Alert archive / Montana / Severe Thunderstorm Warnings in 2001
Severe Thunderstorm Warning 37, NWS Great Falls, MT
NWS Great Falls, MT issued this severe thunderstorm warning at Jul 13, 2001, 5:20 PM MDT for Lewis and Clark County, Montana. 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 the Iowa Environmental Mesonet reconstructed for it; the warning itself named whole counties.
The facts
- Issued
- Jul 13, 2001, 5:20 PM MDT (23:20 UTC)
- Expired
- Jul 13, 2001, 6:00 PM MDT
- In force
- 40 min
- Issued by
- NWS Great Falls, MT
- Area
- Whole counties; the outline is the Mesonet’s reconstruction
County Lewis and Clark County, MT
The radar
The Great Falls radar (KTFX), 97 km from the middle of the area, began a volume at 23:21 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 watch it was issued in
The SPC watch in force over the same counties when this warning went out.
| Issued | Product | Office | Lasted |
|---|---|---|---|
| Jul 13, 2:15 PM MDT | Severe Thunderstorm Watch | SPC | 5 hr |
The nearest sounding before it
Great_falls, MT (KTFX), launched 12:00Z, 11.3 hours before the alert went out and 139 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.
- Mixed-layer CAPE
- 100 J/kg
- Mixed-layer CIN
- -251 J/kg
- Mixed-layer LCL
- 1561 m above ground
- 0-6 km bulk shear
- 32 kt
- 0-1 km storm-relative helicity
- 27 m²/s²
- 0-3 km storm-relative helicity
- 41 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted, in the capitals the NWS used until 2016.
000 WUUS55 KTFX 132321 SVRGTF MTC049-140000- BULLETIN - EAS ACTIVATION REQUESTED SEVERE THUNDERSTORM WARNING NATIONAL WEATHER SERVICE GREAT FALLS MT 520 PM MDT FRI JUL 13 2001 THE NATIONAL WEATHER SERVICE IN GREAT FALLS HAS ISSUED A * SEVERE THUNDERSTORM WARNING FOR... SOUTHERN LEWIS AND CLARK COUNTY IN WEST CENTRAL MONTANA * UNTIL 600 PM MDT * AT 516 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A SEVERE THUNDERSTORM OVER SOUTH CENTRAL LEWIS AND CLARK COUNTY...OR 10 MILES NORTHWEST HELENA...MOVING EAST AT 25 MPH. * THE SEVERE THUNDERSTORM WILL BE NEAR... HELENA AT 530 PM MDT WINDS OF 60 MPH ARE POSSIBLE WITH THIS SEVERE THUNDERSTORM. IF YOU ARE IN THE PATH OF THE STORM...PUT YOUR CAR IN A GARAGE AND MOVE TO A SUBSTANTIAL SHELTER. REPORT SEVERE WEATHER TO THE NEAREST LAW ENFORCEMENT AGENCY. THEY WILL RELAY YOUR REPORT TO THE NATIONAL WEATHER SERVICE FORECAST OFFICE IN GREAT FALLS. A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 700 PM MDT FRIDAY EVENING FOR NORTH CENTRAL MONTANA. A SEVERE THUNDERSTORM WATCH ALSO REMAINS IN EFFECT UNTIL 700 PM MDT FRIDAY EVENING FOR WESTERN MONTANA. LAT...LON 4673 11234 4656 11224 4669 11167 4690 11179
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 13, 2:42 PM MDT, 2 hours 38 minutes earlier.
Area forecast discussion, Jul 13, 2:42 PM MDT, 2 hours 38 minutes before
SOUTHWEST AND NORTH CENTRAL MONTANA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GREAT FALLS MT 242 PM MDT FRI JUL 13 2001 SYNOPSIS...THUNDERSTORMS EXPECTED ACROSS CWA THIS EVENING WITH SEVERE THUNDERSTORM WATCHES IN EFFECT UNTIL 700 PM MDT. SCATTERED THUNDERSTORMS WILL DEVELOP AGAIN SATURDAY AFTERNOON. LITTLE CHANGE EXPECTED IN TEMPERATURES. DISCUSSION...PERSISTENT HIGH PRESSURE RIDGE CENTERED OVER THE SOUTHERN CONUS WITH A LOW PRESSURE TROUGH OFF THE WEST COAST. RESULTANT SOUTHWEST FLOW OF MOIST...UNSTABLE AIR INTO CWA CREATING THUNDERSTORMS AGAIN THIS AFTERNOON WITH POSSIBILITY OF SEVERE THUNDERSTORMS. DYNAMICS IN PLACE...LARGE AREA OF LOWER LEVEL CONVERGENCE COUPLED WITH UPPER LEVEL DIVERGENCE CENTERED OVER CWA... DISTURBANCE PUSHING THROUGH...JET MAX PASSING OVER...NEGATIVE LI/S BLANKETING CWA WITH AREAS BETWEEN -4 AND -6...CAPES 1000 J/KG AND HIGHER...AND TIME SECTIONS SHOWING STRONG OMEGA AROUND 00Z. FORECASTED SOUNDINGS ADVERTISE PRECIPITABLE WATER INCREASING FROM AROUND THREE/QUARTERS OF AN INCH THIS MORNING TO OVER AN INCH THROUGH THE EVENING. SOME THUNDERSTORMS EXPECTED TO CREATE STRONG WIND...HAIL AND HEAVY RAIN...THUS TWO SEVERE THUNDERSTORM WATCHES HAVE BEEN ISSUED FOR THE CWA. ACTIVITY FOR CWA SHOULD DIMINISH AFTER SUNSET AS DISTURBANCES PUSH INTO EASTERN MT AND DYNAMICS WEAKEN. LITTLE CHANGE IN PATTERN SATURDAY...WITH SOUTHWEST FLOW CONTINUING. DYNAMICS NOT QUITE AS IMPRESSIVE HOWEVER...AND WILL PUT POPS IN SCATTERED CATEGORY. MOS GUIDANCE WANTS TO COOL TEMPERATURES SEVERAL DEGREES SATURDAY. THOUGH FLOW SLIGHTLY MORE WESTERLY DO NOT EXPECT MUCH CHANGE AND WILL KEEP FORECASTS WITHIN A DEGREE OR TWO OF TODAY. .EXTENDED... ALL OF THE EXTENDED MODELS SUGGEST LITTLE CHANGE TO THE PATTERN MONDAY THROUGH NEXT FRIDAY. AN UPPER LOW REMAINS PARKED OVER THE PAC NORTHWEST AND SOUTHERN BC THRU WED THEN BEGINS SLOWLY FILLING AND LIFTING NORTHEAST. HOWEVER...FLOW CONTINUES TO BE OUT OF THE SOUTHWEST TOWARDS THE END OF THE WEEK. THEREFORE... EXPECT SCATTERED THUNDERSTORMS THRU PERIOD WITH NEAR NORMAL TEMPS. MIELKE CCF NUMBERS GTF TB 054 084 053 083 054 036334 CTB TB 051 083 050 083 051 035223 HLN zTT 056 085 055 086 055 036345 BZN TT 050 085 051 086 051 036345 WEY TT 053 078 046 080 048 036345 DLN TT 051 084 050 085 050 034344 HVR TB 058 088 059 087 058 036222 LWT TB 054 084 054 085 053 036344
The office that day
Everything else NWS Great Falls, MT issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 12, 7:25 PM MDT | Severe Thunderstorm Warning | TFX | Hill | 50 min |
| Jul 12, 7:43 PM MDT | Severe Thunderstorm Warning | TFX | Blaine | 32 min |
| Jul 12, 7:48 PM MDT | Severe Thunderstorm Warning | TFX | Fergus | 27 min |
| Jul 13, 12:58 PM MDT | Severe Thunderstorm Warning | TFX | Judith Basin | 32 min |
| Jul 13, 1:32 PM MDT | Severe Thunderstorm Warning | TFX | Judith Basin | 28 min |
| Jul 13, 2:52 PM MDT | Severe Thunderstorm Warning | TFX | Gallatin | 28 min |
| Jul 13, 3:21 PM MDT | Severe Thunderstorm Warning | TFX | Fergus | 24 min |
| Jul 13, 5:57 PM MDT | Severe Thunderstorm Warning | TFX | Jefferson | 48 min |
Nearby
Severe Thunderstorm Warnings in Montana, 2001Every 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.