Alert archive / Montana / Severe Thunderstorm Warnings in 2002

Severe Thunderstorm Warning 124, NWS Great Falls, MT

August 22, 2002Judith Basin County, Montana

NWS Great Falls, MT issued this severe thunderstorm warning at Aug 22, 2002, 4:46 PM MDT for Judith Basin County, Montana. It was in force for 59 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 22, 2002, 4:46 PM MDT (22:46 UTC)
Expired: Aug 22, 2002, 5:45 PM MDT
In force: 59 min
Issued by: NWS Great Falls, MT
Area: Counties, with a storm outline in the text

County Judith Basin County, MT

The radar

The Great Falls radar (KTFX), 99 km from the middle of the area, began a volume at 22:48 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

Time	Report	Where	Remark
Aug 22, 5:00 PM MDT	Hail 1	Stanford, MT	A severe thunderstorm produced 1.00 inch hail at Stanford 5S.

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 nearest sounding before it

Great_falls, MT (KTFX), launched 12:00Z, 10.8 hours before the alert went out and 51 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: 74 J/kg
Mixed-layer CIN: -251 J/kg
Mixed-layer LCL: 864 m above ground
0-6 km bulk shear: 25 kt
0-1 km storm-relative helicity: 58 m²/s²
0-3 km storm-relative helicity: 64 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.

292 
WUUS55 KTFX 222246
SVRTFX
MTC045-222345-

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE GREAT FALLS MT
445 PM MDT THU AUG 22 2002

THE NATIONAL WEATHER SERVICE IN GREAT FALLS HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  EASTERN JUDITH BASIN COUNTY IN CENTRAL MONTANA
  THIS INCLUDES THE CITY OF STANFORD

* UNTIL 545 PM MDT

* AT 438 PM MDT...THE PUBLIC REPORTED A SEVERE THUNDERSTORM 9 MILES
  SOUTH OF STANFORD...MOVING EAST AT 5 MPH.

* THE SEVERE THUNDERSTORM WILL BE NEAR...
  7 MILES WEST OF HOBSON AT 545 PM MDT

SEVERE THUNDERSTORMS WILL MOVE ACROSS THE EASTERN HALF OF JUDITH 
BASIN COUNTY THROUGH 545 PM. EXPECT RAINFALL AMOUNTS TO BE NEAR ONE 
INCH...ALONG WITH HAIL UP TO 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.

LAT...LON 4735 11042 4674 11048 4687 10981 4717 10979

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 22, 3:00 PM MDT, 1 hour 46 minutes earlier.

Area forecast discussion, Aug 22, 3:00 PM MDT, 1 hour 46 minutes before

SOUTHWEST AND NORTH CENTRAL MONTANA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
300 PM MDT THU AUG 22 2002

.SHORT TERM...MODELS IN VERY GOOD AGREEMENT KEEPING THE UPPER LEVEL
LOW SPINNING OVER THE PACIFIC NORTHWEST. LOW SHOULD RETROGRADE
SOMEWHAT DURING THE NEXT 24 HOURS...ALLOWING A DOWNSTREAM RIDGE TO
BUILD OVER EASTERN MT AND SOUTHERN CANADA. MODELS PROGRESS THE
ENTIRE UPPER LEVEL PATTERN EAST...WITH THE CORE OF THE TROUGH MOVING
OVER CENTRAL MT ON SUNDAY. ALTHOUGH MODELS HAVE BEEN CONSISTENT RUN
TO RUN WITH THIS SCENARIO...WOULD NOT BE SURPRISED TO SEE SOME
SIGNIFICANT DIFFERENCES AS THE WEEKEND PROGRESSES. FOR TONIGHT...
CONVECTION IS EXPECTED TO MAINLY IMPACT SOUTH CENTRAL MT...WITH
CHANCE POPS AFFECTING THE SOUTHEAST PORTION OF MY CWA. MOISTURE
FIELD AND INSTABILITY SHOULD LIMIT CONVECTION ELSEWHERE IN MY CWA AND
WILL KEEP MENTION OF ONLY ISOLATED ACTIVITY. AIRMASS DESTABILIZES
AGAIN FRIDAY...AND MODELS BRING A SERIES OF UPPER LEVEL DISTURBANCES
OVER THE CWA FOR CHANCE POPS DEVELOPING IN THE SOUTH TOMORROW...AND
MOVING NORTH OVERNIGHT. THIS PATTERN CONTINUES THROUGH SATURDAY...
AND WILL BRING CHANCE POPS TO MUCH OF THE CWA. ON SUNDAY...ASSUMING
THE FORECAST TROUGH POSITION IS ACCURATE...WILL BROADBRUSH MOSTLY
CLOUDY SKIES AND CHANCE POPS. MPJ

.EXTENDED...MEDIUM RANGE MODELS AGAIN SHOWING SIGNS OF
INCONSISTENCY. UPPER TROF OVER THE AREA MONDAY SHOULD KEEP
CONDITIONS UNSETTLED. POSITIVE TILT UPPER RIDGE NOSES INTO WESTERN
MONTANA TUESDAY WITH SOME INSTABILITY REMAINING OVER THE EASTERN
PORTION OF THE CWA. STRONG WESTERLIES SET UP OVER THE AREA
WEDNESDAY AND THURSDAY FOR DRY AND WARMER CONDITIONS. TEMPERATURES
REMAIN FAIRLY STATIC THROUGH THE PERIOD AND WILL CONTINUE AT OR
SLIGHTLY ABOVE NORMAL.

.CCF NUMBERS
GTF BT 049/078 051/076 051 14123
    TTTBB 076/052 078/052 083/052 085/052 085 43333321111
CTB BT 045/076 048/075 048 14112
    TTTBB 075/050 077/050 082/050 084/050 084 33333321111
HLN BT 047/076 050/076 051 14124
    TTTBB 074/052 080/052 084/052 086/052 086 43333332111
BZN TT 042/077 045/077 045 14234
    TTTBB 075/045 080/045 082/045 084/045 084 43333332111
WEY TT 029/071 033/069 033 14244
    TTTBB 070/035 076/035 076/035 077/035 077 43333332111
DLN TT 039/074 041/072 043 14134
    TTTBB 073/045 078/045 083/045 084/045 084 33333221111
HVR BT 051/082 053/082 053 14112
    TTTBB 081/053 085/053 086/053 087/053 087 33333321111
LWT BT 048/078 050/076 050 14324
    TTTBB 075/050 081/050 083/050 084/050 084 53333322111=

.TFX...NONE.

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 21, 7:44 PM MDT	Severe Thunderstorm Warning	TFX	Broadwater	31 min
Aug 21, 8:05 PM MDT	Flash Flood Warning	TFX	Lewis and Clark	115 min
Aug 21, 8:25 PM MDT	Severe Thunderstorm Warning	TFX	Broadwater, Meagher	35 min
Aug 22, 5:10 PM MDT	Severe Thunderstorm Warning	TFX	Fergus	65 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; verification from NCEI's Storm Data; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.