Alert archive / South Dakota / Severe Thunderstorm Warnings in 2001

Severe Thunderstorm Warning 6, NWS Aberdeen, SD

May 18, 2001Potter County, South Dakota

NWS Aberdeen, SD issued this severe thunderstorm warning at May 18, 2001, 8:31 PM CDT for Potter County, South Dakota. It was in force for 29 min. 1 report came from inside the area while it was in force.

The area

The counties it named, with what was reported inside it.

The facts

Issued: May 18, 2001, 8:31 PM CDT (01:31 UTC)
Expired: May 18, 2001, 9:00 PM CDT
In force: 29 min
Issued by: NWS Aberdeen, SD
Area: Whole counties

County Potter County, SD

What was reported inside it

Time	Report	Where	Remark
May 18, 8:40 PM CDT	Hail 0.75	Lebanon, SD

NCEI Storm Data entries that began inside the alert's area while it was in force. Before 2003 the local storm report archive is thin, so this is the record of what happened rather than what was phoned in.

The nearest sounding before it

Aberdeen, SD (KABR), launched 00:00Z, 1.5 hours before the alert went out and 124 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: 32 J/kg
Mixed-layer CIN: -113 J/kg
Mixed-layer LCL: 2389 m above ground
0-6 km bulk shear: 31 kt
0-1 km storm-relative helicity: 13 m²/s²
0-3 km storm-relative helicity: 50 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

000 
WUUS53 KABR 190133
SVRABR
SDC107-190200-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE ABERDEEN SD
831 PM CDT FRI MAY 18 2001

THE NATIONAL WEATHER SERVICE IN ABERDEEN HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  EASTERN POTTER COUNTY IN NORTH CENTRAL SOUTH DAKOTA

* UNTIL 900 PM CDT

* AT 831 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM 7 MILES SOUTH OF LEBANON...OR ABOUT 8 MILES
  EAST OF GETTYSBURG...MOVING EAST AT 20 MPH.

* THE SEVERE THUNDERSTORM WILL REMAIN OVER...
RURAL POTTER COUNTY SOUTH OF LEBANON THROUGH 900 PM CDT

A TRAINED WEATHER SPOTTER REPORTED DIME SIZE HAIL IN GETTYSBURG AT 
810 PM.

THIS IS A DANGEROUS STORM. TAKE SHELTER NOW

THIS STORM HAS A HISTORY OF PRODUCING HAIL. GO INSIDE A STURDY 
BUILDING AND STAY AWAY FROM WINDOWS.

REPORT SEVERE WEATHER TO THE NEAREST LAW ENFORCEMENT AGENCY. THEY
WILL RELAY YOUR REPORT TO THE NATIONAL WEATHER SERVICE OFFICE IN
ABERDEEN.

$$
LAT...LON 4507 9989 4490 9992 4490 9957 4506 9958

PARKIN

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 Aberdeen, SD wrote its last area forecast discussion before this severe thunderstorm warning went out at May 18, 3:20 PM CDT, 5 hours 11 minutes earlier.

Area forecast discussion, May 18, 3:20 PM CDT, 5 hours 11 minutes before

AREA FORECAST DISCUSSION FOR CENTRAL/NORTHCENTRAL AND NORTHEAST
SOUTH DAKOTA AND WEST CENTRAL MINNESOTA
NATIONAL WEATHER SERVICE ABERDEEN SD
320 PM CDT FRI MAY 18 2001

PLENTY OF HEADACHES WITH THIS PACKAGE. FIRST IS TNGHT AND TSRA
CHANCES WEST CWA AND IF/HOW LONG THEY WOULD HOLD. DIURNAL CU FIELD
DVLPING WITH BASES AOA 8KFT...WITH >30 DEGREE T/TD SPREAD. NICE
CLOUD STREETS SHOWING INCREASING SOUTHERLY/WAA FLOW ACROSS CWA.
KBIS/KBLX 88DS SHOWING -SHRA ON THE SLOW INCREASE. KBIS NOW SHOWING
TSRA DVLPMENT AND NOT TOO SURPRISED GIVEN TROF LOCATION AND MOST
UNSTABLE THIS AREA PER LAPS/MSAS SFC ANALYSIS. RUC FCST SNDGS SHOW
THAT ISOLATED STORMS COULD BRING GUSTY WINDS WITH NICE INVERTED V
SOUNDINGS. BUT SVR THREAT MINIMAL GIVEN DEGREE OF INSTABILITY AND
STRENGTH OF TROF. FEEL ALL MDLS WAY OVERDONE ON QPF GIVEN SCANT
MOISTURE/INSTABILITY/VORT ENERGY. ONLY PLUSES TO ORAGANIZED SHRA
WOULD BE JET ENERGY AND WEAK UPPER DIVERGENCE SHOWN ON ETA/AVN. BUT
ONCE DARKNESS SETS IN...LITTLE/NO MOISTURE OR TEMP ADVECTION TO
SUSTAIN CONVECTION. SHOULD DECREASE SUBSTANTIALLY AFTER SUNSET.

BNDRY GLIDES EAST OVRNIGHT INTO SATURDAY...BUT ESSENTIALLY WASHES
OUT AS H5 VORT DAMPENS OUT. THIS CAUSES CONCERN AS ALL GUIDANCE
KEEPS CONVERGENCE LINE IN EAST CWA...WITH MOISTURE/INSTABILITY
POOLING ALONG IT.  VERY WEAK SFC-H7 WIND FIELDS CONTINUE...SO
NOTHING SUBSTANTIAL SHOULD HAPPEN. MENTIONED A SLIGHT POP FOR PM
SHOWER. MAYBE A PULSE T-STORM IN EAST SAT PM BUT WILL NOT MENTION
THUNDER. OTHR AREAS MILD AND P/C.

MAJOR CHANGE IN WX COMING SUN/MON. MARCH-LIKE SYSTEM WITH VERY
STRONG JET ENERGY DIGGING INTO TROF...CARVING OUT AND CLOSING UPPER
LOW ON SUNDAY. LIKE THE ETA TIMING...BUT THE AVN STRENGTH. BOTH MDLS
UNDERESTIMATING 150+KT JET SEEN IN ACARS DATA THIS MORNING IN PAC
OCEAN.  ETA SLOWER BY A BIT WHICH SEEMS BETTER WITH THE STRENGTH OF
SYSTEM...BUT I DO NORMALLY PREFER AVN EVOLUTION OF STRONG PAC JETS
CARVING CONUS TROFS.  EITHER WAY...WINDY AND COOLER ON SUNDAY WITH
FIRST COLD FRONT. IF IT SLOWS ENOUGH...COULD GET STRONG STORMS ON
COLD FRONT SUN AFTERNOON IN EAST CWA...AS HIGH THETA-E AIR ADVECTS
NORTHWARD ALONG/AHEAD OF FRONT. WEST CWA GETS VERY COOL AND
WINDY...WITH STEADY/FALLING TEMPS. 850 TEMPS/1000-850 THICKNESS
CRASH SUNDAY NIGHT...AS SECOND SURGE/VORT LOBE ROTATES THRU AREA.
TEMPS MONDAY LOOK SCARY. (850 TEMPS -3 TO -4).

MANY THANKS TO WFO BIS/FGF FOR COORDINATION.

BINAU

.EXTENDED DISCUSSION...
THERE ARE FEW DISAGREEMENTS IN THE EXTENDED MODELS THIS AFTERNOON
BUT OVERALL THEY DO HAVE SOME CONTINUITY. AFTER ANALYZING THE MODELS
AND THE ENSEMBLES A LITTLE MORE I DECIDED TO GO WITH THE AVN/MRF FOR
THE FORECAST PACKAGE. THE UPPER TROF AND ASSOCIATED SURFACE FRONT
WILL BE EXITING THE CWA ON MONDAY WITH AN UPPER RIDGE AND SURFACE
HIGH BUILDING OVER THE AREA TUESDAY THROUGH FRIDAY. THERE WILL BE
PLENTY OF MOISTURE AND LIFT TO CONTINUE THE CHANCE OF SHOWERS FOR
MONDAY. A FEW THUNDERSTORMS ARE ALSO POSSIBLE. BUT THE MAIN THREAT
OF SHOWERS WILL BE IN THE EAST. THE REST OF THE FORECAST PERIOD
SHOULD BE MOSTLY DRY. STRONG CAA ON MONDAY AND PARTIAL CLEARING
MONDAY NIGHT WILL BRING SOME VERY COLD TEMPERATURES FOR TUESDAY
MORNING. A SLOW WARMING TREND IS IN STORE FOR THE REST OF THE WEEK.
FOR THE TEMPS I TOOK A BLEND OF THE FMR AND MEX GUIDANCE.

SALMONS

.ABR...NONE.

In the hours before

Local storm report, May 18, 8:17 PM CDT, 14 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE ABERDEEN, SD
817 PM CDT FRI MAY 18 2001

TIME(CDT)  .....CITY LOCATION.....STATE   ...EVENT/REMARKS...
           ....COUNTY LOCATION....

0810 PM    GETTYSBURG                SD   .75 INCH HAIL
05/18/01   POTTER                         REPORTED BY LAW
                                          ENFORCEMENT

AP

The office that day

Everything else NWS Aberdeen, SD issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
May 18, 7:15 PM CDT	Severe Thunderstorm Warning	ABR	Dewey	45 min
May 18, 7:47 PM CDT	Severe Thunderstorm Warning	ABR	Potter	43 min

Nearby

Severe Thunderstorm Warnings in South Dakota, 2001 Every severe thunderstorm warning in 2001

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; verification from NCEI's Storm Data; the sounding from the Mesonet's radiosonde archive.