Alert archive / Montana / Flash Flood Warnings in 2002

Flash Flood Warning 3, NWS Billings, MT

August 21, 2002Musselshell County, Montana

NWS Billings, MT issued this flash flood warning at Aug 21, 2002, 5:24 PM MDT for Musselshell County, Montana. It was in force for 3 hr. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued: Aug 21, 2002, 5:24 PM MDT (23:24 UTC)
Expired: Aug 21, 2002, 8:15 PM MDT
In force: 3 hr
Issued by: NWS Billings, MT
Area: Whole counties

County Musselshell County, MT

The radar

The Billings radar (KBLX), 73 km from the middle of the area, began a volume at 23:26 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.

The nearest sounding before it

Great_falls, MT (KTFX), launched 12:00Z, 11.4 hours before the alert went out and 198 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 850 m above ground
0-6 km bulk shear: 31 kt
0-1 km storm-relative helicity: 66 m²/s²
0-3 km storm-relative helicity: 83 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.

000 
WGUS55 KBYZ 212324
FFWBYZ
MTC065-220215-

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE BILLINGS MT
522 PM MDT WED AUG 21 2002

THE NATIONAL WEATHER SERVICE IN BILLINGS HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  SOUTHERN MUSSELSHELL COUNTY IN CENTRAL MONTANA

* UNTIL 815 PM MDT

* AT 522 PM MDT...THE PUBLIC REPORTED WATER FLOWING OVER US 87 AT    
  MILE MARKER 30.

* SLOW MOVING THUNDERSTORMS ARE PRODUCING TORRENTIAL RAINFALL IN     
  THE WARNED AREA. DOPPLER RADAR ESTIMATES OF 3 TO 4 INCHES OF RAIN  
  HAS FALLEN OVER SOUTHERN MUSSELSHELL COUNTY OVER THE LAST 2 HOURS. 

SMALL CREEKS AND STREAMS WILL RAPIDLY FLOOD IN THE WARNED AREA...
POSSIBLY WASHING OUT ROADS AND FLOODING NEARBLY LOW AREAS.

ABSOLUTELY DO NOT DRIVE YOUR VEHICLE INTO AREAS WHERE THE WATER
COVERS THE ROADWAY. VEHICLES CAUGHT IN RISING WATER SHOULD BE
ABANDONED QUICKLY. MOVE TO HIGHER GROUND.

$$

LAT...LON 4644 10817 4628 10812 4626 10839 4615 10843
          4613 10875 4642 10873

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 Billings, MT wrote its last area forecast discussion before this flash flood warning went out at Aug 21, 2:33 PM MDT, 2 hours 51 minutes earlier.

Area forecast discussion, Aug 21, 2:33 PM MDT, 2 hours 51 minutes before

SOUTH CENTRAL AND SOUTHEAST MONTANA FORECAST DISCUSSION...CORRECTED
NATIONAL WEATHER SERVICE BILLINGS MT
ISSUED BY GLASGOW MT NWS
156 PM MDT WED AUG 21 2002

.SHORT TERM...VALID FOR THU AND FRI..

SEVERE WEATHER THREAT WILL CONTINUE TO BE THE PRIMARY FOCUS OF THE SHORT
TERM. UPPER LEVEL LOW POSITIONED ALONG THE OREGON/IDAHO BORDER WILL
CONTINUE TO EJECT SHORT WAVES ACROSS THE CWA OVER THE NEXT 48 HOURS.
THE FIRST OF THESE WAVES IS PRODUCING THUNDERSTORMS OVER NORTHWEST
WYOMING. STRONG UPPER LEVEL DIVERGENCE ACROSS THE REGION WILL AID IN
STRONG THUNDERSTORM DEVELOPMENT. WHILE STRONGEST CAPE CONTINUES TO
BE FORECASTED ACROSS THE EASTERN HALF OF THE CWA...THE BEST DYNAMICS
SHOULD BE OVER THE SOUTH CENTRAL AND SOUTHWESTERN PORTIONS OF CWA.
UPPER LEVEL LOW REMAINS PARKED IN PLACE ON THURSDAY AND BEGINS TO
RETROGRADE A BIT ON THURSDAY NIGHT. MESO-ETA PRODUCING WIDESPREAD
QPF THROUGH THE PERIOD. SOUTHWEST FLOW REMAINS IN PLACE ACROSS THE
CWA INTO THE WEEKEND WITH WEAK WAVES BEING EJECTED FROM PACIFIC
NORTHWEST LOW. WILL CONTINUE SCATTERED POPS ACROSS THE REGION
TONIGHT. WITH BEST CHANCE OF DEVELOPMENT OVER THE WESTERN HALF OF
CWA...WILL DROP POPS OVER THE EAST A NOTCH. CURRENTLY FORECASTED
TEMPERATURES LINE UP WELL WITH MOS GUIDANCE AND SEE NO REASON TO
MAKE DRASTIC CHANGES.

.LONG TERM...VALID FOR SAT...SUN...MON...TUE...WED...

UNSETTLED PATTERN WILL REMAIN IN PLACE FOR A LARGE PORTION OF THE
EXTENDED PERIOD. MRF CONTINUES TO KEEP AN ELONGATED TROUGH ACROSS
THE REGION WHILE THE ECMWF IS A BIT MORE PROGRESSIVE. WILL CONTINUE
CURRENT TREND TOWARD THE END OF THE PERIOD WITH TEMPERATURES
REMAINING NEAR NORMAL.   POHL

    THU     FRI     SAT     SUN     MON     TUE     WED
-------------------------------------------------------
BIL 056/085 054/084 052/086 054/086 053/083 051/082 050/083
    43/T    33/T    33/T    33/T    30/E    00/B    00/B
LVM 051/081 050/082 048/083 048/084 047/081 045/080 045/081
    43/T    33/T    33/T    33/T    30/E    00/B    00/B
HDN 055/087 052/087 050/088 052/088 050/085 048/084 047/084
    43/T    33/T    33/T    33/T    30/E    00/B    00/B
MLS 058/086 056/085 055/087 057/087 056/083 054/082 053/083
    32/T    33/T    33/T    33/T    30/E    00/B    00/B
4BQ 056/085 055/084 054/086 056/086 055/082 053/081 053/081
    32/T    33/T    33/T    33/T    30/E    00/B    00/B
BHK 055/083 053/083 052/084 053/084 053/080 051/079 050/079
    32/T    33/T    33/T    33/T    30/E    00/B    00/B
SHR 053/084 051/084 051/085 050/084 049/080 047/079 046/079
    43/T    33/T    33/T    33/T    30/E    00/B    00/B

.BYZ...
MT...NONE.
WY...NONE.

In the hours before

Local storm report, Aug 21, 1:15 PM MDT, 4 hours 9 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE BILLINGS, MT
115 PM MDT WED AUG 21 2002

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

1005 AM    3 N MILES CITY            MT   .75 INCH HAIL
08/21/02   CUSTER

JZ

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 21, 9:37 AM MDT	Severe Thunderstorm Warning	BYZ	Custer	53 min
Aug 21, 4:41 PM MDT	Severe Thunderstorm Warning	BYZ	Musselshell	64 min

Nearby

Flash Flood Warnings in Montana, 2002 Every flash flood warning in 2002

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.