Flash Flood Warning 18, NWS Raleigh, NC

445 
WGUS72 KRAH 020416
FFSRAH

Flash Flood Statement
National Weather Service Raleigh NC
1216 AM EDT Fri Aug 2 2019

NCC081-020426-
/O.EXP.KRAH.FF.W.0018.000000T0000Z-190802T0415Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Guilford NC-
1216 AM EDT Fri Aug 2 2019

...THE FLASH FLOOD WARNING FOR GUILFORD COUNTY HAS EXPIRED...

The heavy rain has ended. Flood waters have receded. Flooding is no
longer expected to pose a threat. Please continue to heed any
remaining road closures.

LAT...LON 3624 7956 3590 7959 3592 8004 3624 8001

$$

77

AREA FORECAST DISCUSSION
National Weather Service Raleigh NC
934 PM EDT Thu Aug 1 2019

.SYNOPSIS...
An approaching cold front will stall out and hold just northwest of
central North Carolina through the weekend, keeping a high chance of
afternoon and evening showers and thunderstorms in the forecast. A
steady stream of deep moisture from the Gulf of Mexico will keep our
weather unsettled into early next week.

&&

.NEAR TERM /TONIGHT/...
As of 930 PM Thursday...

Deep convection persisting and/or re-firing along a trio of outflow
boundaries over (mainly the wrn two thirds of) cntl NC this evening,
which include at 01Z, 1) a n to s-oriented westbound one from near
MEB to RDU to HNZ - related to convection over ern NC earlier, 2)
another westbound one in an arc from HFF to GSO to SIF - related to
the initial RDU/Raleigh cell, and 3) a southwestbound one in an arc
from MWK to GSO - related to an earlier cluster north of the
Triad/near the VA state line. The first of those outflow boundaries
has been, and will likely continue to serve as, the ern edge of
subsequent initiation tonight, with an ensuing east to west
weakening of the deep(er) convection.

The presence and interaction of the above boundaries are seemingly
doing the necessary work to lift/force parcels through a rain-cooled
and stable near surface layer and to their LFC around 4-5 thousand
ft, where steep lapse rates above --including a GSO-observed maximum
2-6 km lapse rate of near 7 C/km centered at 700 mb-- allow those
parcels to realize around 2000 J/kg of MUCAPE. Indeed, the foregoing
outflow/radar fine lines are evident in regional radar data up to
about that LFC height. Relatively vigorous, isolated severe
convection has resulted/re-developed during the mid-evening, when
climo suggests it should be waning.

Also evident in regional radar data is an apparent MCV centered near
CLT/EQY; and this feature is forecast to drift newd across cntl NC
overnight, to ern or nern NC by 12Z Fri. This mesoscale feature is
also likely contributing to ascent over NC this evening, in an
environment otherwise void of any notable larger scale ascent well
east and removed from a couple of shortwave perturbations evident in
WV satellite data over WV and MS, respectively.

With the above in mind, convection and remnant "stratiform" rain
will likely persist for another several hours over much of the wrn
half of cntl NC, with weakening to light rain with time and ern
extent overnight, before likely dissipating completely with the
passage of the MCV by morning. Persistence lows around 70 degrees
are expected.

&&

.SHORT TERM /FRIDAY THROUGH FRIDAY NIGHT/...
As of 240 PM Thursday...

Central NC will remain in the action zone situated between the broad
scale upper trough draped across the eastern CONUS and the Bermuda
high off the Atlantic Coast. This will continue the gradual surface
warming and moistening trend across central NC, helping to inch up
surface dewpoints, especially along and east of US-1. This will help
to enhance our shower thunderstorm coverage on Friday afternoon,
even with a bit more overhead cloud cover in play attempting to
limit the diurnal destabilization processes. Even so, scattered
shower and thunderstorms are expected to form across central NC,
primarily along any leftover differential heating/outflow boundaries
related to Thursday's convection, along with additional scattered
formation in terrain/sea breeze favored areas. Primary threat
remains the possibility of excessive rainfall which could lead to
pockets of flash flooding, with an isolated severe wind gust threat.
Temperatures are progged to be 4 to 8 degrees cooler on Friday, in
the low to mid 80s, thanks to the persistent overhead cloud deck.
Overnight lows will remain seasonable, bottoming out in the upper
60s to low 70s.

&&

.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
As of 340 PM Thursday...

Shortwave impulses emanating through the upper trough will continue
to interact with the deep moisture(PWATS 1.75-2.0") and instability
in place to bring a good chance of convection each day through
Monday. Given the high likelihood that some these upper disturbances
will be convectively enhanced/augmented, so it's nearly impossible
to get overly specific with timing and location of highest PoPs.
Thus, will continue to advertise diurnally favored PoPs, while
maintaining a slight to small chances overnight. Vertical wind shear
is forecast to be rather weak. Thus, any severe weather should be
largely unorganized(pulse severe) with the primary threat being
locally heavy rain and flash flooding.

Could see a brief reprieve in the wet and unsettled conditions
Tuesday and Wednesday as the axis of deeper moisture slides east and
out to sea. However, a reinforcing trough from the west could bring
another wet and unsettled pattern to end the week.

Lows in the upper 60s to lower 70s. Highs in the lower to mid 80s NW
to upper 80s/lower 90s SE.

&&

.AVIATION /17Z THURSDAY THROUGH TUESDAY/...
As of 720 PM Thursday...

We'll continue to see scattered showers and storms, producing
localized sub-VFR conditions in heavy rain and gusty/erratic winds,
around central NC through 03z, before this activity slowly
diminishes overnight, although we cannot rule out an isolated storm
or two anytime through tonight. Storm motion has been slow and
meandering, following low level boundaries and outflows, with new
updrafts developing near existing storms, so any aviators should be
particularly cautious if attempting to circumnavigate storms through
this evening. FAY will see the highest chance for storms over the
next few hours, but they are possible at all TAF sites. Otherwise,
VFR conditions should dominate until after 06z, when pockets of IFR
vsbys/cigs are possible near any site, lasting through 13z.
Additional scattered to numerous showers and storms are expected to
develop by midday (around 15z-17z) across central NC, as we remain
in this wet and volatile weather pattern. Surface winds will be
light/variable through mid morning Fri before becoming mainly from
the SE and S at 5-10 kts through Fri evening.

Looking beyond 00z Saturday, the wet pattern will persist through
early next week, with high daily chances for showers and storms
mainly in the afternoon and evening. While VFR conditions will hold
the majority of the time, early-morning sub-VFR fog and stratus will
remain a threat, along with the risk of storms. -GIH

&&

.RAH WATCHES/WARNINGS/ADVISORIES...
None.

&&

SYNOPSIS...Hartfield
NEAR TERM...MWS
SHORT TERM...JJM
LONG TERM...CBL
AVIATION...Hartfield

Hazardous Weather Outlook
National Weather Service Raleigh NC
955 PM EDT Thu Aug 1 2019

NCZ021>024-038>040-073>076-083>085-030200-
Forsyth-Guilford-Alamance-Orange-Davidson-Randolph-Chatham-Stanly-
Montgomery-Moore-Lee-Anson-Richmond-Scotland-
955 PM EDT Thu Aug 1 2019

This Hazardous Weather Outlook is for central North Carolina.

.DAY ONE...Tonight.

Scattered to numerous thunderstorms with frequent lightning,
wind gusts capable of tree damage, and locally heavy rain and risk of
flooding, are expected through 1 AM.

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

Scattered to numerous thunderstorms are expected to persist through
Monday, mainly during the afternoon and evening hours. Locally heavy
rain, isolated damaging wind gusts, and frequent lightning will be
the primary hazards with the strongest storms.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is not expected at this time.

NCZ007>011-025>028-041>043-077-078-086-088-089-030200-
Person-Granville-Vance-Warren-Halifax-Durham-Franklin-Nash-Edgecombe-
Wake-Johnston-Wilson-Harnett-Wayne-Hoke-Cumberland-Sampson-
955 PM EDT Thu Aug 1 2019

This Hazardous Weather Outlook is for central North Carolina.

.DAY ONE...Tonight.

Hazardous weather is not expected at this time.

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

Scattered to numerous thunderstorms are expected to persist through
Monday, mainly during the afternoon and evening hours. Locally heavy
rain, isolated damaging wind gusts, and frequent lightning will be
the primary hazards with the strongest storms.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is not expected at this time.

Special Weather Statement
National Weather Service Raleigh NC
842 PM EDT Thu Aug 1 2019

NCZ021-022-038-020130-
Guilford NC-Forsyth NC-Davidson NC-
842 PM EDT Thu Aug 1 2019

...STRONG THUNDERSTORMS WILL AFFECT FORSYTH...NORTHERN DAVIDSON AND
GUILFORD COUNTIES UNTIL 930 PM EDT...

At 839 PM EDT, Doppler radar was tracking strong thunderstorms over
the Triad region, drifting north at 15 mph.

Half inch hail, wind gusts up to 50 mph, frequent deadly cloud to
ground lightning, and torrential downpours are possible with these
storms.

Locations impacted include...
Greensboro, Winston-Salem, High Point, Kernersville, Clemmons,
Bermuda Run, Huntsville, McLeansville, Lewisville and Summerfield.

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.

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

These storms are producing an excessive amount of deadly cloud to
ground lightning. Seek shelter indoors and stay away from windows.
If you cannot seek shelter indoors, an enclosed vehicle can provide
safe shelter.

&&

LAT...LON 3611 8050 3612 8046 3614 8044 3621 8045
      3622 8043 3624 8045 3626 8045 3626 8001
      3624 7956 3591 7955 3594 8038 3596 8038
      3599 8042 3601 8042 3606 8046 3606 8047
      3604 8049 3608 8052
TIME...MOT...LOC 0039Z 174DEG 14KT 3610 7989

GIH

Special Weather Statement
National Weather Service Raleigh NC
842 PM EDT Thu Aug 1 2019

NCZ041-020145-
Wake NC-
842 PM EDT Thu Aug 1 2019

...A STRONG THUNDERSTORM WILL AFFECT WEST CENTRAL WAKE COUNTY UNTIL
945 PM EDT...

At 841 PM EDT, Doppler radar was tracking a strong thunderstorm over
Cary, moving northeast at 5 mph.

Wind gusts up to 45 mph will be possible with this storm.

Heavy rain and minor flooding will also be possible with this storm.

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

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Wind gusts of this magnitude are capable of producing tree damage.

Frequent cloud to ground lightning is occurring with this storm.
Lightning can strike 10 miles away from a thunderstorm. Seek a safe
shelter inside a building or vehicle.

&&

LAT...LON 3588 7868 3578 7865 3571 7869 3569 7881
      3570 7890 3575 7894 3584 7891 3587 7887
      3587 7883 3590 7882
TIME...MOT...LOC 0041Z 230DEG 6KT 3577 7884

26

Special Weather Statement
National Weather Service Raleigh NC
914 PM EDT Thu Aug 1 2019

NCZ040-041-077-020200-
Chatham NC-Harnett NC-Wake NC-
914 PM EDT Thu Aug 1 2019

...A STRONG THUNDERSTORM WILL AFFECT NORTHEASTERN HARNETT...
SOUTHWESTERN WAKE AND EASTERN CHATHAM COUNTIES UNTIL 1000 PM EDT...

At 913 PM EDT, Doppler radar was tracking a strong thunderstorm near
Fuquay-Varina, or 8 miles south of Cary, moving southeast at 10 mph.

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

Locations impacted include...
Cary, Lillington, Garner, Fuquay-Varina, Angier, Apex, Holly Springs,
Coats, Crosswinds Boating Center and Crosswinds Campground.

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.

Frequent cloud to ground lightning is occurring with this storm.
Lightning can strike 10 miles away from a thunderstorm. Seek a safe
shelter inside a building or vehicle.

&&

LAT...LON 3572 7866 3556 7866 3552 7871 3552 7869
      3550 7868 3550 7866 3548 7865 3538 7865
      3539 7896 3551 7898 3552 7897 3554 7899
      3585 7902
TIME...MOT...LOC 0113Z 323DEG 9KT 3567 7883

JFD

Special Weather Statement
National Weather Service Raleigh NC
940 PM EDT Thu Aug 1 2019

NCZ023-024-020215-
Alamance NC-Orange NC-
940 PM EDT Thu Aug 1 2019

...A STRONG THUNDERSTORM WILL AFFECT NORTHEASTERN ALAMANCE AND
NORTHWESTERN ORANGE COUNTIES UNTIL 1015 PM EDT...

At 940 PM EDT, Doppler radar was tracking a strong thunderstorm near
Mebane, or near Graham, moving north at 10 mph.

Pea size hail and wind gusts up to 40 mph will be possible with this
storm.

Locations impacted include...
Burlington, Graham, Mebane, Haw River, Swepsonville, Efland and
Saxapahaw.

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
light outdoor objects.

&&

LAT...LON 3598 7916 3595 7929 3597 7938 3604 7942
      3614 7943 3621 7929 3616 7916 3609 7914
TIME...MOT...LOC 0140Z 174DEG 8KT 3603 7928

GIH

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE RALEIGH NC
1010 PM EDT THU AUG 1 2019

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

0625 PM     TSTM WND DMG     2 S VASS                35.22N 79.29W
08/01/2019                   MOORE              NC   911 CALL CENTER

            TREE DOWN AT FURR RD AND PINE DR.

&&

JFD

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE RALEIGH NC
1015 PM EDT THU AUG 1 2019

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

0614 PM     TSTM WND DMG     4 S VASS                35.19N 79.30W
08/01/2019                   MOORE              NC   911 CALL CENTER

            TREE DOWN ON POWER LINES AT LAKEBAY RD AND
            YOUNGS RD.

&&

JFD