Alert archive / Montana / Severe Thunderstorm Warnings in 2000

Severe Thunderstorm Warning 74, NWS Great Falls, MT

July 9, 2000Fergus County, Montana

NWS Great Falls, MT issued this severe thunderstorm warning at Jul 9, 2000, 3:45 PM MDT for Fergus 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
Jul 9, 2000, 3:45 PM MDT (21:45 UTC)
Expired
Jul 9, 2000, 4:30 PM MDT
In force
45 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), 127 km from the middle of the area, began a volume at 21:48 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

TimeReportWhereRemark
Jul 9, 3:55 PM MDTHail 0.88Grassrange, MT

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 watch it was issued in

The SPC watch in force over the same counties when this warning went out.

IssuedProductOfficeLasted
Jul 9, 2:00 PM MDTSevere Thunderstorm WatchSPC6 hr

The nearest sounding before it

Great_falls, MT (KTFX), launched 12:00Z, 9.8 hours before the alert went out and 143 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, Great_falls, MT at 12:00Z on 2000-07-09Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 192 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, Great_falls, MT at 12:00Z on 2000-07-09The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 16 square meters per square second.1939587897117Sfc1 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
192 J/kg
Mixed-layer CIN
-253 J/kg
Mixed-layer LCL
1254 m above ground
0-6 km bulk shear
44 kt
0-1 km storm-relative helicity
16 m²/s²
0-3 km storm-relative helicity
87 m²/s²
Significant tornado parameter
0.0
Supercell composite
-0.2

Open this sounding in Storm Lab

The text

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

000 
WUUS55 KTFX 092146
SVRGTF
MTC027-092230-

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE GREAT FALLS MT
345 PM MDT SUN JUL 9 2000

THE NATIONAL WEATHER SERVICE IN GREAT FALLS HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  SOUTHERN FERGUS COUNTY IN MONTANA

* UNTIL 430 PM MDT

* AT 342 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED 
TO INDICATE SEVERE THUNDERSTORMS OVER SOUTHERN FERGUS COUNTY 
INCLUDING THE AREAS NEAR GRASS RANGE AND FORESTGROVE. THESE STORMS 
ARE MOVING TO THE EAST AT 20 MPH.

GOLF BALL SIZED HAIL HAS BEEN REPORTED WITH THIS STORM. 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 800 PM MDT SUNDAY
EVENING FOR NORTHWESTERN MONTANA. A SEVERE THUNDERSTORM WATCH ALSO
REMAINS IN EFFECT UNTIL 800 PM MDT SUNDAY EVENING FOR NORTHWESTERN
MONTANA.

LAT...LON 4699 10898 4686 10879 4683 10865 4723 10882

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 9, 3:00 PM MDT, 45 minutes earlier.

Area forecast discussion, Jul 9, 3:00 PM MDT, 45 minutes before
SOUTHWEST AND NORTH CENTRAL MONTANA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
300 PM MDT SUN JUL 9 2000

LOOKS LIKE A TRANSITION TO A LESS ACTIVE CONVECTIVE PATTERN BY TUESDAY.
UPPER TROUGH OVER THE PAC NW SUNDAY AFTERNOON IS FORECAST TO SWING INTO
SRN ALTA AND SW SASK MONDAY AFTERNOON. ON TUE WEAKLY ANTICYCLONIC FLOW
ALOFT IS FORECAST OVER THE AREA. FOR TONIGHT SPC HAS ISSUED SEVERE
THUNDERSTORM WATCH FOR HVR AND LWT ZONES. 19Z SURFACE DATA SHOWS
MOISTURE CONVERGENCE AND LIS DOWN TO MINUS 5 FROM SW MT INTO CENTRAL MT.
NW AREA ALSO HAS MOISTURE CONVERGENCE BUT AIRMASS IS LESS UNSTABLE
THERE.  HAVING SOME TROUBLE PICKING OUT VORTICITY CENTER MODELS FORECAST
S OF MSO AT 18Z. WATER VAPOR IMAGERY GIVING HINTS OF A SHORTWAVE
ANYWHERE FROM FAR SW MT TO SW ID. IN ANY CASE SHOULD HAVE SOME LIFT FROM
DYNAMICS TO HELP DEVELOP STRONG THUNDERSTORMS INTO EARLY THIS EVENING.
MODELS HAVE SHORTWAVES AFFECTING THE AREA LATER TONIGHT INTO MON. THERE
ARE SOME DIFFERENCES ON TIMING. WILL LEAVE IN A THREAT OF
SHOWERS/THUNDERSTORMS LATER TONIGHT AS AIRMASS IS FORECAST TO CONTINUE
TO BE UNSTABLE AND THERE WILL BE LOW LEVEL CONFLUENCE. ON MON AIRMASS IS
FORECAST NOT TO BE AS UNSTABLE AND LOW LEVEL CONFLUENCE SHIFTS E THROUGH
THE FORECAST AREA. WILL LEAVE IN A THREAT OF THUNDERSTORMS BUT GENERALLY
GO WITH A TAD LOWER POPS. FOR TUE AIRMASS IS FORECAST TO BE STABLE AND
MODELS ARE NOT INDICATING ANY SIGNIFICANT SHORTWAVES. EXCEPTION IS THE
SW WHERE ETA HAS BZN ZONE WEAKLY UNSTABLE AND AVN HAS BOTH BZN AND DLN
ZONES WEAKLY UNSTABLE. WAS THINKING OF GOING DRY BUT AFTER COORDINATION
CALL WITH BIL WILL MENTION SOME CONVECTION OVER BZN ZONE. BLANK

EXTENDED DISCUSSION...NEW LONG RANGE PROGS SHOW FAIRLY STRONG UPPER
RIDGE OVER CENTRAL AND EASTERN MONTANA WEDNESDAY...MOVING INTO THE
DAKOTAS ON THURSDAY. HOT TEMPERATURES EXPECTED. SOUTHWEST FLOW ALOFT
WILL CAUSE AREA TO BE VULNERABLE FOR ISOLATED AFTERNOON AND EVENING
THUNDERSTORMS. UPPER TROUGH MOVING INTO THE PACIFIC NORTHWEST AND
BRITISH COLUMBIA FRIDAY FOR INCREASED CHANCE OF DIURNAL THUNDERSTORMS IN
AREA. OARD

CCF NUMBERS
GTF BU 048/080 050/083 055 043210
CTB BU 047/075 048/078 052 042200
HLN BU 050/082 050/085 055 043200
BZN BU 048/082 046/085 050 043321
WEY BU 040/075 038/078 040 043322
DLN BU 046/080 045/083 048 043210
HVR BU 052/081 052/083 057 044310
LWT BU 048/080 048/082 052 044310

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 8, 6:11 PM MDTTornado WarningTFXChouteau, Fergus64 min
Jul 8, 6:16 PM MDTSevere Thunderstorm WarningTFXCascade, Chouteau44 min
Jul 8, 6:41 PM MDTSevere Thunderstorm WarningTFXCascade49 min
Jul 8, 6:51 PM MDTSevere Thunderstorm WarningTFXCascade, Chouteau54 min
Jul 8, 7:12 PM MDTTornado WarningTFXFergus63 min
Jul 8, 7:30 PM MDTSevere Thunderstorm WarningTFXCascade, Chouteau60 min
Jul 8, 7:50 PM MDTSevere Thunderstorm WarningTFXJudith Basin40 min
Jul 8, 8:15 PM MDTSevere Thunderstorm WarningTFXChouteau, Fergus, Judith Basin60 min
Jul 8, 8:25 PM MDTSevere Thunderstorm WarningTFXBlaine, Chouteau65 min
Jul 8, 9:24 PM MDTTornado WarningTFXFergus36 min
Jul 8, 9:25 PM MDTSevere Thunderstorm WarningTFXBlaine, Fergus50 min
Jul 9, 1:25 PM MDTSevere Thunderstorm WarningTFXBlaine65 min
Jul 9, 2:58 PM MDTSevere Thunderstorm WarningTFXFergus47 min
Jul 9, 4:57 PM MDTSevere Thunderstorm WarningTFXFergus48 min
Jul 9, 5:11 PM MDTSevere Thunderstorm WarningTFXFergus, Judith Basin49 min

Nearby

Severe Thunderstorm Warnings in Montana, 2000Every severe thunderstorm warning in 2000

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.