Alert archive / Montana / Severe Thunderstorm Warnings in 2002

Severe Thunderstorm Warning 129, NWS Great Falls, MT

September 3, 2002Blaine County, Lake County, Montana

NWS Great Falls, MT issued this severe thunderstorm warning at Sep 3, 2002, 5:41 PM MDT for Blaine County, Lake County, Montana. It was in force for 49 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued
Sep 3, 2002, 5:41 PM MDT (23:41 UTC)
Expired
Sep 3, 2002, 6:30 PM MDT
In force
49 min
Issued by
NWS Great Falls, MT
Area
Counties, with a storm outline in the text

Counties Blaine County, MT, Lake County, MT

The radar

The Great Falls radar (KTFX), 179 km from the middle of the area, began a volume at 23:43 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.

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 nearest sounding before it

Great_falls, MT (KTFX), launched 12:00Z, 11.7 hours before the alert went out and 126 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 2002-09-03Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 13 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 2002-09-03The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 153 square meters per square second.19395878Sfc1 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
13 J/kg
Mixed-layer CIN
-266 J/kg
Mixed-layer LCL
2650 m above ground
0-6 km bulk shear
50 kt
0-1 km storm-relative helicity
153 m²/s²
0-3 km storm-relative helicity
166 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.

446 
WUUS55 KTFX 032341
SVRTFX
MTC005-047-040030-

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE GREAT FALLS MT
536 PM MDT TUE SEP 3 2002

THE NATIONAL WEATHER SERVICE IN GREAT FALLS HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
EXTREME SOUTH CENTRAL BLAINE COUNTY IN NORTH CENTRAL MONTANA

* UNTIL 630 PM MDT

* AT 538 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM OVER EXTREME SOUTHWESTERN BLAINE COUNTY...OR
  ABOUT 39 MILES SOUTHEAST OF BIG SANDY...MOVING EAST AT 20 MPH.

* THE SEVERE THUNDERSTORM WILL BE NEAR...
RURAL SOUTHWESTERN BLAINE COUNTY AT 620 PM MDT AND NEAR HAYES BY
630 PM.

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 4800 10940 4788 10922 4799 10859 4825 10910

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 Sep 3, 3:00 PM MDT, 2 hours 41 minutes earlier.

Area forecast discussion, Sep 3, 3:00 PM MDT, 2 hours 41 minutes before
SOUTHWEST AND NORTH CENTRAL MONTANA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
300 PM MDT TUE SEP 3 2002

.SHORT TERM...OVERALL PATTERN TO REMAIN STATIC THROUGH THE PERIOD.
SOUTHWEST FLOW ALOFT WILL PERSIST WITH PLENTY OF MOISTURE BEING
ADVECTED INTO THE AREA. A FEW THUNDERSTORMS ALREADY OCCURRING OVER
BEAVERHEAD COUNTY AND NEAR YELLOWSTONE PARK. MODELS MOVE A SHORT
WAVE ACROSS THE AREA LATER THIS EVENING AND WILL GO WITH SCATTERED
POPS FOR TONIGHT. REMAINDER OF FORECAST PERIOD SHOULD SEE SCATTERED
CONVECTIVE ACTIVITY DEVELOPING LATE EACH AFTERNOON AND CONTINUING
INTO THE EVENING HOURS AS WEAK IMPULSES MOVE THROUGH. TEMPERATURES
COOL A LITTLE EACH DAY WITH READINGS AT OR SLIGHTLY BELOW SEASONAL
NORMS. EMANUEL

.EXTENDED...MODELS CONTINUE THE PERSISTENT UNSTABLE SOUTHWEST
FLOW ALOFT THROUGH PERIOD. THOUGH ECWMF A BIT FASTER IN BRINGING
UPPER LOW ACROSS SOUTHERN MONTANA...WHILE MRF HAS WEAK UPPER RIDGE
OVER AREA EARLY IN THE PERIOD...THEN BRING UPPER LOW ACROSS SOUTHWEST
MONTANA BY TUESDAY. THIS WAS DIFFERENT THAN THE MORE ZONAL FLOW
OF THE EARLIER MODEL RUNS. THUS TEMPERATURES WILL BE NEAR SEASONAL
AVERAGES WITH SCATTERED PRECIPITATION. WILL KEEP EYE ON LATEST MRF
RUN AS IT HINTING TOWARD A GOOD RAIN EVENT BY TUESDAY...ESPECIALLY
ACROSS THE SOUTHERN PART OF THE STATE. WILLIAMSON DC

.CCF NUMBERS
GTF BB 052/080 048/073 045 08433
    BBUBB 070/044 072/048 074/048 074/048 074 33033333313
CTB BB 048/074 043/067 041 08433
    BBUBB 065/040 070/047 069/047 069/047 069 33033333303
HLN BB 054/086 051/080 050 08433
    BBUBB 075/047 073/047 073/047 073/047 073 33033333313
BZN BB 047/083 046/075 042 08433
    BBUBB 070/040 074/046 076/046 076/046 076 33033333313
WEY BB 038/076 038/066 037 08334
    BBUBB 065/032 069/037 069/037 069/037 069 33034343414
DLN BB 050/081 050/074 041 08333
    BBUBB 072/038 072/045 071/045 071/045 071 33033333313
HVR BB 053/082 050/075 046 08533
    BBUBB 071/046 073/048 075/048 075/048 075 33033333313
LWT BB 052/082 047/075 046 08533
    BBUBB 070/044 073/047 073/047 073/047 073 33033333313

.TFX...RED FLAG WARNING FOR FIRE ZONES 116 AND 118 until 9 pm.

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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.