Alert archive / Montana / Flash Flood Warnings in 2001

Flash Flood Warning 7, NWS Missoula, MT

July 21, 2001Ravalli County, Montana

NWS Missoula, MT issued this flash flood warning at Jul 21, 2001, 6:53 PM MDT for Ravalli County, Montana. It was in force for 112 min. 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 21, 2001, 6:53 PM MDT (00:53 UTC)
Expired
Jul 21, 2001, 8:45 PM MDT
In force
112 min
Issued by
NWS Missoula, MT
Area
Whole counties; the outline is the Mesonet’s reconstruction

County Ravalli County, MT

The nearest sounding before it

Spokane, WA (KOTX), launched 00:00Z, 0.9 hours before the alert went out and 252 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, Spokane, WA at 00:00Z on 2001-07-22Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 64 joules per kilogram.LCLEL10008507005003002001001 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, Spokane, WA at 00:00Z on 2001-07-22The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 22 square meters per square second.1939Sfc1 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
64 J/kg
Mixed-layer CIN
-6 J/kg
Mixed-layer LCL
2067 m above ground
0-6 km bulk shear
21 kt
0-1 km storm-relative helicity
22 m²/s²
0-3 km storm-relative helicity
54 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 KMSO 220054
FFWMSO

MTC081-220245-

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

THE NATIONAL WEATHER SERVICE IN MISSOULA HAS ISSUED A

* FLASH FLOOD WARNING FOR SKALKAHO CREEK...
  EASTERN RAVALLI COUNTY IN WEST CENTRAL MONTANA.

  LAIRD CREEK...
  AND DICKSON CREEK...
  SOUTHERN RAVALLI COUNTY IN WEST CENTRAL MONTANA

* UNTIL 845 PM MDT

* AT 648 PM MDT...RADAR INDICATED TWO STORMS WITH VERY HEAVY RAINFALL 
  OVER SKALKAHO PASS...OR 25 MILES EAST OF HAMILTON...AND 9 MILES 
  SOUTH OF CONNER...OR 31 MILES SOUTH OF HAMILTON...MOVING NORTH AT 
  20 MPH.

THESE SLOW MOVING THUNDERSTORMS HAVE A HISTORY OF TORRENTIAL RAINFALL 
AND ACCUMULATING HAIL. MUDSLIDES WERE REPORTED BY THE RAVALLI COUNTY 
SHERIFF IN THE SULA AREA FROM EARLIER STORM ACTIVITY. 

A FLASH FLOOD WARNING MEANS FLOODING IS IMMINENT OR OCCURRING. IF YOU
ARE IN THE WARNING AREA MOVE TO HIGHER GROUND IMMEDIATELY. RESIDENTS
LIVING ALONG RIVERS AND CREEKS SHOULD TAKE IMMEDIATE PRECAUTIONS TO
PROTECT LIFE AND PROPERTY. DO NOT CROSS FLOODED ROADWAYS.

CAMPING SHOULD BE AVOIDED ALONG CREEKS OR STREAMS DURING THREATENING
RAINS. EVEN SMALL STREAMS CAN BE DEADLY TORRENTS OF WATER DURING A
FLASH FLOOD.

LAT...LON 4575 11422 4573 11397 4660 11369 4664 11421

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 21, 6:10 PM MDTFlash Flood WarningMSORavalli110 min
Jul 21, 6:30 PM MDTSevere Thunderstorm WarningMSOGranite, Ravalli45 min
Jul 21, 7:08 PM MDTSevere Thunderstorm WarningMSORavalli52 min
Jul 21, 8:00 PM MDTFlash Flood WarningMSORavalli2 hr

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.