Alert archive / Montana / Severe Thunderstorm Warnings in 2003

Severe Thunderstorm Warning 7, NWS Great Falls, MT

May 15, 2003Hill County, Montana

NWS Great Falls, MT issued this severe thunderstorm warning at May 15, 2003, 6:13 PM MDT for Hill County, Montana. It was in force for 47 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: May 15, 2003, 6:13 PM MDT (00:13 UTC)
Expired: May 15, 2003, 7:00 PM MDT
In force: 47 min
Issued by: NWS Great Falls, MT
Area: Counties, with a storm outline in the text

County Hill County, MT

The radar

The Great Falls radar (KTFX), 152 km from the middle of the area, began a volume at 00:12 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, 0.2 hours before the alert went out and 137 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: 11 J/kg
Mixed-layer CIN: -136 J/kg
Mixed-layer LCL: 1998 m above ground
0-6 km bulk shear: 38 kt
0-1 km storm-relative helicity: -26 m²/s²
0-3 km storm-relative helicity: 50 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.

176 
WUUS55 KTFX 160013
SVRTFX
MTC041-160100-

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE GREAT FALLS MT
612 PM MDT THU MAY 15 2003

THE NATIONAL WEATHER SERVICE IN GREAT FALLS HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  WESTERN HILL COUNTY IN NORTH CENTRAL MONTANA

* UNTIL 700 PM MDT

* AT 607 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A 
SEVERE THUNDERSTORM 7 MILES SOUTHEAST OF INVERNESS...OR ABOUT 18 
MILES EAST OF CHESTER...MOVING NORTH AT 40 MPH.

* THE SEVERE THUNDERSTORM WILL BE OVER...
RURAL WESTERN HILL COUNTY AT 630 PM MDT
RURAL NORTHWESTERN HILL COUNTY AT 650 PM MDT

A TRAINED WEATHER SPOTTER REPORTED 0.75 INCH DIAMETER HAIL WITH THIS 
STORM.

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 4844 11073 4841 11045 4891 11000 4898 11037
          4896 11064

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 May 15, 2:00 PM MDT, 4 hours 13 minutes earlier.

Area forecast discussion, May 15, 2:00 PM MDT, 4 hours 13 minutes before

SOUTHWEST AND NORTH CENTRAL MONTANA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
200 PM MDT THU MAY 15 2003

.SHORT TERM...UPPER TROF CONTINUES TO MOVE TOWARDS WESTERN MT.
SURFACE COLD FRONT IN CENTRAL MONTANA SHOULD CONTINUE TO MOVE SLOWLY
SOUTHEAST. ENOUGH HEATING AHEAD OF FRONT AND COOLING BEHIND THE FRONT
FOR MIXING AND DESTABILIZING AIR. RAIN SHOWERS AND THUNDERSTORMS LATE
THIS AFTERNOON INTO LATE THIS EVENING FOR MOST OF CWA. GOOD CHANCE OF
SOME STRONG WINDS WITH THESE STORMS AND POSSIBLY HAIL. MAY BE A FEW
STORMS THAT ARE SEVERE ESPECIALLY IN THE NORTHEASTERN ZONES SO WILL
WORD ZONES AS SUCH. COOLER TEMPERATURES TONIGHT WITH SOME RECOVERY ON
FRIDAY. CLEARING SKIES FRIDAY NIGHT FOR EVEN COOLER TEMPERATURES.
AREA GOES INTO SOUTHWEST FLOW ALOFT ON SATURDAY WITH A SURFACE HIGH
DEVELOPING OVER THE CWA. SURFACE LOW TO DEVELOP SATURDAY NIGHT WITH
INCREASE OF MOISTURE BUT MODELS DISAGREE ON PLACEMENT AND TIMING.
SHORT WAVES TO MOVE THROUGH THE FLOW SATURDAY AND SUNDAY. WILL
GO DRY FOR SATURDAY AND A CHANCE OF PRECIP FOR SUNDAY AT THIS
TIME. CAMP

.EXTENDED...UPPER TROUGH SKIPS PAST THE AREA MONDAY. THE RESULTING
NORTHWEST FLOW WILL CAUSE A DRYING TREND AND WILL ALLOW TEMPS TO
RECOVER TO NEAR AVERAGE BY WEDNESDAY. CANADIAN HIGH PRESSURE THAT
WILL RIDE THE NORTHWEST FLOW INTO THE CWA WILL KEEP WINDS LIGHT
THROUGH THE PERIOD. POMEROY

.CCF NUMBERS
GTF BE 038/057 031/054 034 07600
    EEBBB 048/032 056/032 061/036 065/039 067 00332200000
CTB NE 035/051 029/051 034 07200
    EEBBB 046/032 054/032 059/036 063/039 063 00332200000
HLN BE 040/060 034/055 035 07620
    EBBBB 052/033 059/035 064/037 067/040 069 02332200000
BZN BE 041/060 029/054 032 07722
    EBBBB 051/030 057/031 060/033 064/037 066 22332200000
WEY BE 030/047 026/046 028 07422
    EEBBB 043/029 047/032 056/036 059/038 059 22443300000
DLN BE 037/057 028/051 030 07522
    EBBBB 046/030 054/032 060/034 063/038 064 22332200000
HVR BE 038/059 032/056 037 07700
    EEBBB 048/035 058/035 063/039 068/041 070 00332200000
LWT BE 039/057 029/053 034 07700
    EEBBB 049/032 051/033 056/036 061/039 061 0-332200000

.TFX...NONE.

Hazardous weather outlook, May 15, 6:15 AM MDT, 11 hours 58 minutes before

MTZ008>015-044>055-160010-
HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE GREAT FALLS MT
615 AM MDT THU MAY 15 2003

THIS HAZARDOUS WEATHER OUTLOOK IS FOR NORTH CENTRAL AND SOUTHWEST
MONTANA

.DAY ONE...TODAY

SHOWERS AND THUNDERSTORMS ARE EXPECTED TO DEVELOP THIS
AFTERNOON...AHEAD OF A PACIFIC COLD FRONT. SOME OF THESE STORMS
COULD BE SEVERE. AREAS EAST OF A LINE FROM HAVRE...TO GREAT
FALLS...TO HELENA...AND THEN TO BOZEMAN...WILL HAVE THE HIGHEST
POTENTIAL FOR SEVERE WEATHER. THE BEST CHANCES FOR SEVERE STORMS TO
OCCUR WILL BE FROM 4 PM TO 10 PM THIS EVENING. THE MAIN THREAT FROM
THESE STORMS WILL BE LARGE HAIL AND DAMAGING WIND GUSTS.

.DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY

MUCH COOLER AIR WILL ENTER MONTANA THROUGHOUT THE WEEKEND. BY SUNDAY
MORNING...TEMPERATURES ARE EXPECTED TO RANGE FROM THE UPPER 20S TO
MID 30S IN MANY AREAS...WITH HIGH TEMPERATURES MOSTLY IN THE 40S.
THIS WILL ALLOW FOR A MIXTURE OF RAIN AND SNOW IN THE LOWER
ELEVATIONS...AND ALL SNOW TO FALL IN THE MOUNTAINS. ANYONE WHO HAS
OUTDOOR ACTIVITIES PLANNED FOR LATER THIS WEEKEND SHOULD BE PREPARED
FOR MORE WINTER LIKE CONDITIONS.

.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
May 15, 7:52 PM MDT	Severe Thunderstorm Warning	TFX	Meagher	38 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.