Alert archive / Minnesota / Special Weather Statements in 2018

Special Weather Statement, NWS Twin Cities, MN

September 20, 2018Ramsey County, Minnesota

NWS Twin Cities, MN issued this special weather statement at Sep 20, 2018, 4:50 PM CDT for Ramsey County, Minnesota. It was in force for 85 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: Sep 20, 2018, 4:50 PM CDT (21:50 UTC)
Expired: Sep 20, 2018, 6:15 PM CDT
In force: 85 min
Issued by: NWS Twin Cities, MN

County Ramsey County, MN

The radar

The Minneapolis radar (KMPX), 29 km from the middle of the area, began a volume at 21:51 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

Minneapolis, MN (KMPX), launched 12:00Z, 9.8 hours before the alert went out and 31 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: 18 J/kg
Mixed-layer CIN: -80 J/kg
Mixed-layer LCL: 461 m above ground
0-6 km bulk shear: 48 kt
0-1 km storm-relative helicity: 195 m²/s²
0-3 km storm-relative helicity: 20 m²/s²
Significant tornado parameter: 0.0
Supercell composite: -0.1

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 Twin Cities, MN wrote its last area forecast discussion before this special weather statement went out at Sep 20, 2:49 PM CDT, 2 hours 1 minute earlier.

Area forecast discussion, Sep 20, 2:49 PM CDT, 2 hours 1 minute before

Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
249 PM CDT Thu Sep 20 2018

.SHORT TERM...(This evening through Friday)
Issued at 250 PM CDT Thu Sep 20 2018

Elevated thunderstorms developed along the moisture gradient
across Southwestern and Central MN with heavy rain and wind gusts
near 30- 35 kts. Clearing and an increase in MUCAPE has been
noticed across South Central MN. This clearing trend is expected
to continue through the early afternoon and help destabilized the
boundary layer with near 3000 J/kg of SBCAPE expected by 21Z
(according to the RAP). The surface low will continue to deepen as
it progresses northeastward with its placement over the NE/IA/SD
border at 1930Z.

An Enhanced Risk of Severe Weather remains in place due to the
concern for severe wind, tornado, and hail during the late afternoon
and evening. Thunderstorms are expected to develop along a cold
front with the main mode being linear. However, a few isolated cells
could develop ahead of this line. Bulk shear is expected to be near
60 kts by 00Z across Southern MN and Western WI as 850 mb winds
increase to 50 kts.  LCL values are expected to be near 1000 m and
DCAPE will be near 1300 J/kg, so severe winds will be possible along
the cold front. SFC to 1 km shear will be near 30-40 kts which is
supports the tornado potential.

Storms are expected to exit to the east overnight by 06Z with cold
air advection to follow. Winds will be windy with gusts near 25-30
kts common Friday morning.

.LONG TERM...(Friday night through Thursday)
Issued at 250 PM CDT Thu Sep 20 2018

Surface high pressure will be in place to start the long term
period, which will make for a cool start to Saturday morning. With
light winds and clear skies, expect lows to dip into the mid 30s
from parts of central MN across west central WI. Therefore areas
north of I-94 will have the potential for the first frost of the
season. High pressure prevails through the weekend and brings quiet
and dry weather, with highs in the 60s on Saturday. Temps moderate a
tad on Sunday as the high pressure begins to shift southeast and
southerly flow develops. Expect highs in the mid 60s to lower 70s.

Monday and Monday night there is decent agreement amongst the models
that a decent shortwave trough will move across the north central
CONUS and push a front across the area. Have included high chance
POPs.

Behind this system temperatures cool down slightly below normal,
with highs in the 60s and lows in the 40s.

&&

.AVIATION...(For the 18Z TAFS through 18Z Friday afternoon)
Issued at 1241 PM CDT Thu Sep 20 2018

MVFR/IFR ceilings will prevail through this period. Two rounds of
thunderstorms are expected. The first round is a cluster of
thunderstorms that will continue lifting north through Central MN
and Western WI this afternoon. The second round is expected to
develop as a line over Southwestern MN and lift northwest into
Western WI this evening. After that, status and breezy westerly
to northwesterly winds will follow and continue through Friday
morning.

KMSP... Thunderstorm chances will continue through the early
afternoon. There may be a gap in activity near 21Z before the
next round of thunderstorms arrives after 23Z. Thunderstorm
activity is end near 01Z, but low clouds and breezy winds will
continue. MVFR/IFR conditions are anticipated through late Friday
morning.

/OUTLOOK FOR KMSP/
Fri PM...VFR. Wind NW 15G25 kts.
Sat...VFR. Wind SW 5-10 kts.
Sun...VFR. Wind SE 5-10 kts.

&&

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

SHORT TERM...AMK
LONG TERM...LS
AVIATION...AMK

Hazardous weather outlook, Sep 20, 10:21 AM CDT, 6 hours 29 minutes before

Hazardous Weather Outlook
National Weather Service Twin Cities/Chanhassen MN
1021 AM CDT Thu Sep 20 2018

MNZ051>053-058>063-065>070-073>078-082>085-091>093-WIZ014>016-
023>028-211530-
Sherburne-Isanti-Chisago-Meeker-Wright-Hennepin-Anoka-Ramsey-
Washington-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-Chippewa-Eau Claire-
1021 AM CDT Thu Sep 20 2018

This Hazardous Weather Outlook is for portions of central
Minnesota...east central Minnesota...south central Minnesota...
southeast Minnesota...southwest Minnesota...northwest Wisconsin
and west central Wisconsin.

.DAY ONE...Today and Tonight

Severe thunderstorms are possible this afternoon in south
central and east central Minnesota, as well as in west central
Wisconsin. The primary risk will be strong winds. Large hail and
heavy rain will also be possible, along with a few tornadoes.

.DAYS TWO THROUGH SEVEN...Friday through Wednesday

There is a chance of thunderstorms on Monday.

.SPOTTER INFORMATION STATEMENT...

SKYWARN spotter activation will likely be needed this afternoon
and early evening.

MNZ041>045-047>050-054>057-064-211530-
Douglas-Todd-Morrison-Mille Lacs-Kanabec-Stevens-Pope-Stearns-
Benton-Lac Qui Parle-Swift-Chippewa-Kandiyohi-Yellow Medicine-
1021 AM CDT Thu Sep 20 2018

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

.DAY ONE...Today and Tonight

Thunderstorms are possible this afternoon. The threat for severe
weather is low.

.DAYS TWO THROUGH SEVEN...Friday through Wednesday

There is a chance of thunderstorms on Monday.

.SPOTTER INFORMATION STATEMENT...

SKYWARN spotter activation will not be needed.

In the hours before

Special weather statement, Sep 20, 2:31 PM CDT, 2 hours 19 minutes before

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE Twin Cities/Chanhassen MN
231 PM CDT THU SEP 20 2018

MNC037-053-123-139-163-202130-
Hennepin-Dakota-Scott-Washington-Ramsey-
231 PM CDT THU SEP 20 2018

...URBAN AND SMALL STREAM FLOODING EXPECTED...

Thunderstorms with heavy rain will cause minor flooding in the
following counties...

Hennepin...Dakota...Scott...Washington...Ramsey...

* Until 430 PM CDT.

* At 227 PM CDT, a line of thunderstorms dropped a quick 1 to 2
  inches of rain over the southern Twin Cities metro area. This will
  cause urban and small stream flooding in the area. More storms are
  possible between 3 and 4 pm. Expect flooding to occur in low lying
  areas such as underpasses, drainages, and some creeks and streams.

* Some locations that will experience flooding include...
  Minneapolis, St. Paul, Bloomington, Eagan, Woodbury, Eden Prairie,
  Burnsville, Minnetonka, Apple Valley, Edina, St. Louis Park and
  Maplewood.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Turn around, don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.

&&

LAT...LON 4466 9347 4480 9353 4488 9351 4511 9295
      4488 9293

CCS

Special weather statement, Sep 20, 3:00 PM CDT, 1 hour 50 minutes before

Special Weather Statement
National Weather Service Twin Cities/Chanhassen MN
300 PM CDT THU SEP 20 2018

MNZ056-064-065-202030-
Chippewa-Yellow Medicine-Renville-
300 PM CDT THU SEP 20 2018

...A STRONG THUNDERSTORM WILL AFFECT SOUTH CENTRAL CHIPPEWA...EASTERN
YELLOW MEDICINE AND NORTHWESTERN RENVILLE COUNTIES...

At 300 PM CDT, a strong thunderstorm was located near Hazel Run, or
17 miles south of Montevideo, moving northeast at 50 mph.

Wind gusts up to 50 mph and dime size hail are possible with this
storm.

Locations impacted include...
Granite Falls, Clarkfield, Sacred Heart, Wood Lake, Maynard, Hanley
Falls, Minnesota Falls, Spring Creek, Hazel Run, Granite Falls
Airport and Spellman Lake.

This includes the following highways...
 U.S. Highway 212 between mile markers 42 and 60.
 U.S. Highway 59 between mile markers 88 and 97.

LAT...LON 4494 9551 4472 9525 4469 9534 4470 9536
      4468 9536 4461 9561 4463 9563 4463 9580
      4475 9589
TIME...MOT...LOC 2000Z 246DEG 45KT 4470 9570

JRB

Special weather statement, Sep 20, 3:24 PM CDT, 1 hour 26 minutes before

Special Weather Statement
National Weather Service Twin Cities/Chanhassen MN
324 PM CDT THU SEP 20 2018

MNZ056-057-065-202100-
Chippewa-Kandiyohi-Renville-
324 PM CDT THU SEP 20 2018

...A STRONG THUNDERSTORM WILL AFFECT EAST CENTRAL CHIPPEWA...
NORTHWESTERN RENVILLE AND SOUTHERN KANDIYOHI COUNTIES...

At 324 PM CDT, a strong thunderstorm was located near Sacred Heart,
or 20 miles southeast of Montevideo, moving northeast at 55 mph.

Winds in excess of 40 mph and pea size hail are possible with this
storm.

Locations impacted include...
Olivia, Clara City, Renville, Atwater, Raymond, Sacred Heart,
Prinsburg, Maynard, Danube, Lake Lillian, Blomkest and Thorpe.

This storm may intensify, so be certain to monitor local radio
stations and available television stations for additional
information and possible warnings from the National Weather Service.

LAT...LON 4516 9481 4507 9475 4489 9476 4489 9471
      4467 9519 4466 9524 4466 9529 4494 9552
TIME...MOT...LOC 2024Z 243DEG 47KT 4483 9532

JLT

Special weather statement, Sep 20, 3:45 PM CDT, 1 hour 5 minutes before

Special Weather Statement
National Weather Service Twin Cities/Chanhassen MN
345 PM CDT THU SEP 20 2018

WIZ016-027-202130-
Chippewa-Rusk-
345 PM CDT THU SEP 20 2018

...A STRONG THUNDERSTORM WILL AFFECT SOUTH CENTRAL RUSK AND CHIPPEWA
COUNTIES...

At 345 PM CDT, a strong thunderstorm was located near Bloomer, or 20
miles north of Eau Claire, moving east at 50 mph.

Winds in excess of 40 mph and dime size hail are possible with this
storm.

Locations impacted include...
Chippewa Falls, Stanley, Bloomer, Cornell, Cadott, Boyd, New Auburn,
Sheldon, Tilden, Conrath, Island Lake and Holcombe.

This includes U.S. Highway 53 between mile markers 98 and 119.

LAT...LON 4537 9092 4496 9092 4492 9164 4521 9159
      4521 9154 4531 9154 4544 9091 4538 9090
TIME...MOT...LOC 2045Z 249DEG 45KT 4516 9147

BORGHOFF

Local storm report, Sep 20, 4:33 PM CDT, 17 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
433 PM CDT THU SEP 20 2018

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

0428 PM     HEAVY RAIN       1 ESE BROOKLYN CENTER   45.07N 93.31W
09/20/2018  E2.00 INCH       HENNEPIN           MN   TRAINED SPOTTER

            SPOTTER CALLED TO REPORT PONDING FROM HEAVY
            RAINFALL. NO PHOTO PROVIDED.

&&

CTG

Special weather statement, Sep 20, 4:50 PM CDT, 0 minutes before

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE Twin Cities/Chanhassen MN
450 PM CDT THU SEP 20 2018

MNZ060-062-063-070-202315-
Washington-Dakota-Hennepin-Ramsey-
450 PM CDT THU SEP 20 2018

...VERY HEAVY RAIN AND LOCALIZED FLOODING EXPECTED...

Very heavy rain with the potential for localized flooding will affect
the following counties...

Washington...Dakota...Hennepin...Ramsey...

At 449 PM CDT...Additional thunderstorms were moving into the Twin
Cities metro area. These will bring the potential for an additional
inch or more of rain to locations that have already seen 1 to 3
inches of rain this afternoon. This could lead to flooding of urban
and poor drainage areas.

Locations impacted include...
Minneapolis, St. Paul, Bloomington, Eagan, Woodbury, Burnsville,
Apple Valley, Edina, Maplewood, Richfield, Cottage Grove and Inver
Grove Heights.

Excessive runoff from heavy rainfall will cause ponding of water in
urban areas, highways, streets and underpasses as well as other poor
drainage areas and low lying spots. Do not attempt to travel across
flooded roads. Find alternate routes. It takes only a few inches of
swiftly flowing water to carry vehicles away.

LAT...LON 4473 9333 4479 9333 4478 9338 4480 9340
      4482 9340 4489 9332 4499 9295 4494 9287
      4489 9289 4482 9301 4472 9323
TIME...MOT...LOC 2149Z 239DEG 0KT 4464 9342

The office that day

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

Issued	Product	Office	Counties	Lasted
Sep 20, 12:13 PM CDT	Special Weather Statement	MPX	Brown, Nicollet	32 min
Sep 20, 12:53 PM CDT	Special Weather Statement	MPX	Brown	37 min
Sep 20, 1:33 PM CDT	Special Weather Statement	MPX	Le Sueur, Scott	42 min
Sep 20, 1:49 PM CDT	Special Weather Statement	MPX	Dakota	26 min
Sep 20, 2:07 PM CDT	Special Weather Statement	MPX	Rice, Washington	38 min
Sep 20, 2:31 PM CDT	Special Weather Statement	MPX	Ramsey	119 min
Sep 20, 2:46 PM CDT	River Flood Warning	MPX	Redwood	9 days
Sep 20, 3:00 PM CDT	Special Weather Statement	MPX	Yellow Medicine	30 min
Sep 20, 3:24 PM CDT	Special Weather Statement	MPX	Renville	36 min
Sep 20, 5:21 PM CDT	Special Weather Statement	MPX	Hennepin, Ramsey	54 min
Sep 20, 5:30 PM CDT	Severe Thunderstorm Warning	MPX	Blue Earth, Faribault, Martin, Watonwan	45 min
Sep 20, 5:51 PM CDT	Special Weather Statement	MPX	Carver, Le Sueur, Nicollet, Sibley	24 min
Sep 20, 5:54 PM CDT	Areal Flood Warning	MPX	Anoka, Carver, Dakota, Hennepin, Ramsey, Scott and 2 more	3 hr
Sep 20, 5:59 PM CDT	Severe Thunderstorm Warning	MPX	Blue Earth, Faribault, Waseca	46 min
Sep 20, 6:13 PM CDT	Severe Thunderstorm Warning	MPX	Carver, Dakota, Hennepin, Ramsey, Scott	47 min
Sep 20, 6:15 PM CDT	Severe Thunderstorm Warning	MPX	Carver	15 min
Sep 20, 6:19 PM CDT	Tornado Warning	MPX	Le Sueur, Rice, Waseca	41 min
Sep 20, 6:23 PM CDT	Severe Thunderstorm Warning	MPX	Freeborn, Le Sueur, Rice, Steele, Waseca	52 min
Sep 20, 6:40 PM CDT	Tornado Warning	MPX	Goodhue, Rice, Steele	35 min
Sep 20, 6:41 PM CDT	Severe Thunderstorm Warning	MPX	Anoka, Dakota, Goodhue, Hennepin, Ramsey, Washington	34 min
Sep 20, 6:49 PM CDT	Tornado Warning Tornado observed	MPX	Dakota, Goodhue, Rice	41 min
Sep 20, 3:45 PM CDT	Special Weather Statement	MPX	Chippewa	45 min

Nearby

Special Weather Statements in Minnesota, 2018 Every special weather statement in 2018

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.