Alert archive / South Carolina / Special Weather Statements in 2017

Special Weather Statement, NWS Columbia, SC

July 16, 2017McCormick County, South Carolina

NWS Columbia, SC issued this special weather statement at Jul 16, 2017, 5:11 PM EDT for McCormick County, South Carolina. It was in force for 49 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued: Jul 16, 2017, 5:11 PM EDT (21:11 UTC)
Expired: Jul 16, 2017, 6:00 PM EDT
In force: 49 min
Issued by: NWS Columbia, SC

County McCormick County, SC

The radar

The Columbia radar (KCAE), 95 km from the middle of the area, began a volume at 21:11 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

The nearest sounding before it

Peachtre/Fal Fld, GA (KFFC), launched 12:00Z, 9.2 hours before the alert went out and 228 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.

Mixed-layer CAPE: 758 J/kg
Mixed-layer CIN: -29 J/kg
Mixed-layer LCL: 738 m above ground
0-6 km bulk shear: 14 kt
0-1 km storm-relative helicity: 30 m²/s²
0-3 km storm-relative helicity: 36 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

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What forecasters said that day

The local office's own words before this special weather statement went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Columbia, SC wrote its last area forecast discussion before this special weather statement went out at Jul 16, 4:32 PM EDT, 39 minutes earlier.

Area forecast discussion, Jul 16, 4:32 PM EDT, 39 minutes before

Area Forecast Discussion
National Weather Service Columbia SC
432 PM EDT Sun Jul 16 2017

.SYNOPSIS...
A trough across the area and high moisture will result in
continued chances for showers and thunderstorms which may
linger through Tuesday. Thunderstorms more isolated by midweek
as ridge builds over the area. Temperatures will warm to well
above normal by the end of the week.

&&

.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
Frontal boundary remains north of the area this afternoon. Air
mass remains moist and moderately unstable. Precipitable water
near 2 inches across the east CWA. Short wave trough
approaching from the northwest. Radar showing scattered showers
developing. Severe thunderstorm potential appears lower than
yesterday with weak shear and weaker instability. However there
remains a heavy rain threat. Strong short wave trough over
southern Alabama. Convection along the FL panhandle may advect
northeast as short wave lifts toward the region. This is
supported by latest HRRR. Will continue mention of high chance
to likely pops most of the area although late today the chance
may decrease in the Piedmont. Convection should diminish 03z-
06z. Overnight lows in the low 70s.

&&

.SHORT TERM /6 AM MONDAY MORNING THROUGH TUESDAY NIGHT/...
Weak surface trough remains across the area. This will remain
the focusing mechanism for additional showers and thunderstorms
through Monday. Positively tilted upper level trough over the
eastern CONUS through the period. Relatively cold aloft with 500
mb temperatures to -10C. So steep low-mid level lapse rates
supports resulting in moderate to possible strong instability. Although
shear remains weak...pulse severe possible. Some drier air may
advect in across the north Midlands. Highs around 90 both days.
overnight lows in the low 70s.

&&

.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
Models still indicating the potential for a weak cut-off upper
low developing over the area Tuesday through Wednesday as the
cwa gets squeezed between the strong ridge across the central US
and another ridge in the western Atlantic. By Thursday the
ridge west of the region appears to strengthen and move
eastward, pushing the upper low out of the area late in the
period. Still expecting the convection to become more diurnal
and more scattered to isolated later in the week. Temperatures
near normal early in the period but warming trend late week to
above normal again. Expect temperatures near 100 degrees by next
weekend.

&&

.AVIATION /20Z SUNDAY THROUGH FRIDAY/...
Variable conditions through much of the TAF period.

Stalled frontal boundary remains across the area with showers
and thunderstorms moving through the area. Main concern is a
group of thunderstorms moving toward AGS/DNL from the south and
arriving around 22z. Other concern will again be wind gusts
potential...however potential is lower than yesterday.
Convection will diminish with sunset with potential for stratus
and fog to develop through the early morning hours. Cloud cover
will again lessen impacts...however have remained with MVFR
vsbys at CAE/CUB/DNL and IFR at AGS/OGB. Conditions will return
to VFR by 15z with another round of convection expected to begin
around 18z.

EXTENDED AVIATION OUTLOOK...Showers and thunderstorms with
associated restrictions expected Monday as a front remains
stalled over the area. Low confidence in showers and
thunderstorms Tuesday through Thursday. Restrictions also
possible in late night/early morning stratus and fog each day.

&&

.CAE WATCHES/WARNINGS/ADVISORIES...
GA...None.
SC...None.

&&

Hazardous weather outlook, Jul 16, 3:16 AM EDT, 13 hours 55 minutes before

Hazardous Weather Outlook
National Weather Service Columbia SC
316 AM EDT Sun Jul 16 2017

GAZ040-063>065-077-SCZ015-016-018-020>022-025>031-035>038-041-170730-
Lincoln-McDuffie-Columbia-Richmond-Burke-Lancaster-Chesterfield-
McCormick-Newberry-Fairfield-Kershaw-Edgefield-Saluda-Lexington-
Richland-Lee-Aiken-Sumter-Barnwell-Orangeburg-Calhoun-Clarendon-
Bamberg-
316 AM EDT Sun Jul 16 2017

This Hazardous Weather Outlook is for the Midlands of South Carolina
and the Central Savannah River area of Georgia.

.DAY ONE...Today and Tonight.

Thunderstorms through Tonight could possibly contain strong to
damaging winds, along with heavy rain with localized flooding.

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

Monday, A few thunderstorms with damaging wind will be possible
along a decaying surface front. The storms may also contain heavy
rain with localized flooding.

Friday and Saturday, heat index values may climb back above 105
degrees in many areas.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is not expected at this time.

In the hours before

Special weather statement, Jul 16, 2:18 PM EDT, 2 hours 53 minutes before

Special Weather Statement
National Weather Service Columbia SC
218 PM EDT SUN JUL 16 2017

SCZ031-161845-
Sumter-
218 PM EDT SUN JUL 16 2017

...A STRONG THUNDERSTORM WILL AFFECT CENTRAL SUMTER COUNTIES...

At 217 PM EDT, a strong thunderstorm was just south of
Sumter, moving northeast at 10 mph.

Wind gusts up to 50 mph are possible with this storm along
with small hail. Ponding of water will occur in poor-drainage
areas. Do not drive on flooded roads.

Locations impacted include...
South Sumter.

LAT...LON 3381 8025 3378 8028 3377 8040 3375 8040
      3375 8042 3384 8048 3396 8031 3383 8021
TIME...MOT...LOC 1817Z 236DEG 9KT 3386 8038

Special weather statement, Jul 16, 3:01 PM EDT, 2 hours 10 minutes before

Special Weather Statement
National Weather Service Columbia SC
301 PM EDT SUN JUL 16 2017

SCZ036-038-161945-
Orangeburg-Clarendon-
301 PM EDT SUN JUL 16 2017

...A STRONG THUNDERSTORM WILL AFFECT SOUTH CENTRAL CLARENDON AND EAST
CENTRAL ORANGEBURG COUNTIES...

At 300 PM EDT, a strong thunderstorm was located 7 miles northwest of
Eastern Lake Marion, or 13 miles south of Manning, moving northeast
at 15 mph.

Wind gusts up to 50 mph are possible with this storm.

Locations impacted include...
Manning, Eutawville and Vance.

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.

If you are on or near Lake Marion, get out of the water and move
indoors or inside a vehicle. Remember, lightning can strike out to
10 miles from the parent thunderstorm. If you can hear thunder, you
are close enough to be struck by lightning. Move to safe shelter
now! Do not be caught on the water in a thunderstorm.

LAT...LON 3350 8010 3350 8012 3348 8015 3346 8013
      3346 8015 3345 8015 3346 8016 3345 8017
      3345 8020 3344 8020 3345 8022 3339 8022
      3332 8034 3342 8052 3370 8020 3359 8005
TIME...MOT...LOC 1900Z 230DEG 12KT 3350 8029

CJR

Special weather statement, Jul 16, 5:11 PM EDT, 0 minutes before

Special Weather Statement
National Weather Service Columbia SC
511 PM EDT SUN JUL 16 2017

SCZ018-025-162200-
McCormick-Edgefield-
511 PM EDT SUN JUL 16 2017

...A STRONG THUNDERSTORM WILL AFFECT NORTHWESTERN EDGEFIELD AND
NORTHEASTERN MCCORMICK COUNTIES...

At 509 PM EDT, a strong thunderstorm was located 8 miles east of
Troy, or 15 miles south of Greenwood. The storm is nearly stationary.

Winds up to 40 mph are possible with this storm.

Locations impacted include...
McCormick.

Heavy rainfall is also occurring with this slow moving storm, and
may cause localized flooding and ponding of water on roadways. Do
not drive your vehicle through flooded roadways.

LAT...LON 3398 8228 3402 8224 3398 8221 3397 8218
      3399 8215 3399 8210 3398 8208 3398 8205
      3395 8204 3397 8199 3386 8199 3387 8229
TIME...MOT...LOC 2109Z 273DEG 3KT 3397 8216

CJR

The office that day

Everything else NWS Columbia, SC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jul 15, 8:00 PM EDT	Severe Thunderstorm Warning	CAE	Bamberg	45 min
Jul 15, 8:34 PM EDT	Flash Flood Warning	CAE	Aiken	3 hr
Jul 16, 2:18 PM EDT	Special Weather Statement	CAE	Sumter	27 min
Jul 16, 3:01 PM EDT	Special Weather Statement	CAE	Clarendon	44 min
Jul 16, 4:37 PM EDT	Areal Flood Advisory	CAE	Lee	113 min
Jul 16, 5:50 PM EDT	Special Weather Statement	CAE	Richland	40 min
Jul 16, 5:53 PM EDT	Areal Flood Advisory	CAE	Lexington, Richland	112 min
Jul 16, 5:53 PM EDT	Severe Thunderstorm Warning	CAE	Kershaw, Richland	40 min
Jul 16, 6:20 PM EDT	Flash Flood Warning	CAE	Kershaw, Richland	115 min
Jul 16, 6:39 PM EDT	Areal Flood Advisory	CAE	Calhoun, Lexington, Orangeburg, Richland, Sumter	2 hr
Jul 16, 6:41 PM EDT	Special Weather Statement	CAE	Calhoun	49 min
Jul 16, 7:14 PM EDT	Special Weather Statement	CAE	Newberry	46 min

Nearby

Special Weather Statements in South Carolina, 2017 Every special weather statement in 2017

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.