Flash Flood and Flood in North Carolina, August 3, 2016

Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
150 PM EDT WED AUG 3 2016

.SYNOPSIS...
A frontal boundary will continue sliding through the region today
with rain and thunderstorm chances remaining elevated.  A cool and
moist wedge of high pressure is expected to arrive tonight, lasting
into the later part of the work week.  Another, stronger frontal
boundary will enter the region over the weekend, keeping higher than
normal rainfall chances in the forecast through early next week.

&&

.NEAR TERM /THROUGH TONIGHT/...
As of 1130 AM...The main concern for the morning update is the heavy
rain threat. The air mass in place is quite moist (PWATS in the 1.5
to 2.0" range), with weak steering flow and a light persistent
easterly low-level upslope flow. Many of the CAMs are highlighting
potential for anchored or training cells along the NC Blue Ridge
Escarpment from Avery/Caldwell counties south to northern Greenville
County, especially tonight. These areas have received more rain than
most of the rest of the CWFA in recent days, but the FFG values are
still relatively high. Also, no appreciable synoptic forcing or even
mesoscale forcing will be present outside the orographic effects and
possible outflow boundaries. So while the set-up for heavy rain in
the NC foothills gives me pause, confidence for widespread flooding
is too low to add a Flash Flood Watch at this time. We will evaluate
the 12z guidance once it is all in and also monitor the near-term
trends for a possible watch issuance with the afternoon package.

Otherwise, expect solid likely to categorical shower/TSTM coverage
from I-26 east, and high-end CHC west. Temps will be held below
normal across much of the area due to the cloud cover. In fact, it
looks wedge-like with the low stratus and light NE surface winds.
The max temps look on track from low 80s north to low 90s south.

Later tonight, precip coverage will taper off, but showers will
likely linger, especially near the Blue Ridge. Lows will be above
normal.

&&

.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
As of 230 AM EDT Wednesday:  The short term fcst period initializes
on Thursday morning amidst broad/flat H5 ridging across much of
the southern CONUS, while a closed vortex and associated trof
deepens over Manitoba.  At the surface, high pressure anchored
over the northeast will lead to continued wedging in the lee of
the southern/central Appalachians.  The pattern on Thursday looks
to remain supportive of moderate to heavy rainfall as an easterly
llv moisture fetch prevails keeping pwats elevated in excess of
2 inches.  On Friday the parent surface high shifts out to sea
as the above mentioned upper trof/wave and associated surface
low/front move through the Great Lakes.  With that, llv flow across
the southeast will veer southerly as the subtropical ridge dominates
once again.  That said, abundant moisture remains spread about the
region thus, although somewhat reduced, a heavy rainfall threat
could persist on Friday.  Guidance favors scattered/numerous showers
and thunderstorms both days, with the highest pwats residing east
of the Blue Ridge.  However given the moist orthogonal llv flow,
some focusing of convection along the escarpment is likely.

The fcst will feature widespread low end likely pops on Thursday,
with only high end chances favored across the upper Savannah river
valley where pwats are lowest and less upsloping flow is expected.
Pops taper to slight/chance levels into early Friday before
increasing into the afternoon/evening to likelys over the mtns,
high chances elsewhere.  Temperatures through the period will
fall to below normal levels regionwide amidst abundant sky cover
and convection.

&&

.LONG TERM /SATURDAY THROUGH TUESDAY/...
As of 145 PM EDT Wednesday: the medium range fcst picks up at 12Z on
Sunday with a broad upper trof sliding eastward over New England and
persistent upper ridging in place over the central CONUS. As we move
into early next week, the trof is expected to slowly lift NE while
the ridge spreads farther east and gradually builds towards the end
of the period. At the sfc, the moist pattern is expected to persist
well into the medium range. At the start of the period, a Canadian
high will slide SE and settle over the Great Lakes bringing drier
air to our north. Unfortunately, moist flow associated with the
Bermuda High will persist over the region. This setup will create
a region of persistent low lvl convergence over much of the Carolinas.
This convergence zone will likely weaken towards the end of the
period on Tues and Wed as the high begins to slide offshore and
the resulting flow takes on a more easterly component. As for the
sensible fcst, POPs will remain above climatology for most of the
period with the highest values generally over the escarpment and
ridge tops. Temps will start out just above normal for early August
and drop just below climo early next week as the high sets up to
our north.

&&

.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
At KCLT, The low stratus deck has been slowly lifting and breaking
into an MVFR stratocumulus deck during the early afternoon hours.
The CIGS are expected to eventually lift to VFR before the end of
the daylight, but then start lowering this evening back to IFR
overnight. Persistent easterly to southeasterly low-level flow will
keep showers and possibly a few tsra around this afternoon through
late evening. The highest coverage should be mostly west of KCLT
near the eastern slopes of the Blue Ridge and along the edge of the
stratus deck across the Upstate. For now, I will tempo TSRA from
22-02z, which I think is the timing of greatest chance near the
terminal. Winds will favor an east-northeast direction, but may
occasionally veer to east-southeast this afternoon.

Elsewhere, similar conditions to KCLT. SHRA chances are high at all
the sites thru the evening. Winds are quite variable across the
area, ranging from northeast to southeast. KAVL will see N wind,
then switching to southeast Thursday morning.

Outlook: Moisture will continue on easterly flow through late week
with associated showers and thunderstorms developing - especially in
the afternoon and evening. Restrictions will be possible with any
afternoon/evening convection as well as each morning in the mountain
valleys where fog and low stratus are likely, but will be possible
outside of the mountains as well.

Confidence Table...

            18-24Z        00-06Z        06-12Z        12-18Z
KCLT       Med   75%     Med   75%     Med   67%     High  81%
KGSP       High 100%     High  90%     Med   72%     High  82%
KAVL       High  98%     Med   66%     Med   67%     High  87%
KHKY       Med   76%     Med   67%     Low   52%     High  82%
KGMU       High  99%     High  90%     Med   65%     High  84%
KAND       High 100%     High  99%     Med   74%     High  89%

The percentage reflects the number of guidance members agreeing
with the scheduled TAF issuance flight rule category. Complete hourly
experimental aviation forecast consistency tables and ensemble forecasts
are available at the following link:

www.weather.gov/gsp/aviation

&&

.GSP WATCHES/WARNINGS/ADVISORIES...
GA...None.
NC...None.
SC...None.

&&

SYNOPSIS...CDG/LEV
NEAR TERM...ARK
SHORT TERM...CDG
LONG TERM...CDG
AVIATION...ARK

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
1138 AM EDT WED AUG 3 2016

GAZ010-017-018-026-028-029-NCZ036-037-048-051-052-057>059-062-063-
070>072-082-SCZ001-004>014-019-041545-
RABUN-HABERSHAM-STEPHENS-FRANKLIN-HART-ELBERT-IREDELL-DAVIE-MADISON-
SWAIN-HAYWOOD-ROWAN-GRAHAM-NORTHERN JACKSON-MACON-SOUTHERN JACKSON-
GASTON-MECKLENBURG-CABARRUS-UNION-OCONEE MOUNTAINS-GREATER OCONEE-
GREATER PICKENS-GREATER GREENVILLE-SPARTANBURG-CHEROKEE-YORK-
ANDERSON-ABBEVILLE-LAURENS-CHESTER-GREENWOOD-
1138 AM EDT WED AUG 3 2016

THIS HAZARDOUS WEATHER OUTLOOK IS FOR NORTHEAST GEORGIA...PIEDMONT
NORTH CAROLINA...WESTERN NORTH CAROLINA AND UPSTATE SOUTH CAROLINA.

.DAY ONE...THIS AFTERNOON AND TONIGHT.

SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS WILL DEVELOP
TODAY. GIVEN ABUNDANT MOISTURE IN THE ATMOSPHERE AS WELL AS WEAK
STEERING FLOW...HEAVY RAINFALL AND THUS ISOLATED FLASH FLOODING
WILL BE THE PRIMARY THREATS. ADDITIONALLY...A FEW STORMS COULD BE
STRONG PRODUCING GUSTY WINDS AS WELL AS FREQUENT CLOUD TO GROUND
LIGHTNING.

.DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY.

..THURSDAY...NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.
..FRIDAY...NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.
..SATURDAY...NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.
..SUNDAY...NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.
..MONDAY...NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.
..TUESDAY...NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.SPOTTER INFORMATION STATEMENT...

SKYWARN SPOTTERS ARE REQUESTED TO FORWARD ANY REPORTS OF FLASH
FLOODING TO OUR OFFICE.

NCZ033-035-049-050-053-056-064-065-068-069-501>510-SCZ002-003-041545-
AVERY-ALEXANDER-YANCEY-MITCHELL-BUNCOMBE-CATAWBA-TRANSYLVANIA-
HENDERSON-CLEVELAND-LINCOLN-CALDWELL MOUNTAINS-GREATER CALDWELL-
BURKE MOUNTAINS-GREATER BURKE-MCDOWELL MOUNTAINS-EASTERN MCDOWELL-
RUTHERFORD MOUNTAINS-GREATER RUTHERFORD-POLK MOUNTAINS-EASTERN POLK-
PICKENS MOUNTAINS-GREENVILLE MOUNTAINS-
1138 AM EDT WED AUG 3 2016

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PIEDMONT NORTH
CAROLINA...WESTERN NORTH CAROLINA AND UPSTATE SOUTH CAROLINA.

.DAY ONE...THIS AFTERNOON AND TONIGHT.

SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS WILL DEVELOP
THROUGH THIS AFTERNOON. THESE THUNDERSTORMS ARE FORECAST TO
PRODUCE ISOLATED AREAS OF EXCESSIVE RAINFALL AND FREQUENT CLOUD TO
GROUND LIGHTNING. THIS EVENING AND OVERNIGHT...THE ENVIRONMENT
WILL FAVOR THUNDERSTORMS DEVELOPING ALONG THE EAST FACING SLOPES
OF THE MOUNTAINS AND ADJACENT FOOTHILLS. STEERING WINDS SHOULD
RESULT IN VERY SLOW STORM MOTIONS OR MULTIPLE STORMS TRACKING OVER
THE SAME LOCATION. AS A RESULT...FLASH FLOODING MAY OCCUR IN
SEVERAL AREAS ALONG SMALL CREEKS OR STREAMS...ESPECIALLY NEAR THE
ESCARPMENT OF THE MOUNTAINS.

.DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY.

..THURSDAY...NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.
..FRIDAY...NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.
..SATURDAY...NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.
..SUNDAY...NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.
..MONDAY...NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.
..TUESDAY...NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.SPOTTER INFORMATION STATEMENT...

SKYWARN SPOTTERS ARE REQUESTED TO FORWARD ANY REPORTS OF FLASH
FLOODING TO OUR OFFICE.

NED

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
205 PM EDT WED AUG 03 2016

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

0152 PM     FLOOD            STATESVILLE             35.79N 80.89W
08/03/2016                   IREDELL            NC   COUNTY OFFICIAL

            ROADWAY FLOODING REPORTED IN AND AROUND STATESVILLE, NC.

&&

JPT