Alert archive / Montana / Flash Flood Warnings in 2001

Flash Flood Warning 21, NWS Billings, MT

July 21, 2001Yellowstone County, Montana

NWS Billings, MT issued this flash flood warning at Jul 21, 2001, 11:25 PM MDT for Yellowstone County, Montana. It was in force for 2 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
Jul 21, 2001, 11:25 PM MDT (05:25 UTC)
Expired
Jul 22, 2001, 1:30 AM MDT
In force
2 hr
Issued by
NWS Billings, MT
Area
Whole counties

County Yellowstone County, MT

The nearest sounding before it

Great_falls, MT (KTFX), launched 00:00Z, 5.4 hours before the alert went out and 245 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-pSkew-T log-p diagram, Great_falls, MT at 00:00Z on 2001-07-22Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 33 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Great_falls, MT at 00:00Z on 2001-07-22The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -59 square meters per square second.19395878Sfc1 km3 km6 km9 kmRMLM
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
33 J/kg
Mixed-layer CIN
-187 J/kg
Mixed-layer LCL
2161 m above ground
0-6 km bulk shear
44 kt
0-1 km storm-relative helicity
-59 m²/s²
0-3 km storm-relative helicity
-126 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 220528
FFWBIL
MTC111-220730-

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE BILLINGS MT
1125 PM MDT SAT JUL 21 2001

THE NATIONAL WEATHER SERVICE IN BILLINGS HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  SOUTH CENTRAL YELLOWSTONE COUNTY IN SOUTH CENTRAL MONTANA

* UNTIL 130 AM MDT

* AT 1125 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
  THUNDERSTORMS WITH VERY HEAVY RAIN OVER THE WARNED AREA.

* SLOW MOVING THUNDERSTORMS ARE PRODUCING TORRENTIAL RAINFALL IN     
  THE WARNED AREA...ESPECIALLY IN THE EMERALD HILLS AREA SOUTHEAST   
  OF BILLINGS.

BE ESPECIALLY CAUTIOUS AT NIGHT WHEN IT IS HARDER TO RECOGNIZE THE
DANGERS OF FLOODS AND FLASH FLOODS.

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.

A FLASH FLOOD WARNING MEANS THAT FLOODING IS OCCURRING OR IS
IMMINENT. NEVER ATTEMPT TO CROSS HIGH WATER IN A VEHICLE OR ON FOOT.

$$
&
STROBIN

LAT...LON 4584 10809 4558 10811 4557 10838 4578 10836

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 21, 6:31 PM MDTSevere Thunderstorm WarningBYZWheatland59 min
Jul 21, 6:48 PM MDTSevere Thunderstorm WarningBYZPowder River57 min
Jul 21, 7:31 PM MDTSevere Thunderstorm WarningBYZWheatland59 min
Jul 21, 7:50 PM MDTSevere Thunderstorm WarningBYZGolden Valley25 min
Jul 21, 7:56 PM MDTSevere Thunderstorm WarningBYZCarter64 min
Jul 21, 8:18 PM MDTSevere Thunderstorm WarningBYZMusselshell57 min
Jul 21, 9:17 PM MDTSevere Thunderstorm WarningBYZRosebud58 min
Jul 21, 10:14 PM MDTSevere Thunderstorm WarningBYZRosebud61 min
Jul 21, 10:32 PM MDTSevere Thunderstorm WarningBYZYellowstone58 min
Jul 21, 11:06 PM MDTSevere Thunderstorm WarningBYZCuster, Rosebud54 min
Jul 21, 11:32 PM MDTSevere Thunderstorm WarningBYZYellowstone58 min
Jul 22, 12:07 AM MDTSevere Thunderstorm WarningBYZYellowstone53 min
Jul 22, 12:26 AM MDTSevere Thunderstorm WarningBYZCuster59 min
Jul 22, 1:20 AM MDTSevere Thunderstorm WarningBYZFallon55 min
Jul 22, 2:03 AM MDTSevere Thunderstorm WarningBYZCuster57 min
Jul 22, 2:56 AM MDTSevere Thunderstorm WarningBYZCuster64 min
Jul 22, 2:30 PM MDTSevere Thunderstorm WarningBYZBig Horn60 min
Jul 22, 3:20 PM MDTSevere Thunderstorm WarningBYZRosebud55 min
Jul 22, 3:22 PM MDTSevere Thunderstorm WarningBYZBig Horn, Treasure53 min
Jul 22, 4:04 PM MDTSevere Thunderstorm WarningBYZPowder River86 min
Jul 22, 4:11 PM MDTSevere Thunderstorm WarningBYZRosebud64 min
Jul 22, 4:31 PM MDTSevere Thunderstorm WarningBYZCuster89 min
Jul 22, 5:29 PM MDTSevere Thunderstorm WarningBYZCarter91 min
Jul 22, 5:56 PM MDTSevere Thunderstorm WarningBYZFallon64 min

Nearby

Flash Flood Warnings in Montana, 2001Every 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.