Damaging Wind in Montana, June 20, 2003

Name: Damaging Wind in Montana, June 20, 2003
Start: 2003-06-20T14:55
End: 2003-06-20T14:55
Location: Montana

June 20, 2003 · NWS TFX · 1 event in 1 county or zone

A severe thunderstorm produced a 60 mph wind gust at Chinook 15N. 2 Power poles were knocked down.

Where it happened

Every event with a place to put it. Tap one for its entry below.

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Wind
Hail
Winter weather
Heat and drought
Cold
Fire, smoke and dust
Marine and coastal
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Open the live radar over this ground

The toll

Deaths: 0
Injuries: 0
Property damage: None recorded
Crop damage: None recorded
Events: 1

Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.

What happened

The episode as NWS TFX wrote it up.

A severe thunderstorm produced a 60 mph wind gust at Chinook 15N. 2 Power poles were knocked down.

What forecasters said that day

The local office's own words before the first event, 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 the first event at Jun 20, 1:45 PM MST, 1 hour 10 minutes earlier.

Area forecast discussion, Jun 20, 1:45 PM MST, 1 hour 10 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, 11:00 AM MST, 3 hours 55 minutes before

MTZ008>015-044>055-210010-
HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE GREAT FALLS MT
1200 PM MDT FRI JUN 20 2003

THIS HAZARDOUS WEATHER OUTLOOK IS FOR NORTH CENTRAL AND SOUTHWEST MONTANA

.DAY ONE...TODAY

NO WATCHES, WARNINGS, OR ADVISORIES CURRENTLY IN EFFECT

A SEVERE THUNDERSTORM WATCH IS IN EFFECT UNTIL 8 PM MDT FOR MUCH OF
THE AREA. THUNDERSTORMS WILL BE CAPABLE OF PRODUCING WINDS TO 70 MPH
AND HAIL UP TO ONE INCH IN DIAMETER.

.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, 2:32 PM MST, 23 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, 2:33 PM MST, 22 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 radar

The Glasgow radar (KGGW), 203 km away, was scanning. The volume nearest the first event began at 21:52 UTC.

Open the radar archive at this moment

Event by event

1 thunderstorm wind. Local standard time, as filed.

Thunderstorm Wind, Blaine

When: June 20, 2:55 PM MST
Where: Blaine County, 15 mi N of Chinook
Measured: 52 kt (60 mph) estimated gust
Reported by: TRAINED SPOTTER
Coordinates: 48.800, -109.233

What these are

Thunderstorm Wind: Winds from a thunderstorm of 50 knots (58 mph) or more, or lower winds that caused damage or casualties. Measured gusts are marked MG, estimated EG.

After NWS Directive 10-1605, the rules offices file Storm Data by.

The same day elsewhere

Every storm in Montana in 2003 Every state in 2003 This day in weather history Warnings in Montana, June 2003

Sources

NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24. Each event’s entry at NCEI: 5364304.