Alert archive / Minnesota / Severe Thunderstorm Warnings in 2017

Severe Thunderstorm Warning 127, NWS Twin Cities, MN

July 9, 2017Blue Earth County, Brown County, Nicollet County, Minnesota

NWS Twin Cities, MN issued this severe thunderstorm warning at Jul 9, 2017, 9:26 PM CDT for Blue Earth County, Brown County, Nicollet County, Minnesota. It was in force for 49 min. 7 reports 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: Jul 9, 2017, 9:26 PM CDT (02:26 UTC)
Expired: Jul 9, 2017, 10:15 PM CDT
In force: 49 min
Issued by: NWS Twin Cities, MN
Area: Storm-based polygon
Tornado: Possible
Hail: 2.5 in
Wind: 70.0 mph

Counties Blue Earth County, MN, Brown County, MN, Nicollet County, MN

The radar

The Minneapolis radar (KMPX), 95 km from the middle of the area, began a volume at 02:26 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

Time	Report	Where	Remark
Jul 9, 9:30 PM CDT	HAIL 1.75	3 Ne New Ulm, MN
Jul 9, 9:30 PM CDT	HAIL 1.75	5 N Courtland, MN	PICTURE FROM SOCIAL MEDIA.
Jul 9, 9:38 PM CDT	HAIL 1.5	5 N Courtland, MN
Jul 9, 9:42 PM CDT	TSTM WND DMG	3 Nne Courtland, MN	ROOF OF A HOG BARN BLOWN OFF FROM A POSSIBLE TORNADO. TIME ESTIMATED FROM RADAR.
Jul 9, 9:45 PM CDT	HAIL 1	3 N Lake Crystal, MN
Jul 9, 10:07 PM CDT	HAIL 1	Nicollet, MN
Jul 9, 10:25 PM CDT	TORNADO	2 Nw Lake Crystal, MN	MULTIPLE SPOTTER REPORTS OF A TORNADO 2 MILES NW OF LAKE CRYSTAL.

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

Did it verify

Verified. The Iowa Environmental Mesonet's Cow matched 6 storm reports to this severe thunderstorm warning; the first came 4 minutes after it went out.

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 watch it was issued in

The SPC watch in force over the same counties when this warning went out.

Issued	Product	Office	Lasted
Jul 9, 7:05 PM CDT	Tornado Watch	SPC	7 hr

The nearest sounding before it

Minneapolis, MN (KMPX), launched 00:00Z, 2.4 hours before the alert went out and 93 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: 627 J/kg
Mixed-layer CIN: -187 J/kg
Mixed-layer LCL: 1764 m above ground
0-6 km bulk shear: 45 kt
0-1 km storm-relative helicity: 222 m²/s²
0-3 km storm-relative helicity: 278 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 3.6

Open this sounding in Storm Lab

The text

As transmitted.

195 
WUUS53 KMPX 100226
SVRMPX
MNC013-015-103-100315-
/O.NEW.KMPX.SV.W.0127.170710T0226Z-170710T0315Z/

BULLETIN - EAS ACTIVATION REQUESTED
Severe Thunderstorm Warning
National Weather Service Twin Cities/Chanhassen MN
926 PM CDT SUN JUL 9 2017

The National Weather Service in The Twin Cities has issued a

* Severe Thunderstorm Warning for...
  Southeastern Brown County in south central Minnesota...
  Northwestern Blue Earth County in south central Minnesota...
  Central Nicollet County in south central Minnesota...

* Until 1015 PM CDT

* At 926 PM CDT, a severe thunderstorm was located near Klossner, or
  near New Ulm, moving south at 35 mph.

  HAZARD...Tennis ball size hail and 70 mph wind gusts. 

  SOURCE...Radar indicated. 

  IMPACT...People and animals outdoors will be injured. Expect hail 
           damage to roofs, siding, windows, and vehicles. Expect 
           considerable tree damage. Wind damage is also likely to 
           mobile homes, roofs, and outbuildings. 

* This severe thunderstorm will be near,
  Nicollet and Courtland around 935 PM CDT. 
  Lake Crystal around 955 PM CDT. 

Other locations impacted by this severe thunderstorm include
Klossner, Oshawa, Searles and Judson.

This includes the following highways...
 U.S. Highway 14 between mile markers 103 and 125.
 U.S. Highway 169 between mile markers 42 and 48.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

Intense thunderstorm lines can produce brief tornadoes and widespread
significant wind damage. Although a tornado is not immediately
likely, it is best to move to an interior room on the lowest floor of
a building. This storm may cause serious injury and significant
property damage.

&&

A tornado watch remains in effect until 100 AM CDT for south central
Minnesota.

LAT...LON 4409 9437 4411 9437 4411 9446 4441 9448
      4444 9411 4406 9409
TIME...MOT...LOC 0226Z 351DEG 32KT 4434 9435 

TORNADO...POSSIBLE
HAIL...2.50IN
WIND...70MPH
 
$$

jrb

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 Twin Cities, MN wrote its last area forecast discussion before this severe thunderstorm warning went out at Jul 9, 6:13 PM CDT, 3 hours 13 minutes earlier.

Area forecast discussion, Jul 9, 6:13 PM CDT, 3 hours 13 minutes before

Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
613 PM CDT Sun Jul 9 2017

.updated for the 00z aviation discussion below...

.SHORT TERM...(This evening through Monday)
Issued at 233 PM CDT Sun Jul 9 2017

The short term concerns remain severe potential this evening.

Timing of convective initiation appears to be 22z in the northwest
cwa. Latest mesoscale analysis shows building CAPE of 1000-2000 J/kg
over far western MN and pooling along the surface boundary northwest
of Alexandria. This boundary is forecast to sag south overnight as a
weak surface low over northeast SODAK into northern Iowa by 12z Mon.
Initial convection should be discrete cells...which could generate
large hail/damaging winds or an isolated tornado. Greatest threat
would be over the northwest CWA early. The convection should become
linear/QLCS form with strong deep layer shear 50-60kts available. It
should arrive in the metro area/east central MN 00z-03z period and
move quickly southeast. Damaging winds and torrential rain would
accompany the complex. The best corridor for this to occur appears
to be over about a 50 mile wide area east of a line from Litchfield
to Mankato...and west of a line from Buffalo to Lakeville...then
southeast...which lines up with a tight instability gradient this
evening.  Most of the convection should exit the area through about
05z-06z. We will retain some small pops mainly to the east and south
after that.

We expect drier conditions to move in behind the system into Monday
relieving the convective threat for the area. Temperatures will
remain on the warm side with readings warming through the 80s.

.LONG TERM...(Monday night through Sunday)
Issued at 233 PM CDT Sun Jul 9 2017

Monday night through Wednesday...The main focus on the extended
will be during the early portion of the week as severe weather
again looks to take shape.

This period will commence with high pressure centered over the
region while a quasi-stationary cold front sits nearly east-west
from the Central Plains over to the Ohio Valley and a nearly
north-south warm front resides over the western Dakotas from a low
pressure center in far southern Saskatchewan province. A ridge
aloft in the Dakotas will flatten, allowing for a more progressive
pattern to develop for Tuesday into Tuesday night, including
enhanced jetting. The low pressure center will drift southeast
into North Dakota and strengthen in advance of a shortwave trough
disturbance developing over far south-central Canada. At the same
time, the front to the south will drift north, which will not only
allow warmer temperatures to creep back north but also a good
surge of moisture which will add to the instability. The front
will move into southern MN by midday Tuesday and nearly reach the
I-94 corridor by Tuesday evening, bringing MUCAPES in excess of
3000 j/kg for much of the southern portion of the WFO MPX coverage
area. Sensibly, this will allow highs to reach the mid 80s for
much of the area, with highs near 90 in western MN. In addition,
would not be surprised to see dewpoints hit 70 degrees in southern
and western MN as the front shifts north. Once the morning cap
breaks, convection is expected to develop in the Dakotas which
will then traverse southeast through central-southern Minnesota
late day through the evening and potentially into the Tuesday
night hours. The initial mode looks to be tornadic but as clusters
of storms develop late day through the evening, a more organized
forward-propagating MCS may develop which may well track along
I-94 through the evening into the nighttime hours. This would
create a large hail and damaging wind hazard for a good portion of
the time, especially considering the duration of 35-45kt of bulk
shear from Tuesday afternoon through early Wednesday morning. The
low pressure itself will shift east through south-central MN
Tuesday night and move to nearly atop the Twin Cities metro by
daybreak Wednesday morning. Precipitation will steadily wind down
during the day on Wednesday behind this system with high pressure
moving into the region. For this upcoming system, it is urged to
stay abreast of the latest forecast discussions from both this
office and the Storm Prediction Center since confidence is growing
on a potentially high end severe weather event.

Thursday through Sunday...Much more benign weather is expected for
the remainder of the week into the weekend as high pressure
reasserts itself across the Upper Midwest and northwest flow aloft
takes hold. The pattern of ridge-west and trough-east will again
develop while deep moisture will be relatively absent, meaning
that chances for precipitation will be limited, humidity will be
relatively lower and temperatures will be fairly steady (although
on a slow climb upward through the 80s).

&&

.AVIATION...(For the 00Z TAFS through 00Z Monday evening)
Issued at 620 PM CDT Sun Jul 9 2017

Still expect convection to develop into west central MN 00-02z and
develop into a line through about 04z and drop southeast
overnight. Could see sig thunder threat mainly over the KMSP-KMKT
area into the early evening. Thunder will include wind gust
potential along with tempo IFR conditions. Activity should exit to
the southeast through 06z or so with perhaps some lower
clouds/mvfr cigs and some BR developing over the eastern areas.
This should give way after 14z Mon with n-ne winds and some sct
cumulus.

KMSP...timing of sig thunder threat 0130z-0330z. Continued wind
gust potential along with tempo IFR conditions. This should move
out thereafter with some lower mvfr cigs possible following the
front overnight. Confidence is high enough to include at this
time. Should see this move out after 14z with cumulus cigs lifting
during the day. se-e winds into the evening becoming ne-n with
fropa.

/OUTLOOK FOR KMSP/
Tue...Mainly VFR. Chc +TSRA/MVFR late. Wind SE 5-10 kts.
Wed...Mainly VFR. Chc TSRA/MVFR early. Wind NW 5-10 kts.
Thu...VFR. Wind NE 5-10 kts.

&&

.MPX WATCHES/WARNINGS/ADVISORIES...
WI...None.
MN...None.
&&

SHORT TERM...DWE
LONG TERM...JPC
AVIATION...DWE

Hazardous weather outlook, Jul 9, 12:36 PM CDT, 8 hours 50 minutes before

Hazardous Weather Outlook
National Weather Service Twin Cities/Chanhassen MN
1236 PM CDT Sun Jul 9 2017

MNZ041>045-047>070-073>078-082>085-091>093-WIZ014>016-023>028-
101745-
Douglas-Todd-Morrison-Mille Lacs-Kanabec-Stevens-Pope-Stearns-
Benton-Sherburne-Isanti-Chisago-Lac Qui Parle-Swift-Chippewa-
Kandiyohi-Meeker-Wright-Hennepin-Anoka-Ramsey-Washington-
Yellow Medicine-Renville-McLeod-Sibley-Carver-Scott-Dakota-
Redwood-Brown-Nicollet-Le Sueur-Rice-Goodhue-Watonwan-Blue Earth-
Waseca-Steele-Martin-Faribault-Freeborn-Polk-Barron-Rusk-
St. Croix-Pierce-Dunn-Pepin-Eau Claire-
1236 PM CDT Sun Jul 9 2017

This Hazardous Weather Outlook is for portions of central and
southern Minnesota...and west central Wisconsin.

.DAY ONE...This Afternoon and Tonight

There is an enhanced risk of severe thunderstorms across east
central into southeast Minnesota and a small portion of west
central Wisconsin mainly through this evening. There is a slight
risk across most of the remainder of the area. Large hail,
damaging winds, and heavy rainfall and localized flash flooding
are possible with the storms. The greatest threat of large hail
and widespread damaging winds is located in the enhanced risk
area.

.DAYS TWO THROUGH SEVEN...Monday through Saturday

There is a slight risk of severe thunderstorms late Tuesday
afternoon and Tuesday night. Large hail, damaging winds, and
tornadoes are possible late Tuesday afternoon across western
Minnesota, with a transition to mainly damaging winds Tuesday
night across eastern Minnesota and western Wisconsin. Heavy
rainfall is also possible.

.SPOTTER INFORMATION STATEMENT...

SKYWARN spotter activation may be needed later this afternoon and
evening.

In the hours before

Local storm report, Jul 9, 9:14 PM CDT, 12 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
914 PM CDT SUN JUL 9 2017

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

0913 PM     HAIL             WINTHROP                44.54N 94.36W
07/09/2017  M2.50 INCH       SIBLEY             MN   TRAINED SPOTTER

&&

ETA

Local storm report, Jul 9, 9:16 PM CDT, 10 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
916 PM CDT SUN JUL 9 2017

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

0815 PM     HAIL             9 NNW APPLETON          45.32N 96.09W
07/09/2017  M1.25 INCH       SWIFT              MN   PUBLIC

&&

ETA

Local storm report, Jul 9, 9:17 PM CDT, 9 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
917 PM CDT SUN JUL 9 2017

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

0845 PM     HAIL             APPLETON                45.20N 96.02W
07/09/2017  M2.00 INCH       SWIFT              MN   PUBLIC

&&

ETA

Local storm report, Jul 9, 9:21 PM CDT, 5 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
921 PM CDT SUN JUL 9 2017

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

0915 PM     HAIL             FARMINGTON              44.64N 93.14W
07/09/2017  M1.50 INCH       DAKOTA             MN   TRAINED SPOTTER

&&

ETA

Local storm report, Jul 9, 9:24 PM CDT, 2 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
924 PM CDT SUN JUL 9 2017

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

0923 PM     HAIL             1 WNW MONTEVIDEO        44.95N 95.74W
07/09/2017  E1.75 INCH       CHIPPEWA           MN   PUBLIC

&&

JPC

Local storm report, Jul 9, 9:26 PM CDT, 0 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
926 PM CDT SUN JUL 9 2017

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

0920 PM     HAIL             5 ENE BOYD              44.88N 95.81W
07/09/2017  E1.75 INCH       YELLOW MEDICINE    MN   PUBLIC

&&

JPC

The office that day

Everything else NWS Twin Cities, MN issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jul 9, 7:35 PM CDT	Severe Thunderstorm Warning	MPX	Stevens, Swift	40 min
Jul 9, 7:50 PM CDT	Severe Thunderstorm Warning	MPX	Mille Lacs, Morrison	40 min
Jul 9, 7:51 PM CDT	Severe Thunderstorm Warning	MPX	McLeod, Meeker, Renville	39 min
Jul 9, 7:57 PM CDT	Tornado Warning	MPX	Stevens, Swift	33 min
Jul 9, 8:09 PM CDT	Tornado Warning	MPX	Swift	28 min
Jul 9, 8:21 PM CDT	Tornado Warning	MPX	Chippewa, Lac qui Parle	39 min
Jul 9, 8:22 PM CDT	Severe Thunderstorm Warning	MPX	Benton, Morrison	38 min
Jul 9, 8:25 PM CDT	Severe Thunderstorm Warning	MPX	Kanabec, Mille Lacs	40 min
Jul 9, 8:28 PM CDT	Special Weather Statement	MPX	McLeod, Scott	47 min
Jul 9, 8:33 PM CDT	Severe Thunderstorm Warning	MPX	McLeod, Renville, Sibley	42 min
Jul 9, 8:54 PM CDT	Severe Thunderstorm Warning	MPX	Chippewa, Lac qui Parle, Yellow Medicine	66 min
Jul 9, 8:55 PM CDT	Severe Thunderstorm Warning	MPX	Benton, Sherburne	25 min
Jul 9, 8:56 PM CDT	Severe Thunderstorm Warning	MPX	Dakota, Le Sueur, Rice, Scott	34 min
Jul 9, 8:58 PM CDT	Severe Thunderstorm Warning	MPX	Chippewa, Swift	47 min
Jul 9, 9:03 PM CDT	Severe Thunderstorm Warning	MPX	Nicollet, Sibley	42 min
Jul 9, 9:06 PM CDT	Severe Thunderstorm Warning	MPX	Kandiyohi, Pope, Stearns	27 min
Jul 9, 9:09 PM CDT	Severe Thunderstorm Warning	MPX	Chippewa, Lac qui Parle, Swift	20 min
Jul 9, 9:11 PM CDT	Severe Thunderstorm Warning	MPX	Blue Earth, Le Sueur, Nicollet, Waseca	49 min
Jul 9, 9:16 PM CDT	Severe Thunderstorm Warning	MPX	Dakota, Hennepin, Ramsey, Washington	44 min
Jul 9, 9:23 PM CDT	Severe Thunderstorm Warning	MPX	Dakota, Rice, Scott	53 min
Jul 9, 9:30 PM CDT	Tornado Warning	MPX	Nicollet	30 min
Jul 9, 9:51 PM CDT	Severe Thunderstorm Warning	MPX	Blue Earth, Steele, Waseca	54 min
Jul 9, 10:10 PM CDT	Severe Thunderstorm Warning	MPX	Blue Earth, Nicollet	35 min
Jul 9, 10:19 PM CDT	Tornado Warning	MPX	Blue Earth	41 min
Jul 9, 10:34 PM CDT	Severe Thunderstorm Warning	MPX	Nicollet, Sibley	41 min
Jul 9, 10:41 PM CDT	Severe Thunderstorm Warning	MPX	Faribault, Freeborn, Steele, Waseca	64 min
Jul 9, 10:51 PM CDT	Severe Thunderstorm Warning	MPX	McLeod, Renville, Sibley	39 min
Jul 9, 10:55 PM CDT	Severe Thunderstorm Warning	MPX	Brown, Redwood, Renville	35 min
Jul 9, 11:05 PM CDT	Severe Thunderstorm Warning	MPX	Blue Earth	40 min
Jul 9, 11:17 PM CDT	Severe Thunderstorm Warning	MPX	Faribault, Freeborn	43 min
Jul 9, 11:39 PM CDT	Severe Thunderstorm Warning	MPX	Blue Earth, Brown, Nicollet, Watonwan	37 min
Jul 9, 11:55 PM CDT	Severe Thunderstorm Warning	MPX	Redwood	18 min
Jul 10, 12:05 AM CDT	Severe Thunderstorm Warning	MPX	Blue Earth, Faribault, Martin	40 min
Jul 10, 12:45 AM CDT	Severe Thunderstorm Warning	MPX	Faribault, Freeborn	30 min
Jul 10, 12:47 AM CDT	Severe Thunderstorm Warning	MPX	Nicollet	26 min
Jul 10, 1:30 AM CDT	Severe Thunderstorm Warning	MPX	Blue Earth, Brown, Watonwan	35 min

Nearby

Severe Thunderstorm Warnings in Minnesota, 2017 Every 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.