Special Weather Statement, NWS Raleigh, NC

Area Forecast Discussion
National Weather Service Raleigh NC
1038 AM EDT Thu Aug 2 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 /THIS AFTERNOON THROUGH TONIGHT/...
As of 1038 AM Thursday...

...Flash flood threat continues in the NW Piedmont and Triad area...

Flash flooding was ongoing mid to late morning in the Piedmont Triad
region, with the most reports of flooding coming from Davidson,
Forsyth, and Guilford Counties. Training of showers and
thunderstorms continued to be a problem over this region aiding in
the runoff on saturated ground. The lightning activity has been
weakening a bit during the mid to late morning which is actually
true to form with the diurnal cycle daily minimum. However, an
uptick will occur with the renewed heating as temperatures approach
80 by noon in areas out ahead of the current axis of heavy rainfall.

The Flash Flood Watch for the NW and W portions of the Piedmont will
continue in effect. This is generally the region that has been hit
with several rounds of very heavy rain in the past 3 days with some
totals nearing 6-8 inches, and most recently hit this morning again.

There was consideration in expanding the Watch eastward; however, it
appears that even through showers and thunderstorms are expected
with heavy rain this afternoon and evening, the threat of flash
flooding is expected to be more isolated east of the current Watch
area. In addition, the Flash Flood Guidance is higher as the ground
is not as wet or saturated east of the current Watch area. The more
flood prone and/or urban areas in the Triangle, Fayetteville, and
the recently hard hit Wilson area may be most problematic this
afternoon if training were to develop over these regions.

We will maintain the current likely to categorical POP, with the
diurnal uptick of convection expected through the afternoon lasting
into the early evening. Current data supports MLCapes 1500-2000
J/KG where the breaks occur, bulk shear 30-35kt (NW), and strong
surface moisture convergence along outflows over the region. A few
isolated strong wind gusts are expected (under 50 mph) - yet with
saturated soils and weight of wet trees, even garden variety storms
with gusts to 40 mph may produce downed trees.

CAMS suggest convection will become more scattered to widely
scattered this evening. Another round of convection may evolve
tonight in the west - as yet another disturbance aloft rotates
around the base of the southern Appalachians as the upper trough
slowly weakens, threatening the western third of central NC
(essentially the current Flash Flood Watch area).

&&

.SHORT TERM /FRIDAY THROUGH FRIDAY NIGHT/...
As of 415 AM Thursday...

We will finally start to see a break in this pattern on Fri. The
trough to our W will tilt and lift NE, as the Atlantic ridge begins
to build in from the E. Steering flow will veer to a more SW
direction, with an uptick in heights aloft, serving to kick the
track of mid level waves to our NW. This will also reduce deep layer
shear over central NC, and at the surface, low level flow will veer
slightly so as to draw in less Atlantic-source air. But the low
level flow will remain confluent, with still-notable components from
the Atlantic and Gulf, moderate CAPE during the day, and the PW will
remain near or over 2", so we'll still see numerous showers and
storms with the potential for locally heavy rain and gusty winds.
One more day of highs in the low-mid 80s, under mostly cloudy skies,
before the heat starts gearing back up. Expect lows of 69-73 with
pops slipping to low chance overnight as ascent quiets across the
area. -GIH

&&

.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
As of 315 AM 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. -Blaes

&&

.AVIATION /12Z THURSDAY THROUGH MONDAY/...
As of 625 AM Thursday...

Sub-VFR conditions will be the rule across central NC through much
of this morning, with some improvement in the early afternoon before
more showers/storms fill in. MVFR to IFR conditions (mainly IFR cigs
with VFR to MVFR vsbys) will hold at all sites through mid morning,
followed by slow improvement to MVFR then VFR from late morning
through early afternoon. While isolated showers/storms are possible
anytime this morning, particularly at INT/GSO, activity will really
start to fill in across central NC from late morning through the
afternoon. RDU/RWI/FAY should see the greatest coverage (and,
accordingly, the greater frequency of storm-proximity sub-VFR
conditions) from late morning through mid afternoon, with the W
Piedmont (GSO/INT) seeing the greatest coverage from mid afternoon
through mid evening. The coverage and intensity of storms may start
to decrease a bit after nightfall, but storms will linger areawide
through the night. VFR conditions will remain dominant tonight,
although a period of MVFR cigs is expected to develop after 06z.

Looking beyond 12z Fri, unsettled weather will continue through Fri,
with a similar cycle of late-night/early-morning MVFR conditions
followed by a slow rise to VFR by noon, scattered to numerous
showers in the afternoon and early evening, followed by a trend back
down to MVFR to IFR by midnight. Mid level ridging building in from
the east Sat/Sun should result in a decrease in showers/storms as
well as improved aviation conditions lasting into Mon. -GIH

&&

.RAH WATCHES/WARNINGS/ADVISORIES...
Flash Flood Watch through Friday morning for NCZ021>023-038-
039-073.

&&

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

Hazardous Weather Outlook
National Weather Service Raleigh NC
400 AM EDT Thu Aug 2 2018

NCZ007>011-024>028-040>043-074>078-083>086-088-089-030900-
Person-Granville-Vance-Warren-Halifax-Orange-Durham-Franklin-Nash-
Edgecombe-Chatham-Wake-Johnston-Wilson-Montgomery-Moore-Lee-Harnett-
Wayne-Anson-Richmond-Scotland-Hoke-Cumberland-Sampson-
400 AM EDT Thu Aug 2 2018

This Hazardous Weather Outlook is for central North Carolina.

.DAY ONE...Today and Tonight.

Locally heavy downpours are possible today and tonight. This may lead
to standing water and flooding of creeks and ditches.

.DAYS TWO THROUGH SEVEN...Friday through Wednesday.

The chance for locally heavy rainfall will continue into Friday.

.SPOTTER INFORMATION STATEMENT...

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

NCZ021>023-038-039-073-030900-
Forsyth-Guilford-Alamance-Davidson-Randolph-Stanly-
400 AM EDT Thu Aug 2 2018

...FLASH FLOOD WATCH IN EFFECT THROUGH FRIDAY MORNING...

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...Friday through Wednesday.

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

   Flash Flood Watch.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is not expected at this time.

Special Weather Statement
National Weather Service Raleigh NC
232 PM EDT THU AUG 2 2018

NCZ075>077-086-021930-
Lee NC-Hoke NC-Harnett NC-Moore NC-
232 PM EDT THU AUG 2 2018

...A STRONG THUNDERSTORM WILL AFFECT EASTERN MOORE...SOUTHWESTERN
HARNETT...SOUTHWESTERN LEE AND NORTHERN HOKE COUNTIES UNTIL 330 PM
EDT...

At 231 PM EDT, Doppler radar was tracking a strong thunderstorm near
Southern Pines, moving north at 15 mph.

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

Locations impacted include...
Southern Pines, Carthage, Pinehurst, Aberdeen, Whispering Pines,
Vass, Cameron, Olivia, Pineview and Lemon Springs.

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 3510 7943 3540 7947 3544 7921 3534 7899
      3519 7908 3519 7910 3517 7910 3507 7916
TIME...MOT...LOC 1831Z 192DEG 15KT 3514 7930

HAINES

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE RALEIGH NC
247 PM EDT THU AUG 2 2018

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

0202 PM     TSTM WND DMG     2 ENE GODWIN            35.22N 78.66W
08/02/2018                   CUMBERLAND         NC   911 CALL CENTER

            TREE DOWN AT SHERRILL BAGGETT RD AND DUNN
            RD.

&&

JFD

Special Weather Statement
National Weather Service Raleigh NC
250 PM EDT THU AUG 2 2018

NCZ008-009-026-041-021945-
Franklin NC-Vance NC-Wake NC-Granville NC-
250 PM EDT THU AUG 2 2018

...A STRONG THUNDERSTORM WILL AFFECT SOUTHERN VANCE...CENTRAL
GRANVILLE...NORTH CENTRAL WAKE AND NORTHWESTERN FRANKLIN COUNTIES
UNTIL 345 PM EDT...

At 249 PM EDT, Doppler radar was tracking a strong thunderstorm over
Creedmoor, moving northeast at 20 mph.

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

Locations impacted include...
Henderson, Oxford, Creedmoor, Butner, Kittrell, Stem, Stovall, Falls
Lake State Rec Area, Gillburg and South Henderson.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3630 7828 3627 7830 3597 7864 3602 7871
      3603 7872 3603 7873 3605 7875 3607 7875
      3607 7878 3609 7879 3609 7881 3611 7881
      3647 7860
TIME...MOT...LOC 1849Z 214DEG 17KT 3613 7866

HAINES

Special Weather Statement
National Weather Service Raleigh NC
252 PM EDT THU AUG 2 2018

NCZ041-077-021945-
Harnett NC-Wake NC-
252 PM EDT THU AUG 2 2018

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

At 252 PM EDT, Doppler radar was tracking a strong thunderstorm near
Fuquay-Varina, or 10 miles north of Lillington, moving north at 15
mph.

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

Locations impacted include...
Cary, Garner, Fuquay-Varina, Angier, Apex, Holly Springs, Lake
Wheeler, New Hill, Harris Lake Boat Launch and Duncan.

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 3570 7865 3549 7875 3551 7893 3556 7893
      3558 7892 3559 7894 3572 7895 3575 7879
TIME...MOT...LOC 1852Z 193DEG 14KT 3555 7884

HAINES

Special Weather Statement
National Weather Service Raleigh NC
305 PM EDT THU AUG 2 2018

NCZ041-042-022000-
Johnston NC-Wake NC-
305 PM EDT THU AUG 2 2018

...A STRONG THUNDERSTORM WILL AFFECT CENTRAL WAKE AND NORTHWESTERN
JOHNSTON COUNTIES UNTIL 400 PM EDT...

At 305 PM EDT, Doppler radar was tracking a strong thunderstorm near
Garner, or 14 miles south of Raleigh, moving north at 20 mph.

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

Locations impacted include...
Raleigh, Garner, Clayton, Knightdale, Wendell, Lake Wheeler, Lake
Benson and William B Umstead State Park.

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 3552 7845 3555 7872 3584 7875 3588 7852
      3578 7829
TIME...MOT...LOC 1905Z 192DEG 15KT 3562 7858

HAINES

Special Weather Statement
National Weather Service Raleigh NC
309 PM EDT THU AUG 2 2018

NCZ041-022000-
Wake NC-
309 PM EDT THU AUG 2 2018

...A STRONG THUNDERSTORM WILL AFFECT SOUTHWESTERN WAKE COUNTY UNTIL
400 PM EDT...

At 309 PM EDT, Doppler radar was tracking a strong thunderstorm near
Fuquay-Varina, or 7 miles south of Cary, moving north at 20 mph.

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

Locations impacted include...
Raleigh, Cary, Rdu International, Apex, Holly Springs, Morrisville,
Lake Wheeler, Carpenter and William B Umstead State Park.

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 3561 7873 3564 7889 3586 7888 3588 7875
      3581 7863
TIME...MOT...LOC 1909Z 192DEG 16KT 3567 7881

HAINES