Alert archive / Montana / Flash Flood Warnings in 2001

Flash Flood Warning 2, NWS Glasgow, MT

July 12, 2001Valley County, Montana

NWS Glasgow, MT issued this flash flood warning at Jul 12, 2001, 9:23 PM MDT for Valley County, Montana. It was in force for 4 hr. No storm report in the archive falls inside the area while it was in force.

The area

The outline the Iowa Environmental Mesonet reconstructed for it; the warning itself named whole counties.

The facts

Issued: Jul 12, 2001, 9:23 PM MDT (03:23 UTC)
Expired: Jul 13, 2001, 1:30 AM MDT
In force: 4 hr
Issued by: NWS Glasgow, MT
Area: Whole counties; the outline is the Mesonet’s reconstruction

County Valley County, MT

The nearest sounding before it

Glasgow Intl Airport, MT (KGGW), launched 00:00Z, 3.4 hours before the alert went out and 38 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

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

000 
WGUS55 KGGW 130327 CCA
FFWGGW
MTC105-130730-

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING...CORRECTED SPEED OF STORM SYSTEM
NATIONAL WEATHER SERVICE GLASGOW MT
923 PM MDT THU JUL 12 2001

THE NATIONAL WEATHER SERVICE IN GLASGOW HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  VALLEY COUNTY IN NORTHEAST MONTANA

* UNTIL 130 AM MDT

* AT 910 PM MDT...WEATHER SERVICE DOPPLER RADAR INDICATED
  THUNDERSTORMS WITH VERY HEAVY RAINFALL 4 MILES NORTH OF VANDALIA...
  OR ABOUT 19 MILES NORTHWEST OF GLASGOW...MOVING SOUTHEAST AT 10
  MPH.

* SLOW MOVING THUNDERSTORMS ARE PRODUCING TORRENTIAL RAINFALL IN THE
  WARNED AREA. RUNOFF FROM THIS EXCESSIVE RAINFALL WILL CAUSE FLASH
  FLOODING TO OCCUR. SOME LOCATIONS THAT WILL EXPERIENCE FLASH
  FLOODING INCLUDE...RURAL CENTRAL VALLEY COUNTY

EXCESSIVE RUNOFF FROM THIS STORM WILL CAUSE FLASH FLOODING OF SMALL 
CREEKS AND STREAMS...COUNTRY ROADS...NORMALLY DRY WASHES AND 
COULEES...AS WELL AS FARMLAND ALONG THE BANKS OF CREEKS AND STREAMS.

DO NOT DRIVE YOUR VEHICLE INTO AREAS WHERE THE WATER COVERS THE
ROADWAY. THE WATER DEPTH MAY BE TOO GREAT TO ALLOW YOUR CAR TO CROSS
SAFELY. VEHICLES CAUGHT IN RISING WATER SHOULD BE ABANDONED QUICKLY.
MOVE TO HIGHER GROUND.

LAT...LON 4879 10697 4844 10732 4797 10702 4849 10626

.END
91

What forecasters said that day

The local office's own words before this flash flood 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 flash flood warning went out at Jul 12, 8:45 PM MDT, 38 minutes earlier.

Area forecast discussion, Jul 12, 8:45 PM MDT, 38 minutes before

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

...SEVERE THUNDERSTORM WATCH UNTIL MIDNIGHT FOR ALL CWA EXCEPT
EXTREME NORTHEASTERN COUNTIES...
...UPDATED TO BETTER DEFINE SEVERE WEATHER THREAT...

SEVERE THUNDERSTORMS FORMING MAINLY ALONG A MOIST AXIS STRETCHING
N-S THROUGH OUR WRN COUNTIES THEN EAST ACROSS CENTRAL MT. HAVE HAD
NUMEROUS REPORTS OF HAIL UP TO GOLFBALL SIZE...FLASH FLOODING...HAIL
PILING UP TO DEPTHS OF 4 FEET...FUNNEL CLOUDS...THE WORKS. WORST
SEEMS TO BE YET TO COME. SQUALL LINE(S) NOW APPROACHING WRN ZONES AS
UPR DYNAMICS MOVE INTO CWA. THE FAR NERN ZONES WILL PROBABLY BE
SPARED FROM THE SEVERE WX AS THERE IS COOLER AIR IN PLACE THERE AND
MAIN DYNAMICS WILL WEAKEN AND DIVE SE AS IT MOVES THROUGH ERN
MONTANA. ZONES BROAD-BRUSHED AND HAVE SITUATION COVERED. WILL BE
UPDATING ZONES WHEN THERE IS ANY CHANGE IN WATCH STATUS.   WRIGHT

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

In the hours before

Local storm report, Jul 12, 6:15 PM MDT, 3 hours 8 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, 7:04 PM MDT	Severe Thunderstorm Warning	GGW	Garfield	41 min
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, 9:36 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

Flash Flood Warnings in Montana, 2001 Every flash flood 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; the sounding from the Mesonet's radiosonde archive.