Alert archive / Montana / Flash Flood Warnings in 2012

Flash Flood Warning 4, NWS Missoula, MT

July 16, 2012Silver Bow County, Montana

NWS Missoula, MT issued this flash flood warning at Jul 16, 2012, 2:42 PM MDT for Silver Bow County, Montana. It was in force for 93 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued
Jul 16, 2012, 2:42 PM MDT (20:42 UTC)
Expired
Jul 16, 2012, 4:15 PM MDT
In force
93 min
Issued by
NWS Missoula, MT
Area
Storm-based polygon
Flood severity
None

County Silver Bow County, MT

The radar

The Missoula radar (KMSX), 164 km from the middle of the area, began a volume at 20:43 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, 8.7 hours before the alert went out and 224 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 2012-07-16Temperature 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 12:00Z on 2012-07-16The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 32 square meters per square second.193958Sfc1 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
1163 m above ground
0-6 km bulk shear
12 kt
0-1 km storm-relative helicity
32 m²/s²
0-3 km storm-relative helicity
71 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.

436 
WGUS55 KMSO 162042
FFWMSO
MTC093-162215-
/O.NEW.KMSO.FF.W.0004.120716T2042Z-120716T2215Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE MISSOULA MT
242 PM MDT MON JUL 16 2012

THE NATIONAL WEATHER SERVICE IN MISSOULA HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  BUTTE IN
  CENTRAL SILVER BOW COUNTY IN WEST CENTRAL MONTANA...

* UNTIL 415 PM MDT.

* EXCESSIVE RAINFALL HAS BEEN FALLING OVER THE CITY OF BUTTE AND 
LOCATIONS IMMEDIATELY ADJACENT TO THE CITY. THIS VERY HEAVY RAINFALL 
WILL CAUSE FLOODING ISSUES...PARTICULARLY IN BUTTE PROPER WHERE 
URBAN EFFECTS WILL AID IN FLASH FLOODING.

* WEATHER SPOTTERS HAVE ALREADY REPORTED FLASH FLOODING OVER THE WARNED 
AREA. 

* LOCATIONS IMPACTED INCLUDE...JANNEY...NEWCOMB AND   WALKERVILLE.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A FLASH FLOOD WARNING MEANS THAT FLOODING...MUD AND DEBRIS FLOWS ARE
IMMINENT OR OCCURRING. IF YOU ARE IN THE WARNING AREA MOVE TO HIGHER
GROUND IMMEDIATELY. RESIDENTS LIVING ALONG STREAMS AND CREEKS SHOULD
TAKE IMMEDIATE PRECAUTIONS TO PROTECT LIFE AND PROPERTY.

&&

LAT...LON 4588 11268 4604 11262 4604 11244 4603 11243
      4585 11244

$$
2 follow-up statements
496 
WGUS75 KMSO 162055
FFSMSO

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE MISSOULA MT
255 PM MDT MON JUL 16 2012

MTC093-162215-
/O.CON.KMSO.FF.W.0004.000000T0000Z-120716T2215Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
SILVER BOW MT-
255 PM MDT MON JUL 16 2012

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 415 PM MDT FOR
CENTRAL SILVER BOW COUNTY...

AT 247 PM MDT...DOPPLER RADAR CONTINUED TO INDICATE A NEARLY 
STATIONARY THUNDERSTORM PRODUCING EXCESSIVE RAINFALL OVER THE CITY 
OF BUTTE. TRAINED WEATHER SPOTTERS HAVE REPORTED FLASH FLOODING OVER 
THE WARNED AREA.

CREEKS OF CONCERN THAT WILL HAVE VERY QUICK RISES AND COULD RESULT 
IN FLOOD CONDITIONS IN BUTTE ARE: SILVER BOW CREEK AND LITTLE 
BLACKTAIL CREEK.

&&

LAT...LON 4588 11268 4604 11262 4604 11244 4603 11243
      4585 11244

$$
893 
WGUS75 KMSO 162205
FFSMSO

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE MISSOULA MT
405 PM MDT MON JUL 16 2012

MTC093-162215-
/O.EXP.KMSO.FF.W.0004.000000T0000Z-120716T2215Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
SILVER BOW MT-
405 PM MDT MON JUL 16 2012

...THE FLASH FLOOD WARNING WILL EXPIRE AT 415 PM MDT/315 PM PDT/ FOR
CENTRAL SILVER BOW COUNTY...

LAT...LON 4588 11268 4604 11262 4604 11244 4603 11243
      4585 11244

$$

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 16, 3:04 PM MDTFlash Flood WatchMSODeer Lodge, Granite, Lake, Mineral, Missoula, Powell and 3 more5 hr
Jul 16, 3:08 PM MDTFlash Flood WarningMSOGranite, Ravalli112 min

Nearby

Flash Flood Warnings in Montana, 2012Every flash flood warning in 2012

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.