Alert archive / Montana / Severe Thunderstorm Warnings in 2003

Severe Thunderstorm Warning 62, NWS Great Falls, MT

June 20, 2003Fergus County, Montana

NWS Great Falls, MT issued this severe thunderstorm warning at Jun 20, 2003, 4:00 PM MDT for Fergus County, Montana. It was in force for 60 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: Jun 20, 2003, 4:00 PM MDT (22:00 UTC)
Expired: Jun 20, 2003, 5:00 PM MDT
In force: 60 min
Issued by: NWS Great Falls, MT
Area: Counties, with a storm outline in the text

County Fergus County, MT

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 watch it was issued in

The SPC watch in force over the same counties when this warning went out.

Issued	Product	Office	Lasted
Jun 20, 12:05 PM MDT	Severe Thunderstorm Watch	SPC	8 hr

The nearest sounding before it

Great_falls, MT (KTFX), launched 12:00Z, 10.0 hours before the alert went out and 108 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: 29 J/kg
Mixed-layer CIN: -308 J/kg
Mixed-layer LCL: 1255 m above ground
0-6 km bulk shear: 34 kt
0-1 km storm-relative helicity: -7 m²/s²
0-3 km storm-relative helicity: 162 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.1

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

608 
WUUS55 KTFX 202200
SVRTFX
MTC027-202300-

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE GREAT FALLS MT
359 PM MDT FRI JUN 20 2003

THE NATIONAL WEATHER SERVICE IN GREAT FALLS HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  CENTRAL FERGUS COUNTY IN CENTRAL MONTANA
  THIS INCLUDES THE CITY OF LEWISTOWN

* UNTIL 500 PM MDT

* AT 349 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
  A LINE OF SEVERE THUNDERSTORMS...FROM 9 MILES NORTHWEST OF
  WINIFRED TO LEWISTOWN...MOVING EAST AT 20 MPH.

* SEVERE THUNDERSTORMS WILL BE...
  OVER ROY AT 445 PM MDT
  OVER GRASS RANGE AT 455 PM MDT

HAIL...INTENSE RAIN AND STRONG DAMAGING WINDS ARE LIKELY WITH THESE
STORMS. TAKE COVER IN A SUBSTANTIAL SHELTER UNTIL THE STORM PASSES.

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 800 PM MDT FRIDAY
EVENING FOR CENTRAL MONTANA.

LAT...LON 4780 10896 4761 10869 4681 10865 4680 10935
          4679 10943 4683 10945 4774 10955 4772 10942
          4779 10927

$$

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 Jun 20, 2:45 PM MDT, 1 hour 15 minutes earlier.

Area forecast discussion, Jun 20, 2:45 PM MDT, 1 hour 15 minutes before

SOUTHWEST AND NORTH CENTRAL MONTANA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
245 PM MDT FRI JUN 20 2003

.DISCUSSION...

.TONIGHT THROUGH SUNDAY...CYCLONIC SW FLOW ALOFT WILL BE OVER THE
FORECAST AREA THROUGH LATE SATURDAY THEN TURN MORE WLY ON SUN. FLOW
IS ASSOCIATED WITH AN UPPER LOW OVER B.C. WHICH WINDS ITS WAY SLOWLY
E AND INTO WRN SASK BY LATE SUNDAY. A FEW SHORTWAVES WILL ROTATE
THROUGH THE FLOW DURING THE PERIOD. AT THE SURFACE PRETTY STRONG
DOWNSLOPE WILL BE OVER THE NRN ZONES WHILE LIGHTER DOWNSLOPE OR WEAK
UPSLOPE WILL BE OVER THE SRN ZONES. THIS PATTERN WILL CONTINUE
THROUGH THE PERIOD. MAIN BAND OF STRONGER TSTMS WILL BE NR OR E OF
FORECAST AREA BY 00Z SAT SO WILL DROP MENTION OF STRONGER STORMS
AFTER 6PM THIS EVE. WITH FAIRLY STRONG DOWNSLOPE OVER THE NRN ZONES
PRECIPITATION CHANCES WILL BE LOW LATE TONIGHT THROUGH SUN.
TIME/HEIGHT CROSS SECTIONS SHOW SINKING MOTION BUT THERE WILL BE
SOME WEAK INSTABILITY. WAS GOING TO GO DRY OVER THE PLAINS SAT THRU
SUN BUT WILL BEEF UP POPS FOR THE NRN ZONES FOR SUN TO LINE UP
BETTER WITH GGW. OVER THE SRN ZONES LOW LEVEL CONVERGENCE ALONG WITH
INSTABILITY COULD LEAD TO ISOLATED TSTMS SAT INTO SAT EVENING. OVER
THE ROCKY MOUNTAIN FRONT WINDS SHOULD STAY BELOW HIGH WIND CRITERIA
BUT THEY MAY GET CLOSE AT TIMES. THREAT LOOKS TINY ENOUGH NOT TO
ISSUE A WATCH. ALSO SNOW LEVELS MAY LOWER ENOUGH OVER THE ROCKY
MOUNTAIN FRONT FOR A LITTLE LIGHT SNOWFALL ABOVE 6500 FEET AT NIGHT.

MONDAY AND TUESDAY...UNSETTLED WEATHER TO CONTINUE THROUGH THE EARLY
PART OF NEXT WEEK. UPPER LEVEL LOW PRESSURE TO CROSS MONTANA LATE
MONDAY AND TUESDAY. AN AREA OF SURFACE LOW PRESSURE DEVELOPS IN
SOUTHWEST MONTANA ON MONDAY, AND WITH UPSLOPE CONDITIONS ACROSS THE
AREA, EXPECT THE BEST CHANCE FOR SHOWERS AND ISOLATED THUNDERSTORMS.
TEMPERATURES WILL REMAIN BELOW SEASONAL NORMS DURING THIS TIME. JCA

WEDNESDAY THROUGH FRIDAY...THE AIRMASS THEN CONTINUES TO DRY
WEDNESDAY THROUGH FRIDAY. TEMPS REMAIN BELOW NORMALS MONDAY THROUGH
WEDNESDAY...MOVING BACK NEAR NORMAL THURSDAY AND FRIDAY. ZELZER

.CCF NUMBERS
GTF BB 046/066 044/064 040 044-1
    EEBBB 066/042 065/044 070/046 071/049 076 12344333333
CTB NE 044/060 041/059 040 041-1
    EEBBB 062/042 064/042 069/045 069/047 071 22333332233
HLN BB 047/066 045/065 042 04311
    EEBBB 067/045 067/047 071/049 073/050 079 12344333322
BZN BB 044/065 039/064 039 04522
    EEBBB 064/042 067/043 071/045 070/046 077 -2444334422
WEY BB 038/058 031/058 035 04622
    BEBBB 060/038 059/036 060/037 063/040 065 12444333111
DLN BB 043/064 039/064 039 04322
    EWBBB 064/042 067/044 069/042 072/045 076 -2455333111
HVR BE 049/070 045/067 044 046-1
    BEBBB 067/046 069/047 076/049 075/051 080 22344333322
LWT BB 046/065 042/061 039 046--
    BEBBB 067/043 065/044 066/045 069/047 073 -2344334422

.TFX...SEVERE THUNDERSTORM WATCH CENTRAL AND NORTH CENTRAL THROUGH 8
       PM THIS FRI EVENING (ZONES 11/47/13/50/51
       HILL/BLAINE/CHOUTEAU/FERGUS/JUDITH BASIN)

Hazardous weather outlook, Jun 20, 4:00 PM MDT, 0 minutes before

MTZ008>015-044>055-210010-
HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE GREAT FALLS MT
400 PM MDT FRI JUN 20 2003

THIS HAZARDOUS WEATHER OUTLOOK IS FOR NORTH CENTRAL AND SOUTHWEST
MONTANA

.DAY ONE...TODAY

A SEVERE THUNDERSTORM WATCH IS IN EFFECT FOR
HILL...BLAINE...CHOUTEAU...FERGUS...JUDITH BASIN COUNTIES TIL 8 PM
THIS EVENING.

NO WATCHES, WARNINGS, OR ADVISORIES CURRENTLY IN EFFECT

.DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY

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.

In the hours before

Local storm report, Jun 20, 3:32 PM MDT, 28 minutes before

LOCAL STORM REPORT...CORRECTED
NATIONAL WEATHER SERVICE GREAT FALLS MT
332 PM MDT FRI JUN 20 2003

TIME(MDT)  .....EVENT  LOCATION..... ST   ...EVENT/REMARKS...........
           .....COUNTY LOCATION.....

1145 AM    WOLF CREEK                MT   70 MPH TSTM GUST
06/20/03   LEWIS  AND  CLARK              GAS STN SIGN BLOWN DOWN

1245 PM    SUN RIVER                 MT   0.50 INCH HAIL
06/20/03   CASCADE

1245 PM    SUN RIVER                 MT   45 MPH TSTM GUST
06/20/03   CASCADE

1254 PM    1 N VAUGHN                MT   0.75 INCH HAIL
06/20/03   CASCADE

1254 PM    1 N VAUGHN                MT   45 MPH TSTM GUST
06/20/03   CASCADE

1255 PM    POWER                     MT   0.50 INCH HAIL
06/20/03   TETON                          HEAVY RAIN 0.61 OF AN INCH
                                          IN 20 MIN

1255 PM    POWER                     MT   55 MPH TSTM GUST
06/20/03   TETON

1258 PM    12 SE CONRAD              MT   0.75 INCH HAIL
06/20/03   PONDERA

0115 PM    25 NW FT BENTON           MT   0.75 INCH HAIL
06/20/03   CHOUTEAU

0125 PM    1 N CONRAD                MT   0.25 INCH HAIL
06/20/03   PONDERA

0125 PM    1 N CONRAD                MT   55 MPH TSTM GUST
06/20/03   PONDERA

0225 PM    12 S CHESTER              MT   0.75 INCH HAIL
06/20/03   LIBERTY                        WINDOWS BROKEN

0226 PM    1 S GEYSER                MT   0.75 INCH HAIL
06/20/03   JUDITH  BASIN

0245 PM    9 S GILDFORD              MT   60 MPH TSTM GUST
06/20/03   HILL

0245 PM    11 S HAVRE                MT   60 MPH TSTM GUST
06/20/03   HILL                           SEMI-TRUCK TURNED OVER

0250 PM    12 N HINGHAM              MT   60 MPH TSTM GUST
06/20/03   HILL

0330 PM    HAVRE                     MT   1 INCH HAIL
06/20/03   HILL

0335 PM    HAVRE                     MT   1.50 INCH HAIL
06/20/03   HILL                           56 MPH WIND GUST AT HAVRE
                                          AIRPORT

0335 PM    HAVRE                     MT   56 MPH TSTM GUST
06/20/03   HILL

0335 PM    HOBSON                    MT   0.50 INCH HAIL
06/20/03   JUDITH  BASIN

NNNN

Special weather statement, Jun 20, 3:33 PM MDT, 27 minutes before

MTZ009-011>015-028-034-039>042-044>056-210200-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE GREAT FALLS MT
333 PM MDT FRI JUN 20 2003

SEVERE THUNDERSTORM WATCH 548 HAS BEEN REMOVED FROM THE FOLLOWING
AREAS...LIBERTY...TOOLE...PONDERA...TETON...CASCADE...LEWIS AND
CLARK...MEAGHER...BROADWATER...JEFFERSON...GALLATIN...MADISON.

SEVERE THUNDERSTORM WATCH 548 REMAINS IN EFFECT FOR...HILL...
BLAINE...CHOUTEAU...FERGUS AND JUDITH BASIN COUNTIES...

The office that day

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

Issued	Product	Office	Counties	Lasted
Jun 19, 7:24 PM MDT	Severe Thunderstorm Warning	TFX	Blaine	51 min
Jun 20, 11:25 AM MDT	Severe Thunderstorm Warning	TFX	Lewis and Clark	50 min
Jun 20, 12:13 PM MDT	Severe Thunderstorm Warning	TFX	Cascade	47 min
Jun 20, 12:36 PM MDT	Severe Thunderstorm Warning	TFX	Pondera, Teton	24 min
Jun 20, 12:55 PM MDT	Severe Thunderstorm Warning	TFX	Cascade, Chouteau, Teton	35 min
Jun 20, 1:00 PM MDT	Severe Thunderstorm Warning	TFX	Pondera, Teton	30 min
Jun 20, 1:30 PM MDT	Severe Thunderstorm Warning	TFX	Cascade, Chouteau, Liberty, Pondera, Toole	45 min
Jun 20, 2:14 PM MDT	Severe Thunderstorm Warning	TFX	Hill, Liberty	46 min
Jun 20, 2:25 PM MDT	Severe Thunderstorm Warning	TFX	Fergus, Judith Basin	35 min
Jun 20, 2:47 PM MDT	Severe Thunderstorm Warning	TFX	Chouteau, Hill	43 min
Jun 20, 3:26 PM MDT	Severe Thunderstorm Warning	TFX	Blaine, Hill	64 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.