Alert archive / North Dakota / Special Weather Statements in 2009

Special Weather Statement, NWS Grand Forks, ND

July 20, 2009Cass County, North Dakota

NWS Grand Forks, ND issued this special weather statement at Jul 20, 2009, 12:50 PM CDT for Cass County, North Dakota. It was in force for 40 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, 2009, 12:50 PM CDT (17:50 UTC)
Expired: Jul 20, 2009, 1:30 PM CDT
In force: 40 min
Issued by: NWS Grand Forks, ND

County Cass County, ND

The radar

The Fargo/Grand Forks radar (KMVX), 99 km from the middle of the area, began a volume at 17:53 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

Aberdeen, SD (KABR), launched 12:00Z, 5.8 hours before the alert went out and 223 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: 340 J/kg
Mixed-layer CIN: -406 J/kg
Mixed-layer LCL: 1506 m above ground
0-6 km bulk shear: 30 kt
0-1 km storm-relative helicity: 146 m²/s²
0-3 km storm-relative helicity: 140 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.

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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 Grand Forks, ND wrote its last area forecast discussion before this special weather statement went out at Jul 20, 11:08 AM CDT, 1 hour 42 minutes earlier.

Area forecast discussion, Jul 20, 11:08 AM CDT, 1 hour 42 minutes before

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE GRAND FORKS ND
1108 AM CDT MON JUL 20 2009

.UPDATE...
UPDATE CONCERNS CENTER ON TSTM POTENTIAL THIS AFTN IN THE SRN
VALLEY AND WCNTRL MN. 14Z SFC MAP SHOWED INITIAL TROUGH FROM
WINNIPEG TO BTWN GFK/DVL THEN TO JAMESTOWN TO PIERRE SD. DEW PTS
ALONG BOUNDARY AND JUST EAST AROUND 60 OR A BIT HIGHER.  ACTUAL
COLD FRONT WITH A MORE NORTHWEST WIND AND DROP IN DEW PTS INTO THE
LOW 50S BRANDON-ROLLA-GARRISON-DICKINSON ND LINE. 500 MB UPPER LOW
OVER SASK WILL MOVE EAST AND COLD FRONT WILL MOVE EAST TODAY...BUT
MOVEMENT WILL BE SLOWER OVER SE ND/SD/WCNTRL MN TODAY AND AS SRN
EDGE OF 500 MB VORT AND A BIT HIGHER MID LEVEL WINDS (40 KTS) MOVE
INTO SRN ND/NRN SD SOUTH OF THIS UPPER LOW...ENOUGH SUPPORT FOR
TSTMS TO RE-DEVELOP ALONG BOUNDARY IN THE BIS-JMS-ABR-PIR AREA
MIDDAY AND THEN MOVE EAST. SPC MESOPAGE HAS MUCAPES 2000-3000 J/KG
AND SBCAPES NR 1500 J/KG IN THIS AREA. FREEZING LEVELS HIGH AND
MARGINAL SHEAR...BUT COULD HAVE SOME DEVELOPMENT ENOUGH FOR
HAILERS THIS AFTN IN FAR SE ND/WCNTRL MN INTO SD. DID KEEP POPS UP
A BIT THRU THE DAY IN THIS AREA.

OTHERWISE CHC OF PCPN DVL-NRN VALLEY LESS BUT GOT SOME MID LEVEL
SHOWERS MOVING THRU INTO EARLY AFTN THEN DRYING OUT AS BETTER COLD
FRONT PUSH IN THIS AREA. TEMPS APPEAR REASONABLE...MOSTLY
70S..TOUCH 80 OR SO IN SE ND/WCNTRL MN.

&&

.PREV DISCUSSION... /ISSUED 344 AM CDT MON JUL 20 2009/

DISCUSSION...
MAIN FORECAST CHALLENGE IS PCPN. WHEN LOOKING AT THE LATEST SURFACE
ANALYSIS...AN AREA OF LOW PRESSURE IS LOCATED IN N SD WITH AN
INVERTED TROF EXTENDING THROUGH ND ALONG A BIS TO MOT LINE. WHEN
LOOKING AT THE MODELS...THE MODELS ARE IN PRETTY GOOD AGREEMENT WITH
SOME TIMING DIFFERENCES...ESPECIALLY LATER IN THE FORECAST.
THEREFORE...ENDED UP LEANING TOWARDS THE ADJMAVBC GUIDANCE FOR TEMPS
AND USED A GFS/NAM BLEND FOR POPS.

THE SURFACE BOUNDARY CONTINUES TO MOVE TO THE E TODAY...AND ALONG
WITH IT THE MAIN FOCUS FOR CONVECTION. ISOLD SVR TSRA HAVE BEEN
OCCURRING THROUGH THE NIGHT WITH THE MAIN SEVERE WEATHER THREAT FROM
THESE PULSE STORMS BEING LARGE HAIL. ALTHOUGH A PERIOD OF WEAKENING
CAN BE ANTICIPATED THROUGH THE MORNING INTO EARLY AFTERNOON HOURS...
CONTINUED MONITORING WILL NEED TO OCCUR DUE TO THE NATURE OF THESE
STORMS. THE FRONT IS EXPECTED TO MOVE OUT OF THE AREA TONIGHT...
TAKING THE PCPN THREAT WITH IT.

FOR TUE INTO THU...SURFACE HIGH PRESSURE WILL KEEP THE N PLAINS DRY
WITH TEMPERATURES NEAR TO SLIGHTLY BELOW NORMAL. THE NEXT CHANCE FOR
PCPN ARRIVES ON THU NIGHT AND LASTS INTO THE WEEKEND AS ANOTHER LOW
PRESSURE SYSTEM MOVES OUT OF THE ROCKIES INTO THE N PLAINS.

AVIATION...
VFR CIGS AND VSBYS EXPECTED TODAY WITH THE POTENTIAL FOR TSRA
MOVING FROM W TO E ACROSS THE AREA IN CONJUNCTION WITH A FRONTAL
PASSAGE TODAY INTO THIS EVENING. SE-S WINDS AROUND 15 KTS GUSTING
TO 25 KTS...EXPECTED TO TURN TO THE SW-W AS THE FRONT PASSES AND
DIMINISH TO AROUND 10 KTS.

&&

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

RIDDLE/NG

Hazardous weather outlook, Jul 20, 6:30 AM CDT, 6 hours 20 minutes before

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE GRAND FORKS ND
630 AM CDT MON JUL 20 2009

MNZ001>009-013>017-022>024-027>032-040-NDZ006>008-014>016-024-
026>030-038-039-049-052>054-211130-
WEST POLK-NORMAN-CLAY-KITTSON-ROSEAU-LAKE OF THE WOODS-
WEST MARSHALL-EAST MARSHALL-NORTH BELTRAMI-PENNINGTON-RED LAKE-
EAST POLK-NORTH CLEARWATER-SOUTH BELTRAMI-MAHNOMEN-
SOUTH CLEARWATER-HUBBARD-WEST BECKER-EAST BECKER-WILKIN-
WEST OTTER TAIL-EAST OTTER TAIL-WADENA-GRANT-TOWNER-CAVALIER-
PEMBINA-BENSON-RAMSEY-EASTERN WALSH COUNTY-EDDY-NELSON-
GRAND FORKS-GRIGGS-STEELE-TRAILL-BARNES-CASS-RANSOM-SARGENT-
RICHLAND-WESTERN WALSH COUNTY-
630 AM CDT MON JUL 20 2009

...ISOLATED SEVERE THUNDESTORMS POSSIBLE TODAY INTO EARLY TONIGHT...

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

.DAY ONE...TODAY AND TONIGHT

ISOLATED SEVERE THUNDERSTORMS REMAIN POSSIBLE IN PARTS OF EASTERN
NORTH DAKOTA...NORTHWEST AND WEST CENTRAL MINNESOTA TODAY INTO
EARLY TONIGHT. LARGE HAIL AND DAMAGING WINDS ARE THE MAIN SEVERE
WEATHER THREATS.

.DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY

THUNDERSTORMS ARE POSSIBLE OVER PARTS OF EASTERN NORTH DAKOTA...
NORTHWEST AND WEST CENTRAL MINNESOTA PERIODICALLY FROM THURSDAY
NIGHT INTO SUNDAY.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION MAY BE REQUIRED.

NG

In the hours before

Local storm report, Jul 20, 7:21 AM CDT, 5 hours 29 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE EASTERN ND/GRAND FORKS ND
721 AM CDT MON JUL 20 2009

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

0610 AM     HAIL             8 NE GARDNER            47.23N 96.85W
07/20/2009  E1.00 INCH       CASS               ND   PUBLIC

0615 AM     HAIL             5 ENE GARDNER           47.17N 96.87W
07/20/2009  E0.75 INCH       CASS               ND   PUBLIC

            PEA TO PENNY SIZED HAIL REPORTED.

0620 AM     HAIL             3 SSE HENDRUM           47.22N 96.79W
07/20/2009  E0.75 INCH       NORMAN             MN   PUBLIC

0620 AM     HAIL             5 NE PERLEY             47.23N 96.73W
07/20/2009  E0.88 INCH       NORMAN             MN   PUBLIC

&&

JKAISER

Special weather statement, Jul 20, 12:50 PM CDT, 0 minutes before

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE EASTERN ND/GRAND FORKS ND
1250 PM CDT MON JUL 20 2009

NDZ039-053-201830-
RICHLAND ND-CASS ND-
1250 PM CDT MON JUL 20 2009

...THE NATIONAL WEATHER SERVICE IN GRAND FORKS HAS ISSUED A
SIGNIFICANT WEATHER ADVISORY FOR SOUTHEASTERN CASS COUNTY IN
SOUTHEAST NORTH DAKOTA AND NORTHWESTERN RICHLAND COUNTY IN SOUTHEAST
NORTH DAKOTA...

UNTIL 130 PM CDT

AT 1249 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
THUNDERSTORM CAPABLE OF PRODUCING UP TO PENNY SIZE HAIL. THE STORM
WAS LOCATED 4 MILES SOUTHWEST OF DAVENPORT...OR 21 MILES SOUTHWEST OF
FARGO...MOVING TO THE EAST AT 15 MPH.

THE THUNDERSTORM WILL BE NEAR...
KINDRED AT 105 PM CDT...HORACE AT 130 PM CDT...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

BE PREPARED TO TAKE SHELTER IF THE STORMS INTENSIFY AND BECOME
SEVERE...OR A WARNING IS ISSUED BY THE NATIONAL WEATHER SERVICE.

&&

LAT...LON 4658 9727 4676 9726 4676 9679 4674 9679
      4654 9680
TIME...MOT...LOC 1750Z 252DEG 13KT 4667 9712

SPEICHER

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 19, 11:50 PM CDT	Special Weather Statement	FGF	Benson	25 min
Jul 19, 11:59 PM CDT	Severe Thunderstorm Warning	FGF	Towner	61 min
Jul 20, 12:08 AM CDT	Severe Thunderstorm Warning	FGF	Benson	67 min
Jul 20, 12:27 AM CDT	Severe Thunderstorm Warning	FGF	Benson, Towner	63 min
Jul 20, 12:43 AM CDT	Severe Thunderstorm Warning	FGF	Benson, Ramsey, Towner	62 min
Jul 20, 1:10 AM CDT	Severe Thunderstorm Warning	FGF	Cavalier	65 min
Jul 20, 1:47 AM CDT	Special Weather Statement	FGF	Ramsey	28 min
Jul 20, 2:14 AM CDT	Severe Thunderstorm Warning	FGF	Cavalier	46 min
Jul 20, 3:49 AM CDT	Special Weather Statement	FGF	Grand Forks	26 min
Jul 20, 3:56 AM CDT	Special Weather Statement	FGF	Cavalier	34 min
Jul 20, 4:20 AM CDT	Special Weather Statement	FGF	Grand Forks	25 min
Jul 20, 5:53 AM CDT	Special Weather Statement	FGF	Traill	52 min
Jul 20, 6:09 AM CDT	Severe Thunderstorm Warning	FGF	Cass, Traill	47 min
Jul 20, 12:56 PM CDT	Special Weather Statement	FGF	Cass, Ransom	64 min
Jul 20, 1:12 PM CDT	Severe Thunderstorm Warning	FGF	Cass, Ransom	48 min

Nearby

Special Weather Statements in North Dakota, 2009 Every special weather statement in 2009

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.