Alert archive / Montana / Severe Thunderstorm Warnings in 2001

Severe Thunderstorm Warning 59, NWS Glasgow, MT

July 12, 2001Garfield County, Montana

NWS Glasgow, MT issued this severe thunderstorm warning at Jul 12, 2001, 7:04 PM MDT for Garfield County, Montana. It was in force for 41 min. 1 report came from inside the area while it was in force.

The area

The counties it named, with what was reported inside it.

The facts

Issued: Jul 12, 2001, 7:04 PM MDT (01:04 UTC)
Expired: Jul 12, 2001, 7:45 PM MDT
In force: 41 min
Issued by: NWS Glasgow, MT
Area: Whole counties; the outline is the Mesonet’s reconstruction

County Garfield County, MT

What was reported inside it

Time	Report	Where	Remark
Jul 12, 7:36 PM MDT	Hail 1	Cohagen, MT

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.

The watch it was issued in

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

Issued	Product	Office	Lasted
Jul 12, 6:15 PM MDT	Severe Thunderstorm Watch	SPC	6 hr

The nearest sounding before it

Glasgow Intl Airport, MT (KGGW), launched 00:00Z, 1.1 hours before the alert went out and 109 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: 2495 J/kg
Mixed-layer CIN: -17 J/kg
Mixed-layer LCL: 1031 m above ground
0-6 km bulk shear: 30 kt
0-1 km storm-relative helicity: 34 m²/s²
0-3 km storm-relative helicity: 22 m²/s²
Significant tornado parameter: 0.6
Supercell composite: 3.2

Open this sounding in Storm Lab

The text

The text of this product is not in the archive. The NWS text archive before 2002 is incomplete.

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 Glasgow, MT wrote its last area forecast discussion before this severe thunderstorm warning went out at Jul 12, 2:29 PM MDT, 4 hours 35 minutes earlier.

Area forecast discussion, Jul 12, 2:29 PM MDT, 4 hours 35 minutes before

NORTHEAST MONTANA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GLASGOW MT
229 PM MDT THU JUL 12 2001

THIS AFTERNOON A DEW POINT FRONT ACROSS CENTRAL MONTANA. DEW POINTS
ACROSS THE CWFA IN THE MID TO UPPER 60S. CONVECTION FIRING OVER
WESTERN MONTANA WITH A SHORTWAVE MOVING THROUGH THE WESTERN PART OF
THE STATE THIS AFTERNOON. THIS WAVE CONTINUES TO NNE A PIECE OF THIS
WAVE WILL MOVE ACROSS THE WESTERN AREAS THIS EVENING AND TONIGHT.

THIS EVENING...SHRA/TSRA SHOULD MOVING INTO THE REGION MAINLY OVER
THE WESTERN CWFA...ALREADY HAVING AFTERNOON POPCORN CONVECTION OVER
THE SOUTHERN CWFA WITH DAYTIME HEATING. SPC SWODY1 UPDATE PUTS THE
WESTERN ZONES IN A SLGT RISK FOR SVR. TIME HEIGHT SOUNDINGS SHOW A
BETTER SHEAR ENVIRONMENT FOR THIS EVENING ACROSS THE WEST...WET BULB
ZEROS ARE PRETTY HIGH FOR A SIGNIFICANT THREAT OF LARGE
HAIL...HOWEVER STRONG GUSTS CAN BE EXPECTED WITH LARGER STORMS...AND
MOST OF ALL VERY HEAVY RAINFALL. WILL HOLD UP ON A FLASH FLOOD WATCH
FOR THE EASTERN ZONES SINCE THE BEST CHANCE FOR TSRA REMAINS WEST
AND SOUTH.

AFTER THE CONVECTION MOVES OUT LATE THIS EVENING...DO EXPECT ANOTHER
ROUND OF LOWS ST/FG FOR THE EARLY MORNING HOURS FOR THE MISSOURI AND
MILK RIVER VALLEYS. WILL ADD AM FG TO THE ZONES. ETA TRIES TO KEEP
LOW CLOUDS IN ALL DAY ON FRIDAY...HOWEVER DO EXPECT WITH THIS TIME
OF YEAR THE CLOUDS WILL LIFT OUT WITH THE HEATING OF THE DAY.
LOOKING FOR MORE OF THE SAME WITH PM TSRA AGAIN.  SAME PATTERN FOR
SATURDAY CONTINUES.

FOR TEMPS...GOING TO STAY WITH THE STATUS QUO...MODELS ARE TRYING TO
COOL DOWN THE TEMPS SOME ON SATURDAY...HOWEVER NOT BUYING INTO THAT
YET...WILL KEEP THEM UP.                    PROTON

EXTENDED...MODELS SUGGEST AN OMEGA BLOCK DEVELOPING OVER NORTH
AMERICA DURING THE EXTENDED PERIOD. THE UPPER LEVEL RIDGE IS
FORECAST TO REMAIN EAST OF MONTANA WITH A DEEP TROUGH ALONG THE WEST
COAST AND AN UPPER LOW OVER SOUTHWEST CANADA. THIS PATTERN KEEPS
NORTHEAST MONTANA IN SOUTHWEST FLOW ALOFT FOR THE ENTIRE PERIOD.
WILL CONTINUE WITH CHANCE POPS EACH DAY WITH TEMPERATURES REMAINING
NEAR NORMAL.  WATERHOUSE

KGGW 064/088 062/088 062/088 061/087 060/086 060/086 059/085
     TTTTTTT  943232/9933333
KGDV 064/090 064/092 063/090 062/089 061/088 060/087 059/086
     TTTTTTT  943232/9933333

.GGW...NONE.

In the hours before

Local storm report, Jul 12, 6:15 PM MDT, 49 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GLASGOW MT
615 PM MDT THU JUL 12 2001

TIME(MDT)  .....CITY LOCATION.....STATE   ...EVENT/REMARKS...
           ....COUNTY LOCATION....

0432 PM    10 N EDWARDS              MT   60 MPH TSTM WIND GUST
07/12/01   GARFIELD                       LIFTING SHINGLES OFF ROOF

0445 PM    BRUSSETT                  MT   FLASH FLOODS
07/12/01   GARFIELD                       1 INCH OF RAIN IN LESS
                                          THAN AN HOUR. EXTENSIVE
                                          RUNNING WATER

0445 PM    10 N EDWARDS              MT   1.00 INCH HAIL
07/12/01   GARFIELD                       HAIL COVERING THE GROUND.
                                          VERY HEAVY RAIN.

0505 PM    5 W BRUSSETT              MT   FLASH FLOODS
07/12/01   GARFIELD                       3 INCHES OF RAIN IN LESS
                                          THAN 1 HOUR. 3 FEET OF
                                          WATER IN CULVERTS.

0400 PM    10 NE SAND SPRINGS        MT   1.00 INCH HAIL
07/12/01   GARFIELD                       QUARTER SIZE HAIL FOR 1/2
                                          HOUR. STANDING WATER.

0505 PM    5 W BRUSSETT              MT   1.00 INCH HAIL
07/12/01   GARFIELD

0510 PM    12 W JORDAN               MT   TORNADO
07/12/01   GARFIELD                       ROTATING FUNNEL CLOUD
                                          REPORTED BY SHERIFF

0500 PM    20 W JORDAN               MT   1.75 INCH HAIL
07/12/01   GARFIELD                       HAIL BROKE OUT WINDOWS IN
                                          HOME AND VEHICLES

0500 PM    20 W JORDAN               MT   FLASH FLOODS
07/12/01   GARFIELD                       DEEP WATER RUNNING IN
                                          COULEES

0525 PM    10 N EDWARDS              MT   2.00 INCH HAIL
07/12/01   GARFIELD                       HAIL 4 FEET DEEP IN SOME
                                          SPOTS

WRIGHT

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 12, 7:12 PM MDT	Severe Thunderstorm Warning	GGW	Phillips	63 min
Jul 12, 7:48 PM MDT	Severe Thunderstorm Warning	GGW	Valley	57 min
Jul 12, 8:13 PM MDT	Severe Thunderstorm Warning	GGW	Phillips	62 min
Jul 12, 8:46 PM MDT	Severe Thunderstorm Warning	GGW	Valley	59 min
Jul 12, 8:51 PM MDT	Severe Thunderstorm Warning	GGW	Phillips	54 min
Jul 12, 9:23 PM MDT	Flash Flood Warning	GGW	Valley	4 hr
Jul 12, 9:36 PM MDT	Severe Thunderstorm Warning	GGW	Phillips	54 min
Jul 12, 9:45 PM MDT	Severe Thunderstorm Warning	GGW	Valley	75 min
Jul 12, 10:03 PM MDT	Flash Flood Warning	GGW	Phillips	3 hr
Jul 12, 10:47 PM MDT	Severe Thunderstorm Warning	GGW	Valley	58 min
Jul 12, 11:07 PM MDT	Flash Flood Warning	GGW	Garfield	4 hr

Nearby

Severe Thunderstorm Warnings in Montana, 2001 Every severe thunderstorm warning in 2001

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.