Alert archive / North Carolina / Severe Thunderstorm Warnings in 2017

Severe Thunderstorm Warning 40, NWS Greenville-Spartanburg, SC

March 27, 2017Alexander County, Caldwell County, North Carolina

NWS Greenville-Spartanburg, SC issued this severe thunderstorm warning at Mar 27, 2017, 5:36 PM EDT for Alexander County, Caldwell County, North Carolina. It was in force for 39 min. 1 report came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued
Mar 27, 2017, 5:36 PM EDT (21:36 UTC)
Expired
Mar 27, 2017, 6:15 PM EDT
In force
39 min
Issued by
NWS Greenville-Spartanburg, SC
Area
Storm-based polygon
Hail
1.0 in
Wind
60.0 mph

Counties Alexander County, NC, Caldwell County, NC

The radar

The Roanoke radar (KFCX), 141 km from the middle of the area, began a volume at 21:38 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.

What was reported inside it

TimeReportWhereRemark
Mar 27, 5:40 PM EDTHAIL 0.881 Sw Kings Creek, NCOBSERVED A PHOTO OF HAIL ON FACEBOOK WITH A DIME BESIDE. AT LEAST ONE PIECE OF HAIL SEEMS TO BE A BIT LARGER THAN THE DIME. NICKEL SIZED HAIL.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

Did it verify

Not verified. The Iowa Environmental Mesonet's Cow found no qualifying storm report inside this severe thunderstorm warning while it was in force. That is not proof nothing happened: reports are thin where few people live.

Cow counts a report within 15 km of the polygon while the warning was in force: a tornado for a tornado warning; hail of 1 inch or more, a gust of 58 mph or more or wind damage for a severe thunderstorm warning; a flash flood report for a flash flood warning.

The nearest sounding before it

Greensboro/Hi Pt, NC (KGSO), launched 12:00Z, 9.6 hours before the alert went out and 118 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-pSkew-T log-p diagram, Greensboro/Hi Pt, NC at 12:00Z on 2017-03-27Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 15 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Greensboro/Hi Pt, NC at 12:00Z on 2017-03-27The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 157 square meters per square second.193958Sfc1 km3 km6 km9 kmRMLM
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
15 J/kg
Mixed-layer CIN
-50 J/kg
Mixed-layer LCL
661 m above ground
0-6 km bulk shear
32 kt
0-1 km storm-relative helicity
157 m²/s²
0-3 km storm-relative helicity
173 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

033 
WUUS52 KGSP 272136
SVRGSP
NCC003-027-272215-
/O.NEW.KGSP.SV.W.0040.170327T2136Z-170327T2215Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Greenville-Spartanburg SC
536 PM EDT MON MAR 27 2017

The National Weather Service in Greenville-Spartanburg has issued a

* Severe Thunderstorm Warning for...
  Northern Alexander County in the Piedmont of North Carolina...
  East central Caldwell County in western North Carolina...

* Until 615 PM EDT

* At 536 PM EDT, a severe thunderstorm was located 7 miles east of
  Lenoir, or near Cedar Rock, moving east at 25 mph.

  HAZARD...60 mph wind gusts and quarter size hail. 

  SOURCE...Radar indicated. 

  IMPACT...Hail damage to vehicles is expected. Expect wind damage 
           to roofs, siding, and trees. 

* Locations impacted include...
  Taylorsville, Cedar Rock, Vashti, Ellendale, Kings Creek and Little
  River In Alexander County.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Scattered trees and power lines will be blown down in the warned
area. Seek shelter inside an interior room.

Please report damaging winds, hail, or flooding to the National
Weather Service Greenville-Spartanburg by calling toll free, 1, 800,
2 6 7, 8 1 0 1, or by posting on our Facebook page, or Tweet it using
hashtag nwsgsp. Your message should describe the event and the
specific location where it occurred.

&&

LAT...LON 3599 8100 3594 8101 3587 8147 3596 8151
      3603 8137 3602 8134 3600 8133 3601 8129
      3603 8127 3604 8119 3603 8117 3604 8113
      3603 8107 3605 8103
TIME...MOT...LOC 2136Z 249DEG 20KT 3593 8141 

HAIL...1.00IN
WIND...60MPH
 
$$

CDG
2 follow-up statements
739 
WWUS52 KGSP 272156
SVSGSP

Severe Weather Statement
National Weather Service Greenville-Spartanburg SC
556 PM EDT MON MAR 27 2017

NCC027-272206-
/O.CAN.KGSP.SV.W.0040.000000T0000Z-170327T2215Z/
Caldwell NC-
556 PM EDT MON MAR 27 2017

...THE SEVERE THUNDERSTORM WARNING FOR EAST CENTRAL CALDWELL COUNTY
IS CANCELLED...
    
The severe thunderstorm which prompted the warning has moved out of 
the warned area. Therefore the warning has been cancelled.

LAT...LON 3599 8100 3594 8101 3589 8133 3589 8134
      3592 8134 3599 8133 3601 8129 3603 8127
      3604 8120 3603 8118 3603 8117 3604 8113
      3603 8107 3604 8103
TIME...MOT...LOC 2156Z 249DEG 20KT 3597 8128 

$$

NCC003-272215-
/O.CON.KGSP.SV.W.0040.000000T0000Z-170327T2215Z/
Alexander NC-
556 PM EDT MON MAR 27 2017

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 615 PM EDT
FOR NORTHERN ALEXANDER COUNTY...

At 556 PM EDT, a severe thunderstorm was located 6 miles northwest of
Taylorsville, moving east at 25 mph.

HAZARD...60 mph wind gusts and quarter size hail. 

SOURCE...Radar indicated. 

IMPACT...Hail damage to vehicles is expected. Expect wind damage to 
         roofs, siding, and trees. 

Locations impacted include...
Taylorsville, Vashti, Ellendale and Little River In Alexander County.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Scattered trees and power lines will be blown down in the warned
area. Seek shelter inside an interior room.

Please report damaging winds, hail, or flooding to the National
Weather Service Greenville-Spartanburg by calling toll free, 1, 800,
2 6 7, 8 1 0 1, or by posting on our Facebook page, or Tweet it using
hashtag nwsgsp. Your message should describe the event and the
specific location where it occurred.

&&

LAT...LON 3599 8100 3594 8101 3589 8133 3589 8134
      3592 8134 3599 8133 3601 8129 3603 8127
      3604 8120 3603 8118 3603 8117 3604 8113
      3603 8107 3604 8103
TIME...MOT...LOC 2156Z 249DEG 20KT 3597 8128 

HAIL...1.00IN
WIND...60MPH
 
$$

CDG
321 
WWUS52 KGSP 272210
SVSGSP

Severe Weather Statement
National Weather Service Greenville-Spartanburg SC
610 PM EDT MON MAR 27 2017

NCC003-272220-
/O.EXP.KGSP.SV.W.0040.000000T0000Z-170327T2215Z/
Alexander NC-
610 PM EDT MON MAR 27 2017

...THE SEVERE THUNDERSTORM WARNING FOR NORTHERN ALEXANDER COUNTY WILL
EXPIRE AT 615 PM EDT...
                
The storm which prompted the warning has weakened below severe
limits, and no longer poses an immediate threat to life or property.
Therefore the warning will be allowed to expire.  However small hail
and gusty winds are still possible with this thunderstorm.

LAT...LON 3599 8100 3594 8101 3589 8133 3589 8134
      3592 8134 3599 8133 3601 8129 3603 8127
      3604 8120 3603 8118 3603 8117 3604 8113
      3603 8107 3604 8103
TIME...MOT...LOC 2210Z 249DEG 20KT 3599 8121 

$$

CDG

What forecasters said that day

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

NWS Greenville-Spartanburg, SC wrote its last area forecast discussion before this severe thunderstorm warning went out at Mar 27, 2:44 PM EDT, 2 hours 52 minutes earlier.

Area forecast discussion, Mar 27, 2:44 PM EDT, 2 hours 52 minutes before
Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
244 PM EDT Mon Mar 27 2017

.SYNOPSIS...
Moist southerly flow will linger over the southeast through Tuesday,
with several rounds of showers and thunderstorms possible. Drier air
will briefly return by the middle of the week as a cold front
settles south of the area. Rain chances return to end the week as a
low pressure system approaches from the west and interacts with the
stalled front.

&&

.NEAR TERM /THROUGH TUESDAY/...
As of 240 PM EDT: Isolated to scattered convection will move east
across the area this afternoon and early evening ahead of a lead
short wave moving ahead of an upper trough. An isolated severe storm
cannot be ruled out given the moderate instability and relatively
steep lapse rates, mainly along and south of I-85. Organization is
not expected this afternoon as the best shear will be over the
mountains and doesn't overlap the best instability.

That may change this evening and early tonight as relatively strong
short wave swings across the area just ahead of the approaching
upper trough. This forcing will combine with good upper jet
divergence and deep layer Q vector convergence. Good shear remains
across the area, but elevated instability, while continuing, will be
on the decline. All this means a good chance of convection during
the evening and early overnight across the mountains then spreading
east but diminishing as it moves across the area. Severe storms
cannot be ruled out, especially across the mountains this evening.
The question remains whether organized MCS type convection can get
going across TN. If so, then this may be enough to increase severe
chances if it can hold together as it moves into the mountains. Lows
will be around 15 degrees above normal.

The upper trough swings across the area Tuesday but the surface cold
front moves more slowly. Convective coverage overall will be greater
in the morning as that's when the deepest moisture and forcing will
be over the area. Coverage will be better along and east of the I-77
corridor during the afternoon. The best overlap of instability and
shear will be to our north and east Tuesday. However, there could be
enough overlap during the afternoon along and east of the I-77
corridor for an isolated severe storm. The air mass behind the front
is not very different, and with the slow movement, highs will be 10
to 15 degrees above normal.

&&

.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY/...
As of 215 PM EDT Monday: In the Short Term, an upper ridge will
cross the Eastern CONUS, while a deep upper low ejects out of the
Four Corners region into the Southern Plains. At the surface, a weak
cold front will slide east, as high pressure builds into the the
Great Lakes. Low-level CAA will be weak behind the front, so well
above normal temps are expected Tuesday night and Wednesday.
Conditions should be dry under partly cloudy skies.

Wednesday night and Thursday, as a vigorous low pressure system
tracks across the Plains, low-level flow will turn out of the south
atop the CWFA, with WAA and upglide supporting the development of
clouds and spotty light showers. With an ~1032 mb surface high
centered over central Quebec, hybrid cold air damming should set up
by daybreak Thursday. This will make for a tricky temp forecast, as
precip will be forced mainly by isentropic lift and weak southerly
upslope flow. So mainly drizzle and sprinkles with a few light
showers are expected. PoPs still ramp up to likely in the southwest
corner of the CWFA by the end of the day on Thursday. If the models
prove to be overdone on precip, temps may end up being a couple
categories warmer than the going forecast. Both the NAM and GFS show
elevated CAPE above the wedge in the upper Savannah Valley. So will
keep a chance of thunder mention thursday afternoon there. But
severe threat should remain well to the west closer to the
approaching cold front.

&&

.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
As of 230 PM EDT Monday:  The medium range fcst period kicks off
on Thursday evening amidst a highly amplified upper pattern that
is highlighted by a ridge axis along the east coast, as well as
a closed and robust H5 cyclone embedded in a longwave trof atop
the Plains and MS Valley regions.  At the surface, the pattern
is just as complex thanks to an entrenched hybrid CAD centered
off the Jersey shore, while cyclogenesis dominates the field
across Dixie Alley, eastward into the Southern Appalachians by
way of an approaching zone of baroclynicity.  With that, the
cold front associated with said surface cyclone will be well to
west by fcst initialization, likely yet to cross the MS river,
however a warm front will have laid out across the I75 corridor
region in GA.  Moisture advection tied to this pattern still looks
as if it will lift isentropically atop the wedge airmass leading
to increasing chances for stratiform precipitation into the early
overnight hours.  At that point the fcst becomes quite interesting
given the approaching upper wave to provide synoptic scale lift,
as well as cooling the mid levels and thus increasing lapse rates.
Meanwhile, the CAD will begin to retreat to the east leading to
intrusion of the warm front, and thus providing focus for llv srh
enhancement given remnant backed surface flow.  Eventually the
flow will veer leading to straightening of hodographs, at least in
the 0-1km layer, however improved mid level lapse rates will yield
increasing instability while the primary shortwave passes overhead.
Given the fcst range these details are still a bit uncertain,
yet it still looks as if the pattern could be rather convectively
active Friday morning/afternoon before the cold front sweeps in
Friday evening.

Moving on, remnant northwest flow showers are progged behind the
fropa on Saturday while the remainder of the fcst area tends to dry
out as deep layer ridging builds in for Sunday. This deep ridging
looks dominant through Monday as well, however with sly flow to be
reestablished as the surface ridge shifts over the western Atlantic.
Meanwhile another deep upper system will be building across the
Plains, before sharply ejecting northeast into the OH/TN valleys
toward periods end, which will lead to another round of wet weather
across northeast GA and the western Carolinas into midweek.

As for the fcst itself, pops will ramp up sharply on Thursday night,
holding at widespread high chance to likely levels through much of
the day Friday.  Said pops will taper into the overnight of Saturday
morning given the fropa, thus no mentionable pops are featured by
12z regionwide with the exception of the TN line upslope regions.
By midday Saturday, those pops are removed leading to dry conditions
through Sunday and into Monday when pops increase slowly from
the west as the next system ejects from the southern Plains.
Temperatures through the period will be a bit variable, however
above normal.

&&

.AVIATION /19Z MONDAY THROUGH SATURDAY/...
At KCLT: MVFR cigs have scattered out. However, low VFR and the
potential for convection return during the afternoon. Guidance has
backed off on the potential for TSRA at the airfield, but chance is
high enough to change the TEMPO to VCTS. Decreasing nocturnal
instability should lead to mainly showers overnight. Guidance has
been consistent bringing in MVFR VSBY and IFR cigs overnight, so
have added these to the TAF. Should be a quick VSBY recover Tuesday
but a slow cig recovery. Winds will be S to SSW through the period.

Elsewhere: Similar conditions to KCLT except with an earlier onset
of convection. Wind will shift after daybreak to NW at KAVL and will
go more westerly elsewhere.

Outlook: Another round of thunderstorms will be possible on Tuesday
afternoon, especially near KCLT. Continued low level moisture will
provide a good chances of restrictions throughout. Drier conditions
should briefly return during mid-week before another storm system
begins affecting the region Thursday and Friday.

Confidence Table...

            18-24Z        00-06Z        06-12Z        12-18Z
KCLT       High  90%     High  92%     Low   59%     Med   75%
KGSP       High  97%     High 100%     Med   60%     Med   74%
KAVL       High 100%     High 100%     High  83%     High  84%
KHKY       Med   75%     Med   78%     Med   62%     Low   58%
KGMU       High 100%     High 100%     Med   64%     Med   75%
KAND       High  93%     High 100%     Med   77%     Med   77%

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...Wimberley
NEAR TERM...RWH
SHORT TERM...ARK
LONG TERM...CDG
AVIATION...RWH
Hazardous weather outlook, Mar 27, 4:15 PM EDT, 1 hour 21 minutes before
Hazardous Weather Outlook
National Weather Service Greenville-Spartanburg SC
415 PM EDT Mon Mar 27 2017

GAZ010-017-018-026-028-029-NCZ033-035>037-048>053-056>059-062>065-
068>072-082-501>510-SCZ001>014-019-282015-
Rabun-Habersham-Stephens-Franklin-Hart-Elbert-Avery-Alexander-
Iredell-Davie-Madison-Yancey-Mitchell-Swain-Haywood-Buncombe-Catawba-
Rowan-Graham-Northern Jackson-Macon-Southern Jackson-Transylvania-
Henderson-Cleveland-Lincoln-Gaston-Mecklenburg-Cabarrus-Union-
Caldwell Mountains-Greater Caldwell-Burke Mountains-Greater Burke-
McDowell Mountains-Eastern McDowell-Rutherford Mountains-
Greater Rutherford-Polk Mountains-Eastern Polk-Oconee Mountains-
Pickens Mountains-Greenville Mountains-Greater Oconee-
Greater Pickens-Greater Greenville-Spartanburg-Cherokee-York-
Anderson-Abbeville-Laurens-Chester-Greenwood-
415 PM EDT Mon Mar 27 2017

This Hazardous Weather Outlook is for northeast Georgia, piedmont
North Carolina, western North Carolina and upstate South Carolina.

.DAY ONE...Tonight.

Scattered strong thunderstorms are still expected to develop across
the region into the evening hours. The main threat with any
thunderstorms will be cloud to ground lightning, locally heavy
rainfall, and briefly gusty winds. A few of the thunderstorms may
become severe, capable of producing hail as large as
quarter and isolated damaging wind gusts.

Another round of showers and thunderstorms will arrive from the west
across the southern Appalachians overnight. If severe thunderstorms
develop across central and eastern Tennessee late this evening, some
of these could survive into the North Carolina mountains overnight.
Damaging wind gusts will be the primary threat with any of those
storms.

.DAYS TWO THROUGH SEVEN...Tuesday through Sunday.

..Tuesday...No hazardous weather is expected at this time.
..Wednesday...No hazardous weather is expected at this time.
..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.

.SPOTTER INFORMATION STATEMENT...

Skywarn spotters are requested to forward any reports of large
hail...damaging winds...tornadoes or flash flooding to our office.

ARK

In the hours before

Special weather statement, Mar 27, 4:00 PM EDT, 1 hour 36 minutes before
Special Weather Statement
National Weather Service Greenville-Spartanburg SC
400 PM EDT MON MAR 27 2017

NCZ049-050-503>506-272045-
McDowell Mountains NC-Yancey NC-Burke Mountains NC-Greater Burke NC-
Eastern McDowell NC-Mitchell NC-
400 PM EDT MON MAR 27 2017

...A STRONG THUNDERSTORM WILL IMPACT CENTRAL MCDOWELL...SOUTHEASTERN
MITCHELL...EAST CENTRAL YANCEY AND NORTHWESTERN BURKE COUNTIES UNTIL
445 PM EDT...

At 400 PM EDT, Doppler radar was tracking a strong thunderstorm 7
miles northwest of Marion, or 5 miles northeast of B.R.
Parkway-Little Switzerland To Linville, moving northeast at 35 mph.

Locations to be impacted include...
Marion, Spruce Pine, Lake James State Park, Table Rock, Linville
Falls, Lake James, B.R. Parkway-Little Switzerland To Linville, B.R.
Parkway-Craggy To Little Switzerland, B.R. Parkway-Linville Falls To
Grandfather and Nebo.

Wind gusts up to 40 mph and pea size hail will be possible in these
areas.

LAT...LON 3598 8187 3597 8182 3595 8180 3595 8178
      3593 8178 3593 8175 3588 8171 3587 8169
      3581 8165 3565 8212 3581 8222 3593 8202
      3591 8198 3592 8196 3593 8195 3595 8196
      3600 8190
TIME...MOT...LOC 2000Z 240DEG 28KT 3577 8209

CDG
Special weather statement, Mar 27, 4:46 PM EDT, 50 minutes before
Special Weather Statement
National Weather Service Greenville-Spartanburg SC
446 PM EDT MON MAR 27 2017

NCZ035-501>503-272130-
Caldwell Mountains NC-Burke Mountains NC-Greater Caldwell NC-
Alexander NC-
446 PM EDT MON MAR 27 2017

...A STRONG THUNDERSTORM WILL IMPACT NORTHERN ALEXANDER AND CALDWELL
COUNTIES UNTIL 530 PM EDT...

At 445 PM EDT, Doppler radar was tracking a strong thunderstorm 7
miles northwest of Morganton, or near Table Rock, moving northeast at
45 mph.

Locations to be impacted include...
Lenoir, Gamewell, Hudson, Cajah's Mountain, Cedar Rock, Kings Creek,
Vashti, Collettsville, Patterson and Ellendale.

Wind gusts up to 40 mph and pea size hail will be possible in these
areas.

LAT...LON 3609 8145 3607 8144 3607 8141 3604 8140
      3602 8135 3600 8133 3603 8127 3604 8119
      3603 8117 3604 8113 3603 8107 3605 8103
      3599 8100 3581 8159 3589 8173 3587 8177
      3594 8181 3610 8150
TIME...MOT...LOC 2045Z 242DEG 40KT 3583 8176

CDG

The office that day

Everything else NWS Greenville-Spartanburg, SC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Mar 27, 4:00 PM EDTSpecial Weather StatementGSPMcDowell45 min
Mar 27, 4:46 PM EDTSpecial Weather StatementGSPCaldwell44 min
Mar 27, 6:15 PM EDTSpecial Weather StatementGSPAlexander60 min

Nearby

Severe Thunderstorm Warnings in North Carolina, 2017Every severe thunderstorm warning 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.