Alert archive / Montana / Severe Thunderstorm Warnings in 2002
Severe Thunderstorm Warning 99, NWS Great Falls, MT
NWS Great Falls, MT issued this severe thunderstorm warning at Aug 5, 2002, 7:58 PM MDT for Liberty County, Montana. It was in force for 62 min. 1 report came from inside the area while it was in force.
The area
The outline as issued, with what was reported inside it.
The facts
- Issued
- Aug 5, 2002, 7:58 PM MDT (01:58 UTC)
- Expired
- Aug 5, 2002, 9:00 PM MDT
- In force
- 62 min
- Issued by
- NWS Great Falls, MT
- Area
- Counties, with a storm outline in the text
County Liberty County, MT
The radar
The Great Falls radar (KTFX), 132 km from the middle of the area, began a volume at 01:58 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 |
|---|---|---|---|
| Aug 5, 8:45 PM MDT | Hail 1.25 | Chester, MT | A severe thunderstorm produced 1.25 inch hail and crop damage near Chester. |
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.
Did it verify
Not verified. The Iowa Environmental Mesonet's Cow found no qualifying storm report inside this severe thunderstorm warning while it was in force. That is not proof nothing happened: reports are thin where few people live.
Cow counts a report within 15 km of the polygon while the warning was in force: a tornado for a tornado warning; hail of 1 inch or more, a gust of 58 mph or more or wind damage for a severe thunderstorm warning; a flash flood report for a flash flood warning.
The watch it was issued in
The SPC watch in force over the same counties when this warning went out.
| Issued | Product | Office | Lasted |
|---|---|---|---|
| Aug 5, 3:55 PM MDT | Severe Thunderstorm Watch | SPC | 6 hr |
The nearest sounding before it
Great_falls, MT (KTFX), launched 00:00Z, 2.0 hours before the alert went out and 135 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
- 568 J/kg
- Mixed-layer CIN
- -156 J/kg
- Mixed-layer LCL
- 1251 m above ground
- 0-6 km bulk shear
- 59 kt
- 0-1 km storm-relative helicity
- 30 m²/s²
- 0-3 km storm-relative helicity
- 301 m²/s²
- Significant tornado parameter
- 0.2
- Supercell composite
- 2.7
The text
As transmitted, in the capitals the NWS used until 2016.
266 WUUS55 KTFX 060158 SVRTFX MTC051-060300- BULLETIN - EAS ACTIVATION REQUESTED SEVERE THUNDERSTORM WARNING NATIONAL WEATHER SERVICE GREAT FALLS MT 756 PM MDT MON AUG 5 2002 THE NATIONAL WEATHER SERVICE IN GREAT FALLS HAS ISSUED A * SEVERE THUNDERSTORM WARNING FOR... LIBERTY COUNTY IN NORTH CENTRAL MONTANA THIS INCLUDES THE CITY OF CHESTER * UNTIL 900 PM MDT * AT 753 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A SEVERE THUNDERSTORM MOVING INTO WESTERN AND SOUTHERN LIBERTY COUNTY * THE SEVERE THUNDERSTORM WILL BE NEAR... RURAL EASTERN LIBERTY COUNTY AT 830 PM MDT. RURAL NORTHEASTERN LIBERTY COUNTY AT 840 PM MDT. THESE STORMS HAVE HAD A HISTORY OF PRODUCING HAIL OVER ONE INCH IN DIAMETER. 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 1000 PM MDT MONDAY EVENING FOR WESTERN MONTANA. LAT...LON 4891 11126 4816 11123 4824 11078 4893 11082
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 Aug 5, 3:00 PM MDT, 4 hours 58 minutes earlier.
Area forecast discussion, Aug 5, 3:00 PM MDT, 4 hours 58 minutes before
SOUTHWEST AND NORTH CENTRAL MONTANA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
300 PM MDT MON AUG 5 2002
.SHORT TERM...SOUTHWEST PORTION OF CWA HAS SEEN AMPLE SUNSHINE
THIS AFTERNOON AND INITIAL CONVECTION SHOULD BEGIN THERE. THESE
STORMS WILL ADVANCE IN SWIFT SOUTHWEST FLOW ALOFT INTO SHEAR
ENVIRONMENT OVER THE NORTHERN PART OF THE CWA WHICH IS PROGGED TO BE
QUITE HIGH THIS EVENING. HELICITY...CAPE AND LI VALUES INDICATE THE
BEST POTENTIAL FOR SEVERE WEATHER IS EAST OF A LINE FROM NEAR GREAT
FALLS TO CHESTER. SPC MODERATE RISK CALLS FOR LONG LIVED SUPERCELLS
WITH GREATEST THREAT FROM LARGE HAIL. HELICITY VALUES AND INSTABILITY
SUGGEST ROTATING UPDRAFTS ARE LIKELY. WILL PLAY THIS SCENARIO UP IN
AFTERNOON PACKAGE. SPS ISSUED EARLIER TODAY AS A HAZARDOUS WEATHER
OUTLOOK TO ATTRACT MEDIA ATTENTION FOR POSSIBLE SEVERE WEATHER
OUTBREAK.
MAIN UPPER LOW STILL OVER PACNW AND WILL CONTINUE TO SEND SHORT WAVE
ENERGY THROUGH A MOIST SOUTHWEST FLOW THROUGH WEDNESDAY. MODELS
CONTINUE ADVANCING PARENT LOW EAST AND WILL CONTINUE TO PLAY IT A BIT
SLOWER THAN PROGGED. BOTTOM LINE...WILL KEEP SCATTERED POPS IN FOR
MOST OF CWA THROUGH MOST OF PERIOD. DITTMANN
.EXTENDED...AVN/ECMWF ARE IN PRETTY GOOD AGREEMENT FOR FRI AND SAT
BUT DIVERGE SIGNIFICANTLY BY SUN. 12Z UKMET LEANS TOWARDS THE
00Z/12Z AVN. FOR FRI AND SAT LOOKS LIKE DRY W TO NW FLOW ALOFT WILL
BE OVER THE AREA. SUN AVN BRINGS AN UPPER TROUGH INTO THE AREA
WHILE THE ECMWF HAS AN UPPER RIDGE. ON MON 00Z AVN RUN DUG THE UPPER
TROUGH INTO ERN MT WITH COOL THICKNESSES FOR THE AREA. NCEP
DISCUSSION FAVORS A SLOWER AND LESS AMPLIFIED UPPER TROUGH THAN WHAT
THE 00Z/12Z AVN HAVE. SO WHEREAS THE 00Z AVN BROUGHT A COLD FRONT
THROUGH THE AREA ON SUN WILL HOLD OFF ON COLD FRONTAL PASSAGE UNTIL
MON. HARD TO SAY AT THIS POINT HOW MUCH MOISTURE AND WHETHER
THERE WILL BE MUCH IF ANY UPSLOPE FLOW WITH THE UPPER TROUGH.
WILL GO WITH A SLIGHT CHANCE OF SHOWERS FOR NOW. BLANK
.CCF NUMBERS
GTF BB 052/077 050/074 048 02533
EBNNB 075/052 077/050 083/053 083/050 078 33321111112
CTB BB 048/070 047/069 045 02433
BBNNB 071/048 076/048 080/050 077/046 072 22221111122
HLN BB 052/078 050/076 050 02533
EBBNB 076/050 076/050 085/054 085/053 080 33421111112
BZN BB 048/080 046/078 048 02533
EBBBB 078/044 074/045 082/048 084/047 080 33431111112
WEY BB 040/072 038/070 040 02333
EBBBB 070/038 068/036 075/038 077/039 075 34541111112
DLN BB 048/078 046/076 046 02333
BBBNB 075/044 075/044 080/047 082/049 080 33431111112
HVR BB 056/082 053/078 050 02633
BBBNB 079/050 078/050 085/054 084/054 077 33311111122
LWT BB 052/080 050/076 047 02633
EBBNB 074/047 073/045 081/050 081/050 077 33321111112=
.TFX...The office that day
Everything else NWS Great Falls, MT issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 5, 6:07 PM MDT | Severe Thunderstorm Warning | TFX | Teton | 53 min |
| Aug 5, 6:18 PM MDT | Tornado Warning | TFX | Judith Basin | 27 min |
| Aug 5, 6:45 PM MDT | Tornado Warning | TFX | Chouteau | 30 min |
| Aug 5, 6:48 PM MDT | Severe Thunderstorm Warning | TFX | Cascade | 57 min |
| Aug 5, 6:51 PM MDT | Severe Thunderstorm Warning | TFX | Pondera | 54 min |
| Aug 5, 6:59 PM MDT | Tornado Warning | TFX | Chouteau | 46 min |
| Aug 5, 7:03 PM MDT | Severe Thunderstorm Warning | TFX | Fergus | 57 min |
| Aug 5, 7:27 PM MDT | Severe Thunderstorm Warning | TFX | Teton | 48 min |
| Aug 5, 7:29 PM MDT | Severe Thunderstorm Warning | TFX | Toole | 46 min |
| Aug 5, 7:32 PM MDT | Tornado Warning | TFX | Fergus | 58 min |
| Aug 5, 7:48 PM MDT | Severe Thunderstorm Warning | TFX | Chouteau | 57 min |
| Aug 5, 8:45 PM MDT | Severe Thunderstorm Warning | TFX | Fergus | 30 min |
| Aug 5, 9:18 PM MDT | Severe Thunderstorm Warning | TFX | Fergus | 57 min |
| Aug 6, 4:57 PM MDT | Severe Thunderstorm Warning | TFX | Fergus | 63 min |
| Aug 6, 5:11 PM MDT | Tornado Warning | TFX | Fergus | 64 min |
Nearby
Severe Thunderstorm Warnings in Montana, 2002Every severe thunderstorm warning in 2002
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.