Alert archive / Minnesota / Severe Thunderstorm Warnings in 2004

Severe Thunderstorm Warning 170, NWS Grand Forks, ND

August 29, 2004Polk County, Minnesota

NWS Grand Forks, ND issued this severe thunderstorm warning at Aug 29, 2004, 5:05 PM CDT for Polk County, Minnesota. It was in force for 40 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: Aug 29, 2004, 5:05 PM CDT (22:05 UTC)
Expired: Aug 29, 2004, 5:45 PM CDT
In force: 40 min
Issued by: NWS Grand Forks, ND
Area: Counties, with a storm outline in the text

County Polk County, MN

The radar

The Fargo/Grand Forks radar (KMVX), 53 km from the middle of the area, began a volume at 22:08 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
Aug 29, 5:30 PM CDT	HAIL 1.25	2 N Nielsville, MN	MAJOR CROP DAMAGE REPORTED AS HAIL STRIPPED BARLEY, WHEAT AND CORN. HAIL FELL IN 2 MILE LONG PATH.

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 one storm report to this severe thunderstorm warning; the first came 25 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 nearest sounding before it

International Fa, MN (KINL), launched 12:00Z, 10.1 hours before the alert went out and 268 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: 10 J/kg
Mixed-layer CIN: -71 J/kg
Mixed-layer LCL: 718 m above ground
0-6 km bulk shear: 23 kt
0-1 km storm-relative helicity: 56 m²/s²
0-3 km storm-relative helicity: 68 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 KFGF 292205
SVRFGF
MNC119-292245-

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE EASTERN ND/GRAND FORKS
505 PM CDT SUN AUG 29 2004

THE NATIONAL WEATHER SERVICE IN GRAND FORKS HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...

  WESTERN POLK COUNTY IN NORTHWEST MINNESOTA

* UNTIL 545 PM CDT.

* AT 459 PM...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM 2 MILES NORTHWEST OF NIELSVILLE...OR ABOUT 27
  MILES SOUTHEAST OF GRAND FORKS...MOVING TO THE EAST AT 20 MPH.

* THE SEVERE THUNDERSTORM WILL BE NEAR...

  CROOKSTON AT 520 PM...
  GREENVIEW AT 525 PM...
  HAROLD AT 535 PM AND
  GENTILLY AT 540 PM.

REMEMBER SEVERE THUNDERSTORMS CAN AND OCCASIONALLY DO PRODUCE
TORNADOES WITH LITTLE OR NO ADVANCE WARNING.

LAT...LON 4787 9691 4753 9685 4752 9634 4777 9638

$$

55

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 Grand Forks, ND wrote its last area forecast discussion before this severe thunderstorm warning went out at Aug 29, 2:30 PM CDT, 2 hours 35 minutes earlier.

Area forecast discussion, Aug 29, 2:30 PM CDT, 2 hours 35 minutes before

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE EASTERN ND/GRAND FORKS ND
230 PM CDT SUN AUG 29 2004

.SHORT TERM...FORECAST CHALLENGE DEALS WITH SEVERE POTENTIAL THIS
EVENING AND THEN SLIGHT CONVECTIVE CHANCES THROUGH WEDNESDAY. 12Z
ETA/GFS BOTH SHOW GOOD CONTINUITY WITH PREVIOUS RUNS AND SHOW
SIMILAR SOLUTIONS. HOWEVER THEY DO DIFFER ON MINOR DETAILS AND WILL
UTILIZE ETA FOR SPECIFICS.

TONIGHT...CU LINE FORMING ACROSS EASTERN ND IN ASSOCIATION WITH SFC
TROUGH. CONVECTION STARTING TO FIRE ACROSS NE ND AND EXPECT
ADDITIONAL FORMATION SOUTHWARD AS TIME PROGRESSES. DEW POINTS HAVE
RISEN TO NEAR 60 ACROSS FORECAST AREA (FA). RESIDUAL CLOUDS FROM
MORNING SHOWERS STILL LOCATED ACROSS EASTERN FA. HOWEVER...BETWEEN
THESE CLOUDS AND SFC TROUGH THERE LOOKS TO BE AT LEAST A COUPLE
HOURS OF SUNSHINE (HEATING) WHICH ALLOWS CAPES TO REACH
1000-1500J/KG. UPPER LEVEL SUPPORT IN THE FORM OF STRONG SHORTWAVE
AND LEFT EXIT REGION OF 250MB JET WILL ENHANCE LIFT DURING MAX
HEATING. WITH GOOD SHEAR AND LOW FREEZING LEVELS SEVERE POTENTIAL
REMAINS. THE SEVERE POTENTIAL WILL QUICKLY DIMINISH AFTER SUNSET AS
INSTABILITY DECREASES. THE CURRENT FORECASTED SPEED OF THIS SYSTEM
PROPAGATES ALL PRECIPITATION EAST OF FORECAST AREA BY MIDNIGHT.

MON-WED...UPPER LEVEL RIDGE BUILDS OVER AREA WITH FA TO BE IN WARM
SECTOR AND DRY AIR MASS. HIGHER MOISTURE LOOKS TO REMAIN EAST OF FA
DURING PERIOD. DID ADD A CHANCE FOR THUNDER ACROSS NW MN MONDAY
NIGHT WITH STRONG WARM AIR ADVECTION...30KT LOW LEVEL JET...AND WEAK
SURFACE TROUGH. DID NOT INTRODUCE THUNDER TO REMAINDER OF FORECAST
AREA MONDAY NIGHT WITH SFC-700MB LAYER DRY. PERSISTENT WARM AIR
ADVECTION AND SURFACE TROUGH TO HANG AROUND TUE-WED...BUT WITH LACK
OF MOISTURE FEEL PRECIPITATION THREAT IS MINIMAL AND WILL NOT
MENTION. TEMPERATURES INCREASE INCREMENTALLY EACH DAY.

.LONG TERM...THU THROUGH SUN...MODELS ARE IN PRETTY GOOD
AGREEMENT FOR PORTIONS OF THE EXTENDED FORECAST...WITH SW 500MB FLOW
REMAINING OVER THE AREA. FIRST COLD FRONT MOVES THROUGH ON THU NIGHT
AND FRI IN CONJUNCTION WITH GOOD UPPER LEVEL SHORTWAVE...BRINGING A
CHANCE FOR THUNDERSTORMS TO THE AREA. NEXT SHORTWAVE AND 500MB TROF
MOVE INTO AREA FOR SAT NIGHT...SO ADDED A CHANCE FOR THUNDERSTORMS
TO E PART OF AREA. NEXT SIGNIFICANT COLD FRONT...MOVES IN FOR
MON...SO ADDED A CHANCE FOR THUNDERSTORMS THEN AS WELL. AS FAR AS
TEMPS...REMAIN CLOSE TO NORMAL FOR MUCH OF THE EXTENDED FORECAST.

&&

.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.

&&

TG/NG

Hazardous weather outlook, Aug 29, 6:29 AM CDT, 10 hours 36 minutes before

HAZARDOUS WEATHER OUTLOOK...CORRECTION
NATIONAL WEATHER SERVICE EASTERN ND/GRAND FORKS
629 AM CDT SUN AUG 29 2004

MNZ001>009-013>017-022>024-027>032-040-NDZ006>008-014>016-024-
026>030-038-039-049-052>054-291430-
BARNES-BENSON-CASS-CAVALIER-CLAY-EAST BECKER-EAST MARSHALL-
EAST OTTER TAIL-EAST POLK-EASTERN WALSH COUNTY-EDDY-GRAND FORKS-
GRANT-GRIGGS-HUBBARD-KITTSON-LAKE OF THE WOODS-MAHNOMEN-NELSON-
NORMAN-NORTH BELTRAMI-NORTH CLEARWATER-PEMBINA-PENNINGTON-RAMSEY-
RANSOM-RED LAKE-RICHLAND-ROSEAU-SARGENT-SOUTH BELTRAMI-
SOUTH CLEARWATER-STEELE-TOWNER-TRAILL-WADENA-WEST BECKER-
WEST MARSHALL-WEST OTTER TAIL-WEST POLK-WESTERN WALSH COUNTY-WILKIN-
629 AM CDT SUN AUG 29 2004

...SEVERE THUNDERSTORMS ARE POSSIBLE ACROSS EXTREME EASTERN NORTH
DAKOTA AND NORTHWEST MINNESOTA THIS AFTERNOON AND EVENING...

THIS HAZARDOUS WEATHER OUTLOOK IS FOR EASTERN NORTH DAKOTA...WEST
CENTRAL AND NORTHWEST MINNESOTA.

.DAY ONE...TODAY AND TONIGHT

A SLIGHT RISK OF SEVERE THUNDERSTORMS EXISTS THIS AFTERNOON AND
EVENING FROM THE RED RIVER VALLEY COUNTIES OF NORTH DAKOTA EASTWARD
TO INCLUDE ALL OF WEST CENTRAL AND NORTHWESTERN MINNESOTA. WIND
GUSTS TO 60 MILES PER HOUR AND HAIL TO QUARTER SIZE ARE EXPECTED
WITH THE SEVERE THUNDERSTORMS.

A LOW PRESSURE AREA IN SOUTHERN MANITOBA WILL PUSH A COLD FRONT
ACROSS THE REGION THIS AFTERNOON AND EVENING. UNSTABLE AIR AHEAD OF
THE COLD FRONT WILL ALLOW THUNDERSTORM DEVELOPMENT TO BEGIN BY MID
AFTERNOON AND CONTINUE INTO THE EVENING HOURS. THE FRONT AND
ASSOCIATED THUNDERSTORMS SHOULD MOVE EAST OF THE AREA SOMETIME
AROUND MIDNIGHT.

.DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY

A SLIGHT CHANCE OF THUNDERSTORMS IS POSSIBLE IN WEST CENTRAL
MINNESOTA TUESDAY NIGHT INTO WEDNESDAY. THUNDERSTORMS ARE AGAIN
POSSIBLE FRIDAY INTO SATURDAY.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION MAY BE NEEDED BETWEEN 2 PM AND 10 PM.

FOR ADDITIONAL WEATHER INFORMATION, CHECK OUR WEB SITE AT
HTTP://WWW.CRH.NOAA.GOV/FGF/INDEX.HTML (ALL LOWER CASE)

BRAMER

In the hours before

Local storm report, Aug 29, 3:12 PM CDT, 1 hour 53 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE EASTERN ND/GRAND FORKS
312 PM CDT SUN AUG 29 2004

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

0257 PM     HAIL             LANGDON                 48.76N 98.37W
08/29/2004  0.75 INCH        CAVALIER           ND   LAW ENFORCEMENT

&&

GODON

Local storm report, Aug 29, 4:39 PM CDT, 26 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE EASTERN ND/GRAND FORKS
439 PM CDT SUN AUG 29 2004

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

0429 PM     HAIL             2 NW THOMPSON           47.80N 97.14W
08/29/2004  1.00 INCH        GRAND FORKS        ND   TRAINED SPOTTER

0431 PM     HAIL             1 E THOMPSON            47.78N 97.08W
08/29/2004  0.75 INCH        GRAND FORKS        ND   AIRPLANE PILOT

&&

DTR

Local storm report, Aug 29, 4:40 PM CDT, 25 minutes before

PRELIMINARY LOCAL STORM REPORT ... CORRECTION
NATIONAL WEATHER SERVICE EASTERN ND/GRAND FORKS
440 PM CDT SUN AUG 29 2004

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

0431 PM     HAIL             1 E THOMPSON            47.78N 97.08W
08/29/2004  0.75 INCH        GRAND FORKS        ND   TRAINED SPOTTER

&&

DTR

Local storm report, Aug 29, 4:44 PM CDT, 21 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE EASTERN ND/GRAND FORKS
444 PM CDT SUN AUG 29 2004

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

0437 PM     HAIL             6 NE ALVARADO           48.25N 96.91W
08/29/2004  1.50 INCH        MARSHALL           MN   PUBLIC

            HAIL COVERED THE GROUND

&&

DTR

The office that day

Everything else NWS Grand Forks, ND issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Aug 29, 4:18 PM CDT	Severe Thunderstorm Warning	FGF	Marshall	42 min
Aug 29, 4:30 PM CDT	Severe Thunderstorm Warning	FGF	Kittson	45 min
Aug 29, 4:58 PM CDT	Tornado Warning	FGF	Marshall	47 min
Aug 29, 5:12 PM CDT	Tornado Warning	FGF	Polk	48 min
Aug 29, 5:15 PM CDT	Severe Thunderstorm Warning	FGF	Kittson	45 min
Aug 29, 5:32 PM CDT	Severe Thunderstorm Warning	FGF	Norman	43 min
Aug 29, 5:53 PM CDT	Severe Thunderstorm Warning	FGF	Roseau	37 min
Aug 29, 5:55 PM CDT	Severe Thunderstorm Warning	FGF	Clay	50 min
Aug 29, 6:24 PM CDT	Severe Thunderstorm Warning	FGF	Wilkin	51 min
Aug 29, 6:33 PM CDT	Severe Thunderstorm Warning	FGF	Norman	27 min
Aug 29, 6:37 PM CDT	Severe Thunderstorm Warning	FGF	Marshall	38 min
Aug 29, 6:44 PM CDT	Severe Thunderstorm Warning	FGF	Clay	46 min

Nearby

Severe Thunderstorm Warnings in Minnesota, 2004 Every severe thunderstorm warning in 2004

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.