Special Weather Statement, NWS Raleigh, NC

Area Forecast Discussion
National Weather Service Raleigh NC
245 AM EDT Mon Jul 23 2018

.SYNOPSIS...
An upper level low pressure across the Ohio Valley will move slowly
south across the southern Appalachians into the middle of the work
week. A deep, moist, southerly flow will extend across the
Carolinas through much of the work week, then lift out to the NE
and weaken Thursday.

&&

.NEAR TERM /TODAY/...
As of 245 AM Monday...

In the very short term this morning, flash flood threat developing
near the low level circulation and stalled front, outflow boundaries
extending from near Fayetteville to just south of RDU, to Roanoke
Rapids. In addition, severe thunderstorms have punched the Coastal
Plain in the past few hours in an organized fashion. There continued
to be an area in concern through the early morning hours of flooding
in the FAY to RDU areas, given recent rains and current instability
axis/convective development. Even when this round of convective
wanes in the next few hours, additional storms with very heavy rain
expected again this afternoon and evening.

We are currently collaborating a broad brushed Flash Flood Watch for
all of the area from today through Tuesday night. Several vorticity
maximums will continue to rotate around the expansive mid/upper
trough across our region today through Tuesday night. Deep moisture
will continue to be transported north and when combined with the low
level boundaries and outflows at times, the moist confluent flow
will allow for large clusters and training bands of showers and
thunderstorms to develop and move over the area. While the urban
areas are more at risk of training heavy rains, even the rural areas
Flash Flood Guidance is lowering with each heavy rain episode and
becoming more vulnerable to flash flooding.

While the most intense convection and highest rainfall rates should
be during the afternoon and evening hours Monday and Tuesday, even
nighttime convection will be likely in this pattern.

We will carry likely or categorical POP today through Tuesday night
with QPF of 1 to 2 inches today and again on Tuesday/Tuesday night.
Average basin rainfall of 2-4 inches with local 5 inches is
expected. Given the expected training of storms at times, some areas
may get more than 5 inches.

Highs today and Tuesday generally in the mid to upper 80s. Lows
tonight and Tuesday night in the lower 70s.

&&

.SHORT TERM /TONIGHT THROUGH TUESDAY NIGHT/...
As of 245 AM Monday...

Collaborating Flash Flood Watch through Tuesday night. See above
discussion for details tonight through Tuesday night.

&&

.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
As of 230 PM Sunday...

The active/wet pattern is likely to continue through most/if not all
of the long term period as the area finds itself sandwiched between
a stalled mid/upper-level trough (west) and a sub-tropical Atlantic
High (east). This will exacerbate southerly/southwesterly fetch
across central NC, providing an airmass characterized by high PWAT
values (consistently in the 1.75 to 2.5 inch range) and persistent
diurnal shower/thunder chances. The airmass attempts to wash-out a
bit toward the end of the period as a frontal boundary approaches
the area from the northwest, however, models tend to agree with this
boundary stalling near/slightly north of the VA/NC border, keeping
us in the warm/humid/stormy airmass for the foreseeable future.

QPF amounts are going to be highly difficult to nail down due to the
convective nature of the precipitation. As an area average, expect
generally 1 to 3 inches of precipitation during this period. Higher
amounts will likely be located across the coastal plain with the
best moisture profile, and across the Piedmont/Triad region which
could see greater coverage thanks to mountain aided development each
afternoon. Flooding concerns will generally be locally dependent on
high rainfall rates and/or training storms across a particular area.
Currently, not a strong signal for potential river flooding
according to MMEFS, but with high QPF amounts expected across the
headwaters region in VA/western NC over the next 7 days, it could
easily transition into more of a concern eventually.

With boundary layer moisture ample through the period, thicknesses
are expected to remain generally near to slightly below normal,
thanks in a large part to persistent cloud cover and/or shower
development during prime daytime heating hours. Expect temperatures
generally in the low to mid 80s to begin the period, with a few
places touching 90 late week as the mid level flow flattens a bit,
and a mid to upper-level low is forecast to transverse through the
Great Lakes region by Friday/Saturday. Lows will generally settle a
bit warmer than normal, in the low to mid 70s during this period.

&&

.AVIATION /06Z MONDAY THROUGH FRIDAY/...
As of 105 AM Monday...

Aided by upper support this morning, showers and thunderstorms
are expected in the eastern part of NC, as far west as KFAY and
KRDU. MVFR to IFR CIGS and VSBYS will accompany the showers/storms.
Low stratus is expected to reduce CIGS to LIFR in the KGSO/KINT
areas with MVFR VSBYS in fog through 14z.

A general return to VFR conditions is expected between 14z and
17z, then showers/storms are again expected to develop with
associated MVFR CIGS and VSYBS through this evening.

Beyond 06Z Tuesday...A deep southerly flow of moist and unstable
air will result in an unsettled period through the work week.
Showers and thunderstorms, especially during the afternoon and
evening, combined with periods of low clouds and fog around daybreak
will result in a prolonged threat of adverse aviation conditions
through the week.

&&

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

&&

SYNOPSIS...Badgett
NEAR TERM...Badgett
SHORT TERM...Badgett
LONG TERM...BSD
AVIATION...Badgett

Hazardous Weather Outlook
National Weather Service Raleigh NC
1034 PM EDT Sun Jul 22 2018

NCZ011-027-028-042-043-078-088-089-240245-
Halifax-Nash-Edgecombe-Johnston-Wilson-Wayne-Cumberland-Sampson-
1034 PM EDT Sun Jul 22 2018

This Hazardous Weather Outlook is for central North Carolina.

.DAY ONE...Tonight.

Widely scattered showers and thunderstorms are expected overnight. An
area of more widespread and significant storms may skirt the Coastal
Plain, especially east of Interstate 95, after midnight through
daybreak. Some of these storms will be capable of producing very
heavy rain, gusty winds in excess of 50 mph and frequent lightning.

.DAYS TWO THROUGH SEVEN...Monday through Saturday.

Periods of showers and thunderstorms are expected to bring locally
heavy rainfall during the work week. The greatest threat for
thunderstorms with heavy rain will be during the afternoon and
evening hours each day.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is not expected at this time.

NCZ007>010-021>026-038>041-073>077-083>086-240245-
Person-Granville-Vance-Warren-Forsyth-Guilford-Alamance-Orange-
Durham-Franklin-Davidson-Randolph-Chatham-Wake-Stanly-Montgomery-
Moore-Lee-Harnett-Anson-Richmond-Scotland-Hoke-
1034 PM EDT Sun Jul 22 2018

This Hazardous Weather Outlook is for central North Carolina.

.DAY ONE...Tonight.

Widely scattered showers and thunderstorms are expected overnight. A
few storms could produce very heavy rain, gusty winds in excess of 50
mph and frequent lightning.

.DAYS TWO THROUGH SEVEN...Monday through Saturday.

Periods of showers and thunderstorms are expected to bring locally
heavy rainfall during the work week. The greatest threat for
thunderstorms with heavy rain will be during the afternoon and
evening hours each day.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is not expected at this time.

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE RALEIGH NC
225 AM EDT MON JUL 23 2018

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

1247 AM     TSTM WND DMG     3 W GRANTHAM            35.29N 78.22W
07/23/2018                   WAYNE              NC   TRAINED SPOTTER

            NUMEROUS TREES REPORTED DOWN NEAR HIGHWAY 13
            AND DOBBERSVILLE ROAD.

&&

BSD

Special Weather Statement
National Weather Service Raleigh NC
231 AM EDT MON JUL 23 2018

NCZ023-024-040-230730-
Chatham NC-Alamance NC-Orange NC-
231 AM EDT MON JUL 23 2018

...A STRONG THUNDERSTORM WILL AFFECT SOUTHEASTERN ALAMANCE...SOUTHERN
ORANGE AND CENTRAL CHATHAM COUNTIES UNTIL 330 AM EDT...

At 231 AM EDT, Doppler radar was tracking a strong thunderstorm over
Pittsboro, moving north at 20 mph.

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

Heavy rain and minor flooding and deadly cloud to ground lightning
will also be possible with this storm.

Locations impacted include...
Chapel Hill, Pittsboro, Carrboro, Swepsonville, Bynum, Fearrington,
Sutphin, Cane Creek Reservoir, Saxapahaw and Lake Jordan.

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 3562 7909 3563 7912 3562 7914 3560 7916
      3559 7930 3602 7939 3602 7902
TIME...MOT...LOC 0631Z 181DEG 18KT 3570 7921

77

Special Weather Statement
National Weather Service Raleigh NC
240 AM EDT MON JUL 23 2018

NCZ077-088-230715-
Harnett NC-Cumberland NC-
240 AM EDT MON JUL 23 2018

...A LINE OF STRONG THUNDERSTORMS WILL AFFECT CENTRAL HARNETT AND
WESTERN CUMBERLAND COUNTIES UNTIL 315 AM EDT...

At 240 AM EDT, Doppler radar was tracking a line of strong
thunderstorms along a line extending from 8 miles south of Lillington
to 8 miles southwest of Godwin to near Fayetteville. Movement was
north at 30 mph.

Wind gusts up to 50 mph will be possible with these storms.

Heavy rain and minor flooding and deadly cloud to ground lightning
will also be possible with these storms.

Locations impacted include...
Fayetteville, Lillington, Fort Bragg, Godwin, Pope AFB, Hope Mills,
Spring Lake, Eastover, Wade and Linden.

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.

Locally heavy rain will quickly reduce visibility and result in
ponding of water on roadways, standing water in low lying areas, and
minor flooding of creeks, streams, and areas of poor drainage.
Drivers are urged to slow down and use extra caution to avoid
hydroplaning, especially in urban areas where prolonged heavy rain
can quickly lead to flooding.

&&

LAT...LON 3493 7898 3546 7903 3552 7897 3539 7871
      3511 7865 3503 7874 3492 7897
TIME...MOT...LOC 0640Z 180DEG 25KT 3528 7886 3515 7880 3502 7892

77

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE RALEIGH NC
248 AM EDT MON JUL 23 2018

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

1249 AM     TSTM WND DMG     2 NNE GRANTHAM          35.33N 78.15W
07/23/2018                   WAYNE              NC   TRAINED SPOTTER

            NUMEROUS TREES WERE REPORTED DOWN NEAR
            FALLING CREEK RD AT STEVENS CHURCH ROAD.

&&

BSD

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE RALEIGH NC
250 AM EDT MON JUL 23 2018

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

0230 AM     TSTM WND DMG     5 SW TILLERY            36.19N 77.53W
07/23/2018                   HALIFAX            NC   911 CALL CENTER

            TWO TREES WERE REPORTED DOWN NEAR THE
            INTERSECTION OF HIGHWAY 125 AND KENTUCKY
            LANE.

&&

BSD

Special Weather Statement
National Weather Service Raleigh NC
252 AM EDT MON JUL 23 2018

NCZ040-041-077-230730-
Chatham NC-Harnett NC-Wake NC-
252 AM EDT MON JUL 23 2018

...A LINE OF STRONG THUNDERSTORMS WILL AFFECT NORTH CENTRAL
HARNETT...SOUTHWESTERN WAKE AND SOUTHEASTERN CHATHAM COUNTIES UNTIL
330 AM EDT...

At 252 AM EDT, Doppler radar was tracking a line of strong
thunderstorms along a line extending from 7 miles southwest of Cary
to Fuquay-Varina to 6 miles northwest of Lillington. Movement was
north at 15 mph.

Wind gusts up to 50 mph will be possible with these storms.

Heavy rain and minor flooding and deadly cloud to ground lightning
will also be possible with these storms.

Locations impacted include...
Raleigh, Cary, Fuquay-Varina, Angier, Rdu International, Apex, Holly
Springs, Morrisville, Crosswinds Campground and Lake Wheeler.

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.

Locally heavy rain will quickly reduce visibility and result in
ponding of water on roadways, standing water in low lying areas, and
minor flooding of creeks, streams, and areas of poor drainage.
Drivers are urged to slow down and use extra caution to avoid
hydroplaning, especially in urban areas where prolonged heavy rain
can quickly lead to flooding.

&&

LAT...LON 3589 7879 3569 7869 3541 7873 3550 7897
      3560 7900 3580 7901
TIME...MOT...LOC 0652Z 188DEG 14KT 3569 7885 3556 7879 3543 7891

77