Alert archive / Montana / Severe Thunderstorm Warnings in 2003

Severe Thunderstorm Warning 2, NWS Great Falls, MT

April 12, 2003Chouteau County, Hill County, Liberty County, Montana

NWS Great Falls, MT issued this severe thunderstorm warning at Apr 12, 2003, 9:33 PM MDT for Chouteau County, Hill County, Liberty County, Montana. It was in force for 27 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: Apr 12, 2003, 9:33 PM MDT (03:33 UTC)
Expired: Apr 12, 2003, 10:00 PM MDT
In force: 27 min
Issued by: NWS Great Falls, MT
Area: Counties, with a storm outline in the text

Counties Chouteau County, MT, Hill County, MT, Liberty County, MT

The radar

The Great Falls radar (KTFX), 95 km from the middle of the area, began a volume at 03:27 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, 3.6 hours before the alert went out and 84 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: 147 J/kg
Mixed-layer CIN: -168 J/kg
Mixed-layer LCL: 2291 m above ground
0-6 km bulk shear: 50 kt
0-1 km storm-relative helicity: 57 m²/s²
0-3 km storm-relative helicity: 206 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.

621 
WUUS55 KTFX 130333
SVRTFX
MTC015-041-051-130400-

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE GREAT FALLS MT
933 PM MDT SAT APR 12 2003

THE NATIONAL WEATHER SERVICE IN GREAT FALLS HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  NORTH CENTRAL CHOUTEAU COUNTY IN NORTH CENTRAL MONTANA
  SOUTHWESTERN HILL COUNTY IN NORTH CENTRAL MONTANA
  SOUTHEASTERN LIBERTY COUNTY IN NORTH CENTRAL MONTANA

* UNTIL 1000 PM MDT

* AT 927 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM OVER NORTH CENTRAL CHOUTEAU COUNTY...OR ABOUT
  19 MILES NORTHWEST OF FORT BENTON...MOVING NORTHEAST AT 45 MPH.

* THE SEVERE THUNDERSTORM WILL BE OVER...
RURAL SOUTHWESTERN HILL COUNTY
RURAL NORTHERN CHOUTEAU COUNTY

THIS STORM HAS A HISTORY OF PRODUCING ONE INCH DIAMETER HAIL.

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 4812 11107 4796 11083 4833 11022 4849 11062

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 Apr 12, 8:50 PM MDT, 43 minutes earlier.

Area forecast discussion, Apr 12, 8:50 PM MDT, 43 minutes before

SOUTHWEST AND NORTH CENTRAL MONTANA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
850 PM MDT SAT APR 12 2003

.SHORT TERM...WILL UPDATE THIS EVENING. BUSY NIGHT AS FIRST
CONVECTIVE STORMS OF THE SEASON DEVELOPED OVER GREAT FALLS AND ARE
NOW MOVING INTO CHOUTEAU COUNTY. WILL ADJUST WORDING IN THE ZONES.
SOUTHWEST FLOW ALOFT CONTINUES SUNDAY WITH ANOTHER ROUND OF SHOWERS
AND THUNDERSTORMS DURING THE AFTERNOON A GOOD POSSIBILITY. EMANUEL

.EXTENDED...WEDNESDAY THROUGH SATURDAY...UNSETTLED WEATHER WILL
CONTINUE THROUGH THE FIRST FEW DAYS OF THE EXTENDED. AS A WEAK
SURFACE AREA OF LOW PRESSURE MOVES ACROSS THE CWA ON WEDNESDAY...AND
PLENTY OF COLD AIR ALOFT...EXPECT A CHANCE FOR SHOWERS. ON
THURSDAY...THE FLOW ALOFT STARTS TO SPLIT AROUND MONTANA. WITH A
STRONG LOW GOING TO OUR SOUTH...THERE WILL BE A CHANCE FOR
SHOWERS OVER FAR SOUTHWEST MONTANA...BUT AREAS FURTHER NORTH SHOULD
BE MOSTLY DRY. TEMPERATURES WILL CONTINUE TO BE COOL WEDNESDAY AND
THURSDAY...WITH A CHANCE FOR SNOW AT NIGHT...ESPECIALLY IN THE
MOUNTAINS. FOR FRIDAY AND SATURDAY...EXPECT A WEAK WESTERLY FLOW TO
SET UP ALOFT...AS A POSITIVELY TILTED RIDGE STARTS TO DEVELOP OVER
CENTRAL MONTANA. THIS WILL ALLOW THE AIR MASS TO DRY OUT...AND FOR
A NEW WARMING TREND TO BEGIN. BRUSDA

.CCF NUMBERS
GTF EE 040/064 037/058 037 14444
    EEBBU 052/029 050/031 055/032 056/034 060 43323300000
CTB EE 038/057 033/051 034 14636
    EEBBU 049/026 049/028 054/029 055/031 057 43323300000
HLN TE 042/062 037/059 035 14455
    EEBBU 053/027 050/029 054/030 056/032 058 333233-0000
BZN EE 037/064 034/057 034 14244
    EEEBU 050/026 050/028 051/029 056/031 059 23323330000
WEY TE 024/052 025/049 027 14263
    EEEBU 044/019 043/021 044/022 049/024 051 33433330000
DLN TE 039/057 035/056 032 14365
    EEEBU 049/024 050/026 051/027 056/029 057 23323330000
HVR EE 044/068 039/059 036 14432
    EEBBU 053/028 048/030 055/031 055/033 062 33323300000
LWT BE 040/066 037/058 034 14233
    EEBBU 050/027 047/029 054/030 054/032 058 33323300000

.TFX...NONE.

Hazardous weather outlook, Apr 12, 6:10 AM MDT, 15 hours 23 minutes before

MTZ008>015-044>055-130010-
HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE GREAT FALLS MT
610 AM MDT SAT APR 12 2003

THIS HAZARDOUS WEATHER OUTLOOK IS FOR NORTH CENTRAL AND SOUTHWEST MONTANA

.DAY ONE...TODAY

THE PROBABILITY FOR WIDESPREAD HAZARDOUS WEATHER IS LOW.

NO WATCHES, WARNINGS, OR ADVISORIES CURRENTLY IN EFFECT

.DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY

THE PROBABILITY FOR WIDESPREAD HAZARDOUS WEATHER IS LOW.

.SPOTTER INFORMATION STATEMENT...

WEATHER SPOTTERS ARE ENCOURAGED TO REPORT SIGNIFICANT WEATHER
CONDITIONS ACCORDING TO STANDARD OPERATING PROCEDURES.

The office that day

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

Issued	Product	Office	Counties	Lasted
Apr 12, 8:32 PM MDT	Severe Thunderstorm Warning	TFX	Chouteau	43 min

Nearby

Severe Thunderstorm Warnings in Montana, 2003 Every severe thunderstorm warning in 2003

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.