Alert archive / Minnesota / Severe Thunderstorm Warnings in 2002

Severe Thunderstorm Warning 126, NWS Grand Forks, ND

July 20, 2002Grant County, Minnesota

NWS Grand Forks, ND issued this severe thunderstorm warning at Jul 20, 2002, 4:42 AM CDT for Grant County, Minnesota. It was in force for 48 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
Jul 20, 2002, 4:42 AM CDT (09:42 UTC)
Expired
Jul 20, 2002, 5:30 AM CDT
In force
48 min
Issued by
NWS Grand Forks, ND
Area
Counties, with a storm outline in the text

County Grant County, MN

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

Minneapolis, MN (KMPX), launched 00:00Z, 9.7 hours before the alert went out and 209 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, Minneapolis, MN at 00:00Z on 2002-07-20Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1229 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, Minneapolis, MN at 00:00Z on 2002-07-20The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 20 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
1229 J/kg
Mixed-layer CIN
-98 J/kg
Mixed-layer LCL
947 m above ground
0-6 km bulk shear
34 kt
0-1 km storm-relative helicity
20 m²/s²
0-3 km storm-relative helicity
111 m²/s²
Significant tornado parameter
0.1
Supercell composite
0.7

Open this sounding in Storm Lab

The text

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

081 
WUUS53 KFGF 200942
SVRFAR
MNC051-201030-

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE EASTERN ND/GRAND FORKS
442 AM CDT SAT JUL 20 2002

THE NATIONAL WEATHER SERVICE IN GRAND FORKS HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...

  SOUTHERN GRANT COUNTY IN WEST CENTRAL MINNESOTA.

* UNTIL 530 AM CDT.

* AT 439 AM...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM OVER HERMAN...OR ABOUT 32 MILES SOUTH OF FERGUS
  FALLS...MOVEMENT WAS TO THE EAST AT 30 MPH.

* THE SEVERE THUNDERSTORM WILL BE NEAR...

  BARRETT AT 500 AM AND
  HOFFMAN AT 505 AM.

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

LAT...LON 4590 9622 4572 9620 4571 9536 4597 9539


8

NNNN

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 Jul 20, 2:15 AM CDT, 2 hours 27 minutes earlier.

Area forecast discussion, Jul 20, 2:15 AM CDT, 2 hours 27 minutes before
FORECAST DISCUSSION FOR EASTERN NORTH DAKOTA AND NORTHWEST MINNESOTA
NATIONAL WEATHER SERVICE EASTERN ND/GRAND FORKS ND
215 AM CDT SAT JUL 20 2002

FORECAST CHALLENGE IS CONVECTION TODAY INTO TONIGHT...THEN TEMPS

.OVERVIEW...
SFC TROUGH NOW ENTERING WESTERN ND...ALONG WITH ONE AREA OF LOW
PRESSURE NEAR PIR...AND ANOTHER IN SOUTHERN SASKATCHEWAN. ALL OF
EASTERN ND UNSTABLE WITH DEWPOINTS NEAR 70...WITH MID 60S TO THE
EAST IN MN. ETA DID THE BEST JOB INITIALIZING CONVECTION IN WESTERN
ND AND BOUNDARY LAYER MOISTURE...SO WILL USE THIS FORECAST PACKAGE.

.TODAY...
EXPECT ELEVATED ROUND OF CONVECTION TO BE ONGOING ACROSS EASTERN
ND...INTO WEST CENTRAL MN THIS MORNING ON HEELS OF 45KT 500MB SPEED
MAX AND 30KT LOW LEVEL JET. BY AFTERNOON...CAPES APPROACH
3000J/KG...ALONG WITH PRECIPITABLE WATERS NEAR 2 INCHES AND GOOD
FORCING ALONG SFC TROUGH. CAP SHOULD WEAKEN AROUND 18Z FOR POTENTIAL
SEVERE WEATHER OUTBREAK IN EASTERN ND...THEN MOVING INTO MN BY
EVENING. WITH 50KT NEAR 500MB...GOOD SHEAR AND RIGHT ENTRANCE REGION
OF 75KT 300MB JET...EXPECT A FEW SUPERCELLS WITH ISOLATED
TORNADOES...WHICH MAY CONSOLIDATE INTO MCS AS IT MOVES EAST THIS
EVENING. ANY STORMS WILL DROP HEAVY RAIN...SO WILL MENTION IN ZONES
WITH SEVERE WORDING AND LIKELY POPS. REFER TO SWODY1 FOR FURTHER
DETAILS ON SEVERE WEATHER THREAT.

.TONIGHT THROUGH MONDAY...
DRIER AIR WILL FILTER THROUGH REGION BY 12Z SUNDAY...IN WAKE OF SHORTWAVE
AND SUBSIDENCE BEHIND VORTICITY MAXIMUM. 850MB TEMPS COOL TO AROUND
+15C ON SUNDAY...SO EXPECT TEMPS WITHIN A FEW DEGREES OF 80 ALONG
WITH PLENTY OF SUN. BY MONDAY...A SECONDARY COLD FRONT WILL PUSH INTO
NORTHERN ZONES...SO WILL INSERT SCATTERED THUNDER MENTION IN
NORTHEAST AS TEMPS COOL INTO THE 70S.

.FGF...FLOOD WARNING CONTINUES FOR RED RIVER NEAR OSLO.

KELLENBENZ

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 20, 7:43 AM CDTSevere Thunderstorm WarningFGFMahnomen, Norman47 min

Nearby

Severe Thunderstorm Warnings in Minnesota, 2002Every severe thunderstorm warning in 2002

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.