Alert archive / Montana / Severe Thunderstorm Warnings in 2002

Severe Thunderstorm Warning 39, NWS Great Falls, MT

July 4, 2002Chouteau County, Montana

NWS Great Falls, MT issued this severe thunderstorm warning at Jul 4, 2002, 7:29 PM MDT for Chouteau County, Montana. It was in force for 46 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: Jul 4, 2002, 7:29 PM MDT (01:29 UTC)
Expired: Jul 4, 2002, 8:15 PM MDT
In force: 46 min
Issued by: NWS Great Falls, MT
Area: Counties, with a storm outline in the text

County Chouteau County, MT

The radar

The Great Falls radar (KTFX), 113 km from the middle of the area, began a volume at 01:29 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 00:00Z, 1.5 hours before the alert went out and 59 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 3025 m above ground
0-6 km bulk shear: 59 kt
0-1 km storm-relative helicity: 34 m²/s²
0-3 km storm-relative helicity: 242 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.

114 
WUUS55 KTFX 050129
SVRTFX
MTC015-050215-

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE GREAT FALLS MT
728 PM MDT THU JUL 4 2002

THE NATIONAL WEATHER SERVICE IN GREAT FALLS HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  EAST CENTRAL CHOUTEAU COUNTY IN NORTH CENTRAL MONTANA

* UNTIL 815 PM MDT

* AT 719 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM OVER SOUTHEASTERN CHOUTEAU COUNTY...OR ABOUT 32
  MILES NORTH OF STANFORD...MOVING NORTHEAST AT 25 MPH.

* THE SEVERE THUNDERSTORM WILL BE NEAR...
RURAL EASTERN CHOUTEAU COUNTY AT 740 PM MDT

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 1100 PM MDT
THURSDAY EVENING FOR WESTERN MONTANA.

LAT...LON 4753 11006 4769 10986 4799 10964 4796 11007

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 4, 3:00 PM MDT, 4 hours 29 minutes earlier.

Area forecast discussion, Jul 4, 3:00 PM MDT, 4 hours 29 minutes before

SOUTHWEST AND NORTH CENTRAL MONTANA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
300 PM MDT THU JUL 4 2002

.SHORT TERM...ANOTHER ROUND OF EVENING THUNDERSTORMS JUST GETTING
STARTED IN THE SOUTHERN ZONES AT PRESENT. PRONOUNCED MOISTURE
GRADIENT STRETCHING FROM DILLON T0 LEWISTOWN...AND STORMS WILL STAY
ALONG AND SOUTH OF THIS LINE. MONSTER RIDGE BEGINS TO BUILD IN
TOMORROW WITH INCREASING TEMPERATURES...LIGHT WINDS...AND A LOT OF
SUNSHINE. STILL...THERE IS A SLIGHT CHANCE OF THUNDERSTORMS OVER THE
SOUTHWEST SATURDAY. MODEL SOUNDINGS SHOW A CAP OVER THE NORTHERN
ZONES...SO WILL GO WITH A DRY FORECAST THERE. SUNDAY WILL BE HOT AS
RIDGE STRENGTHENS. SOME INDICATIONS OF LOW LEVEL MOISTURE BEING
ADVECTED IN FROM THE EAST ON SUNDAY. SO FOR NOW WILL BROADBRUSH
SLIGHT CHANCE POPS. POMEROY

.LONG TERM...OVERALL PICTURE IS FOR AN UPPER LEVEL RIDGE TO BUILD
OVER THE AREA FOR THE ENTIRE PERIOD. HOT TEMPERATURES WITH VERY
LITTLE MOISTURE AVAILABLE. DIFFERENCE IN MODELS ON TIMING OF
SHIFTING OF RIDGE AXIS AT END OF PERIOD. WHAT DAY WILL BE THE
HOTTEST WILL DEPEND ON A SURFACE COOL FRONT BEING ABLE TO GO OVER
THE TOP OF THE RIDGE. WILL CONTINUE TO TREND FOR A GENERAL HOT AND
DRY FORECAST. CAMP

.CCF NUMBERS
GTF UU 048/080 050/085 052 19000
    UBBBB 092/054 094/058 095/058 095/058 090 00211111111
CTB UU 043/074 047/081 049 19000
    UBBBB 085/049 088/052 089/052 090/052 086 00211111111
HLN UU 054/083 052/085 057 19000
    UBBBB 090/056 095/058 095/058 095/058 093 11211111111
BZN UU 052/082 050/086 051 19311
    UBBBB 089/050 090/052 092/055 094/053 092 22211111111
WEY UU 046/076 044/081 047 19311
    UBBBB 084/048 085/048 087/048 085/045 083 22221111111
DLN UU 047/083 049/086 052 19211
    UBBBB 090/051 092/053 093/055 094/052 092 22211111111
HVR UU 050/081 052/084 056 19000
    UBBBB 093/055 095/058 095/060 095/059 094 00211111111
LWT UU 048/076 050/080 053 19600
    UBBBB 088/054 090/054 093/057 095/057 093 00211111111

.TFX...NONE.

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 4, 6:06 PM MDT	Severe Thunderstorm Warning	TFX	Blaine	54 min
Jul 4, 6:19 PM MDT	Severe Thunderstorm Warning	TFX	Fergus	26 min
Jul 4, 6:46 PM MDT	Severe Thunderstorm Warning	TFX	Fergus, Judith Basin	44 min
Jul 4, 6:50 PM MDT	Severe Thunderstorm Warning	TFX	Fergus	55 min
Jul 4, 7:23 PM MDT	Severe Thunderstorm Warning	TFX	Fergus	22 min

Nearby

Severe Thunderstorm Warnings in Montana, 2002 Every 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.