as
50 mph are capable of knocking down small or weakened trees and
blowing around trash cans, potted plants, lawn furniture and other
light outdoor objects.

Torrential rainfall is also occurring with this storm, and may lead
to localized flooding. Do not drive your vehicle through flooded
roadways.

&&

LAT...LON 3532 7871 3572 7845 3575 7837 3561 7800
      3544 7783 3540 7780 3532 7783 3518 7784
      3516 7788 3515 7789 3517 7793 3516 7797
      3519 7802 3518 7807 3519 7816 3509 7817
      3508 7816 3490 7815
TIME...MOT...LOC 1852Z 221DEG 36KT 3520 7846

HAINES

Special Weather Statement
National Weather Service Raleigh NC
259 PM EDT FRI AUG 3 2018

NCZ040-076-031945-
Lee NC-Chatham NC-
259 PM EDT FRI AUG 3 2018

...A STRONG THUNDERSTORM WILL AFFECT LEE AND CENTRAL CHATHAM COUNTIES
UNTIL 345 PM EDT...

At 259 PM EDT, Doppler radar was tracking a strong thunderstorm over
Sanford, moving north at 25 mph.

Wind gusts up to 50 mph will be possible with this storm.

Locations impacted include...
Sanford, Pittsboro, Goldston, Lemon Springs, Bynum, Gum Springs,
Cumnock and Tramway.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Seek shelter in a nearby building or vehicle. Wind gusts as high as
50 mph are capable of knocking down small or weakened trees and
blowing around trash cans, potted plants, lawn furniture and other
light outdoor objects.

&&

LAT...LON 3538 7911 3535 7927 3540 7929 3540 7930
      3542 7932 3542 7933 3549 7934 3550 7934
      3551 7935 3576 7940 3584 7928 3585 7913
TIME...MOT...LOC 1859Z 181DEG 21KT 3547 7919

HAINES

Special Weather Statement
National Weather Service Raleigh NC
330 PM EDT FRI AUG 3 2018

NCZ008-025-026-041-032015-
Franklin NC-Durham NC-Wake NC-Granville NC-
330 PM EDT FRI AUG 3 2018

...A STRONG THUNDERSTORM WILL AFFECT SOUTHERN GRANVILLE...NORTHERN
WAKE...DURHAM AND WEST CENTRAL FRANKLIN COUNTIES UNTIL 415 PM EDT...

At 330 PM EDT, Doppler radar was tracking a strong thunderstorm over
Raleigh, moving north at 40 mph.

Wind gusts up to 40 mph will be possible with this storm.

Locations impacted include...
Raleigh, Durham, Cary, Creedmoor, Louisburg, Wake Forest, Butner,
Franklinton, Rdu International and Morrisville.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Seek shelter in a nearby building or vehicle. Wind gusts as high as
40 mph are capable of knocking down tree limbs and blowing around
trash cans, potted plants, lawn furniture and other light outdoor
objects.

&&

LAT...LON 3612 7829 3576 7844 3586 7891 3587 7891
      3587 7893 3620 7893 3620 7860
TIME...MOT...LOC 1930Z 192DEG 34KT 3584 7869

HAINES

Special Weather Statement
National Weather Service Raleigh NC
333 PM EDT FRI AUG 3 2018

NCZ026-041-042-032015-
Johnston NC-Franklin NC-Wake NC-
333 PM EDT FRI AUG 3 2018

...A STRONG THUNDERSTORM WILL AFFECT NORTHEASTERN WAKE...NORTH
CENTRAL JOHNSTON AND SOUTH CENTRAL FRANKLIN COUNTIES UNTIL 415 PM
EDT...

At 332 PM EDT, Doppler radar was tracking a strong thunderstorm near
Garner, or 9 miles southeast of Raleigh, moving northeast at 30 mph.

Wind gusts up to 40 mph will be possible with this storm.

Locations impacted include...
Raleigh, Clayton, Zebulon, Bunn, Knightdale, Wendell, Rolesville and
Pilot.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Seek shelter in a nearby building or vehicle. Wind gusts as high as
40 mph are capable of knocking down tree limbs and blowing around
trash cans, potted plants, lawn furniture and other light outdoor
objects.

Torrential rainfall is also occurring with this storm, and may lead
to localized flooding. Do not drive your vehicle through flooded
roadways.

&&

LAT...LON 3594 7822 3588 7821 3582 7826 3579 7824
      3577 7825 3577 7824 3576 7824 3561 7850
      3579 7862 3604 7833
TIME...MOT...LOC 1932Z 220DEG 24KT 3572 7853

HAINES