Alert archive / Montana / Severe Thunderstorm Warnings in 2001

Severe Thunderstorm Warning 10, NWS Great Falls, MT

June 27, 2001Cascade County, Chouteau County, Judith Basin County, Montana

NWS Great Falls, MT issued this severe thunderstorm warning at Jun 27, 2001, 6:30 PM MDT for Cascade County, Chouteau County, Judith Basin County, Montana. It was in force for 45 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: Jun 27, 2001, 6:30 PM MDT (00:30 UTC)
Expired: Jun 27, 2001, 7:15 PM MDT
In force: 45 min
Issued by: NWS Great Falls, MT
Area: Whole counties; the outline is the Mesonet’s reconstruction

Counties Cascade County, MT, Chouteau County, MT, Judith Basin County, MT

The radar

The Great Falls radar (KTFX), 58 km from the middle of the area, began a volume at 00:33 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
Jun 27, 7:18 PM MDT	Hail 1.5	Raynesford, MT	Actual spotter location is Raynesford 8 SE.

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 00:00Z, 0.5 hours before the alert went out and 14 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: 1392 J/kg
Mixed-layer CIN: -11 J/kg
Mixed-layer LCL: 2183 m above ground
0-6 km bulk shear: 43 kt
0-1 km storm-relative helicity: 54 m²/s²
0-3 km storm-relative helicity: 148 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 5.5

Open this sounding in Storm Lab

The text

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

000 
WUUS55 KTFX 280031
SVRGTF

MTC013-015-045-280115-

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE GREAT FALLS MT
630 PM MDT WED JUN 27 2001

THE NATIONAL WEATHER SERVICE IN GREAT FALLS HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  EASTERN CASCADE COUNTY IN CENTRAL MONTANA
  NORTHERN JUDITH BASIN COUNTY IN CENTRAL MONTANA
  SOUTH CENTRAL CHOUTEAU COUNTY IN NORTH CENTRAL MONTANA

* UNTIL 715 PM MDT

* AT 628 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  LINE OF SEVERE THUNDERSTORMS FROM 5 MILES NORTH OF BELT TO 20 MILES
  SOUTHWEST OF GEYSER...OR FROM 15 MILES EAST OF GREAT FALLS TO 25
  MILES WEST OF STANFORD...MOVING EAST AT 30 MPH.

* SEVERE THUNDERSTORMS WILL BE NEAR...
  OVER GEYSER AT 650 PM MDT
  OVER STANFORD AT 715 PM MDT

STRONG GUSTY WIND OVER 60 MPH AND HAIL UP TO ONE INCH ARE POSSIBLE
WITH THESE STORMS.

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

LAT...LON 4756 11113 4732 11089 4699 11085 4702 11004
          4730 11016 4759 11030

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 Jun 27, 2:45 PM MDT, 3 hours 45 minutes earlier.

Area forecast discussion, Jun 27, 2:45 PM MDT, 3 hours 45 minutes before

SOUTHWEST AND NORTH CENTRAL MONTANA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
245 PM MDT WED JUN 27 2001

AIR EVEN MORE MOIST THAN ANTICIPATED ACROSS MOST OF THE CWA THIS
AFTERNOON WITH LOW LEVEL EASTERLY FLOW. MSAS PLOT AND MODIFIED 12Z
SOUNDING INDICATING AN LI OF -6 OVER GTF AT 2 PM. THE QUESTION IS...
WHERE WILL THE TRIGGER COME FROM TO START CONVECTION? FRONT AND
ASSOCIATED SHOWERS LYING ALONG THE WESTERN BORDER IS THE BEST
POSSIBILITY. THIS FEATURE SEEMS TO BE MOVING SLOWER THAT MODELS HAD
INDICATED...BUT CONVECTION ALSO OCCURRING AHEAD OF IT. STRONGER
SHORTWAVE IN WYOMING WILL MOVE INTO EASTERN MONTANA AND NOT BE A
FACTOR IN OUR FORECAST. FLOW ALOFT BECOMES INCREASING DIFFLUENT OVER
THE NEXT 6-12 HOURS...SO WILL CONTINUE WITH SCATTERED POPS TONIGHT...
EXCEPT FOR NORTHEAST ZONES WHERE LIKELY POPS WILL BE USED. BEST
MOISTURE CONVERGENCE OCCURS THERE AROUND 06Z...AND WITH THE SUN
BREAKING OUT THIS AFTERNOON...TEMPERATURES MAY STILL BE IN THE 70S BY
THE TIME THE BOUNDARY MAKES IT THERE. FOR THURSDAY AND FRIDAY...UPPER
FLOW BECOMES MORE CYCLONIC...ALTHOUGH RESIDUAL INSTABILITY AND WEAK
SHORTWAVES AFFECTING THE SOUTHEAST ZONES WILL ALLOW FOR ISOLATED
THUNDERSTORMS DURING THE AFTERNOON AND EVENING. POMEROY

EXTENDED...UPPER LEVEL LOW PRESSURE TROUGH REMAINS CENTERED OFF BC
COAST EARLY IN PERIOD WITH HIGH PRESSURE RIDGE CENTERED OVER FOUR
CORNERS REGION. TROUGH CONTINUES TO SPIN DISTURBANCES INLAND WITH
SOUTHWEST FLOW OVER PACIFIC NORTHWEST STEERING THE DISTURBANCES
INTO WESTERN MONTANA. THE STRONGEST OF THESE WILL BRUSH ACROSS THE
NORTHWEST AND NORTHERN PORTION OF THE CWA SATURDAY NIGHT AND SUNDAY
FOR THE BEST CHANCE OF SHOWERS. AS THIS DISTURBANCE EXITS...THE
HIGH PRESSURE RIDGE BEGINS STRENGTHENING AND RETROGRADING...WITH
THE CENTER OVER NORTHWEST WY AND THE AXIS SHIFTING TO THE MT/ID
BORDER. THIS SHIFT WILL KEEP TEMPERATURES SEASONABLY WARM WITH ONLY
ISOLATED AFTERNOON SHOWERS OR THUNDERSTORMS OVER THE MOUNTAINS.

GTF BB 054/078 050/078 048 19511
CTB BB 050/072 047/072 045 19511
HLN BB 045/080 050/080 050 19411
BZN BB 052/080 049/080 048 19422
WEY BB 046/072 044/074 042 19422
DLN BB 051/078 047/078 056 19411
HVR BU 054/083 050/083 050 19611
LWT BB 053/074 048/074 046 19422

The office that day

Everything else NWS Great Falls, MT issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jun 27, 7:27 PM MDT	Severe Thunderstorm Warning	TFX	Chouteau, Fergus, Judith Basin	48 min
Jun 27, 9:09 PM MDT	Severe Thunderstorm Warning	TFX	Fergus, Judith Basin	51 min
Jun 27, 10:00 PM MDT	Severe Thunderstorm Warning	TFX	Fergus, Judith Basin	45 min
Jun 27, 11:14 PM MDT	Severe Thunderstorm Warning	TFX	Fergus, Judith Basin	46 min
Jun 28, 12:14 AM MDT	Flash Flood Warning	TFX	Chouteau, Fergus, Judith Basin	4 hr
Jun 28, 12:34 AM MDT	Severe Thunderstorm Warning	TFX	Fergus	41 min
Jun 28, 1:45 AM MDT	Severe Thunderstorm Warning	TFX	Meagher	30 min
Jun 28, 2:56 AM MDT	Severe Thunderstorm Warning	TFX	Fergus, Judith Basin	49 min

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.