Alert archive / Montana / Flash Flood Warnings in 2001

Flash Flood Warning 4, NWS Great Falls, MT

July 31, 2001Broadwater County, Jefferson County, Lewis and Clark County, Montana

NWS Great Falls, MT issued this flash flood warning at Jul 31, 2001, 9:55 AM MDT for Broadwater County, Jefferson County, Lewis and Clark County, Montana. It was in force for 6 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 31, 2001, 9:55 AM MDT (15:55 UTC)
Expired
Jul 31, 2001, 4:00 PM MDT
In force
6 hr
Issued by
NWS Great Falls, MT
Area
Whole counties; the outline is the Mesonet’s reconstruction

Counties Broadwater County, MT, Jefferson County, MT, Lewis and Clark County, MT

The nearest sounding before it

Great_falls, MT (KTFX), launched 12:00Z, 3.9 hours before the alert went out and 143 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 12:00Z on 2001-07-31Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 10 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 12:00Z on 2001-07-31The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 186 square meters per square second.1939587897Sfc1 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
10 J/kg
Mixed-layer CIN
-12 J/kg
Mixed-layer LCL
707 m above ground
0-6 km bulk shear
48 kt
0-1 km storm-relative helicity
186 m²/s²
0-3 km storm-relative helicity
313 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 KTFX 311555
FFWTFX
MTC007-043-049-312200-

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE GREAT FALLS MT
955 AM MDT TUE JUL 31 2001

THE NATIONAL WEATHER SERVICE IN GREAT FALLS HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  MAJOR BURN AREAS OF LEWIS AND CLARK...BROADWATER...AND JEFFERSON
  COUNTIES...INCLUDING AREAS AROUND THE CANYON FERRY
  COMPLEX...BOULDER HILL/HIGH ORE COMPLEX...AND THE TOSTON/MAUDLOW
  COMPLEX...

* UNTIL 400 PM MDT

* AT 930 AM MDT...THE PUBLIC REPORTED FLOODING IN THE VICINITY OF
KIM'S MARINA ON CAVE CREEK. FLOWING MUD AND WATER WAS REPORTED GOING
OVER THE ROAD. AN AREA OF LIGHT TO MODERATE RAIN WAS HEADING SOUTHEAST
TOWARD THE AREA...AND WILL LIKELY AGGREVATE THE FLOODING.

EXCESSIVE RUNOFF FROM THIS RAINFALL WILL CAUSE FLASH FLOODING OF
CREEKS AND STREAMS...ROADS AND ROADSIDE CULVERTS AROUND THE BURN AREAS.
THE HEAVY RAINS COULD ALSO TRIGGER ROCK AND MUDSLIDES IN STEEP
TERRAIN.

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

REPORT SEVERE WEATHER TO THE NEAREST LAW ENFORCEMENT AGENCY OR THE
NATIONAL WEATHER SERVICE FORECAST OFFICE IN GREAT FALLS.

LAT...LON 4639 11219 4627 11121 4673 11155 4686 11235

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 30, 8:30 PM MDTFlash Flood WarningTFXBroadwater, Jefferson, Lewis and Clark10 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.