Alert archive / Montana / Severe Thunderstorm Warnings in 2001

Severe Thunderstorm Warning 72, NWS Great Falls, MT

July 26, 2001Fergus County, Montana

NWS Great Falls, MT issued this severe thunderstorm warning at Jul 26, 2001, 7:53 AM MDT for Fergus County, Montana. It was in force for 52 min. 1 report came from inside the area while it was in force.

The area

The outline the Iowa Environmental Mesonet reconstructed for it; the warning itself named whole counties, with what was reported inside it.

The facts

Issued: Jul 26, 2001, 7:53 AM MDT (13:53 UTC)
Expired: Jul 26, 2001, 8:45 AM MDT
In force: 52 min
Issued by: NWS Great Falls, MT
Area: Whole counties; the outline is the Mesonet’s reconstruction

County Fergus County, MT

The radar

The Billings radar (KBLX), 126 km from the middle of the area, began a volume at 13:52 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 26, 8:20 AM MDT	Hail 1	Grassrange, MT	Actual event location Flatwillow Creek (approximately 20 S of Grassrange).

NCEI Storm Data entries that began inside the alert's area while it was in force. Before 2003 the local storm report archive is thin, so this is the record of what happened rather than what was phoned in.

The nearest sounding before it

Great_falls, MT (KTFX), launched 12:00Z, 1.9 hours before the alert went out and 142 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 1272 m above ground
0-6 km bulk shear: 36 kt
0-1 km storm-relative helicity: 83 m²/s²
0-3 km storm-relative helicity: 271 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 
WUUS55 KTFX 261355
SVRGTF

MTC027-261445-

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE GREAT FALLS MT
753 AM MDT THU JUL 26 2001

THE NATIONAL WEATHER SERVICE IN GREAT FALLS HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  SOUTHEASTERN FERGUS COUNTY IN CENTRAL MONTANA

* UNTIL 845 AM MDT

* AT 750 AM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED   
  A SEVERE THUNDERSTORM 16 MILES SOUTH OF GRASS RANGE...MOVING EAST  
  TO NORTHEAST AT 10 MPH.

* THE SEVERE THUNDERSTORM WILL BE NEAR...
GRASS RANGE AT 810 AM MDT

REPORT SEVERE WEATHER TO THE NEAREST LAW ENFORCEMENT AGENCY. THEY
WILL RELAY YOUR REPORT TO THE NATIONAL WEATHER SERVICE F/ORECAST
OFFICE IN GREAT FALLS.

LAT...LON 4682 10902 4676 10865 4698 10866 4717 10879
          4728 10906

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 Great Falls, MT wrote its last area forecast discussion before this severe thunderstorm warning went out at Jul 26, 2:30 AM MDT, 5 hours 23 minutes earlier.

Area forecast discussion, Jul 26, 2:30 AM MDT, 5 hours 23 minutes before

SOUTHWEST AND NORTH CENTRAL MONTANA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
230 AM MDT THU JUL 26 2001

UPPER LEVEL LOW OVER CNTRL SASK WEAKENS TODAY...LEAVING A BROAD
TROUGH ACROSS SW CANADA WITH WESTERLY FLOW ALOFT OVER CWA.  SURFACE
GRADIENTS ARE FAIRLY WEAK TODAY...BUT FLOW IS EXPECTED TO BE
GENERALLY E-NE OVER PLAINS ZONES. THIS SHOULD ACT TO ADVECT HIGHER
SURFACE DEWPOINTS INTO AREA BY THIS AFTERNOON. MODELS IN GENERAL
AGREEMENT IN ALLOWING AN UNSTABLE AIRMASS TO DEVELOP BY AFTERNOON
ACROSS MUCH OF CWA. AS A RESULT...FEEL THAT AT LEAST SLIGHT CHANCE
POPS ARE A SAFE BET MOST LOCATIONS. CURRENTLY...SURFACE CONVERGENCE
TAKING PLACE FROM NEAR KLWT TO KBTM ALLOWING A FEW TSRA TO DEVELOP.
MODELS CONTINUE THIS CONVERGENT ZONE TODAY...AND ALSO BRING A WEAK
VORT LOBE ACROSS AREA BY 18Z. THIS SCENARIO SEEMS REASONABLE AND
WILL GO WITH LOW SCATTERED POPS FOR EASTERN ZONES. SURFACE COOL
FRONT MOVED THROUGH GTF JUST AFTER 2AM...LOW CLOUDS ARE FORMING
ALONG ROCKY MOUNTAIN FRONT. NW ZONES WILL HAVE MORNING
CLOUDS...BUT EXPECT THEY WILL BURN OFF WELL BEFORE NOON. HIGH
TEMPERATURES HAVE BEEN CONSISTENTLY ABOVE MOS GUIDANCE THE LAST FEW
DAYS...AND EXPECT TREND TO CONTINUE. TODAY WILL BE A DEGREE OR TWO
COOLER THAN WED...BUT THICKNESS VALUES REBOUND NICELY TOMORROW...SO
WILL RAISE HIGHS 3-4 DEGREES FOR FRI.

EXTENDED...TROUGH PROGGED FOR THIS WEEKEND IS NOT AS STRONG ON
NEWEST MRF RUN...BUT TIMING IS ABOUT THE SAME. MRF CONTINUES TO BE
IN DECENT AGREEMENT WITH ECMWF. BOTH MODELS HANG TROUGH BACK OVER
PAC NW AND CONTINUE SW FLOW OVER STATE. EXPECT THAT THIS WILL FUNNEL
MONSOON MOISTURE OVER STATE FOR SCATTERED TSRA SAT AND SUN DESPITE
MRF QPF BEING MOSTLY DRY. CURRENT FORECAST HAS A DECENT HANDLE ON
SITUATION...SO WILL NOT MAKE ANY CHANGES. MPJ

GTF BB 085 049 088 051 092 14220
CTB BB 081 043 084 046 088 14120
HLN BU 087 053 090 053 094 14210
BZN BB 085 047 089 049 093 14221
WEY BB 080 038 083 040 087 14221
DLN BU 085 050 088 050 092 14100
HVR BB 090 051 093 053 098 14230
LWT EB 081 052 084 052 088 14332

Nearby

Severe Thunderstorm Warnings in Montana, 2001 Every severe thunderstorm warning in 2001

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; verification from NCEI's Storm Data; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.