Alert archive / Montana / Flash Flood Warnings in 1990

Flash Flood Warning 1, NWS Missoula, MT

July 31, 1990Madison County, Montana

NWS Missoula, MT issued this flash flood warning at Jul 31, 1990, 6:57 PM MDT for Madison County, Montana. It was in force for 63 min.

The area

The counties it named.

The facts

Issued
Jul 31, 1990, 6:57 PM MDT (00:57 UTC)
Expired
Jul 31, 1990, 8:00 PM MDT
In force
63 min
Issued by
NWS Missoula, MT
Area
Whole counties

County Madison County, MT

The radar

The WSR-88D network and its archive begin in 1991, so there is no radar volume for this alert.

The nearest sounding before it

Great Falls, MT (KGTF), launched 00:00Z, 1.0 hours before the alert went out and 247 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 1990-08-01Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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 1990-08-01The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -8 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
2491 m above ground
0-6 km bulk shear
43 kt
0-1 km storm-relative helicity
-8 m²/s²
0-3 km storm-relative helicity
152 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 
TTAA00 KHLN 010058
FFWHLN
MTC057-010200-
 
BULLETIN - EBS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE HELENA MT
657 PM MDT TUE JUL 31 1990
 
THE NATIONAL WEATHER SERVICE IN HELENA HAS ISSUED A
FLASH FLOOD WARNING EFFECTIVE UNTIL  800 PM MDT
FOR PEOPLE IN THE FOLLOWING LOCATION...
 
IN SOUTHWEST MONTANA
 
   ...NORTHERN MADISON COUNTY
 
THUNDERSTORMS THAT HAVE DEVELOPED THIS EVENING OVER MADISON COUNTY
IN SOUTHWESTERN MONTANA HAVE PRODUCING HEAVY RAINS THAT HAS RESULTED
IN FLOODING OF LOW AREAS. A REPORT FROM MADISON COUNTY SHERIFF AT 6:30
PM MDT WITH THREE FEET OF WATER OVER PARTS OF HIGHWAY 41 BETWEEN
SILVER STAR AND TWIN BRIDGES WHICH FOLLOWS THE JEFFERSON RIVER.
 
WEATHER RADAR INDICATED THAT THE HEAVY RAIN SHOWERS ASSOCIATED WITH
THE THUNDERSTORMS ARE MOVING NORTHEAST AT ABOUT 30 MILES PER HOUR.
 
 
 
A FLASH FLOOD WARNING MEANS THAT FLOODING IS OCCURRING OR IS
IMMINENT.  MOST FLASH FLOOD DEATHS OCCUR IN AUTOMOBILES.  DO NOT
ATTEMPT TO CROSS BRIDGES...DIPS...OR LOW SPOTS IF WATER COVERS
THE ROADWAY.  NEVER TRY TO CROSS A FLOWING STREAM...EVEN A SMALL
ONE...ON FOOT.  TO ESCAPE RISING WATER MOVE UP TO HIGHER GROUND.

Nearby

Flash Flood Warnings in Montana, 1990Every flash flood warning in 1990

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.