Alert archive / Montana / Flash Flood Warnings in 2012

Flash Flood Warning 5, NWS Missoula, MT

July 16, 2012Granite County, Ravalli County, Montana

NWS Missoula, MT issued this flash flood warning at Jul 16, 2012, 3:08 PM MDT for Granite County, 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 as issued.

The facts

Issued
Jul 16, 2012, 3:08 PM MDT (21:08 UTC)
Expired
Jul 16, 2012, 5:00 PM MDT
In force
112 min
Issued by
NWS Missoula, MT
Area
Storm-based polygon
Flood severity
None

Counties Granite County, MT, Ravalli County, MT

The radar

The Missoula radar (KMSX), 87 km from the middle of the area, began a volume at 21:10 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

Spokane, WA (KOTX), launched 12:00Z, 9.1 hours before the alert went out and 251 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 12:00Z on 2012-07-16Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 136 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Spokane, WA at 12:00Z on 2012-07-16The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 72 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
136 J/kg
Mixed-layer CIN
-116 J/kg
Mixed-layer LCL
888 m above ground
0-6 km bulk shear
38 kt
0-1 km storm-relative helicity
72 m²/s²
0-3 km storm-relative helicity
295 m²/s²
Significant tornado parameter
0.0
Supercell composite
1.0

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

779 
WGUS55 KMSO 162108
FFWMSO
MTC039-081-162300-
/O.NEW.KMSO.FF.W.0005.120716T2108Z-120716T2300Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

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

THE NATIONAL WEATHER SERVICE IN MISSOULA HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  EASTERN RAVALLI COUNTY IN WEST CENTRAL MONTANA...
  WESTERN GRANITE COUNTY IN WEST CENTRAL MONTANA...

* UNTIL 500 PM MDT.

* AT 302 PM MDT...DOPPLER RADAR INDICATED FLASH FLOODING OVER        
  THE WARNED AREA. STRONG THUNDERSTORMS CONTINUE TO DEVELOP AND      
  PRODUCE HEAVY RAINFALL NEAR AND OVER SKALKAHO PASS.

* LOCATIONS IMPACTED INCLUDE...SKALKAHO PASS.

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.

IN RUGGED TERRAIN THERE ARE MANY LOW WATER CROSSINGS WHICH ARE
POTENTIALLY DANGEROUS IN HEAVY RAIN. DO NOT ATTEMPT TO TRAVEL ACROSS
FLOODED ROADS. FIND ALTERNATE ROUTES. IT ONLY TAKES A FEW INCHES OF
SWIFTLY FLOWING WATER TO CARRY VEHICLES AWAY.

&&

LAT...LON 4634 11394 4634 11368 4616 11368 4616 11394

$$

DICKERSON
1 follow-up statement
575 
WGUS75 KMSO 162253
FFSMSO

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

MTC039-081-162301-
/O.EXP.KMSO.FF.W.0005.000000T0000Z-120716T2300Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
GRANITE MT-RAVALLI MT-
453 PM MDT MON JUL 16 2012

...THE FLASH FLOOD WARNING WILL EXPIRE AT 500 PM MDT/400 PM PDT/ FOR
EASTERN RAVALLI AND WESTERN GRANITE COUNTIES...

ALTHOUGH LIGHT RAIN WILL CONTINUE TO AFFECT SKALKAHO PASS THROUGH 
THE EVENING...STRONG THUNDERSTORMS CAPABLE OF TORRENTIAL RAIN HAVE 
LEFT THE AREA THUS ENDING THE THREAT OF FLASH FLOODING FOR NOW. 
ADDITIONAL STRONG STORMS WITH HEAVY RAIN MAY BE POSSIBLE YET AGAIN 
LATER TONIGHT.

LAT...LON 4634 11394 4634 11368 4616 11368 4616 11394

$$

DICKERSON

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 16, 2:42 PM MDTFlash Flood WarningMSOSilver Bow93 min
Jul 16, 3:04 PM MDTFlash Flood WatchMSODeer Lodge, Granite, Lake, Mineral, Missoula, Powell and 3 more5 hr

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.